Philip O. Renzullo

The protective effect of circumcision on HIV incidence in rural low-risk men circumcised predominantly by traditional circumcisers in Kenya: two-year follow-up of the Kericho HIV Cohort Study.

Background:Three randomized controlled trials (RCTs) have demonstrated that male circumcision prevents female-to-male HIV transmission in sub-Saharan Africa. Data from prospective cohort studies are helpful in considering generalizability of RCT results to populations with unique epidemiologic/cultural characteristics. Methods:Prospective observational cohort sub-analysis. A total of 1378 men were evaluated after 2 years of follow-up. Baseline sociodemographic and behavioral/HIV risk characteristics were compared between 270 uncircumcised and 1108 circumcised men. HIV incidence rates (per 100 person-years) were calculated, and Cox proportional hazards regression analyses estimated hazard rate ratios (HRs). Results:Of the men included in this study, 80.4% were circumcised; 73.9% were circumcised by traditional circumcisers. Circumcision was associated with tribal affiliation, high school education, fewer marriages, and smaller age difference between spouses (P < 0.05). After 2 years of follow-up, there were 30 HIV incident cases (17 in circumcised and 13 in uncircumcised men). Two-year HIV incidence rates were 0.79 (95% confidence interval [CI]: 0.46 to 1.25) for circumcised men and 2.48 (95% CI: 1.33 to 4.21) for uncircumcised men corresponding to a HR = 0.31 (95% CI: 0.15 to 0.64). In one model controlling for sociodemographic factors, the HR increased and became non-significant (HR = 0.55; 95% CI: 0.20 to 1.49). Conclusions:Circumcision by traditional circumcisers offers protection from HIV infection in adult men in rural Kenya. Data from well-designed prospective cohort studies in populations with unique cultural characteristics can supplement RCT data in recommending public health policy.

Use of Rapid and Conventional Testing Technologies for Human Immunodeficiency Virus Type 1 Serologic Screening in a Rural Kenyan Reference Laboratory

ABSTRACT We report a prospective comparison of human immunodeficiency virus type 1 testing by enzyme immunoassay and Western blot with four rapid tests of 486 subjects performed in rural Kenya. Rapid test sensitivity was 100%. Specificity ranged from 99.1 to 100%. Combined use of two Food and Drug Administration-approved rapid tests yielded a single false-positive result.

HIV-1 seroconversion in United States Army active duty personnel, 1985-1999.

Objective To monitor HIV-1 infection trends among United States Army personnel, a predominantly young population group, tested between 1985 and 1999 for HIV-1 infection. Design Demographic correlates of HIV-1 infection were assessed in the cohort via epidemiologic analysis. Methods Annual seroconversion incidence rates were calculated per 1000 person-years (PY) of follow-up. Poisson regression was used to assess demographic correlates of HIV-1 seroconversion risk. Results There were 1275 seroconverters among 2 004 903 active duty Army personnel accounting for 7 700 231 PY of follow-up. The HIV-1 incidence rate (IR) was 0.17/1000 PY [95% confidence interval (CI), 0.16–0.17]. The highest IR was observed in the first year of testing (IR, 0.43/1000 PY; 95% CI, 0.33–0.52). The IR for male and female soldiers was 0.18/1000 PY and 0.08/1000 PY, respectively. HIV-1 incidence declined with age. Significant risk of HIV-1 seroconversion was associated with age [> 30 years old relative risk (RR), 1.51], race (Black RR, 4.61; Hispanic RR, 2.76), gender (male RR, 3.12), marital status (unmarried RR, 2.01) and rank (enlisted RR, 2.50). Conclusions HIV-1 seroconversions in the US Army have been low and stable since the early 1990s. Continued HIV-1 incidence surveillance in the US Army provides information on the status of the epidemic in the Army, as well as important corroborative data on HIV-1 infections throughout the US.

human Immunodeficiency Virus Type-1 Seroconversion Trends Among Young Adults Serving in the United States Army, 1985-1993

