Eric Muriuki, MBChB, MSc

Muriuki, Eric

Research Site: Kenya

Research Area: HIV, Reproductive Health

Primary Mentor: James Kiarie

Research Project

DMPA Use and Immune Activation Amongst Postpartum HIV-uninfected Kenyan Women

The majority of the 15.4 million human immunodeficiency virus (HIV)-infected women worldwide are of childbearing age and need access to contraception. Hormonal methods of contraception like DMPA are safe, acceptable, and effective in preventing unwanted pregnancies. However, clinical studies suggest a relationship between DMPA use and HIV acquisition. The mechanisms causing HIV acquisition are unclear; this study examines the relationship between DMPA use and immune activation in postpartum HIV-uninfected women in Kenya.

Africa is most in need of this study, where birth rates are high and contraception is a critical aspect of improving women’s health. Current levels of contraception prevent over 173,000 unintended HIV-infected births each year in sub-Saharan Africa.

The injectable form of medroxyprogesterone acetate (MPA) has a prolonged duration of action due to slow progestin release from the muscle. MPA can be detected in systemic circulation within 30 minutes after a 150mg intramuscular injection. Although serum MPA levels vary between individuals, they rise to contraceptively effective blood levels (> 0.5ng/mL) within 24 hours after the injection, and generally plateau at about 1.0ng/mL for about three months and decline gradually. Although levels are sustained for 3-6 months at low levels, higher levels of MPA remain for the first two weeks after injection, thus this time period is when we hypothesize women have increased HIV susceptibility.

Some of the proposed mechanisms by which MPA may increase susceptibility to HIV are: steroid activity, which may depress the immune system; changes in the local genital tract that may permit HIV entry; and changes in the vaginal flora. Given the weak associations between HIV acquisition and use of DMPA, we hypothesize that the early high levels of MPA may represent a window of additional vulnerability that attenuates as DMPA levels fall over the 12 week administration period. This study was designed to gather preliminary data towards that hypothesis.

Advice for Potential Applicants:

I would want to encourage you to go ahead and apply for this fellowship, because it is a program that provides a great opportunity for learning and contributing to the world in research. You will also have an opportunity to meet with top researchers who offer mentorship in their field, which is the key element of this program. In the Fogarty Fellows you also find a new family in research that is very supportive and can groom you to be well focused in global health.