Last data update: Mar 21, 2025. (Total: 48935 publications since 2009)
Records 1-19 (of 19 Records) |
Query Trace: Gueye S[original query] |
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Effect of mass drug administration on malaria incidence in southeast Senegal during 2020-22: a two-arm, open-label, cluster-randomised controlled trial
Ba EKC , Roh ME , Diallo A , Gadiaga T , Seck A , Thiam S , Fogelson A , Gaye S , Diallo I , Lo AC , Diouf E , Ba OG , Gueye AB , Wu X , Milligan P , Kibuka T , Hama M , Eckert E , Thwing J , Bennett A , Gosling R , Hwang J , Sene D , Ba F , Cissé B , Sturm-Ramirez K , Hsiang MS , Ndiaye JL . Lancet Infect Dis 2025 BACKGROUND: In Africa, the scale-up of malaria-control interventions has reduced malaria burden, but progress towards elimination has stalled. Mass drug administration (MDA) is promising as a transmission-reducing strategy, but evidence from low-to-moderate transmission settings is needed. We aimed to assess the safety, coverage, and effect of three cycles of MDA with dihydroartemisinin-piperaquine plus single, low-dose primaquine on Plasmodium falciparum incidence and prevalence in southeast Senegal. METHODS: We conducted a two-arm, open-label, cluster-randomised controlled trial in villages in the Tambacounda health district of southeast Senegal. Eligible villages had a population size of 200-800, were within a health-post catchment area with an annual malaria incidence of 60-160 cases per 1000 people, and had an established or planned Prise en Charge à Domicile Plus model. We randomly assigned villages (1:1) using a stratified, constrained randomisation approach to receive either three cycles of MDA with oral dihydroartemisinin-piperaquine plus single, low-dose primaquine administered at 6-week intervals (intervention) or to standard of care, which included three cycles of seasonal malaria chemoprevention (SMC) with oral sulfadoxine-pyrimethamine plus amodiaquine administered at 4-week intervals (control). Participants, the field team, and all investigators, including those who assessed outcomes and analysed data, were unmasked to allocation assignment. Laboratory technicians were masked to intervention assignment. The primary outcome was village-level, P falciparum-confirmed malaria incidence in the post-intervention year (ie, July to December, 2022). Secondary outcomes included malaria incidence during the intervention year (ie, July to December, 2021), coverage and safety of MDA, and adverse events. We conducted analyses using an intention-to-treat approach. The trial is registered with ClinicalTrials.gov (NCT04864444) and is completed. FINDINGS: Between Sept 1 and Oct 25, 2020, 523 villages were geolocated and screened for eligibility; 111 met the inclusion criteria. Of these, 60 villages were randomly selected and assigned to the intervention arm or control arm. Distribution coverage of all three doses of dihydroartemisinin-piperaquine was 6057 (73·6%) of 8229 participants in the first cycle, 6836 (78·8%) of 8673 participants in the second cycle, and 7065 (81·3%) of 8690 participants in the third cycle. Distribution coverage of single, low-dose primaquine was 6286 (78·6%) of 7999 participants in the first cycle, 6949 (82·1%) of 8462 participants in the second cycle, and 7199 (84·0%) of 8575 participants in the third cycle. Distribution coverage of all three doses of SMC was 3187 (92·2%) of 3457 children aged 3-120 months in the first cycle, 3158 (91·8%) of 3442 children aged 3-120 months in the second cycle, and 3139 (91·4%) of 3434 children aged 3-120 months in the third cycle. In the intervention year (ie, July to December, 2021), the adjusted effect of MDA was 55% (95% CI 28 to 71). In the post-intervention year (ie, July to December 2022), the adjusted MDA effect was 26% (-17 to 53). Malaria incidence during the transmission season of the post-intervention year was 126 cases per 1000 population in the intervention arm and 146 cases per 1000 population in the control arm. No serious adverse events were reported. INTERPRETATION: In southeast Senegal, a low-to-moderate transmission setting where malaria-control measures have been scaled up, three cycles of MDA with dihydroartemisinin-piperaquine plus single, low-dose primaquine was safe and reduced malaria burden during the intervention year. However, its sustained effect was weak and continuation of MDA or another transmission-reducing strategy could be required. FUNDING: US President's Malaria Initiative. |
Functional simulation exercise on functionality of national public health emergency operations centers in the African region: Review of strengths and gaps
Fekadu ST , Gebrewahid AL , Stephen M , Sonko I , Mankoula W , Kawe Y , Assefa Z , Aderinola O , Kol MTM , McGinley L , Collard E , Ilunga T , Middlemiss V , Furtado P , Schneider T , Dieng AB , Kanouté YB , Ramadan OP , Lado A , Yur CT , Mpairwe A , Garcia E , Semedo F , Li J , Eteng W , Conteh IN , Halm A , Menchion C , Rosenfeld E , Aragaw M , Lokossou V , Braka F , Gueye AS . Health Secur 2024 22 (5) 353-362 National public health emergency operations centers (PHEOCs) serve as hubs for coordinating information and resources for effective emergency management. In the International Health Regulations (IHR 2005) Monitoring and Evaluation Framework, a simulation exercise is 1 of 4 components that can be used to test the functionality of a country's emergency response capabilities in a simulated situation. To test the functionality of PHEOCs in World Health Organization African Region member states, a regional functional exercise simulating an Ebola virus disease outbreak was conducted. The public health actions taken in response to the simulated outbreak were evaluated against the exercise objectives. Thematic analysis was conducted to summarize key strengths and areas for improvement. From December 6 to 7, 2022, more than 1,000 representatives from 36 