Last data update: May 06, 2024. (Total: 46732 publications since 2009)
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Query Trace: Weldegebriel G[original query] |
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Genomic characterization of the rotavirus G3P[8] strain in vaccinated children, reveals possible reassortment events between human and animal strains in Manhia District, Mozambique
Manjate F , João ED , Mwangi P , Chirinda P , Mogotsi M , Messa A Jr , Garrine M , Vubil D , Nobela N , Nhampossa T , Acácio S , Tate JE , Parashar U , Weldegebriel G , Mwenda JM , Alonso PL , Cunha C , Nyaga M , Mandomando I . Front Microbiol 2023 14 1193094 Mozambique introduced the rotavirus vaccine (Rotarix®; GlaxoSmithKline Biologicals, Rixensart, Belgium) in 2015, and since then, the Centro de Investigação em Saúde de Manhiça has been monitoring its impact on rotavirus-associated diarrhea and the trend of circulating strains, where G3P[8] was reported as the predominant strain after the vaccine introduction. Genotype G3 is among the most commonly detected Rotavirus strains in humans and animals, and herein, we report on the whole genome constellation of G3P[8] detected in two children (aged 18 months old) hospitalized with moderate-to-severe diarrhea at the Manhiça District Hospital. The two strains had a typical Wa-like genome constellation (I1-R1-C1-M1-A1-N1-T1-E1-H1) and shared 100% nucleotide (nt) and amino acid (aa) identities in 10 gene segments, except for VP6. Phylogenetic analysis demonstrated that genome segments encoding VP7, VP6, VP1, NSP3, and NSP4 of the two strains clustered most closely with porcine, bovine, and equine strains with identities ranging from 86.9-99.9% nt and 97.2-100% aa. Moreover, they consistently formed distinct clusters with some G1P[8], G3P[8], G9P[8], G12P[6], and G12P[8] strains circulating from 2012 to 2019 in Africa (Mozambique, Kenya, Rwanda, and Malawi) and Asia (Japan, China, and India) in genome segments encoding six proteins (VP2, VP3, NSP1-NSP2, NSP5/6). The identification of segments exhibiting the closest relationships with animal strains shows significant diversity of rotavirus and suggests the possible occurrence of reassortment events between human and animal strains. This demonstrates the importance of applying next-generation sequencing to monitor and understand the evolutionary changes of strains and evaluate the impact of vaccines on strain diversity. |
Aetiology and incidence of diarrhoea requiring hospitalisation in children under 5 years of age in 28 low-income and middle-income countries: findings from the Global Pediatric Diarrhea Surveillance network
Cohen AL , Platts-Mills JA , Nakamura T , Operario DJ , Antoni S , Mwenda JM , Weldegebriel G , Rey-Benito G , deOliveira LH , Ortiz C , Daniels DS , Videbaek D , Singh S , Njambe E , Sharifuzzaman M , Grabovac V , Nyambat B , Logronio J , Armah G , Dennis FE , Seheri ML , Magagula N , Mphahlele J , Fumian TM , Maciel ITA , GagliardiLeite JP , Esona MD , Bowen MD , Samoilovich E , Semeiko G , Abraham D , Giri S , Praharaj I , Kang G , Thomas S , Bines J , Liu N , Kyu HH , Doxey M , RogawskiMcQuade ET , McMurry TL , Liu J , Houpt ER , Tate JE , Parashar UD , Serhan F . BMJ Glob Health 2022 7 (9) INTRODUCTION: Diarrhoea remains a leading cause of child morbidity and mortality. Systematically collected and analysed data on the aetiology of hospitalised diarrhoea in low-income and middle-income countries are needed to prioritise interventions. METHODS: We established the Global Pediatric Diarrhea Surveillance network, in which children under 5 years hospitalised with diarrhoea were enrolled at 33 sentinel surveillance hospitals in 28 low-income and middle-income countries. Randomly selected stool specimens were tested by quantitative PCR for 16 causes of diarrhoea. We estimated pathogen-specific attributable burdens of diarrhoeal hospitalisations and deaths. We incorporated country-level incidence to estimate the number of pathogen-specific deaths on a global scale. RESULTS: During 2017-2018, 29 502 diarrhoea hospitalisations were enrolled, of which 5465 were randomly selected and tested. Rotavirus was the leading cause of diarrhoea requiring hospitalisation (attributable fraction (AF) 33.3%; 95% CI 27.7 to 40.3), followed by Shigella (9.7%; 95% CI 7.7 to 11.6), norovirus (6.5%; 95% CI 5.4 to 7.6) and adenovirus 40/41 (5.5%; 95% CI 4.4 to 6.7). Rotavirus was the leading cause of hospitalised diarrhoea in all regions except the Americas, where the leading aetiologies were Shigella (19.2%; 95% CI 11.4 to 28.1) and norovirus (22.2%; 95% CI 17.5 to 27.9) in Central and South America, respectively. The proportion of hospitalisations attributable to rotavirus was approximately 50% lower in sites that had introduced rotavirus vaccine (AF 20.8%; 95% CI 18.0 to 24.1) compared with sites that had not (42.1%; 95% CI 33.2 to 53.4). Globally, we estimated 208 009 annual rotavirus-attributable deaths (95% CI 169 561 to 259 216), 62 853 Shigella-attributable deaths (95% CI 48 656 to 78 805), 36 922 adenovirus 40/41-attributable deaths (95% CI 28 469 to 46 672) and 35 914 norovirus-attributable deaths (95% CI 27 258 to 46 516). CONCLUSIONS: Despite the substantial impact of rotavirus vaccine introduction, rotavirus remained the leading cause of paediatric diarrhoea hospitalisations. Improving the efficacy and coverage of rotavirus vaccination and prioritising interventions against Shigella, norovirus and adenovirus could further reduce diarrhoea morbidity and mortality. |
Effectiveness of monovalent rotavirus vaccine in Mozambique, a country with a high burden of chronic malnutrition
Chissaque A , Burke RM , Guimarães EL , Manjate F , Nhacolo A , Chilaúle J , Munlela B , Chirinda P , Langa JS , Cossa-Moiane I , Anapakala E , Bauhofer AFL , Garrine M , João ED , Sambo J , Gonçalves L , Weldegebriel G , Shaba K , Bello IM , Mwenda JM , Parashar UD , Tate JE , Mandomando I , de Deus N . Vaccines (Basel) 2022 10 (3) Mozambique introduced monovalent rotavirus vaccine (Rotarix(®)) in September 2015. We evaluated the effectiveness of Rotarix(®) under conditions of routine use in Mozambican children hospitalized with acute gastroenteritis (AGE). A test negative case-control analysis was performed on data collected during 2017-2019 from children <5 years old, admitted with AGE in seven sentinel hospital sites in Mozambique. Adjusted VE was calculated for ≥1 dose of vaccine vs. zero doses using unconditional logistic regression, where VE = (1 - aOR) × 100%. VE estimates were stratified by age group, AGE severity, malnutrition, and genotype. Among 689 children eligible for analysis, 23.7% were rotavirus positive (cases) and 76.3% were negative (controls). The adjusted VE of ≥1 dose in children aged 6-11 months was 52.0% (95% CI, -11, 79), and -24.0% (95% CI, -459, 62) among children aged 12-23 months. Estimated VE was lower in stunted than non-stunted children (14% (95% CI, -138, 66) vs. 59% (95% CI, -125, 91)). Rotavirus vaccination appeared moderately effective against rotavirus gastroenteritis hospitalization in young Mozambican children. VE point estimates were lower in older and stunted children, although confidence intervals were wide and overlapped across strata. These findings provide additional evidence for other high-mortality countries considering rotavirus vaccine introduction. |
Delays in presentation of intussusception and development of gangrene in Zimbabwe
