Serologic testing algorithm for recent HIV seroconversion in estimating incidence of HIV-1 among adults visiting a VCT centre at a Kenyan tertiary health institution.

OBJECTIVE: To determine HIV high risk groups among adults visiting Kenyatta National Hospital Voluntary Counselling and Testing Centre by use of Serologic Testing Algorithm for Recent HIV Seroconversion (STARHS). DESIGN: A cross-sectional study of adults. SETTING: Kenyatta National Hospital Voluntary and Counselling Centre. RESULTS: Of the 6,415 adults screened for antibodies to HIV at Kenyatta National Hospital VCT Centre between July 2002 and February 2003, 728 tested positive in the two HIV screening tests used at the center, indicating a prevalence of 11%. Of these seropositive cases, 355 consented to participate in the study. Using STARHS, 34 (9.6%) of the plasma samples were classified as being from individuals with recent infection (within 170 days), giving an annual estimated HIV-1 incidence in this population of 1.3 infections per 100 person-years with a 95% CI of 0.872-1.728%. Young adults had a higher rate of new infection than older adults. Young females were infected much earlier in life, with a peak age of new infections of 26 years, versus 31 years for young males. CONCLUSION: This study confirms our hypothesis that STARHS or Detuned assay can be used to determine HIV incidence in this population. The HIV high risk groups as identified by this study are young women between ages 16 to 26 years old and men between ages 45 to 55 years of age.

Traditional healers and the management of sexually transmitted diseases in Nairobi, Kenya.

To describe the role of traditional healers in STD case management, in-depth interviews were held with 16 healers (seven witchdoctors, five herbalists and four spiritual healers) in four slum areas in Nairobi, Kenya. All healers believed that STDs are sexually transmitted and recognized the main symptoms. The STD-caseload varied largely, with a median of one patient per week. Witchdoctors and herbalists dispensed herbal medication for an average of seven days, whereas spiritual healers prayed. Thirteen healers gave advice on sexual abstinence during treatment, 11 on contact treatment, four on faithfulness and three on condom use. All healers asked patients to return for review and 13 reported referring patients whose conditions persist to public or private health care facilities. Thus, traditional healers in Nairobi play a modest but significant role in STD management. Their contribution to STD health education could be strengthened, especially regarding the promotion of condoms and faithfulness.

Partner notification in the management of sexually transmitted infections in Nairobi, Kenya.

OBJECTIVE: To assess utilization of partner notification as a tool in prevention and control of Sexually transmitted infections in Nairobi City Council clinics. DESIGN: A cross-sectional study carried out between April and September 2000. SETTING: Nairobi City Council health clinics were stratified into eight administrative divisions and a total of 16 out of 54 primary health clinics with at least four STIs patients per day were selected. A standard questionnaire was administered to every fourth patient with clinical diagnosis of STIs who gave consent on exist. Sexual partners referred by index cases during the five day period from each clinic were also enrolled into the study. An additional questionnaire was administered to HCP who were managing STIs patients and their sex partners. RESULTS: Of 407 STIs patients recruited between April and September 2000, 20.6% were primary and 2% were secondary referrals giving an average referral rate of 23%. Respondents with multiple sex partners were less likely to refer their partners compared to those who had one partner (17.9% vs 82.1%, p < 0.005). Counseling of STI patients on the importance of partner referral was more effective than issuing referral cards alone (72.8% vs 56.8% % p = < 0.006). Barriers to partner notification included partners being out of town (44.6%) fear of quarrels and violence from partners (32.5%) and casual partners (15.1%) whose sex partners were unknown. CONCLUSION: Counseling and understanding of STIs patients on the need to treat all sexual partners is pivotal to the success of partner referral.

Childcare practices of commercial sex workers.

