Increased levels of HIV-1-infected cells in endocervical secretions after the luteinizing hormone surge.

Levels of HIV-1 RNA in endocervical specimens fluctuate with the menstrual cycle, suggesting that cell-free HIV-1 levels may vary during the cycle, which could influence infectivity. Here, we examined daily changes in endocervical HIV-1-infected cells during 1 cycle. There were significant positive associations between the number of days from the luteinizing hormone surge and the number of HIV-1 DNA copies/swab (P = 0.001) and the number of total cells/swab (P < 0.001) in endocervical specimens. These data suggest that sampling of cell-associated endocervical HIV-1 increases after the periovulatory period, which could result in increased exposure to HIV-1-infected cells during sexual contact.

Relationship between markers of HIV-1 disease progression and serum beta-carotene concentrations in Kenyan women.

Observational studies have suggested that low serum beta-carotene concentrations may influence HIV-1 disease progression. However, randomized trials have not demonstrated beneficial effects of beta-carotene supplementation. To understand this discrepancy, we conducted a cross-sectional study among 400 HIV-1-seropositive women in Mombasa, Kenya, to correlate serum beta-carotene concentrations with several measures of HIV-1 disease severity. beta-Carotene concentrations were significantly associated with biologic markers of HIV-1 disease progression (CD4 count, HIV-1 plasma viral load, serum C-reactive protein [CRP] concentration, and serum albumin level). In multivariate analysis, beta-carotene concentrations below the median were associated with elevated CRP (>10 mg/l, adjusted odds ratio [aOR] 3.32, 95% confidence interval [CI] 1.99-5.53, P<0.001) and higher HIV-1 plasma viral load (for each log(10) copies/mL increase, aOR 1.38, 95% CI 1.01-1.88, P=0.04). In the context of negative findings from randomized trials of beta-carotene supplementation in HIV-1-seropositive individuals, these results suggest that low beta-carotene concentrations primarily reflect more active HIV-1 infection rather than a deficiency amenable to intervention.

No evidence for rapid subtype C spread within an epidemic in which multiple subtypes and intersubtype recombinants circulate.

There are multiple subtypes of HIV-1 circulating worldwide, but recently, subtype C has become highly prevalent, particularly in certain geographic regions. It is unclear whether the dominance of subtype C or other subtypes is due to increased fitness of certain subtypes for transmission, or a founder effect in new, rapidly growing epidemics. To examine whether the prevalence of one subtype increases over the course of an expanding epidemic that includes several circulating subtypes, we examined the distribution of HIV-1 subtypes in Kenya from 1986 to 2000. We found no evidence for an increase in the prevalence of subtype C, which remained low throughout this approximately 15-year period. Interestingly, the percentage of subtype D present in the population decreased significantly over that period, with a slight increase in subtype A. Throughout that period, intersubtype recombinant viruses were detected, including at the early stages of the epidemic. This latter finding suggests that reinfection may have occurred in high-risk groups early in the epidemic, leading to intersubtype recombinant viruses that underwent secondary spread.

Female-to-male infectivity of HIV-1 among circumcised and uncircumcised Kenyan men.

BACKGROUND: A lack of male circumcision has been associated with increased risk of human immunodeficiency virus type 1 (HIV-1) acquisition in a number of studies, but questions remain as to whether confounding by behavioral practices explains these results. The objective of the present study was to model per-sex act probabilities of female-to-male HIV-1 transmission (i.e., infectivity) for circumcised and uncircumcised men, by use of detailed accounts of sexual behavior in a population with multiple partnerships. METHODS: Data were collected as part of a prospective cohort study of HIV-1 acquisition among 745 Kenyan truck drivers. Sexual behavior with wives, casual partners, and prostitutes was recorded at quarterly follow-up visits. Published HIV-1 seroprevalence estimates among Kenyan women were used to model HIV-1 per-sex act transmission probabilities. RESULTS: The overall probability of HIV-1 acquisition per sex act was 0.0063 (95% confidence interval, 0.0035-0.0091). Female-to-male infectivity was significantly higher for uncircumcised men than for circumcised men (0.0128 vs. 0.0051; P=.04). The effect of circumcision was robust in subgroup analyses and across a wide range of HIV-1 prevalence estimates for sex partners. CONCLUSIONS: After accounting for sexual behavior, we found that uncircumcised men were at a >2-fold increased risk of acquiring HIV-1 per sex act, compared with circumcised men. Moreover, female-to-male infectivity of HIV-1 in the context of multiple partnerships may be considerably higher than that estimated from studies of HIV-1-serodiscordant couples. These results may explain the rapid spread of the HIV-1 epidemic in settings, found throughout much of Africa, in which multiple partnerships and a lack of male circumcision are common.

