Sexual partnership patterns in malawi: implications for HIV/STI transmission.

BACKGROUND: Concurrent sexual partnerships are believed to play an important role in HIV transmission in sub-Saharan Africa, but the contributions of concurrency to HIV and sexually transmitted infection (STI) spread depend on the details of infectious periods and relationship patterns. To contribute to the understanding of sexual partnership patterns in this region, we estimated partnership lengths, temporal gaps between partners, and periods of overlap across partners at an STI clinic in Lilongwe, Malawi. METHODS: Participants underwent physical examinations and HIV tests, and responded to questionnaires about demographics and risk behaviors, including detailed questions about a maximum of 3 sexual partners in the previous 2 months. We calculated partnership length as the time between the first and most recent sexual contact with a partner, and gap length as the time between the most recent contact with 1 partner and the first contact with the next. We defined concurrent and consecutive partnerships as gap length ≤0 days and gap length >0 days, respectively. RESULTS: In the study population (n = 183), 86% reported 0 or 1 partner, 5% reported multiple consecutive partnerships, and 9% reported concurrency. The mean partnership length was 858 days (median = 176 days). Gaps between consecutive partnerships were short (mean = 21 days), and overlaps across concurrent partners tended to be long (mean = 246 days). CONCLUSIONS: Multiple sexual partnerships were uncommon, and partnerships were long on average. Among those reporting multiple recent partners, both long-term concurrency and narrowly spaced consecutive partnerships could present substantial risk for efficient transmission of HIV and classical STIs.

Use of nutritional and water hygiene packages for diarrhoeal prevention among HIV-exposed infants in Lilongwe, Malawi: an evaluation of a pilot prevention of mother-to-child transmission post-natal care service.

SUMMARY OBJECTIVE: To evaluate a pilot prevention of mother-to-child transmission post-natal programme in Lilongwe, Malawi, through observed retention and infant diarrhoeal rates. METHODS: Free fortified porridge and water hygiene packages were offered to mothers to encourage frequent post-natal visits and to reduce diarrhoeal rates in infants on replacement feeding. Participant retention and infant health outcome were assessed. RESULTS: Of 474 patients enrolled, 357 (75.3%) completed 3-month follow-up visits. Ninety-nine percent of women reported hygiene package use, and only 17.7% (95% CI 13.8-22.0%) of the infants had diarrhoea at least once over the 3-month period. Being 12 months or younger, confirmed HIV positive, access to tap water, and having a mother with diarrhoea were all associated with increased risk of infant diarrhoea. CONCLUSION: The majority of participants adhered to their scheduled visits and retention was favourable, possibly because of the introduction of hygiene and nutrition incentives. The infant diarrhoeal rate was low, suggesting benefits of regular medical care with hygiene package usage and reliable replacement feeding options. Continuation and expansion of the programme would allow further studies and improve the post-natal care of HIV-exposed infants in Malawi and in other resource-constrained countries.

The year-long effect of HIV-positive test results on pregnancy intentions, contraceptive use, and pregnancy incidence among Malawian women.

OBJECTIVES: To estimate the effect of receiving HIV-positive test results on intentions to have future children and on contraceptive use and to assess the association between pregnancy intentions and pregnancy incidence among HIV-positive women in Malawi. METHODS: Women of unknown HIV status completed a questionnaire about pregnancy intentions and contraceptive use and then received HIV voluntary counseling and testing (VCT). Women who were HIV-positive and not pregnant were enrolled and followed for 1 year while receiving HIV care and access to family planning (FP) services. RESULTS: Before receiving their HIV test results, 33% of women reported a desire to have future children; this declined to 15% 1 week later (P < 0.0001) and remained constant throughout follow-up. Contraceptive use increased from 38% before HIV testing to 52% 1 week later (P < 0.0001) and then decreased to 46% by 12 months. The pregnancy incidence among women not reporting a desire to have future children after VCT was less than half of the incidence among women reporting this desire. CONCLUSIONS: With knowledge of their HIV-positive status, women were less likely to desire future pregnancies. Pregnancy incidence was lower among women not desiring future children. Integration of VCT, FP, and HIV care could prevent mother-to-child HIV transmission.