Mazingi D , Burnett E , Mujuru HA , Nathoo K , Tate J , Mwenda J , Weldegebriel G , Manangazira P , Mukaratirwa A , Parashar U , Zimunhu T , Mbuwayesango BA . Pan Afr Med J 2021 39 3 INTRODUCTION: prompt diagnosis and treatment are considered key to successful management of intussusception. We examined pre-treatment delay among intussusception cases in Zimbabwe and conducted an exploratory analysis of factors associated with intraoperative finding of gangrene. METHODS: data were prospectively collected as part of the African Intussusception Network using a questionnaire administered on consecutive patients with intussusception managed at Harare Children´s Hospital. Delays were classified using the Three-Delays-Model: care-seeking delay (time from onset of symptoms to first presentation for health care), health-system delay (referral time from presentation to first facility to treatment facility) and treatment delay (time from presentation at treatment facility to treatment). RESULTS: ninety-two patients were enrolled from August 2014 to December 2016. The mean care-seeking interval was 1.9 days, the mean health-system interval was 1.5 days, and the mean treatment interval was 1.1 days. Mean total time from symptom onset to treatment was 4.4 days. Being transferred from another institution added 1.4 days to the patient journey. Gangrene was found in 2 (25%) of children who received treatment within 1 day, 13 (41%) of children who received treatment 2-3 days, and 26 (50%) of children who received treatment more than 3 days after symptom onset (p = 0.34). CONCLUSION: significant care-seeking and health-system delays are encountered by intussusception patients in Zimbabwe. Our findings highlight the need to explore approaches to improve the early diagnosis of intussusception and prompt referral of patients for treatment. |
Epidemiology of intussusception among infants in Ethiopia, 2013-2016
Tadesse A , Teshager F , Weldegebriel G , Ademe A , Wassie E , Gosaye A , Pringle K , Mwenda JM , Parashar UD , Tate JE . Pan Afr Med J 2021 39 2 INTRODUCTION: intussusception is a condition in which one segment of the bowel prolapses into another causing obstruction. Information on the epidemiology of intussusception in sub-Saharan Africa is limited. We describe the sociodemographic and clinical characteristics of children with intussusception in Ethiopia. METHODS: active surveillance for children < 12 months of age with intussusception was conducted at six sentinel hospitals in Ethiopia. Limited socio-economic and clinical data were collected from enrolled children. Characteristics among children who died and children who survived were compared using the Wilcoxon rank sum test for continuous variables and Chi-square tests for categorical variables. RESULTS: total of 164 children < 12 months of age with intussusception were enrolled; 62% were male. The median age at symptom onset was 6 months with only 12 (7%) of cases occurring in the first 3 months of life. Intussusception was reduced by surgery in 90% of cases and 10% were reduced by enema; 13% of cases died. Compared to survivors, children who died had a significantly longer time to presentation to the first health care facility and to the treating health care facility (median 3 days versus 2 days, p = 0.02, respectively). CONCLUSION: the high mortality rate, late presentation of intussusception cases, and lack of modalities for non-surgical management at some facilities highlight the need for better management of intussusception cases in Ethiopia. |
The global landscape of pediatric bacterial meningitis data reported to the World Health Organization-Coordinated Invasive Bacterial Vaccine-Preventable Disease Surveillance Network, 2014-2019
Nakamura T , Cohen AL , Schwartz S , Mwenda JM , Weldegebriel G , Biey JNM , Katsande R , Ghoniem A , Fahmy K , Rahman HA , Videbaek D , Daniels D , Singh S , Wasley A , Rey-Benito G , de Oliveira L , Ortiz C , Tondo E , Liyanage JBL , Sharifuzzaman M , Grabovac V , Batmunkh N , Logronio J , Heffelfinger J , Fox K , De Gouveia L , von Gottberg A , Du Plessis M , Kwambana-Adams B , Antonio M , El Gohary S , Azmy A , Gamal A , Voropaeva E , Egorova E , Urban Y , Duarte C , Veeraraghavan B , Saha S , Howden B , Sait M , Jung S , Bae S , Litt D , Seaton S , Slack M , Antoni S , Ouattara M , Van Beneden C , Serhan F . J Infect Dis 2021 224 S161-s173 BACKGROUND: The World Health Organization (WHO) coordinates the Global Invasive Bacterial Vaccine-Preventable Diseases (IB-VPD) Surveillance Network to support vaccine introduction decisions and use. The network was established to strengthen surveillance and laboratory confirmation of meningitis caused by Streptococcus pneumoniae, Haemophilus influenzae, and Neisseria meningitidis. METHODS: Sentinel hospitals report cases of children <5 years of age hospitalized for suspected meningitis. Laboratories report confirmatory testing results and strain characterization tested by polymerase chain reaction. In 2019, the network included 123 laboratories that follow validated, standardized testing and reporting strategies. RESULTS: From 2014 through 2019, >137 000 suspected meningitis cases were reported by 58 participating countries, with 44.6% (n = 61 386) reported from countries in the WHO African Region. More than half (56.6%, n = 77 873) were among children <1 year of age, and 4.0% (n = 4010) died among those with reported disease outcome. Among suspected meningitis cases, 8.6% (n = 11 798) were classified as probable bacterial meningitis. One of 3 bacterial pathogens was identified in 30.3% (n = 3576) of these cases, namely S. pneumoniae (n = 2177 [60.9%]), H. influenzae (n = 633 [17.7%]), and N. meningitidis (n = 766 [21.4%]). Among confirmed bacterial meningitis cases with outcome reported, 11.0% died; case fatality ratio varied by pathogen (S. pneumoniae, 12.2%; H. influenzae, 6.1%; N. meningitidis, 11.0%). Among the 277 children who died with confirmed bacterial meningitis, 189 (68.2%) had confirmed S. pneumoniae. The proportion of pneumococcal cases with pneumococcal conjugate vaccine (PCV) serotypes decreased as the number of countries implementing PCV increased, from 77.8% (n = 273) to 47.5% (n = 248). Of 397 H. influenzae specimens serotyped, 49.1% (n = 195) were type b. Predominant N. meningitidis serogroups varied by region. CONCLUSIONS: This multitier, global surveillance network has supported countries in detecting and serotyping the 3 principal invasive bacterial pathogens that cause pediatric meningitis. Streptococcus pneumoniae was the most common bacterial pathogen detected globally despite the growing number of countries that have nationally introduced PCV. The large proportions of deaths due to S. pneumoniae reflect the high proportion of meningitis cases caused by this pathogen. This global network demonstrated a strong correlation between PCV introduction status and reduction in the proportion of pneumococcal meningitis infections caused by vaccine serotypes. Maintaining case-based, active surveillance with laboratory confirmation for prioritized vaccine-preventable diseases remains a critical component of the global agenda in public health.The World Health Organization (WHO)-coordinated Invasive Bacterial Vaccine-Preventable Disease (IB-VPD) Surveillance Network reported data from 2014 to 2019, contributing to the estimates of the disease burden and serotypes of pediatric meningitis caused by Streptococcus pneumoniae, Haemophilus influenzae and Neisseria meningitidis. |
The Role of Molecular Testing in Pediatric Meningitis Surveillance in Southern and East African Countries, 2008-2017.
