A case control study was performed to determine the effects of HIV-1-specific cellular immune responses on the odds of acquiring a second HIV-1 infection (superinfection). Changes in the frequency of cytokine-producing or cytolytic CD8+ or CD4+ T cells were not associated with significant alterations in the odds of superinfection, suggesting that HIV-1 specific cellular immune responses at the level induced by chronic infection do not appear to significantly contribute to protection from HIV-1 superinfection.
doi:10.1097/QAD.0b013e3283509a0b
PMCID: PMC3511787
PMID: 22210637
HIV-1; cellular immunity; T cells; superinfection; re-infection
Background
Herpes simplex virus type 2 (HSV-2) is an important cause of genital ulcers and can increase HIV-1 transmission risk. Our objective was to determine the incidence and correlates of HSV-2 infection in HIV-1-seronegative Kenyan men reporting high-risk sexual behavior, compared to high-risk HIV-1-seronegative women in the same community.
Methods
Cohort participants were screened for prevalent HIV-1 infection. HIV-1-uninfected participants had regularly scheduled follow-up visits, with HIV counseling and testing and collection of demographic and behavioral data. Archived blood samples were tested for HSV-2.
Results
HSV-2 prevalence was 22.0% in men and 50.8% in women (p<0.001). HSV-2 incidence in men was 9.0 per 100 person-years, and was associated with incident HIV-1 infection (adjusted incidence rate ratio [aIRR] 3.9, 95% CI 1.3–12.4). Use of soap for genital washing was protective (aIRR 0.3, 95% CI 0.1–0.8). Receptive anal intercourse had a borderline association with HSV-2 acquisition in men (aIRR 2.0, 95% CI 1.0–4.1, p=0.057), and weakened the association with incident HIV-1. Among women, HSV-2 incidence was 22.1 per 100 person-years (p < 0.001 compared to incidence in men), and was associated with incident HIV-1 infection (aIRR 8.9, 95% CI 3.6–21.8) and vaginal washing with soap (aIRR 1.9, 95% CI 1.0–3.4).
Conclusions
HSV-2 incidence in these men and women is among the highest reported, and is associated with HIV-1 acquisition. While vaginal washing with soap may increase HSV-2 risk in women, genital hygiene may be protective in men.
doi:10.1097/OLQ.0b013e31821a6225
PMCID: PMC3157056
PMID: 21844740
HSV-2; HIV-1; herpes; prevalence; incidence; Kenya; hygiene
Data from a randomized trial of oral periodic presumptive treatment (PPT) to reduce vaginal infections were analyzed to assess the effect of the intervention on a healthy vaginal environment (normal flora confirmed by Gram stain with no candidiasis or trichomoniasis). The incidence of a healthy vaginal environment was 608 cases per 100 person-years in the intervention arm and 454 cases per 100 person-years in the placebo arm (hazard ratio [HR], 1.36; 95% confidence interval [CI], 1.17–1.58). Sustained vaginal health (healthy vaginal environment for ≥3 consecutive visits) was also more frequent in the intervention arm (HR, 1.69; 95% CI, 1.23–2.33). PPT is effective at establishing and sustaining a healthy vaginal environment.
doi:10.1093/infdis/jir241
PMCID: PMC3114467
PMID: 21673045
Sociodemographic and behavioral characteristics of 212 Peruvian female sex workers (FSWs) were analyzed. The association between genital tract infections (GTIs) and risk factors by multivariate analysis was evaluated. Eighty-eight percent of FSWs were diagnosed with at least one GTI (HSV-2 80.1%, BV 44.8%, candidiasis 9.9%, syphilis seropositivity 9.4%, Trichomonas vaginalis 2.4%, HIV seropositivity 2.4%). Reported condom use with clients was nearly universal (98.3%), but infrequent with husband/regular partners (7.3%). In multivariate analysis BV was negatively associated with more consistent condom use (PRR = 0.63, 95% CI, 0.42–0.96). Many had not visited a Sexually Transmitted Infection (STI) clinic or been tested for HIV in the past year (40.6%, 47.1%, resp.). Nonclient contraceptive use was low (57%) and induced abortion was common (68%). High GTI burden and abortions suggest that a services-access gap persists among marginalized FSWs. Continued health outreach programs and integrating family planning and reproductive health services into existing STI clinic services are recommended.
doi:10.1155/2012/739624
PMCID: PMC3395213
PMID: 22811592
Background
Few studies have examined the association between self-reported sexual risk behaviors and biological outcomes in HIV-1-seropositive African adults.
Methods
We conducted a prospective cohort study in 898 HIV-1-seropositive women who reported engaging in transactional sex in Mombasa, Kenya. Primary outcome measures included detection of sperm in genital secretions, pregnancy, and sexually transmitted infections (STIs). Because three outcomes were evaluated, data are presented with odds ratios [OR] and 96.7% confidence intervals [CI] to reflect that we would reject a null hypothesis if a p-value were ≤0.033 (Simes’ methodology).
Results
During 2,404 person-years of follow-up, self-reported unprotected intercourse was associated with significantly higher likelihood of detecting sperm in genital secretions (OR 2.32, 96.7% CI 1.93, 2.81), and pregnancy (OR 2.78, 96.7% CI 1.57, 4.92), but not with detection of STIs (OR 1.20, 96.7% CI 0.98, 1.48). At visits where women reported being sexually active, having >1 sex partner in the past week was associated with lower likelihood of detecting sperm in genital secretions (OR 0.74, 96.7% CI 0.56, 0.98). This association became non-significant after adjustment for reported condom use (adjusted OR 0.81, 96.7% CI 0.60, 1.08).
