Thematic Support - Disease Control and Elimination

The theme has a large portfolio that includes research aimed to decrease the burden of the most common causes of illness and mortality in the West African region, namely malaria, infections caused by bacteria and infections caused by viruses. From the start of the COVID-19 pandemic, the theme has developed a large portfolio to try to understand the effect of the pandemic in the country and why the severity of the infections has been lower than anticipated.
The research conducted by the Theme has generated knowledge in the different areas. Some key examples follow:
- Research at the theme works on the control of malaria (to decrease the annual number of cases) and elimination (to reach the 0 cases). In malaria control, the Unit has worked along with the National Malaria Control Program to monitor the efficacy of different anti-malarial medicines and with the results update the National treatment policy of malaria patients. In malaria elimination, the theme has designed novel interventions against malaria in regions where the number of cases is very low (reactive treatment). These studies are important in pre-elimination stages.
- Research conducted by the theme has informed national and international policies on the immunization with the Pneumococcal conjugate vaccine. This is important as Pneumococcus is still a main contributor of under-5 mortality in the region.
- The Theme provided data for the introduction of the Rotavirus vaccine in the country followed by data on the effect of the vaccine in reducing Rotavirus cases and deaths.
- During 2020, the first wave of COVID-19 disease did not increase mortality in the rural areas of the country.

The theme answers scientific questions related to the control and elimination of infectious diseases by designing large epidemiological studies and clinical trials (i.e., individually and cluster randomized). These projects target, beyond clinical cases, asymptomatic infections as these are key for maintaining transmission at community level.
To control and eliminate diseases of public health importance in the region, DCE needs access to large population and geographical areas. The knowledge of population structure provided in part by the three HDSS run in The Gambia, gives DCE a unique knowhow for implementing cluster randomized trials, mainly in rural areas, to evaluate interventions aimed at system-wide changes or to avoid contamination between arms. Access to community for other studies and trials is through governmental health facilities.
The DCE scientific strategy focuses on unravelling the interactions between hosts, pathogens, and vectors and at evaluating interventions aimed at interrupting transmission and/or reducing the disease burden. Both components can inform each other and provide new elements for understanding the dynamics of transmission and identifying new targets for interventions.

DCE has a multidisciplinary approach combining epidemiological research with strong laboratory support (formerly for diagnosis but increasingly for more sophisticated molecular analysis). The core component of epidemiology and laboratory sciences is complemented, whenever possible, by social sciences investigating the human factors influencing the epidemiology of the diseases, the uptake and coverage of interventions as well as health economic research to ensure that successful interventions are promptly translated into practice.
Research areas:
- Malaria. The malaria research activities contribute to a better understanding of malaria epidemiological trends and transmission dynamics needed for better targeting interventions for both control and elimination of malaria.
- Invasive bacterial infections (IBI) remain major causes of morbidity and mortality in childhood with an even higher burden among neonates. The research activities on this area have contributed to a better understanding of etiologies responsible for IBI in The Gambia, community transmission and risk factors. In addition, we have designed context specific trials to decrease neonatal sepsis and associated mortality and have evaluated the impact of new country-wise implementations for children. All the studies and trials have a component to assess trends of antimicrobial resistance (AMR) on bacterial isolates. On this area, the Unit has also pioneered research on S. pneumoniae before and after the implementation of Pneumococcal Conjugate Vaccines (PCVs).
- Diarrhoeas are a leading cause of morbidity and mortality in children. During the last years, we have quantified burden of disease and main aetiologies responsible for diarrhoeas in The Gambia. Our work led to the introduction of Rotavirus vaccine. Trials to evaluate new interventions are also part of our remit.
The Theme conducts research on the links between infections and chronic diseases (such as group A Streptococcus infection and rheumatic heart disease or hepatitis B and liver cancer). Lately, the theme has built a large portfolio on epidemiological research of SARS-CoV-2 and COVID-19 disease.