Karonga Prevention Study
Over the last 30 years the Karonga Prevention Study, based in Karonga District, northern Malawi has made major contributions to the understanding and control of mycobacterial disease, HIV and other infectious diseases. In 2012 we established a new site in Lilongwe, and have started a major programme of work on cardiovascular disease and diabetes. To reflect our expanded focus we are changing our name to the Malawi Epidemiology and Intervention Research Unit (MEIRU).
MEIRU is a partnership between the Malawi College of Medicine, the London School of Hygiene and Tropical Medicine (LSHTM) and the Malawi Ministry of Health. Since August 2013 the Programme has been led by Moffat Nyirenda (Professor of Medicine (Global Non-Communicable Diseases)) at LSHTM and Professor of Research at the Malawi College of Medicine), with Dr Mia Crampin (deputy director), Prof Shabbar Jaffar, Prof Judith Glynn, Prof Basia Zaba (all LSHTM) and Dr Charles Mwansambo, the Ministry of Health, Malawi.
Our research programme started in 1979 to study the incidence and risk factors of leprosy, funded by the British Leprosy Relief Association (LEPRA). We have been predominantly funded by the Wellcome Trust since 1996, with additional funding from many other sources for specific projects.
Over the years, the research focus has been on tuberculosis, demography and HIV/AIDS with field activities based in Karonga District where the programme has a long-term and detailed understanding of demography and infectious disease epidemiology. Our database links work over time and activity and includes data on more than 300,000 individuals. We have a biorepository of over 100,000 samples and continuous demographic surveillance system (DSS) in a sub-population of 35,000.
We have a long record of classical and molecular epidemiological studies, trials, and work on vaccines, strengthened by our proven ability to identify people reliably and trace them and their spouses and relatives over decades; and by strong local community support and trust, built on the project’s role in the elimination of leprosy from the district and the control of TB.
Highlights of work to date include:
- In a trial of >120,000 individuals we showed that BCG vaccine imparts considerable protection against leprosy in this population, but none against tuberculosis.
- We showed that BCG vaccination of adolescents and infants in Malawi, induced different immune responses from those induced in adolescents and infants in the UK.
- As the only long-term molecular epidemiological study of tuberculosis in an area of high HIV prevalence we have shown that recent infection is the predominant cause of TB in HIV-infected individuals, that HIV-infected cases play an important role in transmission, and that HIV may be causing a shift in M. tuberculosis genotypes.
- We have described the earliest HIV subtype C viruses known worldwide, and documented a shift from a mixed epidemic of subtypes A, D and C in the early 1980s, to the current predominance of subtype C.
- We were the first to show that antiretroviral therapy (ART) reduces mortality at the population level, with decentralisation improving the benefit for remote communities, providing strong support for the “public health” approach to ART delivery.
Research in Karonga will continue, building on the past findings to address new questions. In particular we aim to improve understanding of transmission and factors associated with virulence of M.tuberculosis, in a setting of unusually well implemented routine tuberculosis control. We will assess the impacts of antiretroviral therapy (ART) roll-out on mortality, reproductive health and family welfare.
A major new focus for the programme is research on non-communicable diseases (NCDs), prompted by their rapid rise, including among young people in Africa, and the high priority placed by the Malawi government on research in this area. Our studies will document the true burden on common NCDs (such as hypertension, diabetes and hyperlipidaemia) and the distribution of their risk factors, including smoking, diet and other lifestyle factors. We will examine the barriers to accessing care for people with non-communicable diseases. Data from these studies will allow us to design and test novel interventions studies to control NCDs in this population. The new site in Lilongwe is central to this work and will allow urban-rural comparisons.
As well as the strong emphasis in research, MEIRU is developing capacity in medical statistics and epidemiology. Our key partner in capacity development is Prof Ken Maleta, Principal of the Malawi College of Medicine.
MEIRU is part of the ALPHA and INDEPTH Networks.