Micronutrient supplementation increases genital tract shedding of HIV-1 in women: results of a randomized trial.

To test the hypothesis that micronutrient supplementation decreases genital HIV-1 shedding, a double-blind, randomized, placebo-controlled trial of 6 weeks of multivitamin plus selenium supplementation vs. placebo was conducted among 400 HIV-1-seropositive, nonpregnant, antiretroviral-naive women in Mombasa, Kenya. Primary outcome measures included cervical and vaginal shedding of HIV-1-infected cells and RNA. Secondary outcomes included plasma viral load and CD4 count. Surprisingly, the odds of detection of vaginal HIV-1-infected cells were 2.5-fold higher (P = 0.001) and the quantity of HIV-1 RNA in vaginal secretions was 0.37 log10 copies/swab higher (P = 0.004) among women who received micronutrients in comparison to placebo, even after adjustment for potential confounders including baseline HIV-1 shedding and CD4 count. The increase in vaginal HIV-1 shedding was greatest among women who had normal baseline selenium levels. Micronutrient supplementation resulted in higher CD4 (+23 cells/microL, P = 0.03) and CD8 (+74 cells/microL, P = 0.005) counts compared with placebo but did not alter the plasma viral load. In this randomized trial, micronutrients resulted in higher levels of genital HIV-1 shedding compared with placebo. The potential benefit of micronutrient supplementation in HIV-1-seropositive women should be considered in relation to the potential for increased infectivity.

Association of levels of HIV-1-infected breast milk cells and risk of mother-to-child transmission.

Understanding how the level of human immunodeficiency virus type 1 (HIV-1)-infected breast milk cells (BMCs) affects HIV transmission via breast-feeding can shed light on the mechanism of infection and aid in establishing effective interventions. The proportion of infected cells to total cells was measured in serial breast milk samples collected from 291 HIV-1-infected women in Nairobi, Kenya, by use of real-time DNA polymerase chain reaction amplification of BMCs. The number of infected BMCs per million cells was associated with levels of cell-free viral RNA in breast milk (R=.144; P=.032), levels of cell-free virus in blood plasma (R=.365; P<.001), and the detection of proviral DNA in cervical and vaginal secretions (P<.001 and P = .030, respectively). The number of infected BMCs per million cells was lower in colostrum or early milk than in mature milk (P<.001). Previous studies demonstrated that the concentration of BMCs varies throughout lactation, and we used these data to transform infected BMCs per million cells to infected BMCs per milliliter. The estimated concentration of infected BMCs per milliliter was higher in colostrum or early milk than in mature milk (P<.001). Each log10 increase in infected BMCs per milliliter was associated with a 3.19-fold-increased risk of transmission (P=.002), after adjustment for cell-free virus in plasma (hazard ratio [HR], 2.09; P=.03) and breast milk (HR, 1.01; P=1.00). This suggests that infected BMCs may play a more important role in transmission of HIV via breast-feeding than does cell-free virus.

Cyclic shedding of HIV-1 RNA in cervical secretions during the menstrual cycle.

The association between hormone fluctuations during the menstrual cycle and human immunodeficiency virus type 1 (HIV-1) RNA shedding in cervical and vaginal secretions was examined daily for 17 HIV-1-seropositive women, for the duration of 1 cycle. Serum levels of RNA were evaluated 3 times/week. A marginally significant positive correlation between serum levels of progesterone and serum levels of HIV-1 RNA (P=.04) was observed. Cervical virus levels were significantly correlated with the number of days from the midcycle surge in luteinizing hormone (LH) (P=.008). The lowest levels of cervical HIV-1 RNA were present at the LH surge, and this nadir was followed by an increase in virus levels that reached a maximum before the start of menses. In contrast, there was no significant association between the number of days from the LH surge and the level of HIV-1 RNA in vaginal secretions (P=.4). These data support the hypothesis that the level of HIV-1 RNA in cervical secretions is influenced by the menstrual cycle, and they suggest that the risk of heterosexual transmission of HIV-1 may increase as menses is approached.

Risk of HIV-1 in rural Kenya: a comparison of circumcised and uncircumcised men.