du Plessis M , de Gouveia L , Freitas C , Abera NA , Lula BS , Raboba JL , Nhantumbo AA , Jantjies E , Uwimana J , Phungwayo N , Maphalala G , Masona G , Muyombe J , Mugisha D , Nalumansi E , Odongkara M , Lukwesa-Musyani C , Nakazwe R , Dondo V , Macharaga J , Weldegebriel GG , Mwenda JM , Serhan F , Cohen AL , Lessa FC , von Gottberg A . J Infect Dis 2021 224 S194-s203 BACKGROUND: As part of the global Invasive Bacterial Vaccine-Preventable Diseases Surveillance Network, 12 African countries referred cerebrospinal fluid (CSF) samples to South Africa's regional reference laboratory. We evaluated the utility of real-time polymerase chain reaction (PCR) in detecting and serotyping/grouping Haemophilus influenzae, Neisseria meningitidis, and Streptococcus pneumoniae (HNS). METHODS: From 2008 to 2017, CSF samples collected from children <5 years old with suspected meningitis underwent routine microbiology testing in-country, and 11 680 samples were submitted for HNS PCR at the regional reference laboratory. Unconditional logistic regression, with adjustment for geographic location, was performed to identify factors associated with PCR positivity. RESULTS: The overall HNS PCR positivity rate for all countries was 10% (1195 of 11 626 samples). In samples with both PCR and culture results, HNS PCR positivity was 11% (744 of 6747 samples), and HNS culture positivity was 3% (207 of 6747). Molecular serotype/serogroup was assigned in 75% of PCR-positive specimens (762 of 1016). Compared with PCR-negative CSF samples, PCR-positive samples were more often turbid (adjusted odds ratio, 6.80; 95% confidence interval, 5.67-8.17) and xanthochromic (1.72; 1.29-2.28), had elevated white blood cell counts (6.13; 4.71-7.99) and high protein concentrations (5.80; 4.34-7.75), and were more often HNS culture positive (32.70; 23.18-46.12). CONCLUSION: PCR increased detection of vaccine-preventable bacterial meningitis in countries where confirmation of suspected meningitis cases is impeded by limited culture capacity. |
Impact of rotavirus vaccine introduction on rotavirus hospitalizations among children under 5 years of age - World Health Organization African Region, 2008-2018
Mwenda JM , Hallowell BD , Parashar U , Shaba K , Biey JN , Weldegebriel GG , Paluku GK , Ntsama B , N'Diaye A , Bello IM , Bwaka AM , Zawaira FR , Mihigo R , Tate JE . Clin Infect Dis 2021 73 (9) 1605-1608 BACKGROUND: Rotavirus is the leading cause of acute gastroenteritis (AGE) among children worldwide. Prior to rotavirus vaccine introduction, over one third of AGE hospitalizations in Africa were due to rotavirus. We describe the impact of rotavirus vaccines using data from the African Rotavirus Surveillance Network (ARSN). METHODS: For descriptive analysis, we included all sites reporting to ARSN for any length of time between 2008-2018. For vaccine impact analysis, continuous surveillance throughout the year was required to minimize potential bias due to enrollment of partial seasons and sites had to report a minimum of 100 AGE cases per year. We report the proportion of rotavirus AGE cases by year relative to vaccine introduction, and the relative reduction in the proportion of rotavirus AGE cases reported following vaccine introduction. RESULTS: From 2008-2018, 97,366 prospectively enrolled hospitalized children <5 years of age met the case definition for AGE, and 34.1% tested positive for rotavirus. Among countries that had introduced rotavirus vaccine, the proportion of hospitalized AGE cases positive for rotavirus declined from 39.2% in the pre-vaccine period to 25.3% in the post-vaccine period, a 35.5% (95% CI: 33.7-37.3) decline. No declines were observed among countries that had not introduced the vaccine over the 11-year period. CONCLUSION: Rotavirus vaccine introduction led to large and consistent declines in the proportion of hospitalized AGE cases that are positive for rotavirus. To maximize the public health benefit of these vaccines, efforts to introduce rotavirus vaccines to the remaining countries in the region and improve coverage should continue. |
Diarrhea hospitalization costs among children<5years old in Madagascar
Burnett E , Rahajamanana VL , Raboba JL , Weldegebriel G , Vuo Masembe Y , Mwenda JM , Parashar UD , Tate JE , Robinson AL . Vaccine 2020 38 (47) 7440-7444 BACKGROUND: Following a recommendation by the World Health Organization, Madagascar introduced rotavirus vaccine in 2014. Though national rotavirus vaccine coverage has remained <80%, rotavirus hospitalizations declined by 78%. Gavi, the Vaccine Alliance, has provided financial support for rotavirus vaccine, however the Malagasy government has increasing responsibility for the financial cost. METHODS: In this evaluation, we describe the direct medical, direct non-medical, and indirect cost of illness due to diarrhea among children <5 years old at a public pediatric referral hospital. A 3-part structured questionnaire was administered during and following the hospitalization and the child's hospital record was reviewed. RESULTS: In total, 96 children were included in this analysis. The median total cost of the illness was $156.00 (IQR: 104.00, 210.86) and the median direct medical cost was $107.22. Service delivery costs represented a median of 44% of the inpatient costs; medications and diagnostic tests represented a median of 28% and 20% of the total costs of the hospitalization, respectively. The median percentage of the total illness costs paid by the household was 67%. Among households with income of <$61/month, the median costs of the illness paid by the household were $78.55, representing a median of 168% of the household's monthly expenses. Among households earning >$303/month, the median costs paid by the household were $147.30, representing a median of 53% of the household's monthly expenses. Among all household income levels, caregivers commonly paid these bills from savings, borrowed money, and donations. CONCLUSIONS: Our findings will be useful in assessing the cost-effectiveness of rotavirus vaccine by decisionmakers. These results may also help hospital administrators and healthcare providers better understand the financial constraints of families. |
Cost estimates of diarrhea hospitalizations among children <5years old in Zimbabwe