OBJECTIVE: To determine the childcare practices of commercial sex workers (CSWs). DESIGN: A descriptive cross-sectional survey was conducted between July and December 2000 during which a structured questionnaire was administered. SETTING: Kibera slum, Nairobi, Kenya. SUBJECTS: Three hundred eighty five CSWs and four focus group discussions (FGDs) held. Health cards from 126 under five years old children belonging to the respondents were reviewed for immunization status and regularity of growth monitoring. RESULTS: The mean age of the 385 CSWs surveyed was 32 +/- 7 years and mean duration of sex work was 6 +/- 4 years. The mean number of living children was 3.4 +/- 2 and 81.2% of the mothers lived with their children. Three quarters of the CSWs practised prostitution at home. The most common daily childcare activities by the mothers were food preparation (96.2%) and washing children's clothes (91.3%). Overall 96.8% of their under-five years old children were fully immunized and 80% of their under one year old children had their growth monitored monthly. About three quarters of the mothers with adolescent children educated them on HIV/STDs. Health seeking behaviour for the children was hampered by health care cost (71.4%) and consumption of alcohol by the mothers. Like other mothers, the CSWs encouraged their adolescent children to take up some adult roles such as maintaining a clean house (93.3%). However only 2.0% took time to converse or counsel the children. Focus group discussions (FGDs) with the CSWs showed that children were left unattended at night while the mothers went out in search of clients. Efforts to provide better education for the children were undermined by lack of funds (52.2%) and truancy (46.6%). One third of the study population had invested for the future maintenance of their children. CONCLUSION: There was more emphasis on physical, rather than psychological aspect of childcare. The practice of living with the children ensured that earnings from the sex trade were used for the immediate needs of the children such as food. However this practice had a negative influence on the children as the majority of the respondents conducted their sexual business at home with little or no privacy. Health seeking behaviour for the children was hampered by lack of funds and to some extent alcohol consumption by the mothers. Efforts to invest in the education of their children were undermined by lack of funds and truancy.

New insights into HIV-1 specific cytotoxic T-lymphocyte responses in exposed, persistently seronegative Kenyan sex workers.

A clearer understanding of HIV-1 specific immune responses in highly-exposed, persistently seronegative (HEPS) subjects is important in developing models of HIV-1 protective immunity. HIV-1 specific cytotoxic T-lymphocytes (CTL) have been described in a cohort of HEPS Kenyan sex workers, and recent work has further elucidated these responses. CTL specific for HIV-1 Env were found in the blood of over half the sex workers meeting criteria for HIV resistance, and in some women recognized unmapped epitopes. The proportion of women with Env-specific CTL increased with the duration of uninfected HIV exposure, suggesting that these responses were acquired over time. CD8+ lymphocyte responses directed against predefined HIV-1 CTL epitopes from various HIV-1 genes were found in the blood and genital tract of >50% resistant sex workers, at a ten-fold lower frequency than in infected subjects. The epitope specificity of CD8+ responses differs between HEPS and HIV infected women, and in HEPS the maintenance of responses appears to be dependent on persistent HIV exposure. Several HIV-1 'resistant' sex workers have become HIV infected over the past 6 years, possibly related to waning of pre-existing HIV-specific CTL, and infection has often been associated with a switch in the epitope specificity of CD8+ responses. These findings suggest that vaccine-induced protective HIV immunity is a realistic goal, but that vaccine strategies of boosting or persistent antigen may be necessary for long-lived protection.

Functional HIV-1 specific IgA antibodies in HIV-1 exposed, persistently IgG seronegative female sex workers.

Although HIV-specific cellular immune responses are found in a number of HIV highly-exposed, persistently seronegative (HEPS) cohorts, late seroconversion can occur despite pre-existing cytotoxic T lymphocytes (CTL), suggesting that a protective HIV vaccine may need to induce a broader range of HIV-specific immune responses. Low levels of HIV-specific IgA have been found in the genital tract and plasma of the majority of Nairobi HEPS sex workers and appeared to be independent of HIV-specific cellular responses. IgA purified from genital tract, saliva and plasma of most HEPS sex workers were able to neutralize infection of PBMC by a primary (NSI) clade B HIV isolate, as well as viral isolates from clades A and D, which predominate in Kenya. In addition, these IgA were able to inhibit transcytosis of infective HIV virions across a transwell model of the human mucosal epithelium in an HIV-specific manner. Preliminary work in other HEPS cohorts has suggested the recognition of different gp41 epitopes in HEPS and HIV-infected subjects. Although present at low levels, these IgA demonstrated cross-clade neutralizing activity and were able to inhibit HIV mucosal transcytosis, suggesting an important functional role in protection against HIV infection.

Human leucocyte antigen supertypes and immune susceptibility to HIV-1, implications for vaccine design.