Conclusions
Combining behavioral and biological outcomes, which provide complementary information, is advantageous for understanding sexual risk behavior in populations at risk for transmitting HIV-1. The paradoxical relationship between higher numbers of sex partners and less frequent identification of sperm in genital secretions highlights the potential importance of context-specific behavior, such as condom use dependent on partner type, when evaluating sexual risk behavior.
doi:10.1097/OLQ.0b013e31820369f6
PMCID: PMC3155001
PMID: 21217420
HIV-1; sexually transmitted disease; women; Africa; sexual risk behavior
Identifying naturally-occurring neutralizing antibodies (NAb) that are cross-reactive against all global subtypes of HIV-1 is an important step toward the development of a vaccine. Establishing the host and viral determinants for eliciting such broadly NAbs is also critical for immunogen design. NAb breadth has previously been shown to be positively associated with viral diversity. Therefore, we hypothesized that superinfected individuals develop a broad NAb response as a result of increased antigenic stimulation by two distinct viruses. To test this hypothesis, plasma samples from 12 superinfected women each assigned to three singly infected women were tested against a panel of eight viruses representing four different HIV-1 subtypes at matched time points post-superinfection (∼5 years post-initial infection). Here we show superinfected individuals develop significantly broader NAb responses post-superinfection when compared to singly infected individuals (RR = 1.68, CI: 1.23–2.30, p = 0.001). This was true even after controlling for NAb breadth developed prior to superinfection, contemporaneous CD4+ T cell count and viral load. Similarly, both unadjusted and adjusted analyses showed significantly greater potency in superinfected cases compared to controls. Notably, two superinfected individuals were able to neutralize variants from four different subtypes at plasma dilutions >1∶300, suggesting that their NAbs exhibit elite activity. Cross-subtype breadth was detected within a year of superinfection in both of these individuals, which was within 1.5 years of their initial infection. These data suggest that sequential infections lead to augmentation of the NAb response, a process that may provide insight into potential mechanisms that contribute to the development of antibody breadth. Therefore, a successful vaccination strategy that mimics superinfection may lead to the development of broad NAbs in immunized individuals.
Author Summary
A broad and potent antibody response is considered essential for an effective HIV-1 vaccine that will protect against diverse circulating strains. Consequently, there is great interest in both the host and viral factors that impact the development of the neutralizing antibody (NAb) response in natural HIV-1 infections. HIV-infected individuals who become superinfected with a second virus from a different source partner represent unique cases for studying the antibody response, as superinfection reflects exposure to different HIV-1 antigenic variants, and hence may provide insight into the development of broadly NAbs. In support of this model, we show here that superinfected individuals develop broader and more potent NAb responses than singly infected individuals, a result that is likely due to the increased antigenic stimulation from two viruses compared to one. Our findings remained unchanged after controlling for other factors that have been shown to influence the NAbs response, such as CD4+ T cell count and viral load. This study demonstrates that superinfection yields antibodies that have the capacity to recognize diverse circulating HIV-1 variants. Therefore, further characterization of these superinfected individuals' NAb responses could lead to novel insights into pathways that elicit broadly NAbs.
doi:10.1371/journal.ppat.1002611
PMCID: PMC3315492
PMID: 22479183
This study explored perceptions of HIV following local introduction of antiretroviral therapy (ART), among 30 HIV-positive and -negative female sex workers (FSWs) and 10 male bar patrons in Mombasa, Kenya. Semi-structured interviews were analyzed qualitatively to identify determinants of sexual risk behaviors. ART was not perceived as a barrier to safer sex and in some cases led to decreased high-risk behaviors. Barriers to safer sex included economic pressure and sexual partnership types. Many women reported that negotiating condom use is more difficult in long-term partnerships. These women favored short-term partnerships to minimize risk through consistent condom use. For women living with HIV, concern about maintaining health and avoiding HIV superinfection was a strong motivator of protective behaviors. For HIV-negative women, a negative HIV test was a powerful motivator. Incorporation of context- and serostatus-specific factors (e.g., self-protection for HIV-positive women) into tailored prevention counseling may support high-risk women to reduce risk behaviors.
doi:10.1521/aeap.2011.23.4.299
PMCID: PMC3244816
PMID: 21861605
Antiretroviral therapy; sexual risk behavior; human immunodeficiency virus type 1; multiple and concurrent partnerships; Africa
Graham, Susan M. | Masese, Linnet | Gitau, Ruth | Jalalian-Lechak, Zahra | Richardson, Barbra A. | Peshu, Norbert | Mandaliya, Kishor | Kiarie, James N. | Jaoko, Walter | Ndinya-Achola, Jeckoniah | Overbaugh, Julie | McClelland, R. Scott
Persistent genital HIV-1 shedding among women taking antiretroviral therapy (ART) may present a transmission risk. We investigated associations between genital HIV-1 suppression after ART initiation and adherence, resistance, pre-treatment CD4 count, and hormonal contraceptive use. First-line ART was initiated in 102 women. Plasma and genital HIV-1 RNA were measured at months 0, 3, and 6. Adherence was a strong and consistent predictor of genital HIV-1 suppression (p<0.001), while genotypic resistance was associated with higher vaginal HIV-1 RNA at 6 months (p=0.04). These results emphasize the importance of adherence to optimize the potential benefits of ART for reducing HIV-1 transmission risk.
doi:10.1086/656790
PMCID: PMC2957525
PMID: 20923373
antiretroviral therapy; HIV infection; women; genital HIV-1 shedding
McClelland, R. Scott | Graham, Susan M. | Richardson, Barbra A. | Peshu, Norbert | Masese, Linnet N. | Wanje, George H. | Mandaliya, Kishorchandra N. | Kurth, Ann E. | Jaoko, Walter | Ndinya-Achola, J. O.