Improved detection of acute HIV-1 infection in sub-Saharan Africa: development of a risk score algorithm.

OBJECTIVE: Individuals with acute (preseroconversion) HIV infection (AHI) are important in the spread of HIV. The identification of AHI requires the detection of viral proteins or nucleic acids with techniques that are often unaffordable for routine use. To facilitate the efficient use of these tests, we sought to develop a risk score algorithm for identifying likely AHI cases and targeting the tests towards those individuals. DESIGN: A cross-sectional study of 1448 adults attending a sexually transmitted infections (STI) clinic in Malawi. METHODS: Using logistic regression, we identified risk behaviors, symptoms, HIV rapid test results, and STI syndromes that were predictive of AHI. We assigned a model-based score to each predictor and calculated a risk score for each participant. RESULTS: Twenty-one participants (1.45%) had AHI, 588 had established HIV infection, and 839 were HIV-negative. AHI was strongly associated with discordant rapid HIV tests and genital ulcer disease (GUD). The algorithm also included diarrhea, more than one sexual partner in 2 months, body ache, and fever. Corresponding predictor scores were 1 for fever, body ache, and more than one partner; 2 for diarrhea and GUD; and 4 for discordant rapid tests. A risk score of 2 or greater was 95.2% sensitive and 60.5% specific in detecting AHI. CONCLUSION: Using this algorithm, we could identify 95% of AHI cases by performing nucleic acid or protein tests in only 40% of patients. Risk score algorithms could enable rapid, reliable AHI detection in resource-limited settings.

Amplified transmission of HIV-1: comparison of HIV-1 concentrations in semen and blood during acute and chronic infection.

OBJECTIVES: This study was conducted to compare viral dynamics in blood and semen between subjects with antibody negative, acute HIV-1 infection and other subjects with later stages of infection. DESIGN: A prospective cohort study was embedded within a cross-sectional study of HIV screening in a Lilongwe, Malawi STD clinic. METHODS: Blood samples from HIV antibody negative or indeterminate volunteers were used to detect HIV RNA in plasma using a pooling strategy. Blood and seminal plasma HIV-1 RNA concentrations were measured over 16 weeks. RESULTS: Sixteen men with acute HIV infection and 25 men with chronic HIV infection were studied. Blood viral load in subjects with acute HIV infection was highest about 17 days after infection (mean +/- SE, 6.9 +/- 0.5 log10 copies/ml), while semen viral load peaked about 30 days after infection (4.5 +/- 0.4 log10 copies/ml). Semen viral load declined by 1.7 log10 to a nadir by week 10 of HIV infection. Semen and blood viral loads were more stable in chronically infected subjects over 16 weeks. Higher semen levels of HIV RNA were noted in subjects with low CD4 cell counts. CONCLUSIONS: These results provide a biological explanation for reported increases in HIV transmission during the very early (acute) and late stages of infection. Recognizing temporal differences in HIV shedding in the genital tract is important in the development of effective HIV prevention strategies.

Rapid, real-time detection of acute HIV infection in patients in Africa.

BACKGROUND: We conducted a prospective study to evaluate methods of detecting clients with sexually transmitted diseases (STDs) who were acutely coinfected with human immunodeficiency virus (HIV) in Lilongwe, Malawi. METHODS: After informed consent was obtained, all clients with acute STDs were offered voluntary HIV counseling and testing by 2 rapid antibody tests. Samples from rapid test-negative or -discordant subjects were pooled (50 : 5 : 1) and tested for HIV RNA. Western blots were performed on all rapid test-discordant specimens with detectable HIV RNA. A subset of specimens received p24 antigen testing with standard and/or ultrasensitive methods. Patients with possible acute HIV infection were followed to confirm seroconversion. RESULTS: A total of 1450 clients (34% female and 66% male) agreed to testing, of whom 588 (40.55%) had established HIV infection and 21 (1.45%) had acute infection. Discordant rapid antibody tests identified 7 of 21 (33.3% sensitivity), standard p24 antigen identified 12 of 16 (75% sensitivity), and ultrasensitive p24 antigen identified 15 of 17 (88% sensitivity) acute cases. By definition, the sensitivity of the RNA assay was 100%. CONCLUSIONS: Real-time pooled RNA testing for the detection of acute HIV infection is feasible in resource-limited settings. However, parallel rapid testing and p24 antigen testing are technologically simpler and together may detect approximately 90% of acute cases.