Mujuru HA , Burnett E , Nathoo KJ , Ticklay I , Gonah NA , Mukaratirwa A , Berejena C , Manangazira P , Rupfutse M , Chavers T , Weldegebriel GG , Mwenda JM , Parashar UD , Tate JE . Vaccine 2020 38 (43) 6735-6740 INTRODUCTION: Diarrhoea is a leading killer of children <5 years old, accounting for 480,000 deaths in 2017. Zimbabwe introduced Rotarix into its vaccination program in 2014. In this evaluation, we estimate direct medical, direct non-medical, and indirect costs attributable to a diarrhea hospitalization in Zimbabwe after rotavirus vaccine introduction. METHODS: Children <5 years old admitted to Harare Central Hospital from June 2018 to April 2019 with acute watery diarrhea were eligible for this evaluation. A 3-part structured questionnaire was used to collect data by interview from the child's family and by review of the medical record. A stool specimen was also collected and tested for rotavirus. Direct medical costs were the sum of medications, consumables, diagnostic tests, and service delivery costs. Direct non-medical costs were the sum of transportation, meals and lodging for caregivers. Indirect costs are the lost income for household members. RESULTS: A total of 202 children were enrolled with a median age of 12 months (IQR: 7-21) and 48 (24%) had malnutrition. Children were sick for a median of 2 days and most had received outpatient medical care prior to admission. The median monthly household income was higher for well-nourished children compared to malnourished children (p < 0.001). The median total cost of a diarrhea illness resulting in hospitalization was $293.74 (IQR: 188.42, 427.89). Direct medical costs, with a median of $251.74 (IQR: 155.42, 390.96), comprised the majority of the total cost. Among children who tested positive for rotavirus, the median total illness cost was $243.78 (IQR: 160.92, 323.84). The median direct medical costs were higher for malnourished than well-nourished children (p < 0.001). CONCLUSION: Direct medical costs are the primary determinant of diarrhea illness costs in Zimbabwe. The descriptive findings from this evaluation are an important first step in calculating the cost effectiveness of rotavirus vaccine. |
Diversity of rotavirus strains circulating in Botswana before and after introduction of the monovalent rotavirus vaccine
Mokomane M , Esona MD , Bowen MD , Tate JE , Steenhoff AP , Lechiile K , Gaseitsiwe S , Seheri LM , Magagula NB , Weldegebriel G , Pernica JM , Mwenda JM , Kasvosve I , Parashar UD , Goldfarb DM . Vaccine 2019 37 (43) 6324-6328 BACKGROUND: Globally, rotavirus is the leading cause of acute gastroenteritis (AGE) in children aged <5years. Botswana introduced the monovalent rotavirus vaccine (Rotarix) in July 2012. To study the impact of this vaccine on rotavirus genotypes circulating in Botswana, a comparison of the genotypes pre-vaccination (2011-2012) and post-vaccination (2013-2018) periods was conducted. SUBJECTS AND METHODS: Residual samples from 284 children <5years of age that tested positive for rotavirus by enzyme immunoassay were genotyped. One hundred and five samples were from the pre-vaccination period and 179 were from the post-vaccination period. Genotyping was performed using two multiplexed one-step reverse transcription polymerase chain reaction (RT-PCR) assays for the amplification and genotyping of rotavirus VP7 (G) and VP4 (P) genes. RESULTS: Prior to vaccine introduction, the predominant rotavirus circulating genotypes were G9P[8] (n=63, 60%) and G1P[8] (n=22, 21%). During the vaccine period, G2P[4] was the predominant genotype (n=49, 28%), followed by G9P[8] (n=40, 22%) and G1P[8] (n=33, 18.5%). There was a significant decline in the prevalence of G9P[8] (p=0.001) in the post-vaccination period. There was also a notable decline in G1P[8]. A spike in G2P[4] was observed in 2013, one year post-vaccine introduction. Rotavirus strain G3P[4] (n=8) was only detected in the post-vaccine introduction period. In 2018 there was a marked increase in genotype G3P[8] (p=0.0003). CONCLUSIONS: The distribution of circulating rotavirus genotypes in Botswana changed after vaccine implementation. Further studies are needed to examine whether these changes are related to vaccination or simply represent natural secular variation. |
Pneumococcal conjugate vaccine impact on meningitis and pneumonia among children aged <5 years - Zimbabwe, 2010-2016
Dondo V , Mujuru H , Nathoo K , Jacha V , Tapfumanei O , Chirisa P , Manangazira P , Macharaga J , de Gouveia L , Mwenda JM , Katsande R , Weldegebriel G , Pondo T , Matanock A , Lessa FC . Clin Infect Dis 2019 69 S72-s80 BACKGROUND: Streptococcus pneumoniae is a leading cause of pneumonia and meningitis in children aged <5 years. Zimbabwe introduced 13-valent pneumococcal conjugate vaccine (PCV13) in 2012 using a 3-dose infant schedule with no booster dose or catch-up campaign. We evaluated the impact of PCV13 on pediatric pneumonia and meningitis. METHODS: We examined annual changes in the proportion of hospitalizations due to pneumonia and meningitis among children aged <5 years at Harare Central Hospital (HCH) pre-PCV13 (January 2010-June 2012) and post-PCV13 (July 2013-December 2016) using a negative binomial regression model, adjusting for seasonality. We also evaluated post-PCV13 changes in serotype distribution among children with confirmed pneumococcal meningitis at HCH and acute respiratory infection (ARI) trends using Ministry of Health outpatient data. RESULTS: Pneumonia hospitalizations among children aged <5 years steadily declined pre-PCV13; no significant change in annual decline was observed post-PCV13. Post-PCV13 introduction, meningitis hospitalization decreased 30% annually (95% confidence interval [CI], -42, -14) among children aged 12-59 months, and no change was observed among children aged 0-11 months. Pneumococcal meningitis caused by PCV13 serotypes decreased from 100% in 2011 to 50% in 2016. Annual severe and moderate outpatient ARI decreased by 30% (95% CI, -33, -26) and 7% (95% CI, -11, -2), respectively, post-PCV13 introduction. CONCLUSIONS: We observed declines in pediatric meningitis hospitalizations, PCV13-type pneumococcal meningitis, and severe and moderate ARI outpatient visits post-PCV13 introduction. Low specificity of discharge codes, changes in referral patterns, and improvements in human immunodeficiency virus care may have contributed to the lack of additional declines in pneumonia hospitalizations post-PCV13 introduction. |
Pediatric bacterial meningitis surveillance in the World Health Organization African Region using the Invasive Bacterial Vaccine-Preventable Disease Surveillance Network, 2011-2016