T cell responses against HIV-1 have been identified in a number of exposed uninfected populations. We hypothesized that the ability to mount an effective T cell response is partly determined by the human leucocyte antigens (HLA) phenotype of the individual. We examined whether certain HLA supertypes were associated with differential HIV-1 susceptibility in sexually exposed adults and in the setting of mother to child HIV-1 transmission. By multivariate analysis, decreased HIV-1 infection risk was strongly associated with possession of a cluster of closely related class I HLA alleles (A2/6802 supertype) in sexually exposed adults (Hazard ratio=0.42, 95% confidence intervals (CI): 0.22-0.81, P=0.009) and perinatally exposed infants (Odds ratio=0.12, 95% CI: 0.03-0.54, P=0.006). The alleles in this HLA supertype are known in some cases, to present the same peptide epitopes (termed 'supertopes'), for T cell recognition. The identification of HIV-1 supertopes, which are associated with protection from HIV-1 infection, has important implications for the application of epitope-based HIV-l vaccines in a variety of racial groups.

Quality of sexually transmitted disease case management in Nairobi, Kenya: a comparison among different types of healthcare facilities.

BACKGROUND: In Nairobi, the prevalence for sexually transmitted diseases (STDs) among attenders at antenatal and family planning clinics is substantial, but knowledge about the quality of STD case management is scarce. GOAL: To assess quality of STD case management in Nairobi healthcare facilities. STUDY DESIGN: All the facilities in five sublocations were enumerated. In 142 facilities, 165 providers were interviewed, observed during 441 interactions with patients who had STDs, and visited by a simulated patient. RESULTS: For observations of patients with STDs, correct history-taking ranged from 60% to 92% among the various types of facilities, correct examination from 31% to 66%, and correct treatment from 30% to 75%. The percentage of correctness for all three aspects (World Health Organization prevention indicator 6) varied between 14% and 48%. Public clinics equipped for STD care performed best in all aspects, whereas treatment was poorest in pharmacies and private clinics. The providers trained in STD management performed better than those without training. CONCLUSIONS: Quality of STD case management was unsatisfactory except in public STD-equipped clinics. This indicates the need for improvement by interventions such as further training in syndromic management, improved supervision, and the introduction of prepackaged syndromic management kits.

Hormonal contraception and risk of sexually transmitted disease acquisition: results from a prospective study.

OBJECTIVES: To examine the relationship between use of oral contraceptive pills or depot medroxyprogesterone acetate and sexually transmitted disease acquisition. STUDY DESIGN: Prospective cohort included 948 Kenyan prostitutes. Multivariate Andersen-Gill proportional hazards models were constructed, adjusting for sexual behavioral and demographic variables. RESULTS: When compared with women who were using no contraception, users of oral contraceptive pills were at increased risk for acquisition of chlamydia (hazard ratio, 1.8; 95% confidence interval, 1.1-2.9) and vaginal candidiasis (hazard ratio, 1.5; 95% confidence interval, 1.2-1.9) and at decreased risk for bacterial vaginosis (hazard ratio, 0.8; 95% confidence interval, 0.7-1.0). Women using depot medroxyprogesterone acetate had significantly increased risk of chlamydia infection (hazard ratio, 1.6; 95% confidence interval, 1.1-2.4) and significantly decreased risk of bacterial vaginosis (hazard ratio, 0.7; 95% confidence interval, 0.5-0.8), trichomoniasis (hazard ratio, 0.6; 95% confidence interval, 0.4-1.0), and pelvic inflammatory disease (hazard ratio, 0.4; 95% confidence interval, 0.2-0.7). Consistent condom use was associated with significantly decreased risk of gonorrhea, chlamydia, genital ulcer disease, bacterial vaginosis, and pelvic inflammatory disease. CONCLUSIONS: The use of oral or injectable hormonal contraception altered susceptibility to sexually transmitted diseases, which may in turn influence transmission of human immunodeficiency virus type 1. Consistent condom use was protective with regards to sexually transmitted disease and should be encouraged for the prevention of sexually transmitted disease and human immunodeficiency virus type 1 among women who use hormonal contraception.

Sexually transmitted infections and vaginal douching in a population of female sex workers in Nairobi, Kenya.