of the 47 African Region member states participated in the exercise from their respective PHEOCs. Approximately 95% of the 461 participants polled agreed with the positive responses to the postexercise survey. More than half of the PHEOC participants were able to test their existing emergency preparedness and response plans and became familiar with the expected roles to be fulfilled during an event. Of the participants who responded to the survey, over 90% reported that the exercise helped them understand their roles during emergency management. The exercise met its objectives and provided an opportunity to test the functionality of PHEOCs using realistic scenarios, and it helped participants understand existing response systems and procedures. However, the exercise also revealed areas for improvement in terms of the timing and preparation of participants. We recommend conducting functional exercises at the regional and national levels at least once a year, early or midyear, to allow many stakeholders to take part in the exercise. Moreover, there is a need to train country-level evaluators and controllers in designing and conducting functional exercises. |
Case management of imported Crimean-Congo hemorrhagic fever, Senegal, July 2023
Gueye YB , Sall Y , Roka JL , Diagne I , Sow KD , Diallo A , Dièye PS , Diallo JP , Diop B , Pasi O . Emerg Infect Dis 2024 30 (4) 805-807 We report an imported Crimean-Congo hemorrhagic fever case in Senegal. The patient received PCR confirmation of virus infection 10 days after symptom onset. We identified 46 patient contacts in Senegal; 87.7% were healthcare professionals. Strengthening border crossing and community surveillance systems can help reduce the risks of infectious disease transmission. |
Improving global health security through implementation of the National Action Plan for Health Security in Sierra Leone, 2018-2021: lessons from the field
Njuguna C , Vandi M , Singh T , Njeru I , Githuku J , Gachari W , Musoke R , Caulker V , Bunting-Graden J , Mahar M , Brown SM , Bah MA , Idriss MB , Talisuna A , Chamla D , Yoti Z , Sreedharan R , Suryantoro L , Gueye AS , Chungong S . BMC Public Health 2023 23 (1) 2178 BACKGROUND: All countries are required to implement International Health Regulations (IHR) through development and implementation of multi-year National Action Plans for Health Security (NAPHS). IHR implementation requires annual operational planning which involves several tools such as NAPHS, State Party Annual Report (SPAR), Joint External Evaluation (JEE) and WHO IHR Benchmarks tool. Sierra Leone has successfully improved IHR capacities across the years through successful annual operational planning using the above tools. We conducted a study to document and share the country's unique approach to implementation of NAPHS. METHODS: This was an observational study where the process of implementing and monitoring NAPHS in Sierra Leone was observed at the national level from 2018 to 2021. Data was obtained through review and analysis of NAPHS annual operational plans, quarterly review reports and annual IHR assessment reports. Available data was supplemented by information from key informants. Qualitative data was captured as notes and analysed for various themes while quantitative data was analyzed mainly for means and proportions. RESULTS: The overall national IHR Joint External Evaluation self-assessment score for human health improved from 44% in 2018 to 51% in 2019 and 57% in 2020. The score for the animal sector improved from 32% in 2018 to 43% in 2019 and 52% in 2020. A new JEE tool with new indicators was used in 2021 and the score for both human and animal sectors declined slightly to 51%. Key enablers of success included strong political commitment, whole-of-government approach, annual assessments using JEE tool, annual operational planning using WHO IHR Benchmarks tool and real time online monitoring of progress. Key challenges included disruption created by COVID-19 response, poor health infrastructure, low funding and inadequate health workforce. CONCLUSION: IHR annual operational planning and implementation using evidence-based data and tools can facilitate strengthening of IHR capacity and should be encouraged. |
Defining operational research priorities to improve malaria control and elimination in sub-Saharan Africa: Results from a country-driven research prioritization setting process
Tine R , Herrera S , Badji MA , Daniels K , Ndiaye P , Smith Gueye C , Tairou F , Slutsker L , Hwang J , Ansah E , Littrell M . Malar J 2023 22 (1) 219 BACKGROUND: In order to reignite gains and accelerate progress toward improved malaria control and elimination, policy, strategy, and operational decisions should be derived from high-quality evidence. The U.S. President's Malaria Initiative (PMI) Insights project together with the Université Cheikh Anta Diop of Dakar, Senegal, conducted a broad stakeholder consultation process to identify pressing evidence gaps in malaria control and elimination across sub-Saharan Africa (SSA), and developed a priority list of country-driven malaria operational research (OR) and programme evaluation (PE) topics to address these gaps. METHODS: Five key stakeholder groups were engaged in the process: national malaria programmes (NMPs), research institutions in SSA, World Health Organization (WHO) representatives in SSA, international funding agencies, and global technical partners who support malaria programme implementation and research. Stakeholders were engaged through individual or small group interviews and an online survey, and asked about key operational challenges faced by NMPs, pressing evidence gaps in current strategy and implementation guidance, and priority OR and PE questions to address the challenges and gaps. RESULTS: Altogether, 47 interviews were conducted with 82 individuals, and through the online survey, input was provided