Last data update: Mar 10, 2025. (Total: 48852 publications since 2009)
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Query Trace: Shah MP[original query] |
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Integrated approaches for the delivery of maternal and child health services with childhood immunization programs in low- and middle-income countries: Systematic review update 2011-2020
Shah MP , Morgan CJ , Beeson JG , Peach E , Davis J , McPake B , Wallace AS . Vaccines (Basel) 2024 12 (12) Background: The integration of maternal and child health services (MCH) with routine immunization is an important global health strategy, particularly in low- and middle-income countries (LMICs). However, evidence is lacking regarding the best practices for service integration and the effect of integration on immunization and linked health service outcomes. Methods: We searched publication databases and gray literature for articles published between 2011 and 2020 that include approaches to integrating MCH services with immunizations during the first two years of life in LMICs. Abstracts and full-text articles were screened for eligibility. For the included articles, data extraction and analysis examined the descriptive characteristics of studies, outcomes, and implementation considerations. Results: Among the 16,578 articles screened, 44 met the criteria for inclusion, representing 34 studies, of which 29 were from Africa. The commonly linked MCH services were family planning (24%), human immunodeficiency virus (HIV) diagnosis or care (21%), and malaria prevention or control (21%). Multiple integration strategies were typically used; the co-location of linked services (65%), the provision of extra services by immunization staff (41%), and/or the provision of extra information by immunization staff (41%) were the most common. In general, integration improved MCH service outcomes (76%) and was either beneficial (55%) or neutral for immunization (35%), with some examples in family planning, malaria, and HIV where integrated services were not beneficial. Important implementation considerations included the careful matching of target populations in service re-design, ensuring support from policy, logistics, and information systems, the provision of adequate training and support of staff to avoid overload, clear client communication regarding service integration, and the need to address community concerns. Conclusions: Integrating MCH services with routine immunization can expand linked services and improve immunization coverage. This study has identified key implementation considerations relevant to both childhood and adult vaccination programs. More research is needed regarding costs and client preferences. |
Timeliness of childhood vaccinations following strengthening of the second year of life (2YL) immunization platform and introduction of catch-up vaccination policy in Ghana
Muhoza P , Shah MP , Amponsa-Achiano K , Gao H , Quaye P , Opare W , Okae C , Aboyinga PN , Opare JKL , Ehlman DC , Wardle MT , Wallace AS . Vaccines (Basel) 2024 12 (7) Strengthening routine immunization systems to successfully deliver childhood vaccines during the second year of life (2YL) is critical for vaccine-preventable disease control. In Ghana, the 18-month visit provides opportunities to deliver the second dose of the measles-rubella vaccine (MR2) and for healthcare workers to assess for and provide children with any missed vaccine doses. In 2016, the Ghana Health Service (GHS) revised its national immunization policies to include guidelines for catch-up vaccinations. This study assessed the change in the timely receipt of vaccinations per Ghana's Expanded Program on Immunizations (EPI) schedule, an important indicator of service quality, following the introduction of the catch-up policy and implementation of a multifaceted intervention package. Vaccination coverage was assessed from household surveys conducted in the Greater Accra, Northern, and Volta regions for 392 and 931 children aged 24-35 months with documented immunization history in 2016 and 2020, respectively. Age at receipt of childhood vaccines was compared to the recommended age, as per the EPI schedule. Cumulative days under-vaccinated during the first 24 months of life for each recommended dose were assessed. Multivariable Cox regression was used to assess the associations between child and caregiver characteristics and time to MR2 vaccination. From 2016 to 2020, the proportion of children receiving all recommended doses on schedule generally improved, the duration of under-vaccination was shortened for most doses, and higher coverage rates were achieved at earlier ages for the MR series. More timely infant doses and caregiver awareness of the 2YL visit were positively associated with MR2 vaccination. Fostering a well-supported cadre of vaccinators, building community demand for 2YL vaccination, sustaining service utilization through strengthened defaulter tracking and caregiver-reminder systems, and creating a favorable policy environment that promotes vaccination over the life course are critical to improving the timeliness of childhood vaccinations. |
Qualitative insights on barriers to receiving a second dose of measles-containing vaccine (MCV2), Oromia Region of Ethiopia
Solomon K , Aksnes BN , Woyessa AB , Geri C , Matanock AM , Shah MP , Samuel P , Tolera B , Kenate B , Bekele A , Deti T , Wako G , Shiferaw A , Tefera YL , Kokebie MA , Anbessie TB , Wubie HT , Wallace A , Sugerman CE , Kaba M . Vaccines (Basel) 2024 12 (7) Introduction: Ethiopia introduced a second dose of measles-containing vaccine (MCV2) in 2019 to provide further protection against measles and further progress toward elimination. However, the sub-optimal coverage of both MCV1 and MCV2 suggest challenges with vaccine uptake. In this qualitative study, we explored barriers to the uptake of MCV2 among caregivers, community leaders, and healthcare workers (HCWs). Method: A qualitative study was conducted between mid-April and mid-May 2021. We selected ten woredas (districts) in the Oromia Region, Ethiopia, stratified by settlement type (urban/rural), MCV1 coverage (high ≥ 80%; low < 80%), and history of measles outbreaks between June 2019 and June 2020. Experiences surrounding barriers to MCV2 uptake were discussed via focus group discussions (FGDs) and in-depth interviews (IDIs) with caregivers of children 12-23 and 24-36 months and key informant interviews (KIIs) with HCWs who administer vaccines and with community leaders. Participants were recruited via snowball sampling. Recorded data were transcribed, translated to English, and analyzed using ATLAS.ti v.09. Results: Forty FGDs and 60 IDIs with caregivers, 60 IDIs with HCWs, and 30 KIIs with community leaders were conducted. Barriers among caregivers included lack of knowledge and awareness about MCV2 and the vaccination schedule, competing priorities, long wait times at health facilities, vaccine unavailability, negative interactions with HCWs, and transportation challenges. At the community level, trusted leaders felt they lacked adequate knowledge about MCV2 to address caretakers' questions and community misconceptions. HCWs felt additional training on MCV2 would prepare them to better respond to caretakers' concerns. Health system barriers identified included the lack of human, material, and financial resources to deliver vaccines and provide immunization outreach services, which caretakers reported as their preferred way of accessing immunization. Conclusions: Barriers to MCV2 uptake occur at multiple levels of immunization service delivery. Strategies to address these barriers include tools to help caretakers track appointments, enhanced community engagement, HCW training to improve provider-client interactions and MCV2 knowledge, and efforts to manage HCW workload. |
Factors associated with uptake of routine measles-containing vaccine doses among young children, Oromia Regional State, Ethiopia, 2021
Woyessa AB , Shah MP , Azmeraye BM , Pan J , Lisanwork L , Yimer G , Wang SH , Nuorti JP , Artama M , Matanock AM , An Q , Samuel P , Tolera B , Kenate B , Bekele A , Deti T , Wako G , Shiferaw A , Tefera YL , Kokebie MA , Anbessie TB , Wubie HT , Wallace A , Sugerman CE . Vaccines (Basel) 2024 12 (7) Recommended vaccination at nine months of age with the measles-containing vaccine (MCV1) has been part of Ethiopia's routine immunization program since 1980. A second dose of MCV (MCV2) was introduced in 2019 for children 15 months of age. We examined MCV1 and MCV2 coverage and the factors associated with measles vaccination status. A cross-sectional household survey was conducted among caregivers of children aged 12-35 months in selected districts of Oromia Region. Measles vaccination status was determined using home-based records, when available, or caregivers' recall. We analyzed the association between MCV1 and MCV2 vaccination status and household, caregiver, and child factors using logistic regression. The caregivers of 1172 children aged 12-35 months were interviewed and included in the analysis. MCV1 and MCV2 coverage was 71% and 48%, respectively. The dropout rate (DOR) from the first dose of Pentavalent vaccine to MCV1 was 22% and from MCV1 to MCV2 was 46%. Caregivers were more likely to vaccinate their children with MCV if they gave birth at a health facility, believe that their child had received all recommended vaccines, and know the required number of vaccination visits and doses. MCV2 coverage was low, with a high measles dropout rate (DOR). Caregivers with high awareness of MCV and its schedule were more likely to vaccinate their children. Intensified demand generation, defaulter tracking, and vaccine-stock management should be strengthened to improve MCV uptake. |
