Table 1.

A brief overview of the Majengo Observational Cohort Study (MOCS)

•	The MOCS is one of the longest-standing observational cohort studies in the world.
•	It was established in 1984 as a collaborative project between the University of Manitoba, Canada and the University of Nairobi, Kenya with a two-part mandate: (a) to conduct epidemiological research on STIs, and (b) to provide healthcare services to those women diagnosed with active STIs, or their clinical consequences. For more detailed description of the cohort please refer to the work by Kimani and collaborators.12
•	It was not originally intended to be a long standing research enterprise.
•	Over time, the MOCS has become renowned for its contributions to the understanding of HIV/AIDS immunology
•	The cohort currently consists of approximately 3,000 women sex workers.
•	Once recruited to the cohort, the women are eligible for a package of free comprehensive health care services.
•	Today, the MOCS contributes at least US$ 1,088/per woman/per year towards their health care.
•	The incidental discovery, in the late 1980s, of HIV resistance among a small number (about 5%) of cohort members, despite their chronic exposure to HIV through unprotected sex, was a turning point for the MOCS and for HIV/AIDS science.
•	The scientific contributions of the MOCS since its inception have attracted numerous academic institutions from the North to join the original collaboration, which has grown into a multi-institutional and multidisciplinary scientific endeavor.
•	The MOCS has produced approximately 300 research papers over the past 25 years, many co-authored by Kenyan and Northern collaborators.
•	To improve the research capacity in Nairobi, the investigators secured a grant from the Canadian Foundation for Innovation (CFI) for CAN $105 M to help build and equip a Level III bio-containment unit along with expansion of existing infrastructure and capacity related to general bacteriology, virology, serology, and PCR. The lab is awaiting commission in January 2010 and will provide an important resource for the region.
•	The Project office in Nairobi is situated at the University of Nairobi which houses research, administration and other support staff; and also computer and life sciences laboratories.
•	The Majengo clinic (MC) serves as the field site of the MOCS in the Majengo village, an administrative unit of the Nairobi City Council in south-east Nairobi.