Mwenda JM , Soda E , Weldegebriel G , Katsande R , Biey JN , Traore T , de Gouveia L , du Plessis M , von Gottberg A , Antonio M , Kwambana-Adams B , Worwui A , Gierke R , Schwartz S , van Beneden C , Cohen A , Serhan F , Lessa FC . Clin Infect Dis 2019 69 S49-s57 BACKGROUND: Bacterial meningitis is a major cause of morbidity and mortality in sub-Saharan Africa. We analyzed data from the World Health Organization's (WHO) Invasive Bacterial Vaccine-preventable Diseases Surveillance Network (2011-2016) to describe the epidemiology of laboratory-confirmed Streptococcus pneumoniae (Spn), Neisseria meningitidis, and Haemophilus influenzae meningitis within the WHO African Region. We also evaluated declines in vaccine-type pneumococcal meningitis following pneumococcal conjugate vaccine (PCV) introduction. METHODS: Reports of meningitis in children <5 years old from sentinel surveillance hospitals in 26 countries were classified as suspected, probable, or confirmed. Confirmed meningitis cases were analyzed by age group and subregion (South-East and West-Central). We described case fatality ratios (CFRs), pathogen distribution, and annual changes in serotype and serogroup, including changes in vaccine-type Spn meningitis following PCV introduction. RESULTS: Among 49 844 reported meningitis cases, 1670 (3.3%) were laboratory-confirmed. Spn (1007/1670 [60.3%]) was the most commonly detected pathogen; vaccine-type Spn meningitis cases declined over time. CFR was the highest for Spn meningitis: 12.9% (46/357) in the South-East subregion and 30.9% (89/288) in the West-Central subregion. Meningitis caused by N. meningitidis was more common in West-Central than South-East Africa (321/954 [33.6%] vs 110/716 [15.4%]; P < .0001). Haemophilus influenzae (232/1670 [13.9%]) was the least prevalent organism. CONCLUSIONS: Spn was the most common cause of pediatric bacterial meningitis in the African region even after reported cases declined following PCV introduction. Sustaining robust surveillance is essential to monitor changes in pathogen distribution and to inform and guide vaccination policies. |
Global impact of rotavirus vaccine introduction on rotavirus hospitalisations among children under 5 years of age, 2008-16: findings from the Global Rotavirus Surveillance Network
Aliabadi N , Antoni S , Mwenda JM , Weldegebriel G , Biey JNM , Cheikh D , Fahmy K , Teleb N , Ashmony HA , Ahmed H , Daniels DS , Videbaek D , Wasley A , Singh S , de Oliveira LH , Rey-Benito G , Sanwogou NJ , Wijesinghe PR , Liyanage JBL , Nyambat B , Grabovac V , Heffelfinger JD , Fox K , Paladin FJ , Nakamura T , Agocs M , Murray J , Cherian T , Yen C , Parashar UD , Serhan F , Tate JE , Cohen AL . Lancet Glob Health 2019 7 (7) e893-e903 BACKGROUND: Rotavirus vaccine use in national immunisation programmes has led to declines in hospital admissions for rotavirus gastroenteritis among children; however, the global impact of rotavirus vaccine introduction has not been described using primary data. We describe the impact of rotavirus vaccine introduction on admissions for acute rotavirus gastroenteritis in primarily low-income and middle-income countries, using 9 years of data from the WHO-coordinated Global Rotavirus Surveillance Network (GRSN). METHODS: Between Jan 1, 2008, and Dec 31, 2016, children younger than 5 years of age who were admitted to hospital with acute gastroenteritis were prospectively enrolled in GRSN sites. We included sites that enrolled children and collected stool specimens monthly and tested at least 100 specimens annually in the impact analysis, with a separate analysis taking into account site continuity. We compared proportions of acute gastroenteritis cases positive for rotavirus in the pre-vaccine and post-vaccine periods and calculated mean proportion changes for WHO regions, with 95% CIs; these findings were then compared with interrupted time series analyses. We did further sensitivity analyses to account for rotavirus vaccination coverage levels and sites that collected specimens for at least 11 months per year and tested at least 80 specimens per year. We also analysed the age distribution of rotavirus-positive cases before and after vaccine introduction. FINDINGS: 403 140 children younger than 5 years of age admitted to hospital with acute gastroenteritis from 349 sites in 82 countries were enrolled over the study period, of whom 132 736 (32.9%) were positive for rotavirus. We included 305 789 children from 198 sites in 69 countries in the impact analysis. In countries that had not introduced rotavirus vaccine in their national immunisation programmes, rotavirus was detected in 38.0% (95% CI 4.8-73.4) of admissions for acute gastroenteritis annually whereas in those that have introduced the vaccine, rotavirus was detected in 23.0% (0.7-57.7) of admissions for acute gastroenteritis, showing a 39.6% (35.4-43.8) relative decline following introduction. Interrupted time series analyses confirmed these findings. Reductions by WHO regions ranged from 26.4% (15.0-37.8) in the Eastern Mediterranean Region to 55.2% (43.0-67.4) in the European Region and were sustained in nine countries (contributing up to 31 sites) for 6-10 years. The age distribution of children with rotavirus gastroenteritis shifted towards older children after rotavirus vaccine introduction. INTERPRETATION: A significant and sustained reduction in the proportion of hospital admissions for acute gastroenteritis due to rotavirus was seen among children younger than 5 years in GRSN sites following rotavirus vaccine introduction. These findings highlight the need to incorporate rotavirus vaccines into immunisation programmes in countries that have not yet introduced them and underline the importance of high-quality surveillance. FUNDING: The GRSN receives funding from Gavi, the Vaccine Alliance and the US Centers for Disease Control and Prevention. No specific funding was provided for this Article. |
Monovalent rotavirus vaccine effectiveness against rotavirus hospitalizations among children in Zimbabwe
Mujuru HA , Burnett E , Nathoo KJ , Ticklay I , Gonah NA , Mukaratirwa A , Berejena C , Manangazira P , Rupfutse M , Weldegebriel GG , Mwenda JM , Yen C , Parashar UD , Tate JE . Clin Infect Dis 2018 69 (8) 1339-1344 Background: Rotavirus is a leading cause of mortality among children <5 years old. Zimbabwe introduced rotavirus vaccine in May 2014. We evaluated monovalent rotavirus vaccine effectiveness (VE) under conditions of routine use at two surveillance sites in Harare, Zimbabwe. Methods: Children <5 years of age hospitalized or treated in the accident and emergency department (A&E) for acute watery diarrhea were enrolled for routine surveillance. Copies of vaccination cards were collected and reviewed to document the vaccination status of enrolled children. Among children age-eligible to receive rotavirus vaccine, we estimated VE, calculated as 1-odds ratio, using a test-negative case-control design. Results: We included 903 rotavirus positive cases and 2,685 rotavirus negative controls in the analysis; 99% had verified vaccination status. Rotavirus positive children had more severe diarrhea than rotavirus negative children; 61% of cases and 46% of controls had a Vesikari score >/=11 (p<0.01). Among cases, 31% were stunted for their age; 37% of controls were stunted (p<0.01). Among children 6-11 months old, adjusted 2-dose VE against hospitalization or treatment in A&E due to rotavirus of any severity was 61% (95%CI: 21, 81) and 68% (95%CI: 13, 88) against severe rotavirus disease. Stratified by nutritional status, adjusted VE was 45% (95%CI: -148, 88) among stunted infants and 71% (95%CI: 29, 88) among infants with a normal height-for-age. Conclusion : onovalent rotavirus vaccine is effective in preventing hospitalizations due to severe rotavirus diarrhea among infants in Zimbabwe providing additional evidence for countries considering rotavirus vaccine introduction that live, oral rotavirus vaccines are effective in high child mortality settings. |