Objective
The objective of this study was to test the hypothesis that sexual risk behaviour would increase following initiation of antiretroviral therapy (ART) in Kenyan female sex workers (FSWs).
Design
Prospective cohort study.
Setting
FSW cohort in Mombasa, Kenya, 1993-2008.
Subjects
898 women contributed HIV-1-seropositive follow-up visits, of whom 129 initiated ART.
Intervention
Beginning in March 2004, ART was provided to women qualifying for treatment according to Kenyan National Guidelines. Participants received sexual risk reduction education and free condoms at every visit.
Main Outcome Measures
Main outcome measures included unprotected intercourse, abstinence, 100% condom use, number of sexual partners, and frequency of sex. Outcomes were evaluated at monthly follow-up visits using a one week recall interval.
Results
Compared to non-ART-exposed follow-up, visits following ART initiation were not associated with an increase in unprotected sex (adjusted odds ratio [AOR] 0.86, 95% confidence interval [CI] 0.62-1.19, P=0.4). There was a non-significant decrease in abstinence (AOR 0.81, 95% CI 0.65-1.01, P=0.07), which was offset by a substantial increase in 100% condom use (AOR 1.54, 95% CI 1.07-2.20, P=0.02). Numbers of sex partners and frequency of sex were similar before versus after starting ART. A trend for decreased sexually transmitted infections following ART initiation provides additional support for the validity of the self-reported behavioural outcomes (AOR 0.67, 95% CI 0.44-1.02, P=0.06).
Conclusions
In the setting of ongoing risk reduction education and provision of free condoms, initiation of ART was not associated with increased sexual risk behaviour in this cohort of Kenyan FSWs.
doi:10.1097/QAD.0b013e32833616c7
PMCID: PMC2853894
PMID: 20179576
Antiretroviral therapy; sexual risk behaviour; human immunodeficiency virus type 1; sexually transmitted infection; Africa
Chohan, Vrasha | Baeten, Jared M. | Benki, Sarah | Graham, Susan M. | Lavreys, Ludo | Mandaliya, Kishorchandra | Ndinya-Achola, Jeckoniah O. | Jaoko, Walter | Overbaugh, Julie | McClelland, R. Scott
Objectives
Several studies have demonstrated an association between herpes simplex virus type 2 (HSV-2) and human immunodeficiency virus type 1 (HIV-1), but limited data on risk factors for HSV-2 acquisition are available. The objective of this analysis was to determine the incidence and risk factors for HSV-2 acquisition among HIV-1-seronegative Kenyan female sex workers.
Methods
Between February 1993 and December 2006, HIV-1-seronegative women attending a municipal sexually transmitted infections (STI) clinic were invited to enroll in a prospective cohort study. Screening for HIV-1 and STIs were done at monthly follow-up visits. Archived blood samples were tested for HSV-2.
Results
Of 1527 HIV-1-seronegative women enrolled, 302 (20%) were HSV-2-seronegative at baseline, of whom, 297 had at least one follow-up visit. HSV-2 incidence was high (23 cases/100 person-years; 115 cases). In multivariate analysis, HSV-2 was significantly associated with more recent entry into sex work, workplace, and higher number of sex partners per week. Condom use was protective, although this was statistically significant only for the intermediate strata (25–75% condom use, HR 0.43, p=0.05). There were statistical trends for bacterial vaginosis to increase HSV-2 risk (HR 1.56, p=0.07) and for oral contraceptive use to decrease risk (HR 0.50, p=0.08). The 23% annual HSV-2 incidence in this study is among the highest reported anywhere in the world.
Conclusions
Women were at increased risk if they had recently entered sex work, had a higher number of sex partners, or worked in bars. HSV-2 risk reduction interventions are urgently needed among high-risk African women.
doi:10.1136/sti.2009.036103
PMCID: PMC2813217
PMID: 19457873
herpes simplex virus type 2; incidence; risk factors; HIV-1 seronegative; female sex workers
Background
Trachoma is thought to be endemic over large parts of Southern Sudan, but empirical evidence is limited. While some areas east of the Nile have been identified as highly endemic, few trachoma surveys have been conducted in the remainder of the country. This study aimed to determine whether trachoma constitutes a problem to public health in Northern Bahr-el-Ghazal and Unity State, both located west of the Nile.