Mass drug administration: Contextual factor considerations
Schneider ZD , Busbee AL , Boily MC , Shah MP , Hwang J , Lindblade KA , Gutman JR . Am J Trop Med Hyg 2024 In designing mass drug administration (MDA) campaigns, it is imperative to consider contextual factors that affect uptake of the intervention, including acceptability, cost, feasibility, and health system considerations, to ensure optimal coverage. We reviewed the literature on contextual factors influencing MDA delivery to provide programs with information to design a successful campaign. From 1,044 articles screened, 37 included contextual factors relevant to participants' values and preferences, drivers of MDA acceptability, health equity concerns, financial and economic aspects, and feasibility barriers; 13 included relevant modeling data. Key findings were abstracted by two reviewers and summarized. No studies directly assessed values or direct health equity concerns with respect to MDA, which represents an evidence gap as unequal distributions of effects and factors that impact participant acceptability and program feasibility must be considered to ensure equitable access. Participant acceptability was the most widely surveyed factor, appearing in 28 of 37 studies; perceived adverse events were a frequently noted cause of nonparticipation, mentioned in 15 studies. Feasibility considerations included when, where, and how drugs will be delivered and how to address pregnant women, as these can all have substantial implications for participation. Mass drug administration costs (∼$1.04 to $19.40 per person per round) are driven primarily by drug prices, but the delivery mechanism can have varying costs as well, and integration with other interventions may provide cost savings. Both programmatic goals and sociopolitical and economic contexts must be carefully considered before embarking on an MDA program to ensure programmatic success. |
Development of systematic reviews to inform WHO's recommendations for elimination and prevention of re-establishment of malaria: Methodology
Tusell M , Steinhardt LC , Gutman J , Schneider ZD , Bhamani B , Shah MP , Martí Coma-Cros E , Gimnig JE , Allen KC , Akl EA , Lindblade KA . Am J Trop Med Hyg 2023 The basis for an evidence-based recommendation is a well-conducted systematic review that synthesizes the primary literature relevant to the policy or program question of interest. In 2020, the WHO commissioned 10 systematic reviews of potential interventions in elimination or post-elimination settings to summarize their impact on malaria transmission. This paper describes the general methods used to conduct this series of systematic reviews and notes where individual reviews diverged from the common methodology. The paper also presents lessons learned from conducting the systematic reviews to make similar future efforts more efficient, standardized, and streamlined. |
Mass drug administration to reduce malaria transmission: A systematic review and meta-analysis
Schneider ZD , Shah MP , Boily MC , Busbee AL , Hwang J , Lindblade KA , Gutman JR . Am J Trop Med Hyg 2023 Malaria remains a significant cause of morbidity and mortality, even in low-transmission settings. With the advent of longer acting, more effective, and well-tolerated antimalarials, there is renewed interest in the efficacy of mass drug administration (MDA) to accelerate to elimination. We conducted a systematic review and meta-analysis to assess the efficacy of MDA to reduce the incidence and prevalence of Plasmodium falciparum (Pf) and Plasmodium vivax (Pv) infection. From 1,044 articles screened, 14 articles, including 10 randomized controlled trials (RCTs), were identified. Five included data on Pf only; five included Pf and Pv. Two of the Pf studies were conducted in areas of high-moderate transmission, the remainder were in areas of low-very low transmission. In higher transmission areas, MDA reduced incidence of Pf parasitemia (rate ratio = 0.61, 95% CI: 0.40-0.92; moderate certainty) 1 to 3 months after drug administration; no significant effect of MDA on Pf parasitemia prevalence was detected 1 to 3 months post-MDA (risk ratio [RR] = 1.76, 95% CI: 0.58-5.36; low certainty). In lower transmission settings, both incidence and prevalence of Pf parasitemia were reduced 1 to 3 months post-MDA (rate ratio = 0.37, 95% CI: 0.21-0.66; RR = 0.25, 95% CI: 0.15-0.41, respectively). Pv prevalence was reduced 1 to 3 months post-MDA (RR = 0.15, 95% CI: 0.10-0.24); there were no RCTs providing data on incidence of Pv. There was no significant effect of MDA at later time points. MDA may have short-term benefits; however, there was no evidence for longer term impact, although none of the trials assessed prolonged interventions. |
Mass relapse prevention to reduce transmission of plasmodium vivax-a systematic review
Shah MP , Westercamp N , Lindblade KA , Hwang J . Am J Trop Med Hyg 2023 Several temperate countries have used mass chemoprevention interventions with medicines of the 8-aminoquinoline class that prevent relapses from Plasmodium vivax before peak transmission to reduce transmission of malaria. The WHO commissioned a systematic review of the literature and evidence synthesis to inform development of recommendations regarding this intervention referred to as "mass relapse prevention" (MRP). Electronic databases were searched, 866 articles screened, and 25 assessed for eligibility after a full-text review. Two nonrandomized studies were included, one from the Democratic People's Republic of Korea (391,357 participants) and the second from the Azerbaijan Soviet Socialist Republic (∼30,000 participants). The two studies administered a single round of primaquine over 14 days (0.25 mg/kg per day). From 1 to 3 months after the treatment round, the incidence of P. vivax infections was significantly lower in areas that received MRP than those that did not (pooled rate ratio [RR] 0.08, 95% CI 0.07-0.08). At 4 to 12 months after the treatment round, the prevalence of P. vivax infection was significantly lower in MRP villages than non-MRP villages (odds ratio 0.12, 95% CI 0.03-0.52). No severe adverse events were found. The certainty of evidence for all outcomes was very low and no conclusions as to the effectiveness or safety of MRP could be drawn. However, it is not likely that this intervention will be needed in the future as most temperate countries where P. vivax is transmitted are nearing or have already eliminated malaria. |
Predictors for uptake of vaccines offered during the second year of life: Second dose of measles-containing vaccine and meningococcal serogroup A-containing vaccine, Ghana, 2020
Muhoza P , Shah MP , Gao H , Amponsa-Achiano K , Quaye P , Opare W , Okae C , Aboyinga PN , Opare KL , Wardle MT , Wallace AS . Vaccines (Basel) 2023 11 (10) BACKGROUND: Understanding the drivers of coverage for vaccines offered in the second year of life (2YL) is a critical focus area for Ghana's life course approach to vaccination. This study characterizes the predictors of vaccine receipt for 2YL vaccines-meningococcal serogroup A conjugate vaccine (MACV) and the second dose of measles-containing vaccine (MCV2)-in Ghana. METHODS: 1522 children aged 18-35 months were randomly sampled through household surveys in the Greater Accra Region (GAR), Northern Region (NR), and Volta Region (VR). The association between predictors and vaccination status was modeled using logistic regression with backwards elimination procedures. Predictors included child, caregiver, and household characteristics. RESULTS: Coverage was high for infant vaccines (>85%) but lower for 2YL vaccines (ranging from 60.2% for MACV in GAR to 82.8% for MCV2 in VR). Predictors of vaccination status varied by region. Generally, older, first-born children, those living in rural settlements and those who received their recommended infant vaccines by their first birthday were the most likely to have received 2YL vaccines. Uptake was higher among those with older mothers and children whose caregivers were aware of the vaccination schedule. CONCLUSIONS: Improving infant immunization uptake through increased community awareness and targeted strategies, such as parental reminders about vaccination visits, may improve 2YL vaccination coverage. |
Novel application of one-step pooled molecular testing and maximum likelihood approaches to estimate the prevalence of malaria parasitaemia among rapid diagnostic test negative samples in western Kenya.