OBJECTIVE: To assess the association between vaginal douching and sexually transmitted infections (STI) among a group of female sex workers (FSWs) in Nairobi, Kenya. METHODS: This study was part of a randomised, placebo controlled trial of monthly prophylaxis with 1 g of azithromycin to prevent STIs and HIV infection in a cohort of Nairobi FSWs. Consenting women were administered a questionnaire and screened for STIs. RESULTS: The seroprevalence of HIV-1 among 543 FSWs screened was 30%. HIV infection was significantly associated with bacterial vaginosis (BV), trichomoniasis, gonorrhoea, and the presence of a genital ulcer. Regular douching was reported by 72% of the women, of whom the majority inserted fluids in the vagina, generally after each sexual intercourse. Water with soap was the fluid most often used (81%), followed by salty water (18%), water alone (9%), and a commercial antiseptic (5%). Douching in general and douching with soap and water were significantly associated with bacterial vaginosis (p = 0.05 and p = 0.04 respectively). There was a significant trend for increased frequency of douching and higher prevalence of BV. There was no direct relation observed between douching and risk for HIV infection or other STIs. CONCLUSION: The widespread habit of douching among African female sex workers was confirmed. The association between vaginal douching and BV is of concern, given the increased risk of HIV infection with BV, which has now been shown in several studies. It is unclear why we could not demonstrate a direct association between douching and HIV infection. Further research is required to better understand the complex relation between douching, risk for bacterial vaginosis, and risk for HIV and other STIs.

Female condom introduction and sexually transmitted infection prevalence: results of a community intervention trial in Kenya.

OBJECTIVE: To measure the impact on sexually transmitted infection (STI) prevalence of a female condom introduction and risk-reduction program at Kenyan agricultural sites. DESIGN: We conducted a cluster-randomized trial to determine whether a replicable, community-level intervention would reduce STI prevalence. METHODS: Six matched pairs of tea, coffee and flower plantations were identified. The six intervention sites received an information/motivation program with free distribution of female and male condoms, and six control sites received only male condoms and related information. Participants were tested for cervical gonorrhea and chlamydia by ligase chain reaction on urine specimens, and vaginal trichomoniasis by culture, at baseline, 6 and 12 months. RESULTS: Participants at intervention (n = 969) and control sites (n = 960) were similar; baseline STI prevalence was 23.9%. Consistent male condom use was more than 20% at 12 months. Consistent female condom use was reported by 11 and 7% of intervention site women at 6 and 12 months. Unadjusted STI prevalence was 16.5 and 17.4% at 6 months, and 18.3 and 18.5% at 12 months, at the intervention and control sites, respectively. Logistic regression models confirmed the null effect of the female condom intervention. CONCLUSIONS: Female condom introduction did not enhance STI prevention at these sites. It is unclear which aspects of the intervention -- STI education, condom promotion, case management -- were associated with decreased STI prevalence from baseline to follow-up.

CD8(+) lymphocytes respond to different HIV epitopes in seronegative and infected subjects.

HIV-1-specific cytotoxic T-lymphocyte (CTL) responses have been detected at a low frequency in many HIV-1-exposed, persistently seronegative (HEPS) subjects. However, it is unclear how CTLs could protect against HIV acquisition in HEPS subjects, when high levels of circulating CTL fail to prevent disease progression in most seropositive subjects. To address this issue we studied CD8(+) lymphocyte responses to a panel of HIV-1 CTL epitopes in 91 HEPS and 87 HIV-1-infected Nairobi sex workers. HIV-specific responses in seropositive women focused strongly on epitopes rarely or never recognized in HEPS subjects, who targeted epitopes that were subdominant or unrecognized in infected women. These differences in epitope specificity were restricted by only those HLA class I alleles that are associated with a reduced risk of HIV-1 infection in this cohort. Late seroconversion in HEPS donors was associated with a switch in epitope specificity and/or immunodominance to those epitopes preferentially recognized by HIV-1-infected women. The likelihood of detecting HIV-1-specific responses in HEPS women increased with the duration of viral exposure, suggesting that HIV-1-specific CD8(+) responses are acquired over time. The association between differential recognition of distinct CTL epitopes and protection from HIV-1 infection may have significant implications for vaccine design.

Quality of health education during STD case management in Nairobi, Kenya.