Methods and Principal Findings
Trachoma rapid assessments (TRA) were conducted between July and September 2009. Seven villages in Northern Bahr-el-Ghazal State and 13 villages in Unity State were surveyed; an average of 50 children (age 1–9 years) and 44 women (age 15 years and above) were examined per village. Samples for analysis using the APTIMA Combo-2 nucleic acid amplification test (NAAT) were collected from participants with active trachoma in eight villages in Unity State. In Northern Bahr-el-Ghazal State, only three children with active trachoma (trachomatous inflammation follicular (TF) and/or trachomatous inflammation intense (TI)) and two women with trichiasis (TT) were found, in two of the seven villages surveyed. In Unity State, trachoma was endemic in all thirteen villages surveyed; the proportion of children with active trachoma ranged from 33% to 75% between villages, while TF in children ranged from 16% to 44%. Between 4% to 51% of examined women showed signs of TT. Samples from active trachoma cases tested using the NAAT were positive for Chlamydia trachomatis infection for 46.6% of children and 19.0% of women.
Conclusions
Trachoma presents a major problem to public health Unity State, while the disease is of low priority in Northern-Bahr-el-Ghazal State. Implementation of a population-based prevalence survey is now required in Unity State to generate baseline prevalence data so that trachoma interventions can be initiated and monitored over time.
doi:10.1371/journal.pone.0013138
PMCID: PMC2948518
PMID: 20957205
Objective
Vaginal colonization with Lactobacillus species is characteristic of normal vaginal ecology. The absence of vaginal lactobacilli, particularly hydrogen peroxide (H2O2)-producing isolates, has been associated with symptomatic bacterial vaginosis (BV) and increased risk for HIV-1 acquisition. Identification of factors associated with vaginal Lactobacillus colonization may suggest interventions to improve vaginal health.
Methods
We conducted a prospective cohort study of correlates of vaginal Lactobacillus colonization among Kenyan HIV-1 seronegative female sex workers. At monthly follow-up visits, vaginal Lactobacillus cultures were obtained. Generalized estimating equations were used to examine demographic, behavioral, and medical correlates of Lactobacillus isolation, including isolation of H2O2-producing strains.
Results
Lactobacillus cultures were obtained from 1020 women who completed a total of 8896 follow-up visits. Vaginal washing, typically with water alone or with soap and water, was associated with an approximately 40% decreased likelihood of Lactobacillus isolation, including isolation of H2O2-producing strains. Recent antibiotic use, excluding metronidazole and treatments for vaginal candidiasis, reduced Lactobacillus isolation by ~30%. H2O2-producing lactobacilli were significantly less common among women with Trichomonas vaginalis infection and those who were seropositive for herpes simplex virus type 2. In contrast, H2O2-producing lactobacilli were significantly more common among women with concurrent vaginal candidiasis.
Conclusions
Modifiable biologic and behavioral factors are associated with Lactobacillus colonization in African women. Our results suggest intervention strategies to improve vaginal health in women at high risk for HIV-1.
doi:10.1136/sti.2008.035451
PMCID: PMC2837477
PMID: 19329442
vaginal infection; Lactobacillus; vaginal washing; female sex workers; Kenya
McClelland, R. Scott | Richardson, Barbra A. | Hassan, Wisal M. | Graham, Susan M. | Kiarie, James | Baeten, Jared M. | Mandaliya, Kishorchandra | Jaoko, Walter | Ndinya-Achola, Jeckoniah O. | Holmes, King K.
Background:
It has been suggested that vaginal lactobacilli may reduce the risk of vulvovaginal candidiasis (VVC), but supporting data are limited. Our objective was to determine the relationship between vaginal bacterial flora and VVC.
Methods:
We conducted a prospective cohort analysis among 151 Kenyan sex workers. At monthly follow-up, VVC was defined as the presence of yeast buds, pseudohyphae, or both on vaginal wet preparation or KOH preparation. Generalized estimating equations were used to identify correlates of VVC.
Results:
Participants returned for a median of 12 (interquartile range 11-12) visits. Vulvovaginal candidiasis was present at 162 visits, including 26 with symptomatic VVC. Bacterial vaginosis (BV) was associated with fewer episodes of VVC (adjusted odds ratio [aOR] 0.29, 95% confidence interval [CI] 0.16-0.50). After excluding women with concurrent BV, another possible cause of vaginal symptoms, the likelihood of symptomatic VVC was higher in those with yeast on vaginal wet preparation in the past 60 days (aOR 4.06, 95% CI 1.12-14.74) and those with concurrent vaginal Lactobacillus colonization (aOR 3.75, 95% CI 1.30-10.83).
Conclusions:
Contrary to a commonly posed hypothesis of a protective effect, we found that vaginal Lactobacillus colonization was associated with a >4-fold increase in the likelihood of symptomatic VVC.
doi:10.1086/599213
PMCID: PMC2743896
PMID: 19456235
Vulvovaginal candidiasis; Lactobacillus; bacterial vaginosis; women
The determinants of a broad neutralizing antibody (NAb) response and its effect on human immunodeficiency virus type 1 (HIV-1) disease progression are not well defined, partly because most prior studies of a broad NAb response were cross-sectional. We examined correlates of NAb response breadth among 70 HIV-infected, antiretroviral-naïve Kenyan women from a longitudinal seroincident cohort. NAb response breadth was measured 5 years after infection against five subtype A viruses and one subtype B virus. Greater NAb response breadth was associated with a higher viral load set point and greater HIV-1 env diversity early in infection. However, greater NAb response breadth was not associated with a delayed time to a CD4+ T-cell count of <200, antiretroviral therapy, or death. Thus, a broad NAb response results from a high level of antigenic stimulation early in infection, which likely accounts for prior observations that greater NAb response breadth is associated with a higher viral load later in infection.