Shah MP , Chebore W , Lyles RH , Otieno K , Zhou Z , Plucinski M , Waller LA , Odongo W , Lindblade KA , Kariuki S , Samuels AM , Desai M , Mitchell RM , Shi YP . Malar J 2022 21 (1) 319 ![]() BACKGROUND: Detection of malaria parasitaemia in samples that are negative by rapid diagnostic tests (RDTs) requires resource-intensive molecular tools. While pooled testing using a two-step strategy provides a cost-saving alternative to the gold standard of individual sample testing, statistical adjustments are needed to improve accuracy of prevalence estimates for a single step pooled testing strategy. METHODS: A random sample of 4670 malaria RDT negative dried blood spot samples were selected from a mass testing and treatment trial in Asembo, Gem, and Karemo, western Kenya. Samples were tested for malaria individually and in pools of five, 934 pools, by one-step quantitative polymerase chain reaction (qPCR). Maximum likelihood approaches were used to estimate subpatent parasitaemia (RDT-negative, qPCR-positive) prevalence by pooling, assuming poolwise sensitivity and specificity was either 100% (strategy A) or imperfect (strategy B). To improve and illustrate the practicality of this estimation approach, a validation study was constructed from pools allocated at random into main (734 pools) and validation (200 pools) subsets. Prevalence was estimated using strategies A and B and an inverse-variance weighted estimator and estimates were weighted to account for differential sampling rates by area. RESULTS: The prevalence of subpatent parasitaemia was 14.5% (95% CI 13.6-15.3%) by individual qPCR, 9.5% (95% CI (8.5-10.5%) by strategy A, and 13.9% (95% CI 12.6-15.2%) by strategy B. In the validation study, the prevalence by individual qPCR was 13.5% (95% CI 12.4-14.7%) in the main subset, 8.9% (95% CI 7.9-9.9%) by strategy A, 11.4% (95% CI 9.9-12.9%) by strategy B, and 12.8% (95% CI 11.2-14.3%) using inverse-variance weighted estimator from poolwise validation. Pooling, including a 20% validation subset, reduced costs by 52% compared to individual testing. CONCLUSIONS: Compared to individual testing, a one-step pooled testing strategy with an internal validation subset can provide accurate prevalence estimates of PCR-positivity among RDT-negatives at a lower cost. |
Providing differentiated service delivery to the ageing population of people living with HIV
Godfrey C , Vallabhaneni S , Shah MP , Grimsrud A . J Int AIDS Soc 2022 25 Suppl 4 e26002 INTRODUCTION: Differentiated service delivery (DSD) models for HIV are a person-centred approach to providing services across the HIV care cascade; DSD has an increasing policy and implementation support in high-burden HIV countries. The life-course approach to DSD for HIV treatment has focused on earlier life phases, childhood and adolescence, families, and supporting sexual and reproductive health during childbearing years. Older adults, defined as those over the age of 50, represent a growing proportion of HIV treatment cohorts with approximately 20% of those supported by PEPFAR in this age band and have specific health needs that differ from younger populations. Despite this, DSD models have not been designed or implemented to address the health needs of older adults. DISCUSSION: Older adults living with HIV are more likely to have significant co-morbid medical conditions. In addition to the commonly discussed co-morbidities of hypertension and diabetes, they are at increased risk of cognitive impairment, frailty and mental health conditions. Age and HIV-related cognitive impairment may necessitate the development of adapted educational materials. Identifying the optimal package of differentiated services to this population, including the frequency of clinical visits, types and location of services is important as is capacitating the healthcare cadres to adapt to these challenges. Technological advances, which have made remote monitoring of adherence and other aspects of disease management easier for younger populations, may not be as readily available or as familiar to older adults. To date, adaptations to service delivery have not been scaled and are limited to nascent programmes working to integrate treatment of common co-morbidities. CONCLUSIONS: Older individuals living with HIV may benefit from a DSD approach that adapts care to the specific challenges of ageing with HIV. Models could be developed and validated using outcome measures, such as viral suppression and treatment continuity. DSD models for older adults should consider their specific health needs, such as high rates of co-morbidities. This may require educational materials, health worker capacity building and outreach designed specifically to treat this age group. |
Temporal trends in molecular markers of drug resistance in Plasmodium falciparum in human blood and profiles of corresponding resistant markers in mosquito oocysts in Asembo, western Kenya.
Zhou Z , Gimnig JE , Sergent SB , Liu Y , Abong'o B , Otieno K , Chebore W , Shah MP , Williamson J , Ter Kuile FO , Hamel MJ , Kariuki S , Desai M , Samuels AM , Walker ED , Shi YP . Malar J 2022 21 (1) 265 ![]() BACKGROUND: Over the last two decades, the scale-up of vector control and changes in the first-line anti-malarial, from chloroquine (CQ) to sulfadoxine-pyrimethamine (SP) and then to artemether-lumefantrine (AL), have resulted in significant decreases in malaria burden in western Kenya. This study evaluated the long-term effects of control interventions on molecular markers of Plasmodium falciparum drug resistance using parasites obtained from humans and mosquitoes at discrete time points. METHODS: Dried blood spot samples collected in 2012 and 2017 community surveys in Asembo, Kenya were genotyped by Sanger sequencing for markers associated with resistance to SP (Pfdhfr, Pfdhps), CQ, AQ, lumefantrine (Pfcrt, Pfmdr1) and artemisinin (Pfk13). Temporal trends in the prevalence of these markers, including data from 2012 to 2017 as well as published data from 1996, 2001, 2007 from same area, were analysed. The same markers from mosquito oocysts collected in 2012 were compared with results from human blood samples. RESULTS: The prevalence of SP dhfr/dhps quintuple mutant haplotype C(50)I(51)R(59)N(108)I(164)/S(436)G(437)E(540)A(581)A(613) increased from 19.7% in 1996 to 86.0% in 2012, while an increase in the sextuple mutant haplotype C(50)I(51)R(59)N(108)I(164)/H(436)G(437)E(540)A(581)A(613) containing Pfdhps-436H was found from 10.5% in 2012 to 34.6% in 2017. Resistant Pfcrt-76 T declined from 94.6% in 2007 to 18.3% in 2012 and 0.9% in 2017. Mutant Pfmdr1-86Y decreased across years from 74.8% in 1996 to zero in 2017, mutant Pfmdr1-184F and wild Pfmdr1-D1246 increased from 17.9% to 58.9% in 2007 to 55.9% and 90.1% in 2017, respectively. Pfmdr1 haplotype N(86)F(184)S(1034)N(1042)D(1246) increased from 11.0% in 2007 to 49.6% in 2017. No resistant mutations in Pfk13 were found. Prevalence of Pfdhps-436H was lower while prevalence of Pfcrt-76 T was higher in mosquitoes than in human blood samples. CONCLUSION: This study showed an increased prevalence of dhfr/dhps resistant markers over 20 years with the emergence of Pfdhps-436H mutant a decade ago in Asembo. The reversal of Pfcrt from CQ-resistant to CQ-sensitive genotype occurred following 19 years of CQ withdrawal. No Pfk13 markers associated with artemisinin resistance were detected, but the increased haplotype of Pfmdr1 N(86)F(184)S(1034)N(1042)D(1246) was observed. The differences in prevalence of Pfdhps-436H and Pfcrt-76 T SNPs between two hosts and the role of mosquitoes in the transmission of drug resistant parasites require further investigation. |
Mass drug administration for malaria