Evaluation of intussusception after monovalent rotavirus vaccination in Africa
Tate JE , Mwenda JM , Armah G , Jani B , Omore R , Ademe A , Mujuru H , Mpabalwani E , Ngwira B , Cortese MM , Mihigo R , Glover-Addy H , Mbaga M , Osawa F , Tadesse A , Mbuwayesango B , Simwaka J , Cunliffe N , Lopman BA , Weldegebriel G , Ansong D , Msuya D , Ogwel B , Karengera T , Manangazira P , Bvulani B , Yen C , Zawaira FR , Narh CT , Mboma L , Saula P , Teshager F , Getachew H , Moeti RM , Eweronu-Laryea C , Parashar UD . N Engl J Med 2018 378 (16) 1521-1528 BACKGROUND: Postlicensure evaluations have identified an association between rotavirus vaccination and intussusception in several high- and middle-income countries. We assessed the association between monovalent human rotavirus vaccine and intussusception in lower-income sub-Saharan African countries. METHODS: Using active surveillance, we enrolled patients from seven countries (Ethiopia, Ghana, Kenya, Malawi, Tanzania, Zambia, and Zimbabwe) who had intussusception that met international (Brighton Collaboration level 1) criteria. Rotavirus vaccination status was confirmed by review of the vaccine card or clinic records. The risk of intussusception within 1 to 7 days and 8 to 21 days after vaccination among infants 28 to 245 days of age was assessed by means of the self-controlled case-series method. RESULTS: Data on 717 infants who had intussusception and confirmed vaccination status were analyzed. One case occurred in the 1 to 7 days after dose 1, and 6 cases occurred in the 8 to 21 days after dose 1. Five cases and 16 cases occurred in the 1 to 7 days and 8 to 21 days, respectively, after dose 2. The risk of intussusception in the 1 to 7 days after dose 1 was not higher than the background risk of intussusception (relative incidence [i.e., the incidence during the risk window vs. all other times], 0.25; 95% confidence interval [CI], <0.001 to 1.16); findings were similar for the 1 to 7 days after dose 2 (relative incidence, 0.76; 95% CI, 0.16 to 1.87). In addition, the risk of intussusception in the 8 to 21 days or 1 to 21 days after either dose was not found to be higher than the background risk. CONCLUSIONS: The risk of intussusception after administration of monovalent human rotavirus vaccine was not higher than the background risk of intussusception in seven lower-income sub-Saharan African countries. (Funded by the GAVI Alliance through the CDC Foundation.). |
Distribution of rotavirus genotypes associated with acute diarrhoea in Zimbabwean children less than five years old before and after rotavirus vaccine introduction.
Mukaratirwa A , Berejena C , Nziramasanga P , Ticklay I , Gonah A , Nathoo K , Manangazira P , Mangwanya D , Marembo J , Mwenda JM , Weldegebriel G , Seheri M , Tate JE , Yen C , Parashar U , Mujuru H . Vaccine 2018 36 (47) 7248-7255 BACKGROUND: Sentinel surveillance for diarrhoea is important to monitor changes in rotavirus epidemiological trends and circulating genotypes among children under 5years before and after vaccine introduction. The Zimbabwe Ministry of Health and Child Care introduced rotavirus vaccine in national immunization program in May 2014. METHODS: Active hospital-based surveillance for diarrhoea was conducted at 3 sentinel sites from 2008 to 2016. Children aged less than 5years, who presented with acute gastroenteritis as a primary illness and who were admitted to a hospital ward or treated at the emergency unit, were enrolled and had a stool specimen collected and tested for rotavirus by enzyme immunoassay (EIA). Genotyping of positive stools was performed using reverse-transcription polymerase chain reaction and genotyping assays. Pre-vaccine introduction, 10% of all positive stool specimens were genotyped and all adequate positive stools were genotyped post-vaccine introduction. RESULTS: During the pre-vaccine period, a total of 6491 acute gastroenteritis stools were collected, of which 3016 (46%) tested positive for rotavirus and 312 (10%) of the rotavirus positive stools were genotyped. During the post-vaccine period, a total of 3750 acute gastroenteritis stools were collected, of which 937 (25%) tested positive for rotavirus and 784 (84%) were genotyped. During the pre-vaccine introduction the most frequent genotype was G9P[8] (21%) followed by G2P[4] (12%), G1P[8] (6%), G2P[6] (5%), G12P[6] (4%), G9P[6] (3%) and G8P[4] (3%). G1P[8] (30%) was most dominant two years after vaccine introduction followed by G9P[6] (20%), G2P[4] (15%), G9P[8] (11%) and G1P[6] (4%). CONCLUSION: The decline in positivity rate is an indication of early vaccine impact. Diversity of circulating strains underscores the importance of continued monitoring and strain surveillance after vaccine introduction. |
Impact of rotavirus vaccine on rotavirus diarrhoea in countries of East and Southern Africa
Weldegebriel G , Mwenda JM , Chakauya J , Daniel F , Masresha B , Parashar UD , Tate JE . Vaccine 2017 36 (47) 7124-7130 BACKGROUND: Established in 2006 with four countries conducting hospital-based rotavirus surveillance, the African rotavirus surveillance network has expanded over subsequent years. By 2015, 14 countries in the World Health Organization (WHO) East and Southern Africa sub-region (Eritrea, Ethiopia, Kenya, Lesotho, Madagascar, Mauritius, Namibia, Rwanda, Seychelles, Swaziland, Tanzania, Uganda, Zambia and Zimbabwe) were participating in the rotavirus surveillance network coordinated by WHO. We monitored the proportion of rotavirus diarrhoea among children under five years of age who were hospitalized for diarrhoea in the sentinel hospitals from 2010 to 2015 among countries that introduced rotavirus vaccine during or before 2013 (Rwanda, Tanzania, Zambia and Ethiopia) and compared with the other countries in the network. METHODS: Children under the age of five years hospitalized due to acute diarrhoea were enrolled into the sentinel surveillance system and had stool samples collected and tested for rotavirus antigens by enzyme immunoassay. We described trends in rotavirus positivity among tested stool samples before and after rotavirus vaccine introduction. RESULTS: In countries that introduced rotavirus vaccine by 2013 (Rwanda, Tanzania, Zambia and Ethiopia), average rotavirus vaccine coverage from 2010 to 2015 improved from 0% in 2010 and 2011, 13% in 2012, 46% in 2013, 83% in 2014 to 90% in 2015. Annual average rotavirus positivity from 2010 to 2015 was 35%, 33%, 38%, 28%, 27%, and 19%, respectively. In countries that introduced rotavirus vaccine after 2013 or had not introduced by 2015, average rotavirus vaccine coverage was 0% in 2010-2013, 13% in 2014 and 51% in 2015. In these countries, rotavirus positivity was 44% in 2010, 32% in 2011, 33% in 2012, 41% in 2013, 40% in 2014 and 25% in 2015. CONCLUSION: Countries that introduced rotavirus vaccine by 2013 had a lower proportion of rotavirus positive hospitalizations in 2013-2015 as compared to those that had not introduced rotavirus vaccine by 2013. The decrease in rotavirus positivity was inversely related to increase in rotavirus vaccine coverage showing impact of rotavirus vaccines. |
