VIDA HUCS Gambia Mali Survey

Related studies

VIDA Case Control Study
VIDA HUCS Kenya

Background: Despite considerable progress in reducing diarrhea-related mortality over the past two decades, diarrheal diseases remain the second leading cause of post-neonatal death during the first 5 years of life in developing countries. During the next few years, rotavirus vaccines are expected to be introduced into routine infant immunization programs across low-income countries, and marked reductions in child deaths and hospitalizations from rotavirus diarrhea are anticipated. The Vaccine Impact on Diarrhea in Africa (VIDA) Case Control study was conducted to determine the effectiveness of a full course of rotavirus vaccine using a case control design, and to assess the impact of rotavirus introduction on the etiology of moderate-to-severe diarrhea (MSD).

At each VIDA Case Control site, participants were recruited from a censused population with an ongoing Demographic Surveillance System (DSS) which conducts rounds at least twice per year to enumerate and characterize the population in order to measure disease incidence. A Health care utilization and coverage survey (HUCS) was conducted semi-annually for 36 months as part of the DSS at each site with the data linked to the VIDA study.

Objectives:

To determine the proportion of children who do not seek care at sentinel health centers (SHCs) when they have MSD, which can be used to calculate population-based disease incidence estimates derived from children seeking care at the SHCs and adjusted for children who do not seek care at the SHCs for MSD
To allow us to determine where children from the DSS population seek care when they have MSD, to guide the choice of SHCs for case enrollment during the case-control study
To assess rotavirus vaccine coverage
To determine whether vaccinated and unvaccinated children differ with regard to their propensity to seek care at a SHC for MSD

Methodology:

Geographic Location/Study Sites: This study was conducted in two sites in sub-Saharan Africa- Bamako, Mali and Basse, The Gambia, where rotavirus was found to be the most important pathogen during the first 2 years of life in the GEMS study. Mali and The Gambia recently introduced the RotaTeq rotavirus vaccine.

Dates of Data Collection: 2015- 2018

Study Design: Observational cross-sectional study

Sampling: At least twice a year, from the continually updated DSS database at each study site, computerized lists of children were constructed for each of the age groups of interest (0-11, 12-23, and 24-59 months). In The Gambia and Mali, a random selection of approximately 550 eligible children were selected from the 0-11 month age group (over-sampled because of the potential difficulties locating children in this age group), and 500 eligible children from each of the two older age strata were selected (12-23 months and 24-59 months) using the updated census list.

Eligibility Criteria: The participants must have met the following inclusion criteria-

Age 0-59 months
Belongs to the DSS
Randomly selected from the DSS database

Data Collection: The primary caretakers of participants were asked additional questions during the routine DSS interview.

Information was solicited about the household and family composition, household possessions (to calculate a wealth index as a proxy for socioeconomic status), occurrences and nature of recent diarrheal illnesses among children younger than 5 years, and health care utilization practices.
The parent/primary caretaker of each selected child was asked whether the child had diarrhea in the previous 7 days. If so, they were asked a brief panel of ~30 questions such as: i) whether the child had: sunken eyes (more than usual), wrinkled skin, IV hydration, dysentery, or was hospitalized; ii) whether they took the child for care outside of the home, and if so where.
An important component of the HUCS was the determination of the child's vaccine coverage. The child's vaccination card was examined and the dates that the child received vaccines against rotavirus, oral polio, and diphtheria-pertussis-tetanus containing vaccine, and the EPI center attended were recorded.

Study Documentation:

Questionnaires:

HUCS English questionnaire
HUCS English questionnaire- short version

ClinEpiDB Data Integration: Data files were provided to ClinEpiDB as SAS files. Variables were processed and redundant or administrative columns were dropped from presentation on ClinEpiDB.org. All dates were obfuscated per participant through the application of a random number algorithm that shifted dates no more than seven days to comply with the ethical conduct of human subjects research.

Acknowledgements: We wish to express our deep gratitude to the families who participated in these studies, the clinical and field staff for their exceptional hard work and dedication, and to the physicians, administration, and health officials at every site who generously provided facilities and support for the conduct of the study. We are grateful to Catherine Johnson at the Emmes Company, LLC for expert data management and reporting. Special thanks go to Carl Kirkwood, Duncan Steele, and Anita Zaidi at the Bill & Melinda Gates Foundation for helpful oversight, Kathy Neuzil for thoughtful suggestions, and to the following members of our International Scientific Advisory Committee for providing insightful comments and guidance: Janet Wittes (Chair), George Armah, John Clemens, Christopher Duggan, Stephane Helleringer, Ali Mokdad, James Nataro, and Halvor Sommerfelt. This supplement is sponsored by the Center for Vaccine Development and Global Health (CVD) at the University of Maryland School of Medicine, Baltimore (UMB).

Financial Support: The VIDA study was funded by the Bill & Melinda Gates Foundation.

Ethics Statement: Approval was granted by the ethics committees at each institution: University of Maryland School of Medicine, Baltimore, MD, USA; Medical Research Council Unit, The Gambia at the London School of Hygiene & Tropical Medicine, Banjul, The Gambia; Centre pour le Développement des Vaccins du Mali (CVD-Mali), Bamako, Mali.

Last Updated: October 10, 2022During the course of the Vaccine Impact on Diarrhea in Africa (VIDA) study, a Health care Utilization and Coverage Survey (HUCS) was conducted semiannually as part of the Demographic Surveillance System (DSS) at each VIDA study site. In The Gambia and Mali, a random selection of children from three age strata was selected and the HUCS was conducted by the DSS team during their routine rounds. The goal of the survey was to assess rotavirus vaccine coverage and to determine where children in the DSS seek care for moderate-to-severe diarrhea.