HIV infection and risk factors among the armed forces personnel stationed in Kinshasa, Democratic Republic of Congo.

Despite recent declines in HIV incidence, sub-Saharan Africa remains the most heavily affected region in the global HIV/AIDS epidemic. Estimates of HIV prevalence in African military personnel are scarce and inconsistent. We conducted a serosurvey between June and September 2007 among 4043 Armed Forces personnel of the Democratic Republic of Congo (FARDC) stationed in Kinshasa, Democratic Republic of Congo (DRC) to determine the prevalence of HIV and syphilis infections and describe associated risk behaviours. Participants provided blood for HIV and syphilis testing and responded to a demographic and risk factor questionnaire. The prevalence of HIV was 3.8% and the prevalence of syphilis was 11.9%. Women were more likely than men to be HIV positive, (7.5% vs. 3.6% respectively, aOR: 1.66, 95% C.I: 1.21-2.28, p < 0.05). Factors significantly associated with HIV infection included gender and self-reported genital ulcers in the 12 months before date of enrollment. The prevalence of HIV in the military appears to be higher than the general population in DRC (3.8% vs. 1.3%, respectively), with women at increased risk of infection.

HLA class I diversity among rural rainforest inhabitants in Cameroon: identification of A*2612-B*4407 haplotype.

The population distribution of alleles of the classical HLA class I loci in Cameroon has not been well studied but is of particular interest given the AIDS and malarial epidemics afflicting this population. We investigated the genetic diversity of HLA-A, HLA-B and HLA-C alleles in remote populations of Cameroon. Subjects from seven small, isolated, indigenous populations (N = 274) in the rainforest of southern Cameroon were typed for HLA-A, HLA-B and HLA-C alleles using a polymerase chain reaction/sequence-specific oligonucleotide probe assay and sequence analysis. Multiple alleles of the HLA-A (N = 28), HLA-B (N = 41) and HLA-C (N = 21) loci were identified, of which A*2301[allele frequency (AF) = 12.8%], B*5802 (AF = 10.9%) and Cw*0401 (AF = 16.6%) were the most frequent individual alleles and A*02 (AF = 19.0%), B*58 (AF = 15.9%) and Cw*07 (AF = 22.4%) the most common serologically defined groups of alleles. Twenty-six (28.9%) alleles with a frequency of less than 1% (AF < 1%), 39 (43%) with a frequency of 2.0-15.0% (AF = 2.0-15.0%), three globally uncommon alleles [A*2612 (AF = 2.0%), B*4016 (AF = 0.7%) and B*4407 (AF = 1.4%)], and the A*2612-Cw*0701/06/18-B*4407 haplotype (haplotype frequency = 1.3%) were also identified. Heterozygosity values of 0.89, 0.92 and 0.89 were determined for HLA-A, HLA-B and HLA-C, respectively. The extensive allelic and haplotypic diversity observed in this population may have resulted from varied natural selective pressures on the population, as well as intermingling of peoples from multiple origins. Thus, from an anthropologic perspective, these data highlight the challenges in T-cell-based vaccine development, the identification of allogeneic transplant donors and the understanding of infectious disease patterns in different populations.

A controlled trial of nonoxynol 9 film to reduce male-to-female transmission of sexually transmitted diseases.