Shah MP , Hwang J , Choi L , Lindblade KA , Kachur SP , Desai M . Cochrane Database Syst Rev 2021 9 (9) Cd008846 BACKGROUND: Studies evaluating mass drug administration (MDA) in malarious areas have shown reductions in malaria immediately following the intervention. However, these effects vary by endemicity and are not sustained. Since the 2013 version of this Cochrane Review on this topic, additional studies have been published. OBJECTIVES: Primary objectives To assess the sustained effect of MDA with antimalarial drugs on: - the reduction in malaria transmission in moderate- to high-transmission settings; - the interruption of transmission in very low- to low-transmission settings. Secondary objective To summarize the risk of drug-associated adverse effects following MDA. SEARCH METHODS: We searched several trial registries, citation databases, conference proceedings, and reference lists for relevant articles up to 11 February 2021. We also communicated with researchers to identify additional published and unpublished studies. SELECTION CRITERIA: Randomized controlled trials (RCTs) and non-randomized studies comparing MDA to no MDA with balanced co-interventions across study arms and at least two geographically distinct sites per study arm. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed trials for eligibility and extracted data. We calculated relative risk (RR) and rate ratios with corresponding 95% confidence intervals (CIs) to compare prevalence and incidence, respectively, in MDA compared to no-MDA groups. We stratified analyses by malaria transmission and by malaria species. For cluster-randomized controlled trials (cRCTs), we adjusted standard errors using the intracluster correlation coefficient. We assessed the certainty of the evidence using the GRADE approach. For non-randomized controlled before-and-after (CBA) studies, we summarized the data using difference-in-differences (DiD) analyses. MAIN RESULTS: Thirteen studies met our criteria for inclusion. Ten were cRCTs and three were CBAs. Cluster-randomized controlled trials Moderate- to high-endemicity areas (prevalence ≥ 10%) We included data from two studies conducted in The Gambia and Zambia. At one to three months after MDA, the Plasmodium falciparum (hereafter, P falciparum) parasitaemia prevalence estimates may be higher compared to control but the CIs included no effect (RR 1.76, 95% CI 0.58 to 5.36; Zambia study; low-certainty evidence); parasitaemia incidence was probably lower (RR 0.61, 95% CI 0.40 to 0.92; The Gambia study; moderate-certainty evidence); and confirmed malaria illness incidence may be substantially lower, but the CIs included no effect (rate ratio 0.41, 95% CI 0.04 to 4.42; Zambia study; low-certainty evidence). At four to six months after MDA, MDA showed little or no effect on P falciparum parasitaemia prevalence (RR 1.18, 95% CI 0.89 to 1.56; The Gambia study; moderate-certainty evidence) and, no persisting effect was demonstrated with parasitaemia incidence (rate ratio 0.91, 95% CI 0.55 to 1.50; The Gambia study). Very low- to low-endemicity areas (prevalence < 10%) Seven studies from Cambodia, Laos, Myanmar (two studies), Vietnam, Zambia, and Zanzibar evaluated the effects of multiple rounds of MDA on P falciparum. Immediately following MDA (less than one month after MDA), parasitaemia prevalence was reduced (RR 0.12, 95% CI 0.03 to 0.52; one study; low-certainty evidence). At one to three months after MDA, there was a reduction in both parasitaemia incidence (rate ratio 0.37, 95% CI 0.21 to 0.55; 1 study; moderate-certainty evidence) and prevalence (RR 0.25, 95% CI 0.15 to 0.41; 7 studies; low-certainty evidence). For confirmed malaria incidence, absolute rates were low, and it is uncertain whether MDA had an effect on this outcome (rate ratio 0.58, 95% CI 0.12 to 2.73; 2 studies; very low-certainty evidence). For P falciparum prevalence, the relative differences declined over time, from RR 0.63 (95% CI 0.36 to 1.12; 4 studies) at four to six months after MDA, to RR 0.86 (95% CI 0.55 to 1.36; 5 studies) at 7 to 12 months after MDA. Longer-term prevalence estimates showed overall low absolute risks, and relative effect estimates of the effect of MDA on prevalence varied from RR 0.82 (95% CI 0.20 to 3.34) at 13 to 18 months after MDA, to RR 1.25 (95% CI 0.25 to 6.31) at 31 to 36 months after MDA in one study. Five studies from Cambodia, Laos, Myanmar (2 studies), and Vietnam evaluated the effect of MDA on Plasmodium vivax (hereafter, P vivax). One month following MDA, P vivax prevalence was lower (RR 0.18, 95% CI 0.08 to 0.40; 1 study; low-certainty evidence). At one to three months after MDA, there was a reduction in P vivax prevalence (RR 0.15, 95% CI 0.10 to 0.24; 5 studies; low-certainty evidence). The immediate reduction on P vivax prevalence was not sustained over time, from RR 0.78 (95% CI 0.63 to 0.95; 4 studies) at four to six months after MDA, to RR 1.12 (95% CI 0.94 to 1.32; 5 studies) at 7 to 12 months after MDA. One of the studies in Myanmar provided estimates of longer-term effects, where overall absolute risks were low, ranging from RR 0.81 (95% CI 0.44 to 1.48) at 13 to 18 months after MDA, to RR 1.20 (95% CI 0.44 to 3.29) at 31 to 36 months after MDA. Non-randomized studies Three CBA studies were conducted in moderate- to high-transmission areas in Burkina Faso, Kenya, and Nigeria. There was a reduction in P falciparum parasitaemia prevalence in MDA groups compared to control groups during MDA (DiD range: -15.8 to -61.4 percentage points), but the effect varied at one to three months after MDA (DiD range: 14.9 to -41.1 percentage points). AUTHORS' CONCLUSIONS: In moderate- to high-transmission settings, no studies reported important effects on P falciparum parasitaemia prevalence within six months after MDA. In very low- to low-transmission settings, parasitaemia prevalence and incidence were reduced initially for up to three months for both P falciparum and P vivax; longer-term data did not demonstrate an effect after four months, but absolute risks in both intervention and control groups were low. No studies provided evidence of interruption of malaria transmission. |
The effectiveness of older insecticide-treated bed nets (ITNs) to prevent malaria infection in an area of moderate pyrethroid resistance: results from a cohort study in Malawi
Shah MP , Steinhardt LC , Mwandama D , Mzilahowa T , Gimnig JE , Bauleni A , Wong J , Wiegand R , Mathanga DP , Lindblade KA . Malar J 2020 19 (1) 24 BACKGROUND: A previous cohort study in Malawi showed that users of new insecticide-treated bed nets (ITNs) were significantly protected against malaria compared to non-users, despite moderate levels of pyrethroid resistance among the primary mosquito vectors. The present study investigated whether ITNs that were 1-2 years old continued to protect users in the same area with moderate pyrethroid resistance. METHODS: One year following a baseline cross-sectional malaria parasitaemia prevalence survey and universal distribution of deltamethrin ITNs (May 2012), a fixed cohort of 1223 children aged 6-59 months was enrolled (April 2013). Children were tested for parasitaemia at monthly scheduled visits and at unscheduled sick visits from May to December 2013 using rapid diagnostic tests. ITN use the prior night and the condition of ITNs (based on presence of holes) was assessed by caregiver self-report. The incidence rate ratio (RR) comparing malaria infection among users and non-users of ITNs was modelled using generalized estimating equations adjusting for potential confounders and accounting for repeated measures on each child. The protective efficacy (PE) of ITN use was calculated as 1 - RR. RESULTS: In this cohort, self-reported ITN use remained consistently high (> 95%) over the study period. Although users of ITNs were slightly more protected compared to non-users of ITNs, the difference in incidence of infection was not statistically significant (RR 0.83, 95% confidence interval [CI] 0.54-1.27). Among ITN users, malaria incidence was significantly lower in users of ITNs with no holes (of any size) compared to users of ITNs with >/= 1 hole (RR 0.82, 95% CI 0.69-0.98). CONCLUSIONS: There was no significant PE of using 1-2 year-old ITNs on the incidence of malaria in children in an area of moderate pyrethroid resistance, but among ITN users, the authors found increased protection by ITNs with no holes compared to ITNs with holes. Given the moderate levels of pyrethroid resistance in the primary malaria vector and recent evidence of added benefits of ITNs with synergists or non-pyrethroid insecticides, next-generation ITNs may be a useful strategy to address pyrethroid resistance and should be further explored in Malawi. |
Rotavirus vaccine impact assessment surveillance in India: protocol and methods