The direct measurement of the incidence of new infections with the human immunodeficiency virus type 1 (HIV-1) can be made among soldiers because of the routine and periodic nature of HIV-1 testing in the United States Army. Between November 1985 and October 1993, 978 HIV-1 seroconversions were seen among 1,061,768 soldiers, contributing over 3.6 million person-years of follow-up [seroconversion rate (95% confidence interval) = 0.27/1,000 person-years (0.25-0.29)]. A significant decreasing trend in HIV-1 seroconversion rates was seen over the analysis period. The rate of new infections declined significantly from the first interval, 1985-1987, (0.43/1,000 person-years) to the second interval, 1987-1988, (0.28/1,000 person-years), but stabilized at approximately 0.22/1,000 person-years after 1988, representing new infections in approximately 100-150 soldiers annually. The risk of seroconversion among active duty soldiers was significantly associated with racial/ethnic group, age, gender, and marital status. Surveillance of HIV-1 seroconversion rates in the U.S. Army continues to offer a unique opportunity to assess temporal trends in the evolving HIV-1 infection epidemic. Monitoring the rate of new HIV-1 infections allows for identification of subgroups in need of intervention, refocusing of intervention strategies, and evaluation of their effectiveness.

Hiv-1 Incidence Rates and Risk Factors in Agricultural Workers and Dependents in Rural Kenya: 36-month Follow-up of the Kericho Hiv Cohort Study

Background:Incidence data from prospective cohort studies using rigorous laboratory methods are important in designing and evaluating HIV vaccine and therapeutic clinical trials and health care programs. We report 36-month HIV-1 incidence rates and demographic and psychosocial risks from the Kericho cohort in rural Kenyas southern Rift Valley Province. Methods:Thirty-six month, prospective, closed, observational cohort study of adult plantation workers and dependents followed biannually. HIV-1 incidence rates per 100 person-years (py) were calculated, and Cox regression analyses were used to estimate hazards ratios (HR) associated with seroconversion. Results:Two thousand four hundred volunteers (mean age ± SD = 30.1 ± 8.5 years; 36.5% women) participated. Twenty-nine new HIV cases were identified in year 1 of follow-up, which increased to cumulative totals of 49 and 63 cases in years 2 and 3, respectively. The corresponding 1-, 2-, and 3-year incidence rates were 1.41 [95% confidence interval (CI) = 0.95-2.02], 1.16 (95% CI = 0.86-1.54), and 1.00 (95% CI = 0.77-1.28) per 100 py. Risk factors associated with HIV seroconversion included the following: of the Luo tribe (HR = 3.31; 95% CI = 1.65-6.63), marriage more than once (HR = 2.83; 95% CI = 1.20-6.69), self-reported male circumcision (HR = 0.32; 95% CI = 0.17-0.60), history of sexually transmitted infection (HR = 2.40; 95% CI = 1.09-5.26), history of substance abuse during sex (HR = 2.44; 95% CI = 1.16-5.13), and history of transactional sex (HR = 3.30; 95% CI = 1.79-6.09). Conclusions:HIV-1 incidence rates were relatively low in adult plantation workers and dependents in rural Kenya. Cohorts including higher risk populations (eg, commercial sex workers) warrant consideration for regional HIV preventive vaccine trials. Even low incidence, well-described cohorts generate valuable epidemiological clinical trial data.

Epidemiology of HIV-1 infection in agricultural plantation residents in Kericho, Kenya: preparation for vaccine feasibility studies.

Summary: A cross-sectional study was performed to determine the prevalence and risk factors for HIV-1 infection among agricultural plantation residents in Kericho, Kenya. Volunteers were recruited, interviewed, and phlebotomized for HIV-1 serologic testing. Sex-specific adjusted odds ratios were estimated using logistic regression. The overall HIV-1 prevalence was 9.9% (81/820), with prevalence in women more than twice that in men (17.4% vs 8.0%, P = 0.001). Among men, elevated HIV-1 prevalence was seen with increasing age, peaking in those older than 30 years (10.3%), marriage (10.4%), Luo tribe affiliation (23.5%), employment (8.9%), travel (11.0%), and being uncircumcised (29.2%). Among women, elevated HIV-1 prevalence was seen in those with no formal education (36.8%) and those who received goods in exchange for sex (36.0%). More than 97% of volunteers expressed a willingness to participate in future HIV-1 studies requiring semiannual visits. HIV prevention efforts have been implemented, along with further research to characterize this population for future cohort feasibility studies and HIV-1 vaccine efficacy trials.