by 46 global technical partners. A total of 33 emergent OR and PE topics were identified through the consultation process and were subsequently evaluated and prioritized by an external evaluation committee of experts from NMPs, research institutions, and the WHO. The resulting prioritized OR and PE topics predominantly focused on generating evidence needed to close gaps in intervention coverage, address persistent challenges faced by NMPs in the implementation of core strategic interventions, and inform the effective deployment of new tools. CONCLUSION: The prioritized research list is intended to serve as a key resource for informing OR and PE investments, thereby ensuring future investments focus on generating the evidence needed to strengthen national strategies and programme implementation and facilitating a more coordinated and impactful approach to malaria operational research. |
Public health emergency operations centres in Africa: a cross-sectional study assessing the implementation status of core components and areas for improvement, December 2021
Fekadu ST , Gebrewahid AL , Mankoula W , Eteng W , Lokossou V , Kawe Y , Abdullah A , Jian L , Kol MTM , Wilton MC , Rosenfeld E , Bemo VN , Collard E , McGinley L , Halm A , Aragaw M , Conteh IN , Braka F , Gueye AS . BMJ Open 2023 13 (6) e068934 OBJECTIVE: To assess implementation status of public health emergency operations centres (PHEOCs) in all countries in Africa. DESIGN: Cross-sectional. SETTING: Fifty-four national PHEOC focal points in Africa responded to an online survey between May and November 2021. Included variables aimed to assess capacities for each of the four PHEOC core components. To assess the PHEOCs' functionality, criteria were defined from among the collected variables by expert consensus based on PHEOC operations' prioritisation. We report results of the descriptive analysis, including frequencies of proportions. RESULTS: A total of 51 (93%) African countries responded to the survey. Among these, 41 (80%) have established a PHEOC. Twelve (29%) of these met 80% or more of the minimum requirements and were classified as fully functional. Twelve (29%) and 17 (41%) PHEOCs that met 60%-79% and below 60% the minimum requirements were classified as functional and partially functional, respectively. CONCLUSIONS: Countries in Africa made considerable progress in setting up and improving functioning of PHEOCs. One-third of the responding countries with a PHEOC have one fulfilling at least 80% of the minimum requirements to operate the critical emergency functions. There are still several African countries that either do not have a PHEOC or whose PHEOCs only partially meet these minimal requirements. This calls for significant collaboration across all stakeholders to establish functional PHEOCs in Africa. |
Attrition, physical integrity and insecticidal activity of long-lasting insecticidal nets in sub-Saharan Africa and modelling of their impact on vectorial capacity
Briet O , Koenker H , Norris L , Wiegand R , Vanden Eng J , Thackeray A , Williamson J , Gimnig JE , Fortes F , Akogbeto M , Yadouleton AW , Ombok M , Bayoh MN , Mzilahowa T , Abílio AP , Mabunda S , Cuamba N , Diouf E , Konaté L , Hamainza B , Katebe-Sakala C , Ponce de León G , Asamoa K , Wolkon A , Smith SC , Swamidoss I , Green M , Gueye S , Mihigo J , Morgan J , Dotson E , Craig AS , Tan KR , Wirtz RA , Smith T . Malar J 2020 19 (1) 310 BACKGROUND: Long-lasting insecticidal nets (LLINs) are the primary malaria prevention and control intervention in many parts of sub-Saharan Africa. While LLINs are expected to last at least 3 years under normal use conditions, they can lose effectiveness because they fall out of use, are discarded, repurposed, physically damaged, or lose insecticidal activity. The contributions of these different interrelated factors to durability of nets and their protection against malaria have been unclear. METHODS: Starting in 2009, LLIN durability studies were conducted in seven countries in Africa over 5 years. WHO-recommended measures of attrition, LLIN use, insecticidal activity, and physical integrity were recorded for eight different net brands. These data were combined with analyses of experimental hut data on feeding inhibition and killing effects of LLINs on both susceptible and pyrethroid resistant malaria vectors to estimate the protection against malaria transmission-in terms of vectorial capacity (VC)-provided by each net cohort over time. Impact on VC was then compared in hypothetical scenarios where one durability outcome measure was set at the best possible level while keeping the others at the observed levels. RESULTS: There was more variability in decay of protection over time by country than by net brand for three measures of durability (ratios of variance components 4.6, 4.4, and 1.8 times for LLIN survival, use, and integrity, respectively). In some countries, LLIN attrition was slow, but use declined rapidly. Non-use of LLINs generally had more effect on LLIN impact on VC than did attrition, hole formation, or insecticide loss. CONCLUSIONS: There is much more variation in LLIN durability among countries than among net brands. Low levels of use may have a larger impact on effectiveness than does variation in attrition or LLIN degradation. The estimated entomological effects of chemical decay are relatively small, with physical decay probably more important as a driver of attrition and non-use than as a direct cause of loss of effect. Efforts to maximize LLIN impact in operational settings should focus on increasing LLIN usage, including through improvements in LLIN physical integrity. Further research is needed to understand household decisions related to LLIN use, including the influence of net durability and the presence of other nets in the household. |
Genetic evidence for imported malaria and local transmission in Richard Toll, Senegal.