doi:10.1128/JVI.01149-09
PMCID: PMC2748011
PMID: 19640996
Hypermutation, the introduction of excessive G-to-A substitutions by host proteins in the APOBEC family, can impair replication of the human immunodeficiency virus (HIV). Because hypermutation represents a potential antiviral strategy, it is important to determine whether greater hypermutation is associated with slower disease progression in natural infection. We examined the level of HIV-1 hypermutation among 28 antiretroviral-naive Kenyan women at two times during infection. By examining single-copy gag sequences from proviral DNA, hypermutation was detected in 16 of 28 individuals. Among individuals with any hypermutation, a median of 15% of gag sequences were hypermutated (range, 5 to 43%). However, there was no association between the level of gag hypermutation and the viral load or CD4 count. Thus, we observed no overall relationship between hypermutation and markers of disease progression among individuals with low to moderate levels of hypermutation. In addition, one individual sustained a typical viral load despite having a high level of hypermutation. This individual had 43% of gag sequences hypermutated and harbored a partially defective Vif, which was found to permit hypermutation in a peripheral blood mononuclear cell culture. Overall, our results suggest that a potential antiviral therapy based on hypermutation may need to achieve a substantially higher level of hypermutation than is naturally seen in most individuals to impair virus replication and subsequent disease progression.
doi:10.1128/JVI.00280-09
PMCID: PMC2715790
PMID: 19494014
van der Elst, Elisabeth M. | Okuku, Haile Selassie | Nakamya, Phellister | Muhaari, Allan | Davies, Alun | McClelland, R. Scott | Price, Matthew A. | Smith, Adrian D. | Graham, Susan M. | Sanders, Eduard J. | Pai, Nitika Pant
Background
Audio computer-assisted self-interview (ACASI) may elicit more frequent reporting of socially sensitive behaviours than face-to-face (FtF)-interview. However, no study compared responses to both methods in female and male sex workers (FSW; MSW) in Africa.
Methodology/Principal Findings
We sequentially enrolled adults recruited for an HIV-1 intervention trial into a comparative study of ACASI and FtF-interview, in a clinic near Mombasa, Kenya. Feasibility and acceptability of ACASI, and a comparative analysis of enrolment responses between ACASI and FtF on an identical risk assessment questionnaire were evaluated. In total, 139 women and 259 men, 81% of eligible cohort participants, completed both interviews. ACASI captured a higher median number of regular (2 vs. 1, p<0.001, both genders) and casual partners in the last week (3 vs. 2, p = 0.04 in women; 2 vs. 1, p<0.001 in men). Group sex (21.6 vs. 13.5%, p<0.001, in men), intravenous drug use (IDU; 10.8 vs. 2.3%, p<0.001 in men; 4.4 vs. 0%, p = 0.03 in women), and rape (8.9 vs. 3.9%, p = 0.002, in men) were reported more frequently in ACASI. A surprisingly high number of women reported in ACASI that they had paid for sex (49.3 vs. 5.8%, p<0.001). Behaviours for recruitment (i.e. anal sex, sex work, sex between males) were reported less frequently in ACASI. The majority of women (79.2%) and men (69.7%) felt that answers given in ACASI were more honest. Volunteers who were not able to take ACASI (84 men, and 37 women) mostly lacked reading skills.
Conclusions/Significance
About 1 in 5 cohort participants was not able to complete ACASI, mostly for lack of reading skills. Participants who completed ACASI were more likely to report IDU, rape, group sex, and payment for sex by women than when asked in FtF interview. ACASI appears to be a useful tool for high risk behaviour assessments in the African context.
doi:10.1371/journal.pone.0005340
PMCID: PMC2671594
PMID: 19412535
Reports of HIV-1 superinfection (re-infection) have demonstrated that the immune response generated against one strain of HIV-1 does not always protect against other strains. However, studies to determine the incidence of HIV-1 superinfection have yielded conflicting results. Furthermore, few studies have attempted to identify superinfection cases occurring more than a year after initial infection, a time when HIV-1-specific immune responses would be most likely to have developed. We screened a cohort of high-risk Kenyan women for HIV-1 superinfection by comparing partial gag and envelope sequences over a 5-y period beginning at primary infection. Among 36 individuals, we detected seven cases of superinfection, including cases in which both viruses belonged to the same HIV-1 subtype, subtype A. In five of these cases, the superinfecting strain was detected in only one of the two genome regions examined, suggesting that recombination frequently occurs following HIV-1 superinfection. In addition, we found that superinfection occurred throughout the course of the first infection: during acute infection in two cases, between 1–2 y after infection in three cases, and as late as 5 y after infection in two cases. Our results indicate that superinfection commonly occurs after the immune response against the initial infection has had time to develop and mature. Implications from HIV-1 superinfection cases, in which natural re-exposure leads to re-infection, will need to be considered in developing strategies for eliciting protective immunity to HIV-1.