BACKGROUND: Most studies that have found an association between uncircumcised status and infection with human immunodeficiency virus type 1 (HIV-1) have compared participants from various demographic backgrounds, among which the prevalence of other risk factors might have varied. We report findings from a study conducted among men within a single ethnic community in which circumcision was dictated by the religious denomination to which the men belonged. METHODS: Of the 1217 eligible men, we included in the analysis 845 who gave blood samples for HIV-1 testing and who were confirmed as either fully circumcised (n = 398) or uncircumcised (n = 447). The seroprevalence of HIV-1 was compared between the 2 groups. RESULTS: All correlates of HIV-1 prevalence that we measured were distributed similarly between circumcised and uncircumcised men. The seroprevalence of HIV-1 was 30% among the uncircumcised men and 20% among the circumcised men. Among uncircumcised men, HIV-1 seroprevalence was similar between men from circumcising denominations (31%; n = 111) and noncircumcising denominations (30%; n = 336). The crude prevalence ratio for HIV infection associated with not being circumcised was 1.5 (95% confidence interval = 1.2-2.0); and adjustment for other measured risk factors for HIV-1 infection had little impact on this result. CONCLUSION: Our study provides evidence that circumcision is associated with a reduced risk of HIV-1 infection.

Human herpesvirus 8 seroconversion in Kenyan women by enzyme-linked immunosorbent assay and immunofluorescence assay.

BACKGROUND: Human herpesvirus 8 (HHV-8) antibody tests vary in reported sensitivity and specificity, depending on the population tested and the assay. OBJECTIVE: The purpose of this study was to compare the ability to detect seroconversion to HHV-8 in a cohort of HHV-8 seronegative female commercial sex workers in Kenya using three tests: HHV-8 viral lysate-based enzyme-linked immunosorbent assay (ELISA), an immunofluorescence assay for HHV-8 lytic antigens (IFA-lytic) and IFA for latent nuclear antigens (IFA-LANA). STUDY DESIGN: By ELISA, 16 women from a prospective cohort of commercial sex workers were identified as seroconverting to HHV-8. A total of 124 post-enrollment samples from these 16 women as well as the enrollment samples were tested for HHV-8 antibodies by all three assays to monitor seroconversion. RESULTS: Of 16 women with apparent seroconversion by ELISA, 8 had a rise in IFA-lytic titers either concomitant with or prior to the first positive ELISA sample and no initial LANA by IFA. Five of the 16 women were IFA-LANA positive at entry, indicating prior infection with HHV-8. Three women had no evidence of seroconversion by either IFA-lytic or IFA-LANA and two of these three had increased ELISA reactivity concomitant with HIV-1 infection. CONCLUSIONS: Conversion from a negative to a positive ELISA result for HHV-8 antibody indicated seroconversion in only half of the study cohort of 16 women when IFA-lytic and IFA-LANA results were considered. The IFA-lytic assay was more sensitive than ELISA for early antibody responses. The IFA-LANA was positive in some women who had neither IFA-lytic nor ELISA antibodies suggesting it may be a marker for latent infections. Presumptive identification of incident HHV-8 infection by ELISA screening followed by IFA-lytic testing to confirm the positive test and IFA-LANA to rule out prior infection provides the most accurate documentation of HHV-8 seroconversion.

Vitamin A supplementation and genital shedding of herpes simplex virus among HIV-1-infected women: a randomized clinical trial.

Cross-sectional analyses have associated vitamin A deficiency with genital shedding of herpes simplex virus (HSV) among human immunodeficiency virus type 1 (HIV-1)-infected women. A randomized clinical trial of vitamin A supplementation given daily for 6 weeks was conducted among 376 women in Mombasa, Kenya, who were coinfected with HSV-2 and HIV-1. At follow-up, there was no significant difference in the detection of genital HSV DNA between women receiving vitamin A supplementation and women receiving placebo (40% vs. 44%, respectively; P = .5) Among women shedding HSV, there was no significant difference in the mean HSV DNA quantity between the group that received vitamin A supplementation and the group that received placebo (4.51 vs. 4.67 log10 copies/swab; P = .6). HSV shedding was associated with significantly higher vaginal and cervical HIV-1 shedding, even after controlling for the plasma HIV-1 load and the CD4 count. Vitamin A supplementation is unlikely to decrease HSV shedding and infectivity.

Identification of modifiable factors that affect the genetic diversity of the transmitted HIV-1 population.