Daniels RF , Schaffner SF , Dieye Y , Dieng G , Hainsworth M , Fall FB , Diouf CN , Ndiop M , Cisse M , Gueye AB , Sarr O , Guinot P , Deme AB , Bei AK , Sy M , Thwing J , MacInnis B , Earle D , Guinovart C , Sene D , Hartl DL , Ndiaye D , Steketee RW , Wirth DF , Volkman SK . Malar J 2020 19 (1) 276 ![]() BACKGROUND: Malaria elimination efforts can be undermined by imported malaria infections. Imported infections are classified based on travel history. METHODS: A genetic strategy was applied to better understand the contribution of imported infections and to test for local transmission in the very low prevalence region of Richard Toll, Senegal. RESULTS: Genetic relatedness analysis, based upon molecular barcode genotyping data derived from diagnostic material, provided evidence for both imported infections and ongoing local transmission in Richard Toll. Evidence for imported malaria included finding that a large proportion of Richard Toll parasites were genetically related to parasites from Thiès, Senegal, a region of moderate transmission with extensive available genotyping data. Evidence for ongoing local transmission included finding parasites of identical genotype that persisted across multiple transmission seasons as well as enrichment of highly related infections within the households of non-travellers compared to travellers. CONCLUSIONS: These data indicate that, while a large number of infections may have been imported, there remains ongoing local malaria transmission in Richard Toll. These proof-of-concept findings underscore the value of genetic data to identify parasite relatedness and patterns of transmission to inform optimal intervention selection and placement. |
Proactive community case management in Senegal 2014-2016: a case study in maximizing the impact of community case management of malaria
Gaye S , Kibler J , Ndiaye JL , Diouf MB , Linn A , Gueye AB , Fall FB , Ndiop M , Diallo I , Cisse M , Ba M , Thwing J . Malar J 2020 19 (1) 166 The Senegal National Malaria Control Programme (NMCP) introduced home-based malaria management for all ages, with diagnosis by rapid diagnostic test (RDT) and treatment with artemisinin-based combination therapy (ACT) in 2008, expanding to over 2000 villages nationwide by 2014. With prise en charge a domicile (PECADOM), community health workers (CHWs) were available for community members to seek care, but did not actively visit households to find cases. A trial of a proactive model (PECADOM Plus), in which CHWs visited all households in their village weekly during transmission season to identify fever cases and offer case management, in addition to availability during the week for home-based management, found that CHWs detected and treated more cases in intervention villages, while the number of cases detected weekly decreased over the transmission season. The NMCP scaled PECADOM Plus to three districts in 2014 (132 villages), to a total of six districts in 2015 (246 villages), and to a total of 16 districts in 2016 (708 villages). A narrative case study with programmatic results is presented. During active sweeps over approximately 20 weeks, CHWs tested a mean of 77 patients per CHW in 2014, 89 patients per CHW in 2015, and 90 patients per CHW in 2016, and diagnosed a mean of 61, 61 and 43 patients with malaria per CHW in 2014, 2015 and 2016, respectively. The number of patients who sought care between sweeps increased, with a 104% increase in the number of RDTs performed and a 77% increase in the number of positive tests and patients treated with ACT during passive case detection. While the number of CHWs increased 7%, the number of patients receiving an RDT increased by 307% and the number of malaria cases detected and treated by CHWs increased 274%, from the year prior to PECADOM Plus introduction to its first year of implementation. Based on these results, approximately 700 additional CHWs in 24 new districts were added in 2017. This case study describes the process, results and lessons learned from Senegal's implementation of PECADOM Plus, as well as guidance for other programmes considering introduction of this innovative strategy. |
Immunogenicity of fractional-dose vaccine during a yellow fever outbreak - final report
Casey RM , Harris JB , Ahuka-Mundeke S , Dixon MG , Kizito GM , Nsele PM , Umutesi G , Laven J , Kosoy O , Paluku G , Gueye AS , Hyde TB , Ewetola R , Sheria GKM , Muyembe-Tamfum JJ , Staples JE . N Engl J Med 2019 381 (5) 444-454 BACKGROUND: In 2016, the response to a yellow fever outbreak in Angola and the Democratic Republic of Congo led to a global shortage of yellow fever vaccine. As a result, a fractional dose of the 17DD yellow fever vaccine (containing one fifth [0.1 ml] of the standard dose) was offered to 7.6 million children 2 years of age or older and nonpregnant adults in a preemptive campaign in Kinshasa. The goal of this study was to assess the immune response to the fractional dose in a large-scale campaign. METHODS: We recruited participants in four age strata at six vaccination sites. We assessed neutralizing