Author Summary
Superinfection with HIV-1 occurs when an individual infected with one strain of HIV-1 acquires a second strain, from a different partner. There are more than 20 published cases of HIV-1 superinfection. These cases have raised concerns for HIV-1 vaccine design because they indicate that the immune response generated against natural infection is not always sufficient to protect against later exposures to the virus. However, it remains unclear how often HIV-1 superinfection occurs, especially at times in infection after an immune response would be expected. We investigated the incidence of HIV-1 superinfection in a cohort of 36 high-risk women followed for approximately five years after their first HIV-1 infections. We found seven cases of HIV-1 superinfection. Five cases occurred more than a year after the initial infection, a time when the immune response would have had time to develop and broaden. In three cases, the initial and superinfecting viruses were classified as the same HIV-1 genetic subtype, indicating a lack of protection against closely related viruses. Our results suggest that natural HIV-1 infection does not always elicit a protective immune response, an important consideration in developing strategies for HIV-1 vaccine design and testing.
doi:10.1371/journal.ppat.0030177
PMCID: PMC2077901
PMID: 18020705
Studies of human immunodeficiency virus type 1 (HIV-1) transmission suggest that genital HIV-1 RNA and DNA may both be determinants of HIV-1 infectivity. Despite its potential role in HIV-1 transmission, there are limited quantitative data on genital HIV-1 DNA. Here we validated an in-house real-time PCR method for quantification of HIV-1 DNA in genital specimens. In reactions with 100 genomes to 1 genome isolated from a cell line containing one HIV-1 provirus/cell, this real-time PCR assay is linear and agrees closely with a commercially available real-time PCR assay specific for a cellular housekeeping gene. In mock genital samples spiked with low numbers of HIV-1-infected cells such that the expected HIV-1 DNA copy number/reaction was 100, 10, or 5, the average copy number/reaction was 80.2 (standard deviation [SD], 28.3), 9.1 (SD, 5.4), or 3.1 (SD, 2.1), respectively. We used this method to examine genital HIV-1 DNA levels in specimens from women whose low plasma HIV-1 RNA levels are typical of HIV-1 nontransmitters. The median HIV-1 DNA copy number in endocervical secretions from these women (1.8 HIV-1 DNA copies/10,000 cells) was lower than that for women with higher plasma HIV-1 RNA levels (16.6 HIV-1 DNA copies/10,000 cells) (P = 0.04), as was the median HIV-1 DNA copy number in vaginal secretions (undetectable versus 1.0 HIV-1 DNA copies/10,000 cells). These data suggest that women with low plasma HIV-1 RNA and thus a predicted low risk of HIV-1 transmission have low levels of genital HIV-1 cell-associated virus. The assay described here can be utilized in future efforts to examine the role of cell-associated HIV-1 in transmission.
doi:10.1128/JCM.01481-06
PMCID: PMC1698424
PMID: 17050820
Platelet microbicidal proteins (PMPs), small cationic peptides released at sites of endovascular damage, kill common bloodstream pathogens in vitro. Our group previously showed that in vitro resistance of clinical staphylococcal and viridans group streptococcal bacteremic strains to PMPs correlated with the diagnosis of infective endocarditis (IE) (Wu et al., Antimicrob. Agents Chemother. 38:729–732, 1994). However, that study was limited by (i) the small number of Staphylococcus aureus isolates from IE patients, (ii) the retrospective nature of the case definitions, and (iii) the diverse geographic sources of strains. The present study evaluated the in vitro PMP susceptibility phenotype of a large number of staphylococcemic isolates (n = 60), collected at a single medical center and categorized by defined and validated clinical criteria. A significantly higher proportion of staphylococcemic strains from patients with IE was PMP resistant in vitro than the proportion of strains from patients with soft tissue sepsis (83% and 33%, respectively; P < 0.01). Moreover, the levels of PMP resistance (mean percent survival of strains after 2-h exposure to PMP in vitro) were significantly higher for isolates from patients with IE and with vascular catheter sepsis than for strains from patients with abscess sepsis (P < 0.005 and P < 0.01, respectively). These data further support the concept that bloodstream pathogens that exhibit innate or acquired PMP resistance have a survival advantage with respect to either the induction or progression of endovascular infections.
PMCID: PMC106018
PMID: 9835510
Background
Following male circumcision for HIV prevention, a high proportion of men fail to return for their scheduled seven-day post-operative visit. We evaluated the effect of short message service (SMS) text messages on attendance at this important visit.
Methodology
We enrolled 1200 participants >18 years old in a two-arm, parallel, randomized controlled trial at 12 sites in Nyanza province, Kenya. Participants received daily SMS text messages for seven days (n = 600) or usual care (n = 600). The primary outcome was attendance at the scheduled seven-day post-operative visit. The primary analysis was by intention-to-treat.
Principal Findings
Of participants receiving SMS, 387/592 (65.4%) returned, compared to 356/596 (59.7%) in the control group (relative risk [RR] = 1.09, 95% confidence interval [CI] 1.00–1.20; p = 0.04). Men who paid more than US$1.25 to travel to clinic were at higher risk for failure to return compared to those who spent ≤US$1.25 (adjusted relative risk [aRR] 1.35, 95% CI 1.15–1.58; p<0.001). Men with secondary or higher education had a lower risk of failure to return compared to those with primary or less education (aRR 0.87, 95% CI 0.74–1.01; p = 0.07).
Conclusions
Text messaging resulted in a modest improvement in attendance at the 7-day post-operative clinic visit following adult male circumcision. Factors associated with failure to return were mainly structural, and included transportation costs and low educational level.
Trial Registration
ClinicalTrials.gov
NCT01186575
doi:10.1371/journal.pone.0043832
PMCID: PMC3434192
PMID: 22957034
Graham, Susan M. | Holte, Sarah E. | Dragavon, Joan A. | Ramko, Kelly M. | Mandaliya, Kishor N. | McClelland, R. Scott | Peshu, Norbert M. | Sanders, Eduard J. | Krieger, John N. | Coombs, Robert W. | Lama, Javier R.