Nair NP , Reddy NS , Giri S , Mohan VR , Parashar U , Tate J , Shah MP , Arora R , Gupte M , Mehendale SM , Kang G . BMJ Open 2019 9 (4) e024840 INTRODUCTION: Rotavirus infection accounts for 39% of under-five diarrhoeal deaths globally and 22% of these deaths occur in India. Introduction of rotavirus vaccine in a national immunisation programme is considered to be the most effective intervention in preventing severe rotavirus disease. In 2016, India introduced an indigenous rotavirus vaccine (Rotavac) into the Universal Immunisation Programme in a phased manner. This paper describes the protocol for surveillance to monitor the performance of rotavirus vaccine following its introduction into the routine childhood immunisation programme. METHODS: An active surveillance system was established to identify acute gastroenteritis cases among children less than 5 years of age. For all children enrolled at sentinel sites, case reporting forms are completed and a copy of vaccination record and a stool specimen obtained. The forms and specimens are sent to the referral laboratory for data entry, analysis, testing and storage. Data from sentinel sites in states that have introduced rotavirus vaccine into their routine immunisation schedule will be used to determine rotavirus vaccine impact and effectiveness. ETHICS AND DISSEMINATION: The Institutional Review Board of Christian Medical College, Vellore, and all the site institutional ethics committees approved the project. Results will be disseminated in peer-reviewed journals and with stakeholders of the universal immunisation programme in India. |
The effect of text message reminders to health workers on quality of care for malaria, pneumonia, and diarrhea in Malawi: A cluster-randomized, controlled trial
Steinhardt LC , Mathanga D , Mwandama D , Nsona H , Moyo D , Gumbo A , Kobayashi M , Namuyinga R , Shah MP , Bauleni A , Troell P , Zurovac D , Rowe AK . Am J Trop Med Hyg 2019 100 (2) 460-469 The use of mobile technologies in medicine, or mHealth, holds promise to improve health worker (HW) performance, but evidence is mixed. We conducted a cluster-randomized controlled trial to evaluate the effect of text message reminders to HWs in outpatient health facilities (HFs) on quality of care for malaria, pneumonia, and diarrhea in Malawi. After a baseline HF survey (2,360 patients) in January 2015, 105 HFs were randomized to three arms: 1) text messages to HWs on malaria case management; 2) text messages to HWs on malaria, pneumonia, and diarrhea case management (latter two for children < 5 years); and 3) control arm (no messages). Messages were sent beginning April 2015 twice daily for 6 months, followed by an endline HF survey (2,536 patients) in November 2015. An intention-to-treat analysis with difference-in-differences binomial regression modeling was performed. The proportion of patients with uncomplicated malaria managed correctly increased from 42.8% to 59.6% in the control arm, from 43.7% to 55.8% in arm 1 (effect size -4.7%-points, 95% confidence interval (CI): -18.2, 8.9, P = 0.50) and from 30.2% to 50.9% in arm 2 (effect size 3.9%-points, 95% CI: -14.1, 22.0, P = 0.67). Prescription of first-line antibiotics to children < 5 years with clinically defined pneumonia increased in all arms, but decreased in arm 2 (effect size -4.1%-points, 95% CI: -42.0, 33.8, P = 0.83). Prescription of oral rehydration solution to children with diarrhea declined slightly in all arms. We found no significant improvements in malaria, pneumonia, or diarrhea treatment after HW reminders, illustrating the importance of rigorously testing new interventions before adoption. |
The norovirus epidemiologic triad: Predictors of severe outcomes in US norovirus outbreaks, 2009-2016
Burke RM , Shah MP , Wikswo ME , Barclay L , Kambhampati A , Marsh Z , Cannon JL , Parashar UD , Vinje J , Hall AJ . J Infect Dis 2018 219 (9) 1364-1372 Background: Noroviruses are the leading cause of acute gastroenteritis outbreaks worldwide. Clarifying the viral, host, and environmental factors (epidemiologic triad) associated with severe outcomes can help target public health interventions. Methods: Acute norovirus outbreaks reported to the National Outbreak Reporting System (NORS) in 2009-2016 were linked to laboratory-confirmed norovirus outbreaks reported to CaliciNet. Outbreaks were analyzed for differences in genotype (GII.4 vs non-GII.4), hospitalization, and mortality rates by timing, setting, transmission mode, demographics, clinical symptoms, and health outcomes. Results: A total of 3747 norovirus outbreaks were matched from NORS and CaliciNet. Multivariable models showed that GII.4 outbreaks (n = 2353) were associated with healthcare settings (odds ratio [OR], 3.94 [95% confidence interval {CI}, 2.99-5.23]), winter months (November-April; 1.55 [95% CI, 1.24-1.93]), and older age of cases (>/=50% aged >/=75 years; 1.37 [95% CI, 1.04-1.79]). Severe outcomes were more likely among GII.4 outbreaks (hospitalization rate ratio [RR], 1.54 [95% CI, 1.23-1.96]; mortality RR, 2.77 [95% CI, 1.04-5.78]). Outbreaks in healthcare settings were also associated with higher hospitalization (RR, 3.22 [95% CI, 2.34-4.44]) and mortality rates (RR, 5.65 [95% CI, 1.92-18.70]). Conclusions: Severe outcomes more frequently occurred in norovirus outbreaks caused by GII.4 and those in healthcare settings. These results should help guide preventive interventions for targeted populations, including vaccine development. |
Annual changes in rotavirus hospitalization rates before and after rotavirus vaccine implementation in the United States
Shah MP , Dahl RM , Parashar UD , Lopman BA . PLoS One 2018 13 (2) e0191429 BACKGROUND: Hospitalizations for rotavirus and acute gastroenteritis (AGE) have declined in the US with rotavirus vaccination, though biennial peaks in incidence in children aged less than 5 years occur. This pattern may be explained by lower rotavirus vaccination coverage in US children (59% to 73% from 2010-2015), resulting in accumulation of susceptible children over two successive birth cohorts. METHODS: Retrospective cohort analysis of claims data of commercially insured US children aged <5 years. Age-stratified hospitalization rates for rotavirus and for AGE from the 2002-2015 rotavirus seasons were examined. Median age and rotavirus vaccination coverage for biennial rotavirus seasons during pre-vaccine (2002-2005), early post-vaccine (2008-2011) and late post-vaccine (2012-2015) years. RESULTS: Age-stratified hospitalization rates decreased from pre-vaccine to early post-vaccine and then to late post-vaccine years. The clearest biennial pattern in hospitalization rates is the early post-vaccine period, with higher rates in 2009 and 2011 than in 2008 and 2010. The pattern diminishes in the late post-vaccine period. For rotavirus hospitalizations, the median age and the difference in age between biennial seasons was highest during the early post-vaccine period; these differences were not observed for AGE hospitalizations. There was no significant difference in vaccination coverage between biennial seasons. CONCLUSIONS: These observations provide conflicting evidence that incomplete vaccine coverage drove the biennial pattern in rotavirus hospitalizations that has emerged with rotavirus vaccination in the US. As this pattern is diminishing with higher vaccine coverage in recent years, further increases in vaccine coverage may reach a threshold that eliminates peak seasons in hospitalizations. |
Norovirus illnesses in children and adolescents
Shah MP , Hall AJ . Infect Dis Clin North Am 2018 32 (1) 103-118 Norovirus is a leading cause of childhood vomiting and diarrhea in the United States and globally. Although most illnesses caused by norovirus are self-resolving, severe outcomes may occur from dehydration, including hospitalization and death. A vast majority of deaths from norovirus occur in developing countries. Immunocompromised children are at risk for more severe outcomes. Treatment of norovirus illness is focused on early correction of dehydration and maintenance of fluid status and nutrition. Hand hygiene, exclusion of ill individuals, and environmental cleaning are important for norovirus outbreak prevention and control, and vaccines to prevent norovirus illness are currently under development. |
The effect of holes in long-lasting insecticidal nets on malaria in Malawi: results from a case-control study