antibody titers against yellow fever virus in blood samples obtained before vaccination and at 1 month and 1 year after vaccination, using a plaque reduction neutralization test with a 50% cutoff (PRNT50). Participants with a PRNT50 titer of 10 or higher were considered to be seropositive. Those with a baseline titer of less than 10 who became seropositive at follow-up were classified as having undergone seroconversion. Participants who were seropositive at baseline and who had an increase in the titer by a factor of 4 or more at follow-up were classified as having an immune response. RESULTS: Among 716 participants who completed the 1-month follow-up, 705 (98%; 95% confidence interval [CI], 97 to 99) were seropositive after vaccination. Among 493 participants who were seronegative at baseline, 482 (98%; 95% CI, 96 to 99) underwent seroconversion. Among 223 participants who were seropositive at baseline, 148 (66%; 95% CI, 60 to 72) had an immune response. Lower baseline titers were associated with a higher probability of having an immune response (P<0.001). Among 684 participants who completed the 1-year follow-up, 666 (97%; 95% CI, 96 to 98) were seropositive for yellow fever antibody. The distribution of titers among the participants who were seronegative for yellow fever antibody at baseline varied significantly among age groups at 1 month and at 1 year (P<0.001 for both comparisons). CONCLUSIONS: A fractional dose of the 17DD yellow fever vaccine was effective at inducing seroconversion in participants who were seronegative at baseline. Titers remained above the threshold for seropositivity at 1 year after vaccination in nearly all participants who were seropositive at 1 month after vaccination. These findings support the use of fractional-dose vaccination for outbreak control. (Funded by the U.S. Agency for International Development and the Centers for Disease Control and Prevention.). |
Evaluation of Senegal's prevention of mother to child transmission of HIV (PMTCT) program data for HIV surveillance
Diouf O , Gueye-Gaye A , Sarr M , Mbengue AS , Murrill CS , Dee J , Diaw PO , Ngom-Faye NF , Diallo PAN , Suarez C , Gueye M , Mboup A , Toure-Kane C , Mboup S . BMC Infect Dis 2018 18 (1) 588 BACKGROUND: With the expansion of Prevention of Mother to Child Transmission (PMTCT) services in Senegal, there is growing interest in using PMTCT program data in lieu of conducting unlinked anonymous testing (UAT)-based ANC Sentinel Surveillance. For this reason, an evaluation was conducted in 2011-2012 to identify the gaps that need to be addressed while transitioning to using PMTCT program data for surveillance. METHODS: We conducted analyses to assess HIV prevalence rates and agreements between Sentinel Surveillance and PMTCT HIV test results. Also, a data quality assessment of the PMTCT program registers and data was conducted during the Sentinel Surveillance period (December 2011 to March 2012) and 3 months prior. Finally, we also assessed selection bias, which was the percentage difference from the HIV prevalence among all women enrolled in the antenatal clinic and the HIV prevalence among women who accepted PMTCT HIV testing. RESULTS: The median site HIV prevalence using routine PMTCT HIV testing data was 1.1% (IQR: 1.0) while the median site prevalence from the UAT HIV Sentinel Surveillance data was at 1.0% (IQR: 1.6). The Positive per cent agreement (PPA) of the PMTCT HIV test results compared to those of the Sentinel Surveillance was 85.1% (95% CI 77.2-90.7%), and the percent-negative agreement (PNA) was 99.9% (95% CI 99.8-99.9%). The overall HIV prevalence according to UAT was the same as that found for women accepting a PMTCT HIV test and those who refused, with percent bias at 0.00%. For several key PMTCT variables, including "HIV test offered" (85.2%), "HIV test acceptance" (78.0%), or "HIV test done" (58.8%), the proportion of records in registers with combined complete and valid data was below the WHO benchmark of 90%. CONCLUSIONS: The PPA of 85.1 was below the WHO benchmarks of 96.6%, while the combined data validity and completeness rates was below the WHO benchmark of 90% for many key PMTCT variables. These results suggested that Senegal will need to reinforce the quality of onsite HIV testing and improve program data collection practices in preparation for using PMTCT data for surveillance purposes. |
Immunogenicity of fractional-dose vaccine during a yellow fever outbreak - preliminary report