BACKGROUND: Our previous studies have shown that the majority of African women were infected with multiple HIV-1 genetic variants, while in the remaining women only a single viral genotype was detected early in infection. Infection with multiple viral variants was associated with higher plasma HIV-1 RNA levels and faster CD4 T-cell decline. METHOD: Socio-behavioral characteristics, use of hormonal contraceptives, and the presence of sexually transmitted diseases were prospectively assessed at approximately monthly intervals around the time of HIV-1 acquisition in female sex workers in Kenya. We assessed the relationship between these factors and HIV-1 genetic complexity early in infection. RESULTS: One hundred and fifty-six women were included in this analysis, of whom 89 had multiple viral genotypes and 67 had a single genotype at primary infection. Women with multiple variants were more likely to have a genital tract infection [odds ratio (OR), 4.7; 95% confidence interval (CI), 1.4-18.1] or to be using hormonal contraceptives (OR, 2.7; 95% CI, 1.3-5.6) at the time of their infection than those with a single variant. In multivariate analyses, these factors were independent predictors of early HIV-1 genetic complexity, and the presence of multiple viral variants early in infection remained significantly associated with a higher steady state plasma HIV-1 RNA level. CONCLUSION: The presence of genital tract infections and hormonal contraceptive use at the time of transmission were associated with the acquisition of multiple HIV-1 variants.

The effect of hormonal contraception on genital tract shedding of HIV-1.

OBJECTIVE: A previous cross-sectional study reported that hormonal contraception may be associated with increased infectivity in HIV-1 infected women. We conducted a prospective study to determine if cervical shedding of HIV-1 increased after initiating hormonal contraception. DESIGN: Shedding of HIV-1 DNA (a marker of HIV-1 infected cells) and HIV-1 RNA were measured before and after initiating hormonal contraception. METHODS: HIV-1 seropositive women were recruited from a Kenyan family planning clinic. At baseline, cervical secretions were collected for HIV-1 DNA and RNA assays in women initiating hormonal contraception; follow-up samples were collected a median of 64 days later. RESULTS: One-hundred and one women chose depot medroxyprogesterone (Depo), 53 chose low-dose oral contraceptives (OC), seven high-dose OC, and 52 progesterone-only OC. At follow-up, there was a significant increase in the prevalence of cervical HIV-1 DNA detection [from 42% to 52%, odds ratio (OR), 1.62; 95% confidence interval (CI), 1.03-2.63) for all hormonal contraception combined, and a trend for an increase for each individual type. Although the prevalence of cervical HIV-1 RNA increased slightly (from 82% to 86%; OR, 1.56; 95% CI, 0.83-3.03), the concentration of cervical HIV-1 RNA did not change significantly overall (from 2.81 to 2.84 log10 copies/swab; P = 0.77) or for individual contraception types. CONCLUSIONS: A modest but significant increase in shedding of HIV-1 DNA but not of HIV-1 RNA was detected after starting hormonal contraception. Our results may have important implications regarding the infectivity of women using hormonal contraception, and highlight the need for epidemiologic studies of transmission rates from women using and not using hormonal contraception.

Injectable contraceptive use and genital ulcer disease during the early phase of HIV-1 infection increase plasma virus load in women.

We examined the association between host factors present near the time of human immunodeficiency virus type 1 (HIV-1) acquisition and subsequent virus loads, in a prospective cohort study of women in Mombasa, Kenya. Women were prospectively followed monthly before HIV-1 infection. One hundred sixty-one commercial sex workers who became infected with HIV-1 were followed for a median of 34 months, and 991 plasma samples collected > or =4 months after infection were tested for HIV-1 RNA. The median virus set point at 4 months after infection was 4.46 log10 copies/mL, and the average virus load increase during subsequent follow-up was 0.0094 log10 copies/mL/month. In a multivariate analysis that controlled for sexual behavior, the use of the injectable contraceptive depot medroxyprogesterone acetate (DMPA) at the time of HIV-1 infection was associated with a higher virus set point, and the presence of genital ulcer disease (GUD) during the early phase of HIV-1 infection was associated with greater change in virus load during follow-up. These findings suggest that, in women, the use of DMPA and the presence of GUD during the early phase of HIV-1 infection may influence the natural course of infection.

Use of serum retinol-binding protein for prediction of vitamin A deficiency: effects of HIV-1 infection, protein malnutrition, and the acute phase response.

