A5075206683- Viral gastroenteritis research and epidemiology
- Salmonella and Campylobacter epidemiology
- Child Nutrition and Water Access
- Vibrio bacteria research studies
- Hepatitis Viruses Studies and Epidemiology
- Bacterial Infections and Vaccines
- Immune Response and Inflammation
- Viral Infections and Immunology Research
- Clostridium difficile and Clostridium perfringens research
- Delphi Technique in Research
- Escherichia coli research studies
- Health Systems, Economic Evaluations, Quality of Life
- Listeria monocytogenes in Food Safety
- Poverty, Education, and Child Welfare
- Antibiotic Use and Resistance
- Meta-analysis and systematic reviews
- Food Security and Health in Diverse Populations
- Viral Infections and Outbreaks Research
- Parasitic Infections and Diagnostics
- Amoebic Infections and Treatments
- SARS-CoV-2 and COVID-19 Research
- Pneumonia and Respiratory Infections
University of Maryland, Baltimore
2018-2025
BackgroundRandomised controlled trials of typhoid conjugate vaccines among children in Africa and Asia have shown high short-term efficacy. Data on the durability protection beyond 2 years are sparse. We present final analysis a randomised trial Malawi, encompassing more than 4 follow-up, with aim investigating vaccine efficacy over time by age group.MethodsIn this phase 3, double-blind, Blantyre, healthy aged 9 months to 12 were randomly assigned (1:1) an unmasked statistician receive...
Abstract Background Diarrheal diseases remain a health threat to children in low- and middle-income countries. The Vaccine Impact on Diarrhea Africa (VIDA) study was 36-month, prospective, matched case-control designed estimate the etiology, incidence, adverse clinical consequences of moderate-to-severe diarrhea (MSD) aged 0–59 months. VIDA conducted following rotavirus vaccine introduction at 3 censused sites sub-Saharan that participated Global Enteric Multicenter Study (GEMS) ∼10 years...
Abstract Typhoid fever is a serious disease that disproportionately impacts children in low-resource settings sub-Saharan Africa, South and Southeast Asia, the Western Pacific. The prevalence of antimicrobial-resistant strains S. Typhi continue to increase worldwide. Two safe, effective, cost-effective typhoid conjugate vaccines (TCVs) are World Health Organization-prequalified for prevention as young 6 months. have proven effectiveness preventing drug-resistant been deployed successfully...
Abstract Background Stunting affects >20% of children <5 years old worldwide and disproportionately impacts underserved communities. The Vaccine Impact on Diarrhea in Africa (VIDA) Study examined the association between an episode moderate-to-severe diarrhea (MSD) risk subsequent stunting living 3 sub-Saharan African countries. Methods In this prospective, matched, case-control study among years, data were collected over 36 months from 2 groups. “Children with MSD” visited a...
Abstract Background Reducing diarrhea-related morbidity and mortality is a global priority, particularly in low-resource settings. We assessed adherence to diarrhea case management indicators the Global Enteric Multisite Study (GEMS) Vaccine Impact of Diarrhea Africa (VIDA) study. Methods GEMS (2007–2010) VIDA (2015–2018) were age-stratified case-control studies moderate-to-severe (MSD) children aged <5 years. In this case-only analysis, we included enrolled The Gambia, Kenya, Mali. A...
Abstract Background Despite antibiotic prescription being recommended for dysentery and suspected cholera only, diarrhea still triggers unwarranted prescription. We evaluated antibiotic-prescribing practices their predictors among children aged 2–59 months in the Vaccine Impact on Diarrhea Africa (VIDA) Study performed The Gambia, Mali, Kenya. Methods VIDA was a prospective case-control study (May 2015–July 2018) presenting care with moderate-to-severe (MSD). defined inappropriate use as or...
The World Health Organization pre-qualified single-dose typhoid conjugate vaccine (TCV) and requested data on co-administration with routine vaccines. of Typbar TCV (Bharat Biotech International) group A meningococcal (MCV-A) measles-rubella (MR) was tested.This a double-blind, randomized controlled trial performed in Ouagadougou, Burkina Faso. Children were recruited at the 15-month vaccination visit assigned randomly (1:1:1) to three groups. Group 1 children received plus control...
ObjectivesIn 2017, the World Health Organisation (WHO) pre-qualified a single-dose typhoid conjugate vaccine (TCV) and identified TCV co-administration studies as research priority. Accordingly, we tested of Typbar TCV® (Bharat Biotech International) with measles-rubella (MR) yellow fever (YF) vaccines.MethodsWe conducted randomized, double-blind, controlled, phase 2 trial in Ouagadougou, Burkina Faso. Healthy children aged 9–11 months were randomized 1:1 to receive (Group 1) or control...