Ahuka-Mundeke S , Casey RM , Harris JB , Dixon MG , Nsele PM , Kizito GM , Umutesi G , Laven J , Paluku G , Gueye AS , Hyde TB , Sheria GKM , Muyembe-Tanfum JJ , Staples JE . N Engl J Med 2018 381 (5) 444-454 Background In 2016, the response to a yellow fever outbreak in Angola and the Democratic Republic of Congo led to a global shortage of yellow fever vaccine. As a result, a fractional dose of the 17DD yellow fever vaccine (containing one fifth [0.1 ml] of the standard dose) was offered to 7.6 million children 2 years of age or older and nonpregnant adults in a preemptive campaign in Kinshasa. The goal of this study was to assess the immune response to the fractional dose in a large-scale campaign. Methods We recruited participants in four age strata at six vaccination sites. We assessed neutralizing antibody titers against yellow fever virus in blood samples obtained before vaccination and 28 to 35 days after vaccination, using a plaque reduction neutralization test with a 50% cutoff (PRNT50). Participants with a PRNT50 titer of 10 or higher at baseline were considered to be seropositive. Those with a baseline titer of less than 10 who became seropositive at follow-up were classified as having undergone seroconversion. Participants who were seropositive at baseline and who had an increase in the titer by a factor of 4 or more at follow-up were classified as having an immune response. Results Among 716 participants who completed follow-up, 705 (98%; 95% confidence interval [CI], 97 to 99) were seropositive after vaccination. Among 493 participants who were seronegative at baseline, 482 (98%; 95% CI, 96 to 99) underwent seroconversion. Among 223 participants who were seropositive at baseline, 148 (66%; 95% CI, 60 to 72) had an immune response. Lower baseline titers were associated with a higher probability of having an immune response (P<0.001). Conclusions A fractional dose of the 17DD yellow fever vaccine was effective at inducing seroconversion in most of the participants who were seronegative at baseline. These findings support the use of fractional-dose vaccination for outbreak control. (Funded by the U.S. Agency for International Development and the Centers for Disease Control and Prevention.). |
Yellow Fever Outbreak - Kongo Central Province, Democratic Republic of the Congo, August 2016
Otshudiema JO , Ndakala NG , Mawanda EK , Tshapenda GP , Kimfuta JM , Nsibu LN , Gueye AS , Dee J , Philen RM , Giese C , Murrill CS , Arthur RR , Kebela BI . MMWR Morb Mortal Wkly Rep 2017 66 (12) 335-338 On April 23, 2016, the Democratic Republic of the Congo's (DRC's) Ministry of Health declared a yellow fever outbreak. As of May 24, 2016, approximately 90% of suspected yellow fever cases (n = 459) and deaths (45) were reported in a single province, Kongo Central Province, that borders Angola, where a large yellow fever outbreak had begun in December 2015. Two yellow fever mass vaccination campaigns were conducted in Kongo Central Province during May 25-June 7, 2016 and August 17-28, 2016. In June 2016, the DRC Ministry of Health requested assistance from CDC to control the outbreak. As of August 18, 2016, a total of 410 suspected yellow fever cases and 42 deaths were reported in Kongo Central Province. Thirty seven of the 393 specimens tested in the laboratory were confirmed as positive for yellow fever virus (local outbreak threshold is one laboratory-confirmed case of yellow fever). Although not well-documented for this outbreak, malaria, viral hepatitis, and typhoid fever are common differential diagnoses among suspected yellow fever cases in this region. Other possible diagnoses include Zika, West Nile, or dengue viruses; however, no laboratory-confirmed cases of these viruses were reported. Thirty five of the 37 cases of yellow fever were imported from Angola. Two-thirds of confirmed cases occurred in persons who crossed the DRC-Angola border at one market city on the DRC side, where ≤40,000 travelers cross the border each week on market day. Strategies to improve coordination between health surveillance and cross-border trade activities at land borders and to enhance laboratory and case-based surveillance and health border screening capacity are needed to prevent and control future yellow fever outbreaks. |
Notes from the field: Adverse events following a mass yellow fever immunization campaign - Kongo Central Province, Democratic Republic of the Congo, September 2016
Otshudiema JO , Ndakala NG , Loko ML , Mawanda EK , Tshapenda GP , Kimfuta JM , Gueye AS , Dee J , Philen RM , Giese C , Murrill CS , Arthur RR , Kebela BI . MMWR Morb Mortal Wkly Rep 2017 66 (12) 343-344 On April 23, 2016, the Democratic Republic of the Congo (DRC) Ministry of Health reported an outbreak of yellow fever. As of May 24, 2016, among 41 confirmed yellow fever cases, 31 (75.6%) had occurred in Kongo Central Province, in the western part of the country bordering Angola (1), where a large yellow outbreak had begun in December 2015. In response, during May 25–June 7, 2016, the DRC Ministry of Health administered approximately 240,000 doses of yellow fever vaccine to all persons aged ≥9 months during a mass vaccination campaign in Matadi, one of 31 health zones in the Kongo Central Province. The administrative vaccination coverage (i.e., the number of vaccine doses administered divided by the most recent census estimates for the target population), was estimated to have reached >99%. | During the campaign, health workers in the Matadi Health Zone were trained to identify adverse events following immunization (AEFIs), complete case report forms, and send forms weekly to both provincial officials and a national expert committee for vaccine pharmacovigilance. Although a provisional classification of AEFIs by severity is made at peripheral and provincial levels at the time of an initial investigation, responsibilities at the national level are to guide the investigation of suspected serious AEFIs, classify them according to standard AEFI cause–specific definitions, recommend additional testing of biologic specimens if warranted, and determine causality. |