Early impact of rotavirus vaccination in children less than five years of age in Mozambique
de Deus N , Chilaule JJ , Cassocera M , Bambo M , Langa JS , Sitoe E , Chissaque A , Anapakala E , Sambo J , Guimaraes EL , Bero DM , Joao ED , Cossa-Moiane I , Mwenda JM , Weldegebriel GG , Parashar UD , Tate JE . Vaccine 2017 36 (47) 7205-7209 BACKGROUND: Mozambique introduced rotavirus vaccine (Rotarix, GSK Biologicals) in the National Immunization Program in September 2015 with the objective of reducing the burden of total diarrheal disease and specifically severe rotavirus disease. This study aimed to evaluate the early impact of rotavirus vaccine in reducing all-cause diarrhea and rotavirus-specific hospitalizations. METHODS: We analysed stool specimens collected from children under five years old, between January 2014 and June 2017 within the National Surveillance for Acute Diarrhea. We compared annual changes in rotavirus positivity, median age of children hospitalized for rotavirus and the number of all-cause for diarrheal hospitalizations. Rotavirus detection was performed using enzyme immunoassay. RESULTS: During this period, 1296 samples were collected and analyzed. Rotavirus positivity before vaccine introduction was 40.2% (39/97) in 2014 and 38.3% (225/588) in 2015, then after vaccine introduction reduced to 12.2% and 13.5% in 2016 and 2017, respectively. The median age of children hospitalized for rotavirus was 9 and 11 months in 2014 and 2015 and 10 months in 2016 and 2017. Rotavirus hospitalizations exhibited a seasonal peak prior to vaccine introduction, between June and September in 2014 and 2015, coinciding with winter period in Mozambique. After vaccine introduction, the peak was delayed until August to December in 2016 and was substantially diminished. There was a reduction in all-cause acute diarrhea hospitalizations in children aged 0-11 months after vaccine introduction. CONCLUSION: We observed a reduction in rotavirus positivity and in the number of all-cause diarrhea hospitalizations after vaccine introduction. The data suggest rotavirus vaccine is having a positive impact on the control of rotavirus diarrheal disease in Mozambique. |
Impact of rotavirus vaccine on all-cause diarrhea and rotavirus hospitalizations in Madagascar
Rahajamanana VL , Raboba JL , Rakotozanany A , Razafindraibe NJ , Andriatahirintsoa Ejpr , Razafindrakoto AC , Mioramalala SA , Razaiarimanga C , Weldegebriel GG , Burnett E , Mwenda JM , Seheri M , Mphahlele MJ , Robinson AL . Vaccine 2017 36 (47) 7198-7204 BACKGROUND: Rotavirus vaccine was introduced into the Extended Program on Immunization in Madagascar in May 2014. We analyzed trends in prevalence of all cause diarrhea and rotavirus hospitalization in children <5years of age before and after vaccine introduction and assessed trend of circulating rotavirus genotypes at Centre Hospitalier Universitaire Mere Enfant Tsaralalana (CHU MET). METHODS: From January 2010 to December 2016, we reviewed the admission logbook to observe the rate of hospitalization caused by gastroenteritis among 19619 children <5years of age admitted at the hospital. In June 2013-December 2016, active rotavirus surveillance was also conducted at CHUMET with support from WHO. Rotavirus antigen was detected by EIA from stool specimen of children who are eligible for rotavirus gastroenteritis surveillance at sentinel site laboratory and rotavirus positive specimens were further genotyped at Regional Reference Laboratory by RT-PCR. RESULTS: Diarrhea hospitalizations decreased after rotavirus vaccine introduction. The median proportion of annual hospitalizations due to diarrhea was 26% (range: 31-22%) before vaccine introduction; the proportion was 25% the year of vaccine introduction, 17% in 2015 and 16% in 2016. Rotavirus positivity paralleled patterns observed in diarrhea. Before vaccine introduction, 56% of stool specimens tested positive for rotavirus; the percent positive was 13% in 2015, 12% in 2016. Diverse genotypes were detected in the pre-vaccine period; the most common were G3P[8] (n=53; 66%), G2P[4] (n=12; 15%), and G1P[8] (n=11; 14%). 6 distinct genotypes were found in 2015; the most common genotype was G2P[4] (n=10; 67%), the remaining, 5, G12[P8], G3[P8], G1G3[P4], G3G12[P4][P8] and G1G3[NT] had one positive specimen each. CONCLUSIONS: Following rotavirus vaccine introduction all-cause diarrhea and rotavirus-specific hospitalizations declined dramatically. The most common genotypes detected in the pre-vaccine period were G3P[8] and G2P[4] in 2015, the post vaccine period. |
Early impact of rotavirus vaccine in under 5year old children hospitalized due to diarrhea, Swaziland
Maphalala G , Phungwayo N , Masona G , Lukhele N , Tsegaye G , Dube N , Sindisiwe D , Khumalo L , Daniel F , Katsande R , Tate JE , Mwenda JM , Weldegebriel G . Vaccine 2017 36 (47) 7210-7214 BACKGROUND: Swaziland introduced rotavirus vaccine in the National Immunization Program, in May 2015, with the objective of reducing the burden of rotavirus diarrheal disease. We monitored the early impact of the vaccine in reducing rotavirus diarrhea. METHODS: We conducted sentinel rotavirus surveillance from January 2013 to December 2016 in children under five years of age admitted due to diarrhea attending Mbabane Government Referral Hospital in the Hhohho Region and Raleigh Fitkin Memorial Hospital in the Manzini Region. All cases had stool samples collected and tested for rotavirus antigen by enzyme immunoassay. RESULTS: Between 2013 and 2016, 596 samples were collected and tested. Rotavirus positivity reduced from average of 50.8% (172/338) (in 2013-2014 (pre vaccine period)) to 29% (24/82) in 2016, post-vaccine introduction. The median age of children with rotavirus infection increased from average of 10months in 2013-2014 to 13.7months in 2016. The peak season for all-cause diarrhea and rotavirus-specific hospitalizations among children under five years of age was June-August in all years with a blunting of the peak season in 2016. Rotavirus positivity among children 0-11months reduced from an average of 49% in 2013-2014 (116/236) to 33% (15/45) in 2016, a 33% reduction following rotavirus vaccine introduction. CONCLUSION: There has been a rapid reduction of all-cause diarrhea and rotavirus hospitalizations in Swaziland, particularly in young children and during the rotavirus season, after the introduction rotavirus vaccine. Continued surveillance is needed to monitor the long-term impact of rotavirus vaccine introduction. |