Objectives
Antiretroviral therapy (ART) decreases HIV-1 RNA levels in semen and reduces sexual transmission from HIV-1-infected men. Our objective was to study the time course and magnitude of seminal HIV-1 RNA decay after initiation of efavirenz-based ART among 13 antiretroviral-naïve Kenyan men.
Methods
HIV-1 RNA was quantified (lower limit of detection, 120 copies/mL) in blood and semen at baseline and over the first month of ART. Median log10 HIV-1 RNA was compared at each time-point using Wilcoxon Signed Rank tests. Perelson’s two-phase viral decay model and nonlinear random effects were used to compare decay rates in blood and semen.
Results
Median baseline HIV-1 RNA was 4.40 log10 copies/mL in blood (range, 3.20–5.08 log10 copies/mL) and 3.69 log10 copies/mL in semen (range, <2.08–4.90 log10 copies/mL). The median reduction in HIV-1 RNA by day 28 was 1.90 log10 copies/mL in blood (range, 0.56–2.68 log10 copies/mL) and 1.36 log10 copies/mL in semen (range, 0–2.66 log10 copies/mL). ART led to a decrease from baseline by day 7 in blood and day 14 in semen (p = 0.005 and p = 0.006, respectively). The initial modeled decay rate was slower in semen than in blood (p = 0.06). There was no difference in second-phase decay rates between blood and semen.
Conclusions
Efavirenz-based ART reduced HIV-1 RNA levels more slowly in semen than in blood. Although this difference was of borderline significance in this small study, our observations suggest that there is suboptimal suppression of seminal HIV-1 RNA for some men in the early weeks of treatment.
doi:10.1371/journal.pone.0043086
PMCID: PMC3418270
PMID: 22912795
Graham, Susan M. | Krieger, John N. | Githua, Peter L. M. | Wamuyu, Lorraine W. | Wale, Steven | Ramko, Kelly M. | Dragavon, Joan A. | Muller, Charles H. | Holte, Sarah E. | Mandaliya, Kishor N. | McClelland, R. Scott | Peshu, Norbert M. | Sanders, Eduard J. | Coombs, Robert W.
Objectives
Genitourinary tract samples are required to investigate male HIV-1 infectivity. Because semen collection is often impractical, we evaluated the acceptability, feasibility, and validity of post-prostatic massage fluid/urine (post-PMF/U) for studying male genitourinary HIV-1 shedding.
Methods
HIV-1-seropositive men were evaluated after 48 hours of sexual abstinence. At each visit, a clinician performed prostatic massage, then post-PMF/U and blood were collected. Participants provided semen specimens one week later. An audio computer-assisted self-interview (ACASI) administered after each specimen collection evaluated acceptability, adherence to instructions, and recent genitourinary symptoms. HIV-1 RNA was quantified using a real-time PCR assay. Detection and quantitation of HIV-1 RNA and stability over visits were compared for semen, post-PMF/U, and blood.
Results
Post-PMF/U was successfully obtained at 106 visits (64%) and semen at 136 visits (81%, p<0.001). In ACASI, discomfort was rated higher for post-PMF/U collection (p=0.003), but there was no significant difference in acceptability. Detection of HIV-1 RNA in post-PMF/U was associated with detection in semen (p=0.02). Semen and post-PMF/U HIV-1 RNA levels were correlated (ρ=0.657, p<0.001). Concordance of results at repeat visits was 78.9% for post-PMF/U (κ = 0.519, p = 0.02), and 89.5% for both blood and semen (κ = 0.774, p = 0.001).
Conclusions
Although semen collections were more successful, both post-PMF/U and semen collections were acceptable to many participants. HIV-1 RNA detection and levels were closely associated in semen and post-PMF/U, and results were relatively stable across visits. To assess male HIV-1 infectivity, post-PMF/U may represent a valid alternative when semen cannot be obtained.
doi:10.1136/sti.2010.047118
PMCID: PMC3075574
PMID: 21278399
HIV-1; semen; prostate; infectivity; validation
Graham, Susan M. | Masese, Linnet | Gitau, Ruth | Richardson, Barbra A. | Mandaliya, Kishor | Peshu, Norbert | Jaoko, Walter | Ndinya-Achola, Jeckoniah | Overbaugh, Julie | McClelland, R. Scott
Objectives
Genital ulcer disease (GUD) is associated with increased HIV-1 RNA shedding in antiretroviral therapy (ART)-naïve women. The effect of GUD on HIV-1 shedding among ART-treated women is not known. Our objective was to test the hypothesis that genital ulcerations increase genital HIV-1 RNA shedding in women receiving ART.
Methods
Eligible women initiated ART and attended monthly visits with inspection for genital lesions and collection of genital swabs. GUD cases diagnosed after ≥2 months on ART were included for analysis and served as their own controls. HIV-1 RNA was quantitated in specimens collected before, during, and after GUD for all cases. The lower limit of quantitation was 100 HIV-1 RNA copies/swab. Using the pre-GUD visit as the reference, we compared detection of genital HIV-1 RNA before versus during and after GUD episodes.