The cost-effectiveness of treating male trichomoniasis to avert HIV transmission in men seeking sexually transmitted disease care in Malawi.

OBJECTIVE: Allocation of funds to program areas where they may have an impact is critical to the success of any HIV control program. We examined the cost-effectiveness of providing first-line treatment for male trichomoniasis in Malawi, a condition not commonly considered in syndromic management throughout sub-Saharan Africa. METHODS: We used decision tree analysis to assess program costs and outcomes among a 1-year population of male sexually transmitted disease (STD) clinic attendees estimated at 10,000 in Lilongwe. Our main outcomes were program costs from the government perspective and HIV infections averted. We conducted univariate and multivariate sensitivity analyses on selected parameters. RESULTS: In our study population of male STD clinic attendees with an HIV prevalence of 44% and a Trichomonas vaginalis prevalence of 20%, including universal metronidazole as a first-line treatment for trichomoniasis at $0.05 per dose would increase program costs by $277 (year 2000 US dollars) and avert 23 cases of HIV. The incremental cost-effectiveness ratio (ICER) over the current STD management guidelines was $15.42 per case of HIV averted. The number of HIV infections averted under sensitivity analysis ranged from 2 to 52, with attendant ICERs varying from cost savings to $162.92. Consideration of wider social benefits, such as the costs of HIV infections to the individual or the government, would further enhance the cost-effectiveness of this program. CONCLUSIONS: As part of a larger program to control STDs, incorporating metronidazole to treat male trichomoniasis could represent a cost-effective means to reduce HIV transmission in this high-risk group.

A phase III clinical trial of antibiotics to reduce chorioamnionitis-related perinatal HIV-1 transmission.

OBJECTIVE: A multisite study was conducted in Africa to assess the efficacy of antibiotics to reduce mother-to-child transmission (MTCT) of HIV-1. DESIGN: A randomized, double-blinded, placebo-controlled, phase III clinical trial. METHODS: HIV-1-infected women were randomly assigned at 20-24 weeks' gestation to receive either antibiotics (metronidazole plus erythromycin antenatally and metronidazole plus ampicillin intrapartum) or placebo. Maternal study procedures were performed at 20-24, 26-30, and 36 weeks antenatally, and at labor/delivery. Infants were seen at birth, 4-6 weeks, and 3, 6, 9 and 12 months. The primary efficacy endpoints were overall infant HIV-1 infection and HIV-1-free survival at 4-6 weeks. All women and infants received single-dose nevirapine prophylaxis in this study. RESULTS: A total of 1510 live-born infants were included in the primary analysis. The proportions of HIV-1-infected infants at birth were similar (antibiotics 7.1%; placebo 8.3%; P = 0.41). Likewise, there were no statistically significant differences at 4-6 weeks in the overall risk of MTCT of HIV-1 (antibiotics 16.2%; placebo 15.8%; P = 0.89) or HIV-1-free survival (79.4% in each study arm). Post-randomization, the proportion of women with bacterial vaginosis at the second antenatal visit was significantly lower in the antibiotics arm compared with the placebo arm (23.8 versus 39.7%; P < 0.001), but the frequency of histological chorioamnionitis was not different (antibiotics 36.9%; placebo 39.7%; P = 0.30). Adverse events in mothers and their infants did not differ by randomization arm. CONCLUSION: This simple antepartum and peripartum antibiotic regimen did not reduce the risk of MTCT of HIV-1.

Heterosexually transmitted HIV infection among African Americans in North Carolina.