Minta AA , Landman KZ , Mwandama DA , Shah MP , Eng JLV , Sutcliffe JF , Chisaka J , Lindblade KA , Mathanga DP , Steinhardt LC . Malar J 2017 16 (1) 394 BACKGROUND: Long-lasting insecticidal nets (LLINs) are a cornerstone of malaria prevention. Holes develop in LLINs over time and compromise their physical integrity, but how holes affect malaria transmission risk is not well known. METHODS: After a nationwide mass LLIN distribution in July 2012, a study was conducted to assess the relationship between LLIN damage and malaria. From March to September 2013, febrile children ages 6-59 months who consistently slept under LLINs (every night for 2 weeks before illness onset) were enrolled in a case-control study at Machinga District Hospital outpatient department. Cases were positive for Plasmodium falciparum asexual parasites by microscopy while controls were negative. Digital photographs of participants' LLINs were analysed using an image-processing programme to measure holes. Total hole area was classified by quartiles and according to the World Health Organization's proportionate hole index (pHI) cut-offs [< 79 cm2 (good), 80-789 cm2 (damaged), and > 790 cm2 (too torn)]. Number of holes by location and size, and total hole area, were compared between case and control LLINs using non-parametric analyses and logistic regression. RESULTS: Of 248 LLINs analysed, 97 (39%) were from cases. Overall, 86% of LLINs had at least one hole. The median number of holes of any size was 9 [interquartile range (IQR) 3, 22], and most holes were located in the lower halves of the nets [median 7 (IQR 2, 16)]. There were no differences in number or location of holes between LLINs used by cases and controls. The median total hole area was 10 cm2 (IQR 2, 125) for control LLINs and 8 cm2 (IQR 2, 47) for case LLINs (p = 0.10). Based on pHI, 109 (72%) control LLINs and 83 (86%) case LLINs were in "good" condition. Multivariable modeling showed no association between total hole area and malaria, controlling for child age, caregiver education, and iron versus thatched roof houses. CONCLUSIONS: LLIN holes were not associated with increased odds of malaria in this study. However, most of the LLINs were in relatively good condition 1 year after distribution. Future studies should examine associations between LLIN holes and malaria risk with more damaged nets. |
Household costs among patients hospitalized with malaria: evidence from a national survey in Malawi, 2012
Hennessee I , Chinkhumba J , Briggs-Hagen M , Bauleni A , Shah MP , Chalira A , Moyo D , Dodoli W , Luhanga M , Sande J , Ali D , Gutman J , Lindblade KA , Njau J , Mathanga DP . Malar J 2017 16 (1) 395 BACKGROUND: With 71% of Malawians living on < $1.90 a day, high household costs associated with severe malaria are likely a major economic burden for low income families and may constitute an important barrier to care seeking. Nevertheless, few efforts have been made to examine these costs. This paper describes household costs associated with seeking and receiving inpatient care for malaria in health facilities in Malawi. METHODS: A cross-sectional survey was conducted in a representative nationwide sample of 36 health facilities providing inpatient treatment for malaria from June-August, 2012. Patients admitted at least 12 h before study team visits who had been prescribed an antimalarial after admission were eligible to provide cost information for their malaria episode, including care seeking at previous health facilities. An ingredients-based approach was used to estimate direct costs. Indirect costs were estimated using a human capital approach. Key drivers of total household costs for illness episodes resulting in malaria admission were assessed by fitting a generalized linear model, accounting for clustering at the health facility level. RESULTS: Out of 100 patients who met the eligibility criteria, 80 (80%) provided cost information for their entire illness episode to date and were included: 39% of patients were under 5 years old and 75% had sought care for the malaria episode at other facilities prior to coming to the current facility. Total household costs averaged $17.48 per patient; direct and indirect household costs averaged $7.59 and $9.90, respectively. Facility management type, household distance from the health facility, patient age, high household wealth, and duration of hospital stay were all significant drivers of overall costs. CONCLUSIONS: Although malaria treatment is supposed to be free in public health facilities, households in Malawi still incur high direct and indirect costs for malaria illness episodes that result in hospital admission. Finding ways to minimize the economic burden of inpatient malaria care is crucial to protect households from potentially catastrophic health expenditures. |
Estimated reductions in hospitalizations and deaths from childhood diarrhea following implementation of rotavirus vaccination in Africa
Shah MP , Mwenda JM , Tate JE , Steele AD , Parashar UD . Expert Rev Vaccines 2017 16 (10) 987-995 INTRODUCTION: Rotavirus is the leading cause of hospitalizations and deaths from diarrhea. 33 African countries had introduced rotavirus vaccines by 2016. We estimate reductions in rotavirus hospitalizations and deaths for countries using rotavirus vaccination in national immunization programs and the potential of vaccine introduction across the continent. Areas covered: Regional rotavirus burden data were reviewed to calculate hospitalization rates, and applied to the under-5 population to estimate baseline hospitalizations. Rotavirus mortality was based on 2013 WHO estimates. Regional pre-licensure vaccine efficacy and post-introduction vaccine effectiveness studies were used to estimate summary effectiveness, and vaccine coverage was applied to calculate prevented hospitalizations and deaths. Uncertainties around input parameters were propagated using boot-strapping simulations. In 29 African countries that introduced rotavirus vaccination prior to end 2014, 134,714 (IQR 112,321-154,654) hospitalizations and 20,986 (IQR 18,924-22,822) deaths were prevented in 2016. If all African countries had introduced rotavirus vaccines at benchmark immunization coverage, 273,619 (47%) (IQR 227,260-318,102) hospitalizations and 47,741 (39%) (IQR 42,822-52,462) deaths would have been prevented. Expert Commentary: Rotavirus vaccination has substantially reduced hospitalizations and deaths in Africa; further reductions are anticipated as additional countries fully implement vaccination. These estimates bolster wider introduction and continued support of existing rotavirus vaccination programs. |
Quality of case management for pneumonia and diarrhea among children seen at health facilities in southern Malawi
Kobayashi M , Mwandama D , Nsona H , Namuyinga RJ , Shah MP , Bauleni A , Eng JV , Rowe AK , Mathanga DP , Steinhardt LC . Am J Trop Med Hyg 2017 96 (5) 1107-1116 Pneumonia and diarrhea are leading causes of child deaths in Malawi. Guidelines to manage childhood illnesses in resource-poor settings exist, but studies have reported low health-care worker (HCW) adherence to guidelines. We conducted a health facility survey from January to March 2015 to assess HCW management of pneumonia and diarrhea in children < 5 years of age in southern Malawi, and to determine factors associated with case management quality. Descriptive statistics and multivariable logistic regression models examined patient, HCW, and health facility factors associated with recommended pneumonia and diarrhea management, using Malawi's national guidelines as the gold standard. Of 694 surveyed children 2-59 months of age at 95 health facilities, 132 (19.0%) met survey criteria for pneumonia; HCWs gave recommended antibiotic treatment to 90 (68.2%). Of 723 children < 5 years of age, 222 (30.7%) had uncomplicated diarrhea; HCWs provided recommended treatment to 94 (42.3%). In multivariable analyses, caregivers' spontaneous report of children's symptoms was associated with recommended treatment of both pneumonia (odds ratio [OR]: 2.8, 95% confidence interval [CI]: 1.2-6.8, P = 0.023) and diarrhea (OR: 24.2, 95% CI: 6.0-97.0, P < 0001). Malaria diagnosis was negatively associated with recommended treatment (OR for pneumonia: 0.5, 95% CI: 0.2-1.0, P = 0.046; OR for diarrhea: 0.3, 95% CI: 0.1-0.6, P = 0.003). To improve quality of care, children should be assessed systematically, even when malaria is suspected. Renewed efforts to invigorate such a systematic approach, including HCW training, regular follow-up supervision, and monitoring HCW performance, are needed in Malawi. |