Results
Thirty-six women had GUD episodes after ART initiation. HIV-1 RNA was detected before, during, and after GUD in cervical secretions from 4 (11%), 1 (3%), and 6 (17%) women respectively, and in vaginal secretions from 3 (8%), 4 (11%) and 4 (11%) women respectively. After adjustment for time on ART, there was no difference in detection of cervical HIV-1 RNA before versus during GUD (aOR 0.22, 95% CI 0.04–1.23). Likewise, GUD did not increase HIV-1 detection in vaginal secretions (adjusted odds ratio [aOR] 1.32, 95% CI 0.29–5.92).
Conclusions
GUD did not significantly increase cervical or vaginal HIV-1 shedding. Our results suggest that ART maintains its effectiveness for genital HIV-1 suppression despite GUD episodes.
doi:10.1136/sti.2010.045369
PMCID: PMC3081651
PMID: 20980464
genital ulcer; antiretroviral therapy; HIV infection; women
GITAU, Ruth W. | GRAHAM, Susan M. | MASESE, Linnet N. | OVERBAUGH, Julie | CHOHAN, Vrasha | PESHU, Norbert | RICHARDSON, Barbra A. | JAOKO, Walter | NDINYA-ACHOLA, Jeckoniah O. | MCCLELLAND, R. Scott
Background
Cervicitis increases the quantity of HIV-1 RNA in cervical secretions when women are not taking antiretroviral therapy (ART), and successful treatment of cervicitis reduces HIV-1 shedding in this setting.
Objective
To determine the effect of acquisition and treatment of cervical infections on genital HIV-1 shedding in women receiving ART.
Design
Prospective cohort study.
Methods
We followed 147 women on ART monthly for incident non-specific cervicitis, gonorrhea, and chlamydia. Cervical swabs for HIV-1 RNA quantitation were collected at every visit. The lower limit for linear quantitation was 100 copies/swab. We compared the prevalence of HIV-1 RNA detection before (baseline) versus during and after treatment of cervical infections.
Results
Thirty women contributed a total of 31 successfully treated episodes of non-specific cervicitis (N=13), gonorrhea (N=17), and chlamydia (N=1). HIV-1 RNA was detected in cervical secretions before, during, and after cervicitis at 1 (3.2%), 5 (16.1%), and 3 (9.7%) visits respectively. Compared to baseline, detection of HIV-1 RNA was increased when cervical infections were present (adjusted odds ratio 5.7, 95% confidence interval 1.0–30.3, P=0.04). However, even in the subset of women with cervical HIV-1 RNA levels above the threshold for quantitation, most had low concentrations during cervical infections (median 115, range 100–820 copies/swab).
Conclusions
While these data show a statistically significant increase in cervical HIV-1 RNA detection when cervical infections are present, most cervical HIV-1 RNA concentrations were near the threshold for detection, suggesting that infectivity remains low. Antiretroviral therapy appears to limit increases in genital HIV-1 shedding caused by cervical infections.
doi:10.1097/QAD.0b013e32833f9f43
PMCID: PMC2978313
PMID: 20871388
Cervical infection; HIV-1 Shedding; Antiretroviral therapy; Women; Africa
Masese, Linnet N | Graham, Susan M | Gitau, Ruth | Peshu, Nobert | Jaoko, Walter | Ndinya-Achola, Jeckoniah O | Mandaliya, Kishorchandra | Richardson, Barbra A | Overbaugh, Julie | McClelland, R Scott
Background
Trichomonas vaginalis has been associated with increased vaginal HIV-1 RNA shedding in antiretroviral therapy (ART)-naïve women. The effect of trichomoniasis on vaginal HIV-1 shedding in ART-treated women has not been characterized. We tested the hypothesis that T. vaginalis infection would increase vaginal HIV-1 RNA shedding in women on ART, and that successful treatment would reduce vaginal HIV-1 RNA levels.
Methods
We conducted a prospective cohort study including monthly follow-up of 147 women receiving ART in Mombasa, Kenya. Those with T. vaginalis infection, defined by the presence of motile trichomonads on vaginal saline wet mount, received treatment with single dose metronidazole (2 g). Test of cure was performed at the next monthly visit. Using the pre-infection visit as the reference category, we compared detection of vaginal HIV-1 RNA before versus during and after infection using generalized estimating equations. A cut-off of 100 HIV-1 RNA copies/swab was used as the lower limit for linear quantitation.
Results
Among 31 women treated for trichomoniasis, the concentration of vaginal HIV-1 RNA was above the limit for quantitation before, during, and after T. vaginalis infection in 4 (13% [95% CI 4% - 30%]), 4 (13% [95% CI 4% - 30%]), and 5 (16% [95% confidence interval {CI} 5% - 34%]) women respectively. After adjusting for potential confounding factors, we could detect no difference in the likelihood of detecting vaginal HIV-1 RNA before versus during infection (odds ratio [OR] 1.41, 95% CI 0.23 - 8.79, p = 0.7). In addition, detection of HIV-1 RNA was similar before infection versus after successful treatment (OR 0.68, 95% CI (0.13 - 3.45), p = 0.6).
Conclusion
Detection of vaginal HIV-1 RNA during ART was uncommon at visits before, during and after T. vaginalis infection.
doi:10.1186/1471-2334-11-307
PMCID: PMC3231993
PMID: 22047086
Trichomonas vaginalis; vaginal infection; antiretroviral therapy; HIV-1; women; Africa