Reduction in diarrhea- and rotavirus-related healthcare visits among children <5 years of age following national rotavirus vaccine introduction in Zimbabwe
Mujuru HA , Yen C , Nathoo KJ , Gonah NA , Ticklay I , Mukaratirwa A , Berejena C , Tapfumanei O , Chindedza K , Rupfutse M , Weldegebriel G , Mwenda JM , Burnett E , Tate JE , Parashar UD , Manangazira P . Pediatr Infect Dis J 2017 36 (10) 995-999 BACKGROUND: In Zimbabwe, rotavirus accounted for 41-56% of acute diarrhea hospitalizations prior to rotavirus vaccine introduction in 2014. We evaluated rotavirus vaccination impact on acute diarrhea and rotavirus-related healthcare visits in children. METHODS: We examined monthly and annual acute diarrhea and rotavirus test-positive hospitalizations and A&E visits among children <60 months at three active surveillance hospitals during 2012-2016; we compared pre-vaccine introduction (2012-2013) with post-vaccine introduction (2015 and 2016) data for two of the hospitals. We examined monthly acute diarrhea hospitalizations by year and age group for 2013-2016 from surveillance hospital registers and monthly acute diarrhea outpatient visits reported to the Ministry of Health and Child Care during 2012-2016. RESULTS: Active surveillance data showed winter seasonal peaks in diarrhea and rotavirus-related visits among children <60 months during 2012-2014 that were substantially blunted in 2015 and 2016 following vaccine introduction; the percentage of rotavirus test-positive visits followed a similar seasonal pattern and decrease. Hospital register data showed similar pre-introduction seasonal variation and post-introduction declines in diarrhea hospitalizations among children 0-11 and 12-23 months. Monthly variation in outpatient diarrhea-related visits mirrored active surveillance data patterns. At two surveillance hospitals, the percentage of rotavirus-positive visits declined by 40% and 43% among children 0-11 months and by 21% and 33% among children 12-23 months in 2015 and 2016, respectively. CONCLUSION: Initial reductions in diarrheal illness among children <60 months, particularly among those 0-11 months, following vaccine introduction are encouraging. These early results provide evidence to support continued rotavirus vaccination and rotavirus surveillance in Zimbabwe. |
Environmental surveillance for polioviruses in the Global Polio Eradication Initiative.
Asghar H , Diop OM , Weldegebriel G , Malik F , Shetty S , El Bassioni L , Akande AO , Al Maamoun E , Zaidi S , Adeniji AJ , Burns CC , Deshpande J , Oberste MS , Lowther SA . J Infect Dis 2014 210 Suppl 1 S294-303 This article summarizes the status of environmental surveillance (ES) used by the Global Polio Eradication Initiative, provides the rationale for ES, gives examples of ES methods and findings, and summarizes how these data are used to achieve poliovirus eradication. ES complements clinical acute flaccid paralysis (AFP) surveillance for possible polio cases. ES detects poliovirus circulation in environmental sewage and is used to monitor transmission in communities. If detected, the genetic sequences of polioviruses isolated from ES are compared with those of isolates from clinical cases to evaluate the relationships among viruses. To evaluate poliovirus transmission, ES programs must be developed in a manner that is sensitive, with sufficiently frequent sampling, appropriate isolation methods, and specifically targeted sampling sites in locations at highest risk for poliovirus transmission. After poliovirus ceased to be detected in human cases, ES documented the absence of endemic WPV transmission and detected imported WPV. ES provides valuable information, particularly in high-density populations where AFP surveillance is of poor quality, persistent virus circulation is suspected, or frequent virus reintroduction is perceived. Given the benefits of ES, GPEI plans to continue and expand ES as part of its strategic plan and as a supplement to AFP surveillance. |
Survey of poliovirus antibodies in Kano, Northern Nigeria
Iliyasu Z , Nwaze E , Verma H , Mustapha AO , Weldegebriel G , Gasasira A , Wannemuehler KA , Pallansch MA , Gajida AU , Pate M , Sutter RW . Vaccine 2014 32 (12) 1414-20 INTRODUCTION: In 1988, the World Health Assembly resolved to eradicate poliomyelitis. Since then, much progress towards this goal has been made, but three countries including Nigeria remain polio-endemic as of end 2012. To assess the immunity level against poliomyelitis in young children in Northern Nigeria, we conducted a seroprevalence survey in the Kano Metropolitan Area (KMA) in May 2011. METHODS: Parents or guardians of infants aged 6-9 months or children aged 36-47 months presenting to the outpatient department of Murtala Mohammad Specialist Hospital were approached for participation, screened for eligibility and were asked to provide informed consent. After that, a questionnaire was administered and blood was collected for neutralization assay. RESULTS: A total of 327 subjects were enrolled. Of these, 313 (96%) met the study requirements and were analyzed (161 [51%] aged 6-9 months and 152 [49%] aged 36-47 months). Among subjects aged 6-9 months, seroprevalence was 81% (95% confidence interval [CI] 75-87%) to poliovirus type 1, 76% (95% CI 68-81%) to poliovirus type 2, and 73% (95% CI 67-80%) to poliovirus type 3. Among subjects aged 36-47 months, the seroprevalence was 91% (95% CI 86-95%) to poliovirus type 1, 87% (95% CI 82-92%) for poliovirus type 2, and 86% (95% CI 80-91%) to poliovirus type 3. Seroprevalence was associated with history of oral poliovirus vaccine (OPV) doses, maternal education and gender. CONCLUSIONS: Seroprevalence is lower than required levels for poliovirus interruption in the KMA. Persistence of immunity gaps in the 36-47 months group is a big concern. Since higher number of vaccine doses is associated with higher seroprevalence, it implies that failure-to-vaccinate and not vaccine failure accounts for the suboptimal seroprevalence. Intensified efforts are necessary to administer polio vaccines to all target children and surpass the threshold levels for herd immunity. |
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