Use of internet search data to monitor rotavirus vaccine impact in the United States, United Kingdom, and Mexico
Shah MP , Lopman BA , Tate JE , Harris J , Esparza-Aguilar M , Sanchez-Uribe E , Richardson V , Steiner CA , Parashar UD . J Pediatric Infect Dis Soc 2017 7 (1) 56-63 Background.: Previous studies have found a strong correlation between internet search and public health surveillance data. Less is known about how search data respond to public health interventions, such as vaccination, and the consistency of responses in different countries. In this study, we aimed to study the correlation between internet searches for "rotavirus" and rotavirus disease activity in the United States, United Kingdom, and Mexico before and after introduction of rotavirus vaccine. Methods.: We compared time series of internet searches for "rotavirus" from Google Trends with rotavirus laboratory reports from the United States and United Kingdom and with hospitalizations for acute gastroenteritis in the United States and Mexico. Using time and location parameters, Google quantifies an internet query share (IQS) to measure the relative search volume for specific terms. We analyzed the correlation between IQS and laboratory and hospitalization data before and after national vaccine introductions. Results.: There was a strong positive correlation between the rotavirus IQS and laboratory reports in the United States (R2 = 0.79) and United Kingdom (R2 = 0.60) and between the rotavirus IQS and acute gastroenteritis hospitalizations in the United States (R2 = 0.87) and Mexico (R2 = 0.69) (P < .0001 for all correlations). The correlations were stronger in the prevaccine period than in the postvaccine period. After vaccine introduction, the mean rotavirus IQS decreased by 40% (95% confidence interval [CI], 25%-55%) in the United States and by 70% (95% CI, 55%-86%) in Mexico. In the United Kingdom, there was a loss of seasonal variation after vaccine introduction. Conclusions.: Rotavirus internet search data trends mirrored national rotavirus laboratory trends in the United States and United Kingdom and gastroenteritis-hospitalization data in the United States and Mexico; lower correlations were found after rotavirus vaccine introduction. |
Near Real-Time Surveillance of U.S. Norovirus Outbreaks by the Norovirus Sentinel Testing and Tracking Network - United States, August 2009-July 2015.
Shah MP , Wikswo ME , Barclay L , Kambhampati A , Shioda K , Parashar UD , Vinje J , Hall AJ . MMWR Morb Mortal Wkly Rep 2017 66 (7) 185-189 ![]() Norovirus is the leading cause of endemic and epidemic acute gastroenteritis in the United States. New variant strains of norovirus GII.4 emerge every 2-4 years and are often associated with increased disease and health care visits. Since 2009, CDC has obtained epidemiologic data on norovirus outbreaks from state health departments through the National Outbreak Reporting System (NORS) and laboratory data through CaliciNet. NORS is a web-based platform for reporting waterborne, foodborne, and enteric disease outbreaks of all etiologies, including norovirus, to CDC. CaliciNet, a nationwide electronic surveillance system of local and state public health and regulatory agency laboratories, collects genetic sequences of norovirus strains associated with gastroenteritis outbreaks. Because these two independent reporting systems contain complementary data, integration of NORS and CaliciNet records could provide valuable public health information about norovirus outbreaks. However, reporting lags and inconsistent identification codes in NORS and CaliciNet records have been an obstacle to developing an integrated surveillance system. |
Adherence to national guidelines for the diagnosis and management of severe malaria: a nationwide, cross-sectional survey in Malawi, 2012
Shah MP , Briggs-Hagen M , Chinkhumba J , Bauleni A , Chalira A , Moyo D , Dodoli W , Luhanga M , Sande J , Ali D , Gutman J , Mathanga DP , Lindblade KA . Malar J 2016 15 (1) 369 BACKGROUND: Severe malaria has a case fatality rate of 10-20 %; however, few studies have addressed the quality of severe malaria case management. This study evaluated the diagnostic and treatment practices of malaria patients admitted to inpatient health facilities (HF) in Malawi. METHODS: In July-August 2012, a nationwide, cross-sectional survey of severe malaria management was conducted in 36 HFs selected with equal probability from all eligible public sector HFs in Malawi. Patient records from all admissions during October 2011 and April 2012 (low and high season, respectively) were screened for an admission diagnosis of malaria or prescription of any anti-malarial. Eligible records were stratified by age (< 5 or ≥ 5 years). A maximum of eight records was randomly selected within each age and month stratum. Severe malaria was defined by admission diagnosis or documentation of at least one sign or symptom of severe malaria. Treatment with intravenous (IV) quinine or artesunate was considered correct. Patients without documentation of severe malaria were analysed as uncomplicated malaria patients; treatment with an artemisinin-based combination therapy (ACT) or oral quinine based on malaria test results was considered correct. All analyses accounted for HF level clustering and sampling weights. RESULTS: The analysis included 906 records from 35 HFs. Among these, 42 % (95 % confidence interval [CI] 35-49) had a severe malaria admission diagnosis and 50 % (95 % CI 44-57) had at least one severe malaria sign or symptom documented. Severe malaria patients defined by admission diagnosis (93, 95 % CI 86-99) were more likely to be treated correctly compared to patients defined by a severe sign (82, 95 % CI 75-89) (p < 0.0001). Among uncomplicated malaria patients, 26 % (95 % CI 18-35) were correctly treated and 53 % (95 % CI 42-64) were adequately treated with IV quinine alone or in combination with an ACT or oral quinine. CONCLUSIONS: A majority of patients diagnosed with severe malaria received the recommended IV therapy in accordance with national treatment guidelines. However, the inconsistencies between diagnosis of severe malaria and documentation of severe signs and symptoms highlight the need to improve healthcare worker recognition and documentation of severe signs and symptoms. |
Decline in emergency department visits for acute gastroenteritis among children in 10 US states following implementation of rotavirus vaccination, 2003-2013
Shah MP , Tate JE , Steiner CA , Parashar UD . Pediatr Infect Dis J 2016 35 (7) 782-6 BACKGROUND: Rotavirus vaccination of all infants began in the United States in 2006. While the effect of vaccination on childhood hospitalizations for rotavirus have been well described, the effects of rotavirus vaccine on ED visits are less well documented. METHODS: Using the State Emergency Department Databases (SEDD) for 10 US states, we compared rates of gastroenteritis- and rotavirus-coded ED visits among children < 5 years of age in pre-vaccine (2003-2006) with post-vaccine (2008-2013) years; 2007 was excluded as a transition year. We analyzed ED visit rates by age group, sex, race, and rotavirus season. RESULTS: The pre-vaccine annual gastroenteritis-coded ED visit rate among children < 5 years of age of 426 per 10,000 (annual range, 396-477 per 10,000) declined to 382 per 10,000 in post-vaccine years, a 10.3% (+/-0.3%, p<.0001) rate reduction overall. Compared with pre-vaccine years, annual ED visit rates for gastroenteritis decreased by 6.5% (+/-0.6%) in 2008, 12.3% (+/-0.6%) in 2010, 14.8% (+/-0.5%) in 2011, 20.4% (+/-0.5%) in 2012 and 10.1% (+/-0.6%) in 2013; a small increase of 1.8% (+/-0.6%) was seen in 2009 (p<.0001 for all individual comparisons). Declines were similar by sex and race and were greater in children <2 years of age (range 14.1-20.6%, p<.0001) than in older children (increase of 3.3% +/- 0.6%, p<.0001). A decline of 21.2% (+/-0.4%, p<.0001) in ED visits was seen during the rotavirus season months from January through June versus an increase of 9.5% (+/-0.6%, p<.0001) during July to December. ED visits specifically coded for rotavirus showed more prominent declines than for all gastroenteritis. CONCLUSIONS: ED visits for gastroenteritis in US children have declined since introduction of rotavirus vaccine. |
Genetic diversity of Plasmodium falciparum parasite by microsatellite markers after scale-up of insecticide-treated bed nets in western Kenya.