Abstract Background While rotavirus causes severe diarrheal disease in children aged <5 years, data on other viral sub-Saharan Africa are limited. Methods In the Vaccine Impact Diarrhea study (2015–2018), we analyzed stool from 0–59 months with moderate-to-severe diarrhea (MSD) and without (controls) Kenya, Mali, The Gambia using quantitative polymerase chain reaction. We derived attributable fraction (AFe) based association between MSD pathogen, accounting for pathogens, site, age. A...
Abstract Background As part of the Vaccine Impact on Diarrhea in Africa (VIDA) Study, we examined prevalence, clinical presentation, and seasonality Cryptosporidium children to understand its relative burden after introduction rotavirus vaccine. Methods VIDA was a 3-year, age-stratified, matched case-control study medically attended acute moderate-to-severe diarrhea (MSD) aged 0–59 months residing censused populations at sites Kenya, Mali, The Gambia. Clinical epidemiologic data were...
Typhoid conjugate vaccines are being introduced in low-income and middle-income countries to prevent typhoid illness children. Vaccine effectiveness studies assess vaccine performance after introduction. The test-negative design is a commonly used method estimate that has not been applied because of concerns over blood culture insensitivity. overall aim the study was evaluate appropriateness using Vi polysaccharide-tetanus toxoid (Vi-TT) gold standard randomised controlled trial...
Abstract We assessed anti-Vi IgG/IgA responses to typhoid conjugate vaccine (TCV) in children enrolled a double-blind randomized controlled, phase 2 trial Burkina Faso. Anti-Vi IgG seroconversion and IgA titers were higher TCV than control recipients at 30–35 months post-vaccination. induces durable immunity Burkinabe vaccinated 15 months.
Vaccine safety and immunogenicity data in human immunodeficiency virus (HIV)-exposed uninfected (HEU) children are important for decision-making HIV typhoid co-endemic countries. In an open-label study, we recruited Malawian HEU unexposed (HUU) infants aged 9 - 11 months. participants were randomized to receive Vi-tetanus toxoid conjugate vaccine (Vi-TT) at months, Vi-TT 15 or HUU received Safety outcomes included solicited unsolicited adverse events (AE) serious AEs (SAEs) within 7 days, 28...
The health consequences of typhoid, including increasing prevalence drug-resistant strains, can stress healthcare systems. While vaccination is one the most successful and cost-effective interventions, vaccine introduction take years require considerable effort. Typhoid Vaccine Acceleration Consortium (TyVAC) employs an integrated, proactive approach to accelerate a new typhoid conjugate reduce burden in countries eligible for support from Gavi, Alliance. TyVAC its partners are executing...
Abstract Background To address a paucity of data from sub-Saharan Africa, we examined the prevalence, severity, and seasonality norovirus genogroup II (NVII) among children <5 years old in The Gambia, Kenya, Mali following rotavirus vaccine introduction. Methods Population-based surveillance was conducted to capture medically-attended moderate-to-severe diarrhea (MSD) cases, defined as child 0–59 months passing ≥3 loose stools 24-hour period with ≥1 following: sunken eyes, poor skin...
Abstract Background To address knowledge gaps regarding diarrheagenic Escherichia coli (DEC) in Africa, we assessed the clinical and epidemiological features of enteroaggregative E. (EAEC), enteropathogenic (EPEC), Shiga toxin–producing (STEC) positive children with moderate-to-severe diarrhea (MSD) Mali, The Gambia, Kenya. Methods Between May 2015 July 2018, aged 0–59 months medically attended MSD matched controls without were enrolled. Stools tested conventionally using culture multiplex...
Background: Randomised controlled trials of typhoid conjugate vaccines among children in Africa and Asia demonstrate high short-term efficacy. Data on durability protection beyond two years, particularly younger children, are limited. We present the final analysis a randomised trial Malawi, encompassing more than 4 years follow-up.Methods: In phase 3 double-blinded efficacy trial, healthy aged 9 months-12 were randomly assigned 1:1 ratio to receive single dose Vi polysaccharide conjugated...
The recent Typhoid Fever Surveillance in Africa Program demonstrated an overall adjusted incidence of typhoid fever 2-3 times higher than previous estimates Africa. Recently, a single-dose conjugate vaccine that allows infants as young 6 months old to be vaccinated was prequalified by the World Health Organization (WHO). This Vi-based robust immunogenicity after 1 dose and children through 23 age India with no safety signal, is currently being tested for first time on African continent...
Background. The World Health Organization (WHO) pre-qualified a single-dose typhoid conjugate vaccine (TCV) in December 2017. WHO requested data on co-administration of TCV with Expanded Programme Immunisation vaccines typhoid-endemic countries. We tested Typbar TCV® [Bharat Biotech International] routine group A meningococcal (MCV-A) and measles-rubella (MR) vaccine. Methods: conducted double-blind, randomised, controlled trial at Schiphra Protestant Hospital outpatient paediatric clinic,...