CONTEXT: Rates of heterosexually transmitted HIV infection among African Americans in the southeastern United States greatly exceed those for whites. OBJECTIVE: Determine risk factors for heterosexually transmitted HIV infection among African Americans. METHODS: Population-based case-control study of black men and women, aged 18-61 years, reported to the North Carolina state health department with a recent diagnosis of heterosexually transmitted HIV infection and age- and gender-matched controls randomly selected from the state driver's license file. A lower-risk stratum of respondents was created to identify transmission risks among people who denied high-risk behaviors. RESULTS: Most case subjects reported annual household income < $16,000, history of sexually transmitted diseases, and high-risk behaviors, including crack cocaine use and sex partners who injected drugs or used crack cocaine. However, 27% of case subjects (and 69% of control subjects) denied high-risk sexual partners or behavior. Risk factors for HIV infection in this subset of participants were less than high school education (adjusted odds ratio [OR] 5.0; 95% CI: 2.2, 11.1), recent concern about having enough food for themselves or their family (OR 3.7; 1.5, 8.9), and having a sexual partner who was not monogamous during the relationship with the respondent (OR 2.9; 1.3, 6.4). CONCLUSION: Although most heterosexually transmitted HIV infection among African Americans in the South is associated with established high-risk characteristics, poverty may be an underlying determinant of these behaviors and a contributor to infection risk even in people who do not have high-risk behaviors.

Correlates of syphilis seroreactivity among pregnant women: the HIVNET 024 Trial in Malawi, Tanzania, and Zambia.

OBJECTIVES: The objectives of this cross-sectional study were to determine correlates of syphilis seroprevalence among HIV-infected and -uninfected antenatal attendees in an African multisite clinical trial, and to improve strategies for maternal syphilis prevention. RESULTS: A total of 2,270 (86%) women were HIV-infected and 366 (14%) were HIV-uninfected. One hundred seventy-five (6.6%) were syphilis-seropositive (7.3% among HIV-infected and 2.6% HIV-uninfected women). Statistically significant correlates included geographic site (odds ratio [OR] = 4.5, Blantyre; OR = 3.2, Lilongwe; OR = 9.0, Lusaka vs. Dar es Salaam referent); HIV infection (OR = 3.3); age 20 to 24 years (OR = 2.5); being divorced, widowed, or separated (OR = 2.9); genital ulcer treatment in the last year (OR = 2.9); history of stillbirth (OR = 2.8, one stillbirth; OR = 4.3, 2-5 stillbirths); and history of preterm delivery (OR = 2.7, one preterm delivery). CONCLUSION: Many women without identified risk factors were syphilis-seropositive. Younger HIV-infected women were at highest risk. Universal integrated antenatal HIV and syphilis screening and treatment is essential in sub-Saharan African settings.

HIV-1 populations in blood and breast milk are similar.

Mother-to-child transmission (MTCT) of human immunodeficiency virus type 1 (HIV-1) through breast milk is a significant mechanism of infection in many regions of the world. We compared the HIV-1 populations in paired blood and breast milk samples using a heteroduplex tracking assay (HTA) for the V1/V2 regions of env (V1/V2-HTA). V1/V2-HTA patterns were similar in the eight pairs of samples for which adequate template sampling could be demonstrated. No unique variants existed in either compartment, and differences detected in the relative abundance of variants between compartments were small, occurred among low abundance variants, and were not statistically significant. We also documented the impact of template sampling as a limiting feature in comparing two viral populations. The absence of unique variants and the lack of significant differences in the relative abundance of variants between these compartments support the conclusion that viruses in the blood plasma and breast milk are well equilibrated.

Frequent detection of acute primary HIV infection in men in Malawi.