Gatei W , Gimnig JE , Hawley W , Ter Kuile F , Odero C , Iriemenam NC , Shah MP , Howard PP , Omosun YO , Terlouw DJ , Nahlen B , Slutsker L , Hamel MJ , Kariuki S , Walker E , Shi YP . Malar J 2014 13 Suppl 1 495 ![]() BACKGROUND: An initial study of genetic diversity of Plasmodium falciparum in Asembo, western Kenya showed that the parasite maintained overall genetic stability 5 years after insecticide-treated bed net (ITN) introduction in 1997. This study investigates further the genetic diversity of P. falciparum 10 years after initial ITN introduction in the same study area and compares this with two other neighbouring areas, where ITNs were introduced in 1998 (Gem) and 2004 (Karemo). METHODS: From a cross-sectional survey conducted in 2007, 235 smear-positive blood samples collected from children ≤15-year-old in the original study area and two comparison areas were genotyped employing eight neutral microsatellites. Differences in multiple infections, allele frequency, parasite genetic diversity and parasite population structure between the three areas were assessed. Further, molecular data reported previously (1996 and 2001) were compared to the 2007 results in the original study area Asembo. RESULTS: Overall proportion of multiple infections (MA) declined with time in the original study area Asembo (from 95.9 %-2001 to 87.7 %-2007). In the neighbouring areas, MA was lower in the site where ITNs were introduced in 1998 (Gem 83.7 %) compared to where they were introduced in 2004 (Karemo 96.7 %) in 2007. Overall mean allele count (MAC ~ 2.65) and overall unbiased heterozygosity (H e ~ 0.77) remained unchanged in 1996, 2001 and 2007 in Asembo and was the same level across the two neighbouring areas in 2007. Overall parasite population differentiation remained low over time and in the three areas at FST < 0.04. Both pairwise and multilocus linkage disequilibrium showed limited to no significant association between alleles in Asembo (1996, 2001 and 2007) and between three areas. CONCLUSIONS: This study showed the P. falciparum high genetic diversity and parasite population resilience on samples collected 10 years apart and in different areas in western Kenya. The results highlight the need for long-term molecular monitoring after implementation and use of combined and intensive prevention and intervention measures in the region. |
The effectiveness of long-lasting, insecticide-treated nets in a setting of pyrethroid resistance: a case-control study among febrile children 6 to 59 months of age in Machinga District, Malawi
Mathanga DP , Mwandama DA , Bauleni A , Chisaka J , Shah MP , Landman KZ , Lindblade KA , Steinhardt LC . Malar J 2015 14 (1) 457 BACKGROUND: The escalating level of mosquito resistance to pyrethroid insecticides threatens the effectiveness of insecticide-treated nets (ITNs) for malaria control in Malawi. An evaluation of the effectiveness of ITNs for preventing malaria in children aged 6-59 months old, after 1 year of mass distribution of LLINs was conducted in Machinga District, Malawi, an area of moderate pyrethroid resistance. METHODS: A facility-based, case-control study among children 6-59 months was conducted in an area of pyrethroid resistance between March and September 2013 in Machinga District. Cases and controls were children with fever who sought care from the same hospital and tested positive and negative, respectively, for malaria parasites by microscopy. RESULTS: A high proportion of both cases (354 of 404 or 87.6 %) and controls (660 of 778 or 84.8 %) slept under an ITN the night before the survey. In univariable logistic regression, older age (24-59 months versus 6-23 months, p < 0.001), sleeping on the floor versus a mattress (p < 0.001), and open versus closed house eaves (p = 0.001) were associated with increased odds of malaria, whilst secondary education of the caretaker, having windows on multiple walls, and being in the least poor wealth quintile (p < 0.001 for each) reduced the odds of malaria; ITN use was not associated with malaria (p = 0.181). In multivariable analysis, older age (p < 0.001) and secondary education of the caregiver (p = 0.011) were the only factors significantly associated with malaria. CONCLUSION: This study did not find a significant personal protective effect of ITNs. However, high use of ITNs in the community and recent findings of lower malaria incidence in ITN users compared to bed net non-users from a cohort study in the same area suggest that ITNs provide community protection to both users and non-users alike in this area. |
Home visits to assess the reliability of caregiver-reported use of insecticide-treated bednets by children in Machinga District, Malawi
Wong J , Shah MP , Mwandama D , Gimnig JE , Lindblade KA , Mathanga DP . Am J Trop Med Hyg 2015 92 (4) 825-7 A malaria cohort study was conducted among young children in Machinga District, Malawi, following distribution of insecticide-treated bednets (ITN) in May 2012. To assess ITN use, two independently sampled subsets of children (211 during survey 1 [December 2012-January 2013] and 325 during survey 2 [September-October 2013]) were randomly selected to compare the proportions of positive and negative agreement between caregiver verbal reports at monthly interviews with visual observation of the ITN at home visits. Caregiver-reported ITN use was consistently high during both surveys (96.0% and 98.1%, respectively; P = 0.17). Home visit-based ITN use fell significantly (P < 0.001) from survey 1 (98.6%) to survey 2 (88.6%). The proportions of positive agreement between caregiver report and home visit in the first and second surveys were 98.8% (95% confidence interval [CI] 97.6-99.8%) and 93.3% (95% CI 91.2-95.3%), respectively. The proportions of negative agreement in the first and second surveys were 28.6% (95% CI 0-75.0%) and 20.0% (95% CI 0.1-35.0%), respectively. ITN use by children was high in Machinga District, and caregiver reports and home visits with visual confirmation of the net demonstrated a high level of agreement for use of ITNs, but a low level of agreement when ITNs were not used. |
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