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Data From Largest Global Diarrheal Disease Study Available to Scientists on Public Sites

December 20, 2018

Myron M. Levine, MD, DTPH

Shared Data from the Global Enteric Multicenter Study Will Help Future Research in Diarrheal Diseases

Data collected from the Global Enteric Multicenter Study (GEMS), a multi-site research project studying diarrheal diseases that was designed and coordinated by researchers in the Center for Vaccine Development and Global Health (CVD) at the University of Maryland School of Medicine (UMSOM), are now available to scientists on two online data resources.

Access to this important data will help scientists around the world in their research into treatments and interventions for diarrheal diseases, a leading cause of death among the most vulnerable populations.

The GEMS study was the largest, most comprehensive study of childhood diarrheal diseases ever conducted in developing country settings. It was coordinated by CVD, and the keystone component was a case-control study conducted at seven diverse, high-burden sites in sub-Saharan Africa (The Gambia, Kenya, Mali and Mozambique) and South Asia (Bangladesh, India and Pakistan).

The study enrolled 22,568 children under five years of age, a sample size large enough to provide comprehensive data on the causes, incidence, and impact of the range of diarrheal diseases affecting children around the world.

“At the time that the GEMS project was initiated, diarrheal diseases constituted the second leading cause of death among children under five years in developing countries. Although there were known effective treatments such as oral rehydration solutions (ORS) and intravenous fluids and zinc supplements, many young children in rural areas and urban slums did not have easy access to health care to receive such treatments,said Myron M. Levine, MD, DTPH, Principal Investigator for GEMS, the Simon and Bessie Grollman Distinguished Professor of Medicine and Associate Dean for Global Health, Vaccinology and Infectious Diseases. “Moreover, when the GEMS study began there were no vaccines against specific causes of childhood diarrhea in routine use in sub-Saharan Africa or South Asia to prevent such diarrheal infections. Nor was there broad agreement on what were the major pathogens responsible for the more severe forms of young child diarrheal illness in Africa and South Asia.

Whereas many different bacteria, viruses and other pathogens were recognized as agents that can cause diarrheal disease prior to GEMS, there was not agreement on their relative importance in children in developing countries or whether their incidence varied in infants (0-11 months of age), toddlers (12-23 months of age) and pre-school children (24-59 months of age). In addition, there was no robust data on whether there were marked difference in the array of pathogens from country-to-country and from year-to-year within the same country.

Dr. Levine addedGEMS not only quantified the overall burden of moderate-to-severe diarrhea in children under five years of age in the two global regions where 80 percent of diarrheal disease deaths were occurring. It also revealed that a small number of specific pathogens accounted for a notable proportion of all moderate-to-severe diarrhea. These results paved the way for accelerated development of vaccines against some pathogens (for example, Shigella) and for the implementation of some existing vaccines (for example, rotavirus vaccines).”

Information was particularly lacking from sub-Saharan Africa, which includes most of the world’s countries with the highest young child mortality rates. Researchers in the GEMS study systematically collected these data and filled the knowledge void, thereby allowing the rational setting of priorities for research and for implementing interventions in specific populations. The availability of GEMS data provides unique data to help researchers, policymakers, donors, and advocates to make evidence-based decisions to reduce the global burden of diarrheal diseases.

This important data will help scientists around the world in their research to combat diseases that affect children under five in low resource settings,” said UMSOM Dean E. Albert Reece, MD, PhD, MBA, who is also the Executive Vice President for Medical Affairs, University of Maryland, and the John Z. and Akiko K. Bowers Distinguished Professor. “It will also help set the stage for evidence-based policy decisions to help reduce the global burden of diarrheal diseases.”

About the Data Site launched earlier this year through a global collaboration of University of Pennsylvania’s School of Arts and Sciences, Perelman School of Medicine, University of Georgia’s Institute of Bioinformatics, and the University of Liverpool. It allows users to browse GEMS data through an intuitive, point-and-click open access resource, while maintaining the rigorous privacy protection through a protected user registration system. Available data include critical study documentation, advanced quantitative molecular TaqManTM Array Card diagnostics and conventional microbiologic test results from more than 25,000 participants. In February, data from affiliated CVD projects, the Healthcare Utilization and Attitudes Survey and GEMS1A will become available on

GEMS microbiome data from over 1,000 stool samples is also available at MicrobiomeDB development is led by the University of Pennsylvania's School of Veterinary Medicine. This web-based discovery tool empowers scientists to search through large and complex microbiome datasets, while providing sophisticated tools for data visualization and analysis.

“Public accessibility of microbiome data from GEMS, combined with the ability to integrate these data with other microbiome studies, helps us gain new insight into the ways in which intestinal microbes impact the overall health and well-being of children,” said Daniel Beiting, PhD, who is an Assistant Professor of Pathobiology at the University of Pennsylvania’s School of Veterinary Medicine.

About the University of Maryland School of Medicine

Now in its third century, the University of Maryland School of Medicine was chartered in 1807 as the first public medical school in the United States. It continues today as one of the fastest growing, top-tier biomedical research enterprises in the world -- with 43 academic departments, centers, institutes, and programs; and a faculty of more than 3,000 physicians, scientists, and allied health professionals, including members of the National Academy of Medicine and the National Academy of Sciences, and a distinguished recipient of the Albert E. Lasker Award in Medical Research. With an operating budget of more than $1 billion, the School of Medicine works closely in partnership with the University of Maryland Medical Center and Medical System to provide research-intensive, academic and clinically-based care for more than 1.2 million patients each year. The School has over 2,500 students, residents, and fellows, and more than $530 million in extramural funding, with most of its academic departments highly ranked among all medical schools in the nation in research funding. As one of the seven professional schools that make up the University of Maryland, Baltimore campus, the School of Medicine has a total workforce of nearly 7,000 individuals. The combined School and Medical System (“University of Maryland Medicine”) has an annual budget of nearly $6 billion and an economic impact more than $15 billion on the state and local community. The School of Medicine faculty, which ranks as the 8th highest among public medical schools in research productivity, is an innovator in translational medicine, with 600 active patents and 24 start-up companies. The School works locally, nationally, and globally, with research and treatment facilities in 36 countries around the world. Visit

About the UMSOM Center for Vaccine Development and Global Health

For over 40 years, researchers in the Center for Vaccine Development and Global Health have worked domestically and internationally to develop, test, and deploy vaccines to aid the world’s underserved populations. CVD is an academic enterprise engaged in the full range of infectious disease intervention from basic laboratory research through vaccine development, pre-clinical and clinical evaluation, large-scale pre-licensure field studies, and post-licensure assessments. CVD has worked to eliminate vaccine-preventable diseases. CVD has created and tested vaccines against cholera, typhoid fever, paratyphoid fever, non-typhoidal salmonella disease, shigellosis (bacillary dysentery), Escherichia coli diarrhea, nosocomial pathogens, tularemia, influenza, and other infectious diseases. CVD’s research covers the broader goal of improving global health by conducting innovative, leading research in Baltimore and around the world. CVD researchers are developing new and improved ways to diagnose, prevent, treat, control, and eradicate diseases of global impact. Currently, these diseases include malaria, typhoid, shigella and vaccine-preventable infectious diseases. CVD researchers have been involved in critical vaccine development for emerging pathogens such as Zika and Ebola. In addition, CVD’s work focuses on the ever-growing challenge of anti-microbial resistance.


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