BACKGROUND: Nonoxynol 9 is a proved spermicide, but whether it is also a microbicide is uncertain. A truly effective vaginal microbicide would reduce the susceptibility of women to sexually transmitted diseases, including infection with the human immunodeficiency virus (HIV). METHODS: We enrolled 1292 HIV-negative female sex workers in Cameroon and enrolled them in a double-blind, placebo-controlled study in which the participants were randomly assigned to use either a film containing 70 mg of nonoxynol 9 or a placebo film, inserted into the vagina before intercourse. All of the women were provided with latex condoms and were instructed to have their male sexual partners use them. At monthly follow-up visits, we examined the women with a colposcope for genital lesions, tested endocervical specimens for gonorrhea and chlamydia infection with DNA probes, tested for HIV infection, and treated the women for curable sexually transmitted diseases. RESULTS: The rates of HIV infection (cases per 100 woman-years) were 6.7 in the nonoxynol 9 group and 6.6 in the placebo group (rate ratio, 1.0; 95 percent confidence interval, 0.7 to 1.5). The rates of genital lesions were 42.2 cases per 100 woman-years in the nonoxynol 9 group and 33.5 in the placebo group (rate ratio, 1.3; 95 percent confidence interval, 1.0 to 1.6). The rates of gonorrhea were 33.3 and 31.1 cases per 100 woman-years in the nonoxynol 9 and placebo groups, respectively (rate ratio, 1.1; 95 percent confidence interval, 0.8 to 1.4). The corresponding rates of chlamydia infection in the nonoxynol 9 group and the placebo group were 20.6 and 22.2 per 100 woman-years (rate ratio, 0.9; 95 percent confidence interval, 0.7 to 1.3). The women reported that condoms were used during 90 percent of sexual acts. CONCLUSIONS: The use of a nonoxynol 9 vaginal film did not reduce the rate of new HIV, gonorrhea, or chlamydia infection in this group of sex workers who used condoms and received treatment for sexually transmitted diseases.

PIP: The potential of nonoxynol-9 to reduce women's susceptibility to sexually transmitted diseases (STDs) was investigated in a double-blind, placebo-controlled trial conducted among 1170 HIV-negative sex workers in Cameroon. Participants were randomly assigned to receive either a film containing 70 mg of nonoxynol-9 (n = 595) or a placebo film (n = 575). Women in both groups were provided with latex condoms for their male partners. At monthly follow-up visits during the 12-month study period, colposcopy was used to examine women for genital lesions, endocervical smears were tested for gonorrhea and chlamydia, HIV testing was performed, and curable STDs were treated. Nonoxynol-9 film failed to confer any additional protection against infection with HIV, gonorrhea, or chlamydia beyond that provided by condoms alone and STD treatment. The rates of genital lesions were 42.2 cases per 100 woman-years in the nonoxynol-9 group and 33.5 in the placebo group (rate ratio (RR), 1.3; 95% confidence interval (CI), 1.0-1.6). The majority of genital lesions in the nonoxynol-9 group were external. The rates of gonorrhea were 33.3 and 31.1 cases per 100 woman-years in the nonoxynol-9 and placebo groups, respectively (RR, 1.1; 95% CI, 0.8-1.4), while those of chlamydia were 20.6 and 22.2 cases per 100 woman-years, respectively (RR, 0.9; 95% CI, 0.7-1.3). Finally, there were 6.7 cases of HIV infection per 100 woman-years in the nonoxynol-9 group and 6.6 in the placebo group (RR, 1.0; 95% CI, 0.7-1.5). Condoms were used during 90% of sexual acts.

Characteristics associated with prevalent HIV infection among a cohort of sex workers in Cameroon.

OBJECTIVE: To determine prevalence of HIV infection in a cohort of female sex workers in Cameroon, and to describe characteristics associated with HIV infection in this population. METHODS: In a cross sectional study, 2260 female sex workers in Cameroon were interviewed and screened for HIV serostatus. A standardised questionnaire was used to collect information on sociodemographic characteristics and sexual and health behaviours. RESULTS: Seropositive participants (18%) were more likely to be over age 25, have four or more children, live in Yaoundé or Douala for 5 years or less, solicit clients in their homes or on the street, have a low educational level, earn a weekly income of less than $24, and have no other occupation outside of sex work. A logistic regression model of selected sociodemographic characteristics indicated that women at particularly high odds of HIV infection were older, poorer, and new immigrants to their city of residence. CONCLUSION: This seroprevalence study found a lower HIV prevalence than had been previously reported. Although our results are different, this group is still at much higher risk of HIV infection than the population as a whole.