HIV-1 infection among civilian applicants for US military service, 1985 to 2000: epidemiology and geography.

Objectives: This study examined demographic and geographic correlates of HIV‐1 prevalence among civilian applicants for US military service. Methods: HIV‐1 test results and demographic and geographic data were available for 5.3 million applicants. Results: Between October 1985 and December 2000, a total of 5,340,694 individuals applied to join one of the armed service branches of the US military. Overall, HIV‐1 prevalence was 0.80 per 1000 applicants (95% CI: 0.78‐0.82), with 4276 applicants testing positive for HIV‐1 infection. Prevalence declined over the 16‐year period from a high of 2.89 per 1000 applicants in 1985 to 0.36 per 1000 applicants in 2000. The majority of applicants (82.7%) were male, and the majority of HIV‐1 cases (89.4%) occurred in men. HIV‐1 prevalence was higher among African Americans (2.47/1000) and Hispanics (0.90/1000) than among white applicants (0.36/1000). HIV‐1 prevalence was lowest in the West North Central region of the United States (0.33/1000) and highest in the Middle Atlantic region (1.61/1000) and Puerto Rico (3.56/1000). Conclusions: Civilian applicants for US military service comprise a unique cohort for following trends in the evolving HIV‐1 epidemic.

HIV Infection and Risk Behaviors in Thai Men After Their Service in the Royal Thai Army: Informing Vaccine Cohort Development

A cohort of Royal Thai Army (RTA) conscripts was followed in civilian life after completing 2 years of military service, to determine whether such a cohort might be suitable for HIV vaccine trials. Objectives were to identify correlates of participation and to determine the occurrence of risk behaviors for HIV infection after discharge from the military. The cohort was selected from among conscripts who had participated in HIV studies from 1991 to 1993. Risk factors were surveyed at 3, 9, and 15 months after discharge (1993–1995). Change in risk was evaluated based on deviations from expected distributions of risk categories for sentinel behaviors, assessed with chi-square analysis. HIV seroconversion rates (SR) and 95% confidence intervals (CI) were calculated. A total of 380 men returned after discharge. Seven men seroconverted after discharge; the SR (95% CI) was 2.02/100 person-years (0.81–4.17). Among changes in risk were reduced visits to commercial sex workers (CSWs), more condom use with CSWs, and less alcohol use prior to CSW visits. Behaviors associated with increased risk of HIV seroconversion declined after military service. Thus, sufficient numbers of outcome events for vaccine trials may not be attained with this type of cohort. Nonetheless, these findings provide data on the dynamics of the HIV epidemic in Thailand and the development of HIV vaccine cohorts.

Detection and quantification of HIV type 1 RNA in nasopharyngeal washes from HIV-infected subjects.

Human immunodeficiency virus type 1 (HIV) RNA load was measured in paired samples of peripheral blood plasma and nasopharyngeal (NP) washes from 97 Thai subjects infected with subtype E or B. HIV RNA was quantifiable in 93% of peripheral blood plasma samples tested and was inversely correlated (rho =-0.524; p < 0.001) with CD4 absolute count. HIV RNA was quantifiable in 29% of NP samples tested, and the median value was less than that of plasma viral load. HIV RNA load in NP samples was correlated (rho = 0.388; p < 0.001) with viral load in peripheral blood. HIV RNA was not detected in NP washes from subjects with undetectable plasma viral load. Virus isolation attempts on two NP samples were negative. The results do not support local HIV production in the nasopharynx, but extend current knowledge of HIV shedding to include the NP compartment.

United States Department of Defense HIV-1 Vaccine Development in Thailand

For nearly 40 years, the AFRIMS, located in Bangkok, Thailand, has been the cornerstone of many research efforts essential for the Royal Thai Army (RTA), Thailand and the U.S. Department of Defense (DoD). The primary focus of this joint activity has been research into the prevention of endemic infectious diseases affecting both the RTA and the U.S. deployed forces in Southeast Asia.