Quality of health education during STD case management in Nairobi was assessed in 142 healthcare facilities, through interviews of 165 providers, observation of 441 STD patients managed by these providers, and 165 visits of simulated patients. For observations, scores were high for education on contact treatment (74-80%) and compliance (83%), but unsatisfactory for counselling (52%) and condom promotion (20-41%). The World Health Organization (WHO) indicator for STD case management Prevention Indicator 7 (PI7) (condom promotion plus contact treatment) was poor (38%). Public clinics strengthened for STD care generally performed best, whereas pharmacies and mission clinics performed worst. Compared with observations, scores were higher during interviews and lower during simulated patient visits, indicating that knowledge was not fully translated into practice. Interventions to improve the presently unsatisfactory service quality would be wide distribution of health education materials, ongoing training and supervision of providers, implementation of STD management checklists, and the introduction of pre-packaged kits for STD management.

Vitamin A and risk of HIV-1 seroconversion among Kenyan men with genital ulcers.

BACKGROUND: Vitamin A is involved in normal immune function and the maintenance of mucosal integrity through complex effects on cellular differentiation. OBJECTIVE: We sought to determine whether serum vitamin A levels were associated with altered susceptibility to primary infection with HIV-1 in men with high-risk sexual behaviour and genital ulcers who presented for treatment at an STD clinic in Nairobi, Kenya. METHODS: HIV-1 seronegative men were prospectively followed. Vitamin A levels at study entry were compared among 38 men who HIV-1 seroconverted versus 94 controls who remained HIV seronegative. RESULTS: Vitamin A deficiency (retinol less than 20 microg/dl) was very common and was present in 50% of HIV-1 seroconverters versus 76% of persistent seronegatives. Seroconversion was independently associated with a retinol level greater than 20 microg/dl (HR 2.43, 95% CI 1.25-4.70, P = 0.009), and a genital ulcer aetiology caused by Haemophilus ducreyi (HR 3.49, 95% CI 1.03-11.67, P = 0.04). Circumcision was independently associated with protection (HR 0.46, 95% CI 0.23-0.93, P = 0.03). CONCLUSION: Vitamin A deficiency was not associated with an increased risk of HIV-1 infection among men with concurrent STD. A decreased risk of HIV-1 seroconversion was independently associated with lower retinol levels. The effects of vitamin A on macrophage and lymphoid cell differentiation may paradoxically increase mucosal susceptibility to HIV-1 in some vulnerable individuals, such as men with genital ulcers. Lack of circumcision and chancroid are confirmed as important co-factors for heterosexual HIV-1 transmission. The role of vitamin A in heterosexual HIV-1 transmission requires further study.

Selenium deficiency is associated with shedding of HIV-1--infected cells in the female genital tract.

OBJECTIVE: To assess the relation between selenium deficiency and vaginal or cervical shedding of HIV-1-infected cells. DESIGN: Cross-sectional study of 318 HIV-1 seropositive women in Mombasa, Kenya. METHODS: Vaginal and cervical swab specimens were tested for the presence of HIV-1 DNA by polymerase chain reaction. Multivariate logistic regression models, adjusting for CD4 count and vitamin A deficiency, were used. RESULTS: Selenium deficiency (defined as levels <85 microg/L) was observed in 11% of the study population. In unstratified multivariate analyses, there was no significant association between selenium deficiency and vaginal or cervical shedding. In stratified analyses, however, significant associations became apparent after excluding women with predictors of shedding with strong local effects on the genital tract mucosa. Among women who did not use oral contraceptives and who did not have vaginal candidiasis, selenium deficiency was significantly associated with vaginal shedding (adjusted odds ratio [AOR] 2.9, 95% confidence interval [CI] 1.0--8.8, p =.05). Effect modification was also observed in the relation between selenium deficiency and cervical shedding, with a significant association seen among those women who were not using oral contraceptive pills or depot medroxyprogesterone acetate and who did not have Neisseria gonorrhoeae infection (AOR 2.8, 95% CI 1.1--7.0, p =.02). CONCLUSIONS: We found selenium deficiency to be associated with a nearly threefold higher likelihood of genital mucosal shedding of HIV-1--infected cells, suggesting that deficiency may increase the infectiousness of women with HIV-1. Nutritional interventions to prevent HIV-1 transmission warrant investigation.