BACKGROUND: Serum retinol is the most commonly used indicator of vitamin A status. Retinol is transported in a 1-to-1 complex with retinol-binding protein (RBP). RBP is easy and inexpensive to measure, and studies have shown a high correlation between concentrations of RBP and concentrations of retinol. The performance of RBP in the context of infection or protein malnutrition, however, has not been evaluated. OBJECTIVE: Our aim was to determine whether RBP is a good surrogate measure for retinol in the context of HIV-1 infection, protein malnutrition, and the acute phase response. DESIGN: The relation between RBP and retinol was examined in a cross-sectional study of 600 Kenyan women. RESULTS: There was a high correlation between concentrations of RBP and those of retinol (r = 0.88). When equimolar cutoffs were used, RBP predicted marginal vitamin A status (retinol < 1.05 micro mol/L) with 93% sensitivity and 75% specificity and vitamin A deficiency (retinol < 0.70 micro mol/L) with 91% sensitivity and 94% specificity. Similarly high sensitivities and specificities were found among subgroups with HIV-1 infection, a positive acute phase response, and protein malnutrition. Protein malnutrition and a positive acute phase response were common, especially among HIV-1-infected women, and were independently and synergistically associated with lower RBP concentrations. CONCLUSIONS: Equimolar RBP cutoffs predict vitamin A deficiency with high sensitivity and specificity, even in the context of infection and protein malnutrition. Like retinol, RBP may not accurately identify true vitamin A status under all conditions, because the acute phase response and protein malnutrition depress RBP concentrations. However, RBP may be a simple, inexpensive tool for assessment of vitamin A deficiency in population studies.

Infection with multiple human immunodeficiency virus type 1 variants is associated with faster disease progression.

Human immunodeficiency virus type 1 (HIV-1)-infected individuals develop a genetically diverse virus population over time, but often only a limited number of viral variants are transmitted from a chronic carrier to a newly infected person. Interestingly, many women but few men are infected by multiple HIV-1 variants from a single partner. To determine whether the complexity of the infecting virus population influences clinical outcome, we examined viral diversity in the HIV-1 envelope sequences present at primary infection in 156 women from Kenya for whom we had follow-up data on viral RNA levels and CD4 T-cell counts. Eighty-nine women had multiple viral genotypes, while 67 women had a single genotype at primary infection. Women who acquired multiple viral genotypes had a significantly higher viral load (median, 4.84 versus 4.64 log(10) copies/ml, P = 0.04) and a significantly lower CD4(+)-T-cell count (median, 416 versus 617 cells/mm(3), P = 0.01) 4 to 24 months after infection compared to women who were infected with a single viral genotype. These studies suggest that early HIV-1 genetic diversity is linked to faster disease progression.

Comparison of human immunodeficiency virus type 1 viral loads in Kenyan women, men, and infants during primary and early infection.

Steady-state levels of human immunodeficiency virus type 1 (HIV-1) RNA in plasma reached at approximately 4 months postinfection are highly predictive of disease progression. Several studies have investigated viral levels in adults or infants during primary and early infection. However, no studies have directly compared these groups. We compared differences in peak and set point plasma HIV-1 RNA viral loads among antiretrovirus-naive Kenyan infants and adults for whom the timing of infection was well defined. Peak and set point viral loads were significantly higher in infants than in adults. We did not observe any gender-specific differences in viral set point in either adults or infants. However, infants who acquired HIV-1 in the first 2 months of life, either in utero, intrapartum, or through early breast milk transmission, had significantly higher set point HIV-1 RNA levels than infants who were infected after 2 months of age through late breast milk transmission or adults who were infected through heterosexual transmission.

Breast-milk infectivity in human immunodeficiency virus type 1-infected mothers.

Human immunodeficiency virus type 1 (HIV-1) is transmitted through blood, genital secretions, and breast milk. The probability of heterosexual transmission of HIV-1 per sex act is.0003-.0015, but little is known regarding the risk of transmission per breast-milk exposure. We evaluated the probability of breast-milk transmission of HIV-1 per liter of breast milk ingested and per day of breast-feeding in a study of children born to HIV-1-infected mothers. The probability of breast-milk transmission of HIV-1 was.00064 per liter ingested and.00028 per day of breast-feeding. Breast-milk infectivity was significantly higher for mothers with more-advanced disease, as measured by prenatal HIV-1 RNA plasma levels and CD4 cell counts. The probability of HIV-1 infection per liter of breast milk ingested by an infant is similar in magnitude to the probability of heterosexual transmission of HIV-1 per unprotected sex act in adults.