BACKGROUND: Acute (antibody-negative) HIV infection is associated with high transmission potential but is rarely recognized. DESIGN: Cross-sectional study. METHODS: We examined the prevalence and predictors of acute HIV infection among 1361 consecutive male outpatients attending sexually transmitted disease (STD; n = 929) and dermatology (n = 432) clinics in Lilongwe, Malawi. Serum specimens negative for HIV antibodies were screened by HIV RNA PCR using a highly specific pooling/resolution testing algorithm. RESULTS: Five-hundred and fifty-three men (40.6%) were HIV antibody positive and 24 (1.8%) had acute HIV infection; 23 of 24 acutely infected men were from the STD clinic, where they represented 4.5% of all HIV antibody-negative men and 5.0% of all HIV infections. HIV RNA levels for acutely infected men were significantly higher [median (interquartile range), 6.10 (5.19-6.54) log10 HIV RNA copies/ml] than for 58 HIV antibody-positive men [4.42 (3.91-4.95) log10 copies/ml; P < 0.0001]. The factor most strongly associated with acute HIV infection was STD clinic attendance: (odds ratio, 15.2; 95% confidence interval, 2.04-113.0). In multivariate analysis considering only STD patients, factors associated with acute HIV infection included inguinal adenopathy, genital ulceration and age 24-26 years, the age stratum associated with peak incidence of HIV infection among Malawian men. CONCLUSIONS: Traditional HIV antibody tests alone are not sufficient to exclude HIV infection among men with acute STD in Malawi due to a surprising proportion of acute HIV infections in this population. Alternative screening methods are required for diagnosis of acute HIV infection; such screening could be important for research and for prevention of the sexual transmission of HIV in select populations.

Concurrent partnerships among rural African Americans with recently reported heterosexually transmitted HIV infection.

OBJECTIVES: To investigate concurrent sexual partnerships among African Americans in North Carolina with recently reported heterosexually transmitted HIV infection. DESIGN: Population-based case series of persons with newly reported HIV infection. METHODS: Household interviews concerning sexual and other risk behaviors for HIV transmission were conducted among African Americans, 18-59 years old, who had been reported to the state health department within the preceding 6 months as having heterosexually acquired HIV infection. Dates of sexual partnerships were analyzed to identify concurrency among the 3 most recent partnerships. RESULTS: Concurrency prevalence in the past 1 and 5 years, respectively, was 45 and 63% for men and 37 and 58% for women. Most respondents (87%) believed that a recent partner had had a concurrent partnership. Multivariate analysis revealed associations between concurrency and male gender, youth, crack cocaine smoking, and incarceration of a sex partner. CONCLUSIONS: Concurrent partnerships likely accelerate heterosexual HIV transmission among blacks in the rural southeastern United States. Future research should examine the socioeconomic context that supports this network pattern.

Human immunodeficiency virus type 1 RNA in breast-milk components.

We conducted the present study to determine which of the 4 components of breast milk (whole milk, skim milk, lipid layer, and breast-milk cells) had the highest sensitivity and concentration of human immunodeficiency virus (HIV) type 1 RNA burden and to determine biological correlates to these factors. The probability of detection of HIV (sensitivity) and the concentration of HIV-1 RNA were both associated with the choice of milk component, CD4(+) cell count, concentration of blood serum HIV-1 RNA, and the presence of breast inflammation. Whole milk demonstrated higher sensitivity and mean concentration than any other single component. Sensitivity was enhanced by analyzing all 4 components of breast milk.

Concurrent sexual partnerships among women in the United States.

BACKGROUND: The marked racial disparity in sexually transmitted infection (STI) rates in the United States remains inadequately explained. One important factor may be concurrent sexual partnerships (relationships that overlap in time), which can transmit STIs more rapidly through a population than does sequential monogamy. METHODS: To determine prevalence, distribution, and correlates of U.S. women's involvement in concurrent partnerships, we analyzed sexual partnership data reported by the 10,847 women, age 15-44 years, in the 1995 National Survey of Family Growth. Overlapping sexual partnership dates were determined by computer program and visual review of the data. RESULTS: Prevalence of concurrent partnerships since January 1991 was 12% overall. Prevalence was lowest among currently married respondents (4%) and highest among those who were formerly married (22%), never married (19%), in the lowest income stratum (17%), age 18-24 years when interviewed (23%), or who first had sexual intercourse at age 12 or 13 (35%). Prevalence was 21% among blacks, 11% among whites, 8% among Hispanics, and 6% among Asian American and Pacific Islanders. Multiple logistic analysis substantially weakened the relationship between concurrency and black race (OR = 1.2; 95% CI = 1.1-1.4). CONCLUSIONS: Marital status in particular is strongly related to concurrency; thus, lower marriage rates among blacks and the associated higher concurrency of sexual partners may contribute to racial disparities in STI rates.