Sequence and peptide-binding motif for a variant of HLA-A*0214 (A*02142) in an HIV-1-resistant individual from the Nairobi Sex Worker cohort.

As part of the ongoing study of natural HIV-1 resistance in the women of the Nairobi Sex Workers' study, we have examined a resistance-associated HLA class I allele at the molecular level. Typing by polymerase chain reaction using sequence-specific primers determined that this molecule is closely related to HLA-A*0214, one of a family of HLA-A2 supertype alleles which correlate with HIV-1 resistance in this population. Direct nucleotide sequencing shows that this molecule differs from A*0214, having a silent nucleotide substitution. We therefore propose to designate it HLA-A*02142. We have determined the peptide-binding motif of HLA-A*0214/02142 by peptide elution and bulk Edman degradative sequencing. The resulting motif, X-[Q,V]-X-X-X-K-X-X-[V,L], includes lysine as an anchor at position 6. The data complement available information on the peptide-binding characteristics of this molecule, and will be of use in identifying antigenic peptides from HIV-1 and other pathogens.

Validation of a modified commercial enzyme-linked immunoassay for detection of human immunodeficiency virus type 1 immunoglobulin G antibodies in saliva.

This study was performed to evaluate the performance of a saliva collection device (OmniSal) and an enzyme-linked immunoassay (EIA) designed for use on serum samples (Detect HIV1/2) to detect human immunodeficiency virus type 1 (HIV-1) antibodies in the saliva of high-risk women in Mombasa, Kenya. The results of the saliva assay were compared to a "gold standard" of a double-EIA testing algorithm performed on serum. Individuals were considered HIV-1 seropositive if their serum tested positive for antibodies to HIV-1 by two different EIAs. The commercial serum-based EIA was modified to test the saliva samples by altering the dilution and lowering the cutoff point of the assay. Using the saliva sample, the EIA correctly identified 102 of the 103 seropositive individuals, yielding a sensitivity of 99% (95% confidence interval [CI], 94 to 100%), and 96 of the 96 seronegative individuals, yielding a specificity of 100% (95% CI, 95 to 100%). In this high-risk population, the positive predictive value of the assay was 100% and the negative predictive value was 99%. We conclude that HIV-1 antibody testing of saliva samples collected with this device and tested by this EIA is of sufficient sensitivity and specificity to make this protocol useful in epidemiological studies.

Treatment of cervicitis is associated with decreased cervical shedding of HIV-1.

OBJECTIVE: To determine whether cervical mucosal shedding of HIV-1 RNA and HIV-1 infected cells decreases following successful treatment of cervicitis. DESIGN: Prospective interventional study. SETTING: Sexually Transmitted Infections Clinic, Coast Provincial General Hospital, Mombasa, Kenya. PARTICIPANTS: Thirty-six HIV-1 seropositive women with cervicitis: 16 with Neisseria gonorrhoeae, seven with Chlamydia trachomatis, and 13 with non-specific cervicitis. INTERVENTIONS: Treatment of cervicitis. MAIN OUTCOME MEASURES: Levels of total (cell-free and cell-associated) HIV-1 RNA and presence of HIV-1 DNA (a marker for infected cells) in cervical secretions before and after resolution of cervicitis. RESULTS: After treatment of cervicitis, the median HIV-1 RNA concentration in cervical secretions was reduced from 4.05 to 3.24 log10 copies/swab (P = 0.001). Significant decreases in cervical HIV-1 RNA occurred in the subgroups with N. gonorrhoeae (3.94 to 3.28 log10 copies/swab; P = 0.02) and C. trachomatis (4.21 to 3.19 log10 copies/swab; P = 0.02). Overall, the prevalence of HIV-1 infected cells in cervical secretions also decreased after treatment, from 67% to 42% (odds ratio, 2.8; 95% confidence interval, 1.3-6.0; P = 0.009). Detection of infected cells was associated with higher mean HIV-1 RNA levels (4.04 versus 2.99 log10 copies/swab; P< 0.0001). CONCLUSIONS: Effective treatment of cervicitis resulted in significant decreases in shedding of HIV-1 virus and infected cells in cervical secretions. Treatment of sexually transmitted diseases may be an important means of decreasing the infectivity of HIV-1 seropositive women by reducing exposure to HIV-1 in genital secretions.