Epidemiological and statistical research on health problems of developing countries: MRC Tropical Epidemiology Group

Lead Research Organisation: London Sch of Hygiene and Trop Medicine
Department Name: Epidemiology and Population Health

Abstract

The past decade has seen significant progress in health in developing countries as well as setbacks and new challenges. Gains in health in many low-income countries have been reversed due to the global epidemic of HIV/AIDS and steep increases in tuberculosis (TB). Malaria remains a major killer of children in Africa despite declines in some countries. There is an urgent need to find effective means of controlling these major diseases.

The main aim of the MRC Tropical Epidemiology Group, based at the London School of Hygiene & Tropical Medicine, is to conduct research on interventions against diseases of major public health importance in Africa and other parts of the developing world. We collaborate with scientific groups overseas, including MRC Units in The Gambia and Uganda, assisting with the planning and analysis of research studies. These studies are designed to improve our understanding of risk factors for these diseases, and to evaluate the impact of different control measures. During the next five years, our main focus will continue to be on HIV, TB and malaria, and we will expand our work on non-communicable diseases, which are rapidly increasing in importance in developing countries.

There have been major advances in HIV prevention in recent years, especially around the potential for antiretroviral drugs to be used to prevent HIV transmission. We will work on further studies to evaluate methods of preventing and treating HIV infection, and to scale up interventions, such as voluntary medical male circumcision, that are known to reduce the risk of HIV infection. We will also expand work on integration of care for HIV-patients with treatment of other chronic diseases such as heart disease and diabetes. Research on human papillomavirus (HPV), which can cause cervical cancer, will include studies of how best to deliver HPV vaccination to girls and young women in sub-Saharan Africa.

Our TB research will focus on large-scale trials to assess how best to treat patients co-infected with both TB and HIV, and to improve the ways in which care for TB and HIV are integrated. A new diagnostic test for TB which has the potential to revolutionize TB diagnosis has recently been developed (Xpert MTB/RIF). We will also evaluate the impact and cost-effectiveness of this test for routine TB diagnosis in South Africa.

Substantial reductions in malaria have been reported recently, but much of this progress has been in countries with low levels of malaria, and malaria rates remain unacceptably high in many African countries. In the Sahel region, most of the malaria mortality and morbidity occurs during the short rainy season. We have been closely involved in research showing that giving effective malaria chemoprevention during this period prevents illness and death from malaria in children. We will continue our research in this area, including assessing the impact of this treatment strategy on malaria cases and deaths when delivered through routine health services. We will also continue research on promising malaria vaccines, and to evaluate new methods to control the mosquitoes that transmit malaria.

While the major infectious diseases continue to play a major role, especially in sub-Saharan Africa, there is increasing recognition of the impact of non-communicable diseases. The prevalence of conditions such as cardiovascular disease, diabetes and mental illness is increasing, especially in growing urban centres in developing countries, and will require innovative approaches to prevention and control.

There are few experienced medical statisticians in research institutions and universities in Africa, and an important aspect of our work is to support a fellowship scheme, which provides a two-year training programme for statisticians. In addition, we teach research methods at workshops at collaborating sites and provide informal mentoring and supervision to statisticians and epidemiologists we work with.

Technical Summary

We will conduct epidemiological research on HIV, TB, malaria and other diseases of public health importance in developing countries with an emphasis on randomised intervention trials.

In HIV, we will conduct the first trial of the impact of a test-and-treat intervention on HIV incidence in Africa, implementation research on scale-up of male circumcision, and RCTs to reduce early mortality among patients with low CD4 counts and to evaluate different treatment strategies for cryptococcal meningitis.

In TB, we will complete a trial of a four-month pulmonary TB treatment regimen. We will extend our research on treatment strategies for TB and HIV co-infection, including trials to compare 3 treatment strategies in ARV-naïve TB/HIV patients, a CRT to assess the effect of a point-of-care TB test-and-treat algorithm on early mortality in HIV-infected patients accessing ART; and a CRT of the impact of TB diagnosis by Xpert MTB/RIF on mortality and time-to-initiation of treatment.

Malaria research will build on previous work on Seasonal Malaria Chemoprevention (SMC), to evaluate effectiveness of delivery through routine health services, to monitor for adverse effects and to determine the effectiveness of adding SMC to existing control strategies for malaria. We will continue to evaluate multi-component malaria control on Bioko Island, and will develop new collaborations to assess the role of the RTS,S vaccine if licensed.

We will continue trials on lay-health worker interventions to treat common mental disorders, on the beneficial and adverse effects of helminths and antihelmintics on other conditions and of the effectiveness of pneumococcal vaccines. Methodological work will include spatial analysis of spill-over effects in CRTs, and evaluation and prediction of vaccine impact. Finally, we will continue to build research capacity in Africa, including development of the MRC-supported Mwanza Intervention Trials Unit and our programme of TEG training fellowships.

Planned Impact

As highlighted in the Millennium Development Goals, there is a strong synergy between ill-health and poverty. Our research focuses on diseases that are major causes of morbidity and mortality in resource-poor countries. These diseases have a substantial impact on the socio-economic development of many of these countries. By reducing the rates of important causes of ill health, such measures have the potential to alleviate poverty as well as improving life expectancy. We are expanding our focus on implementation research of proven interventions, and health systems research, which can improve the effectiveness and efficiency of health care delivery and ensure that resources reach the right people.

Many of the diseases we focus on typically affect the poorest in resource-poor countries, and those marginalised from society. We have a strong focus on community-based interventions (for example, in the PopART and TB trials which incorporate home-based HIV and TB testing) which help to overcome barriers to health service access and minimize stigma and discrimination. We also focus on scaling-up interventions which have been proven to be effective - for example male circumcision for HIV prevention, and seasonal malaria chemoprevention in areas with highly seasonal malaria transmission. This implementation research will help ensure access to effective prevention technologies for those who need it, regardless of socio-economic status. Our expanding health systems research (for example on integrating HIV and non-communicable disease treatment and care) will also increase the population-level impact of known effective treatment.

Our research is locally disseminated to study populations, and to regional and national stakeholders and policymakers, as appropriate. This includes providing information to enable policy-makers to make decisions about cost-effective strategies of roll-out (for example, for HPV vaccination or male circumcision scale-up), or access to new technology (such as TB diagnostics including Xpert MTB/RIF). We also play an active role in influencing global health policy and directions for future research, through membership of international technical and policy advisory committees including chairing the WHO Joint Technical Expert Group on Malaria Vaccines in Pivotal Phase 3 Trials & Beyond, the WHO Malaria Policy Advisory Committee Evidence Review Group on Malaria Burden Estimation and the EDCTP Partnership Board; and membership of several other Committees, as outlined in the Case for Support.

Organisations

Publications

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Kinyanda E (2018) Major Depressive Disorder: Longitudinal Analysis of Impact on Clinical and Behavioral Outcomes in Uganda. in Journal of acquired immune deficiency syndromes (1999)

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