The following is a post from Center for Global Health Policy Officer Carol Bergman, who recently traveled to Kenya with a group of Capitol Hill staff from key Congressional offices with jurisdiction over global health funding or programs.
We went to the U.S. Centers for Disease Control & Prevention (CDC) Kisian Field Station – about 12 km from Kisumu, Kenya – to meet with Dr. Lisa Mills and Dr. Kevin Cain. Dr. Mills is the HIV Research Branch chief, and served as the Principal Investigator on the (National Institutes of Health) HPTN 052 study on discordant HIV couples; Dr. Kevin Cain is the CDC branch chief and heads up the station’s research on TB. Below I detail their individual work at the Kisian Field Station.
Dr. Lisa Mills
The Kenya Medical Research Institute (KEMRI)-CDC HIV Research Branch was started in 2001, a collaboration with the U.S. government and the Kenya Ministry of Health. The goal is to perform high-impact HIV prevention research with U.S. domestic and worldwide relevance. In order to do HIV prevention research, you need to go where the rates are high enough; e.g., Africa and Thailand, which are the international sites. In this particular catchment area, four percent of adolescent girls acquire HIV infection annually. There are 60 ongoing research studies at KEMRI/CDC focused on:
- Global Disease Detection
- Tuberculosis; and
- Health and Demographic Surveillance System.
The most critical research tool used is the household survey – done every four months –which covers socio-economic and educational status; immunization status for children less than two years of age; the use of bed nets and other interventions. In addition, specimens are collected for malaria, flu and rotavirus; there is home-based HIV counseling and testing; and verbal autopsies are done to help determine cause of death. There is a state of the art laboratory at Kisian to support this work. This CDC facility hosts a national reference laboratory for HIV resistance testing and has conducted more than 20,000 HIV diagnostic tests on infants.
The greatest burden of HIV/AIDS in the country is in the rural population. Home studies show that 30 to 45 percent of women who breastfeed are likely to transfer the infection to the baby; with intervention this can be reduced to a seven percent chance of transmission.
Completed Studies: The Baseline Cross-Section Survey was the first study to do systematic in-home HIV testing in the region. The survey objective was to characterize the burden of HIV in rural African demographic survey area from 2003 to 2005. The findings were published and used as the basis for future work on HIV epidemiology in Kenya’s Nyanza Province.
The Kisumu Breastfeeding Study (KIBS) aimed to explore the prevention of mother-to-child transmission (PMTCT) of HIV among breastfeeding women in a resource limited setting using combination maternal antiretroviral therapy (ART). Completed in 2009, the study showed a strong reduction of MTCT; the results were disseminated and incorporated into World Health Organization (WHO) and Kenyan treatment guidelines.
The Kisumu Breastfeeding Follow-on Study: The objective is to determine if ART treatment outcomes differ in women with past exposure to ART for PMTCT in KIBS, versus other settings, versus no exposure to ART through PMTCT.
The Kisumu Incidence Cohort Studies: The objective is to determine HIV incidence and correlates of successful recruitment and retention in longitudinal community-based cohort studies in preparation for future HIV prevention trials in Kisumu with young sexually active adults, sexually active adolescents, and high risk persons. Initial findings indicate a higher prevalence and incidence of HIV in younger people and females. This will be a platform for future vaccine and microbicide trials including for U.S. Food & Drug Administration licensing and U.S. implementation.
The HIV Prevention Trials Network (HPTN) Study 052: HPTN 052 runs from 2207-2015; Kenya joined in 2009. Other sites include Malawi, Botswana, Zimbabwe, South Africa, Thailand, India and Brazil. This randomized, controlled trial aims to evaluate the effectiveness of ART plus HIV primary care versus HIV primary care alone to prevent the sexual transmission of HIV-1 in serodiscordant couples. There are sixty discordant couples in the study in Kenya—many of whom were identified through home-based testing. The study is ongoing and fully enrolled; early data was released in May 2011 due to the extraordinary findings with worldwide implications that 96 percent of infections transmitted within discordant couples can be stopped with use of antiretrovirals by the infected partner.
Additional ongoing studies include: Unintended Pregnancies and HIV; Kenya Free of AIDS PMTCT 2-phase study in collaboration with the University of Washington and the University of Nairobi; and the HIV-1 Acquisition During and After Pregnancy.
New Studies include: HIV Sub-Study in KEMRI-CDC Health and Demographic Surveillance System (objective to evaluate impact of HIV prevention and care and treatment services on sexual behaviors, and HIV incidence at individual and community levels); Evaluating Acute and Recent HIV Infection Longitudinally (objective to evaluate virologic, immunologic, clinical, demographic and behavioral factors associated with early HIV infection and to evaluate new incidence in western Kenya).
Dr. Mills noted that federal resources for this kind of research are growing increasingly scarce. She had hoped that this Kenya site could participate in the CAPRISA follow-up study testing a vaginal gel with antiretroviral drugs, but CDC had no additional resources that could be committed. She also reported that the CDC research site in Botswana has been closed due to the resource crunch—the same site that conducted the Partners Pre-exposure Prophylaxis (PrEP) study.
Dr. Kevin Cain
Dr. Cain directs the research on TB at the station; he discussed the partnership on TB between KEMRI and CDC. Tuberculosis is one of the deadliest public health threats today – he called the Nyanza Province the TB epicenter in Kenya. TB is also still an issue in the U.S. with a disproportionate number of TB cases coming from the ranks of immigrants. One of the biggest challenges is the lack of a good diagnostic test. The most widely used method for diagnosis in most countries is the 125-year-old sputum smear microscopy test, which has a number of drawbacks including low sensitivity (especially in HIV-positive individuals and children), and inability to determine drug-susceptibility. The sputum test misses 50 percent of all TB cases; for those persons with HIV, the sputum test misses 60 percent. According to WHO, only five percent of the estimated global burden of multidrug-resistant (MDR) cases are detected due to critical gaps in laboratory capacity in many endemic countries.
The process of diagnosing TB through culture can take longer than a person lives – especially if the patient has drug-resistant TB. A better diagnostic test is needed to ensure that the identification process is shorter so as to impact the treatment protocol. A new diagnostic tool has been developed recently – GeneXpert – which works very quickly. This is a cartridge-based automated diagnostic test. However, the lab equipment required is very expensive (approximately $12/test). The Congressional staff were very interested in Dr. Cain’s presentation and acknowledged that they knew very little about tuberculosis, especially compared to their knowledge about HIV infection. They were able to see the GeneXpert and to tour the state-of-the-art TB laboratory.