Assessment of the utility of a symptom-based algorithm for identifying febrile patients for malaria diagnostic testing in Senegal
Thwing J , Ba F , Diaby A , Diedhiou Y , Sylla A , Sall G , Diouf MB , Gueye AB , Gaye S , Ndiop M , Cisse M , Ndiaye D , Ba M . Malar J 2017 16 (1) 95 BACKGROUND: Malaria rapid diagnostic tests (RDTs) enable point-of-care testing to be nearly as sensitive and specific as reference microscopy. The Senegal National Malaria Control Programme introduced RDTs in 2007, along with a case management algorithm for uncomplicated febrile illness, in which the first step stipulates that if a febrile patient of any age has symptoms indicative of febrile illness other than malaria (e.g., cough or rash), they would not be tested for malaria, but treated for the apparent illness and receive an RDT for malaria only if they returned in 48 h without improvement. METHODS: A year-long study in 16 health posts was conducted to determine the algorithm's capacity to identify patients with Plasmodium falciparum infection identifiable by RDT. Health post personnel enrolled patients of all ages with fever (≥37.5 degrees C) or history of fever in the previous 2 days. After clinical assessment, a nurse staffing the health post determined whether a patient should receive an RDT according to the diagnostic algorithm, but performed an RDT for all enrolled patients. RESULTS: Over 1 year, 6039 patients were enrolled and 58% (3483) were determined to require an RDT according to the algorithm. Overall, 23% (1373/6039) had a positive RDT, 34% (1130/3376) during rainy season and 9% (243/2661) during dry season. The first step of the algorithm identified only 78% of patients with a positive RDT, varying by transmission season (rainy 80%, dry 70%), malaria transmission zone (high 75%, low 95%), and age group (under 5 years 68%, 5 years and older 84%). CONCLUSIONS: In all but the lowest malaria transmission zone, use of the algorithm excludes an unacceptably large proportion of patients with malaria from receiving an RDT at their first visit, denying them timely diagnosis and treatment. While the algorithm was adopted within a context of malaria control and scarce resources, with the goal of treating patients with symptomatic malaria, Senegal has now adopted a policy of universal diagnosis of patients with fever or history of fever. In addition, in the current context of malaria elimination, the paradigm of case management needs to shift towards the identification and treatment of all patients with malaria infection. |
Notes from the field: Baseline assessment of the use of Ebola rapid diagnostic tests - Forecariah, Guinea, October-November 2015
Huang JY , Louis FJ , Dixon MG , Sefu M , Kightlinger L , Martel LD , Jayaraman GC , Gueye AS . MMWR Morb Mortal Wkly Rep 2016 65 (12) 328-329 The Ebola virus disease (Ebola) epidemic in West Africa began in Guinea in early 2014. The reemergence of Ebola and risk of ongoing, undetected transmission continues because of the potential for sexual transmission and other as yet unknown transmission pathways. On March 17, 2016, two new cases of Ebola in Guinea were confirmed by the World Health Organization. This reemergence of Ebola in Guinea is the first since the original outbreak in the country was declared over on December 29, 2015. The prefecture of Forecariah, in western Guinea, was considerably affected by Ebola in 2015, with an incidence rate of 159 cases per 100,000 persons. Guinea also has a high prevalence of malaria; in a nationwide 2012 survey, malaria prevalence was reported to be 44% among healthy children aged ≤5 years. Malaria is an important reason for seeking health care; during 2014, 34% of outpatient consultations were related to malaria. |
Strategies and approaches to vector control in nine malaria-eliminating countries: a cross-case study analysis
Smith Gueye C , Newby G , Gosling RD , Whittaker MA , Chandramohan D , Slutsker L , Tanner M . Malar J 2016 15 (1) 2 BACKGROUND: There has been progress towards malaria elimination in the last decade. In response, WHO launched the Global Technical Strategy (GTS), in which vector surveillance and control play important roles. Country experiences in the Eliminating Malaria Case Study Series were reviewed to identify success factors on the road to elimination using a cross-case study analytic approach. METHODS: Reports were included in the analysis if final English language draft reports or publications were available at the time of analysis (Bhutan, Cape Verde, Malaysia, Mauritius, Namibia, Philippines, Sri Lanka, Turkey, Turkmenistan). A conceptual framework for vector control in malaria elimination was developed, reviewed, formatted as a matrix, and case study data was extracted and entered into the matrix. A workshop was convened during which participants conducted reviews of the case studies and matrices and arrived at a consensus on the evidence and lessons. The framework was revised and a second round of data extraction, synthesis and summary of the case study reports was conducted. RESULTS: Countries implemented a range of vector control interventions. Most countries aligned with integrated vector management, however its impact was not well articulated. All programmes conducted entomological surveillance, but the response (i.e., stratification and targeting of interventions, outbreak forecasting and strategy) was limited or not described. Indoor residual spraying (IRS) was commonly used by countries. There were several examples of severe reductions or halting of IRS coverage and subsequent resurgence of malaria. Funding and operational constraints and poor implementation had roles. Bed nets were commonly used by most programmes; coverage and effectiveness were either not measured or not articulated. Larval control was an important intervention for several countries, preventing re-introduction, however coverage and impact on incidence were not described. Across all interventions, coverage indicators were incomparable, and the rationale for which tools were used and which were not used appeared to be a function of the availability of funding, operational issues and cost instead of evidence of effectiveness to reduce incidence. CONCLUSIONS: More work is required to fill gaps in programme guidance, clarify the best methods for choosing and targeting vector control interventions, and support to measure cost, cost-effectiveness and cost-benefit of vector surveillance and control interventions. |
The challenge of artemisinin resistance can only be met by eliminating Plasmodium falciparum malaria across the Greater Mekong subregion
Smith Gueye C , Newby G , Hwang J , Phillips AA , Whittaker M , MacArthur JR , Gosling RD , Feachem RG . Malar J 2014 13 286 Artemisinin-based combinations are currently the most effective anti-malarials and, in addition to vector control, have led to significant declines in malaria morbidity and mortality. However, foci of artemisinin drug resistance have been identified in the Greater Mekong subregion (GMS) of the Asia Pacific, threatening the major gains made in malaria control and potentially creating a parasite pool that is more difficult to treat and eliminate. Efforts are underway to halt the spread of artemisinin resistance, including coordination of activities and funding, and identification of areas of suspected artemisinin resistance, now using a newly identified molecular marker. However, targeting resources to the containment of resistant parasites is likely inefficient and monitoring impact is challenging. A more sustainable solution is the rapid elimination of all Plasmodium falciparum parasites from the GMS. This strategy is more efficient for several reasons. First, a subregional strategy is in line with current commitment to elimination and will build upon the existing national political support for elimination as well as enhancing collaboration among countries. Second, the challenge of human mobility in the GMS is subregional in scope and requires a harmonized elimination strategy. Third, countries will need to improve and intensify malaria operations to reach elimination, and this will be a singular goal across the subregion. Rallying around the goal of P. falciparum elimination will not only utilize existing regional bodies to catalyze political and funding support, but will also leverage the funding already in place to achieve this subregional goal. |
An evaluation of methods for assessing the quality of case management for inpatients with malaria in Benin
Mace KE , Gueye AS , Lynch MF , Tassiba EM , Rowe AK . Am J Trop Med Hyg 2014 91 (2) 354-60 To improve healthcare quality for hospitalized patients with malaria in Benin, a feasible and valid evaluation method is needed. Because observation of inpatients is challenging, chart abstraction is an attractive option. However, the quality of inpatient charts is unknown. We employed three methods in five hospitals to assess 11 signs of malaria and severe disease: 1) chart abstraction (probability sample of inpatients), 2) chart abstraction compared to interviews of inpatients and health workers (HWs), and 3) abstraction from charts of recently discharged inpatients compared to interviews with HWs. Method 1 showed that of 473 malaria signs (from 43 charts), 178 (38%, 95% confidence interval 24-51%) were documented. Method 2 showed that 96% (45 of 47) of documented signs were valid. Method 3 suggests that 65% (36 of 55) of non-documented signs were assessed (but not documented) by HWs. Chart abstraction was feasible and documented data were valid, but results should be interpreted cautiously in consideration of low levels of documentation. |
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