Anuvat Roongpisuthipong

Maternal viral load and timing of mother-to-child HIV transmission Bangkok Thailand.

OBJECTIVES To determine the proportion of HIV-1-infected infants infected in utero and intrapartum, the relationship between transmission risk factors and time of transmission, and the population-attributable fractions for maternal viral load. DESIGN Prospective cohort study of 218 formula-fed infants of HIV-1-infected untreated mothers with known infection outcome and a birth HIV-1-positive DNA PCR test result. METHODS Transmission in utero was presumed to have occurred if the birth sample (within 72 h of birth) was HIV-1-positive by PCR; intrapartum transmission was presumed if the birth sample tested negative and a later sample was HIV-1-positive. Two comparisons were carried out for selected risk factors for mother-to-child transmission: infants infected in utero versus all infants with a HIV-1-negative birth PCR test result, and infants infected intrapartum versus uninfected infants. RESULTS Of 49 infected infants with an HIV-1 birth PCR result, 12 (24.5%) [95% confidence interval (CI), 14 -38] were presumed to have been infected in utero and 37 (75.5%) were presumed to have been infected intrapartum. The estimated absolute overall transmission rate was 22.5%; this comprised 5.5% (95% CI, 3-9) in utero transmission and 18% (95% CI, 13-24) intrapartum transmission. Intrapartum transmission accounted for 75.5% of infections. High maternal HIV-1 viral load (> median) was a strong risk factor for both in utero [adjusted odds ratio (AOR) 5.8 (95% CI, 1.4-38.8] and intrapartum transmission (AOR, 4.4; 95% CI, 1.9-11.2). Low birth-weight was associated with in utero transmission, whereas low maternal natural killer cell and CD4(+) T-lymphocyte percentages were associated with intrapartum transmission. The population-attributable fraction for intrapartum transmission associated with viral load > 10 000 copies/ml was 69%. CONCLUSIONS Our results provide further evidence that most perinatal HIV-1 transmission occurs during labor and delivery, and that risk factors may differ according to time of transmission. Interventions to reduce maternal viral load should be effective in reducing both in utero and intrapartum transmission.

Maternal Virus Load and Perinatal Human Immunodeficiency Virus Type 1 Subtype E Transmission, Thailand

To determine the rate and risk factors for human immunodeficiency virus (HIV)-1 subtype E perinatal transmission, with focus on virus load, pregnant HIV-infected women and their formula-fed infants were followed prospectively in Bangkok. Of 281 infants with known outcome, 68 were infected (transmission rate, 24.2%; 95% confidence interval, 19.3%-29.6%). Transmitting mothers had a 4.3-fold higher median plasma HIV RNA level at delivery than did nontransmitters (P<.001). No transmission occurred at <2000 copies/mL. On multivariate analysis, prematurity (adjusted odds ratio [AOR], 4.5), vaginal delivery (AOR, 2.9), low NK cell percentage (AOR, 2.4), and maternal virus load were associated with transmission. As RNA quintiles increased, the AOR for transmission increased linearly from 4.5 to 24.8. Two-thirds of transmission was attributed to virus load>10,000 copies/mL. Although risk is multifactorial, high maternal virus load at delivery strongly predicts transmission. This may have important implications for interventions designed to reduce perinatal transmission.

Update on perinatal HIV transmission

Over the past decade, much progress has been made in understanding the risk factors and timing of perinatal HIV transmission. Even more impressive have been the successful clinical trials with antiretrovirals, such as ZDV, ZDV-3TC, and nevirapine, that demonstrated significant reductions in the risk for infant infection. Within the United States and Europe, these trial results have led to rapid implementation and dramatic decreases in new perinatal HIV cases since 1994. An immediate challenge is to rapidly translate the short-course antiretroviral trial results with ZDV and nevirapine into public health policy and practice in resource-poor settings, where almost 600,000 neonates continue to become infected by mother-infant HIV transmission each year. Physicians must also test strategies to further decrease the risk for infant HIV infection during the breast-feeding period.

Human papillomavirus (HPV) detection among human immunodeficiency virus-infected pregnant Thai women: implications for future HPV immunization.

Background: Human immunodeficiency virus (HIV)–infected women are at increased risk for developing cervical cancer and for infection with human papillomavirus (HPV). Prophylactic vaccines targeting HPV types 16 and 18 are being evaluated for efficacy among young women. Goal: The goal was to assess the prevalence of HPV among HIV-infected pregnant women in Bangkok and to evaluate the need for prophylactic HPV vaccines studies in this population. Study Design: The study population consisted of 256 HIV-infected pregnant women who participated in a mother-to-child HIV transmission trial. Stored cervicovaginal lavage samples were tested for the presence of HPV DNA by polymerase chain reaction with PGMY09/11 primers and reverse line-blot hybridization for determination of anogenital HPV types. Results: HPV prevalence was 35.5% (91/256); high-risk HPV prevalence was 23.4% (60/256). HPV type 16 or 18 was present in 8.2% (21/256). Almost half of all infections were multiple. Furthermore, overall HPV detection was associated with abnormal cervical cytology (P <0.001) and higher HIV-plasma viral load (P = 0.007). Conclusions: Only one-quarter of HIV-infected pregnant women in Bangkok had high-risk HPV types; less than 10% had HPV types 16 or 18. As the HPV prevalence is expected to increase during HIV disease, prophylactic vaccines targeting HPV types 16 and 18 should be studied among HIV-infected women not yet infected with these HPV types and not previously exposed.

Reduced Mother-to-Child Transmission of HIV Associated with Infant but not Maternal GB Virus C Infection

BACKGROUND Prolonged coinfection with GB virus C (GBV-C) has been associated with improved survival in human immunodeficiency virus (HIV)-infected adults. We investigated whether maternal or infant GBV-C infection was associated with mother-to-child transmission (MTCT) of HIV-1 infection. METHODS The study population included 1364 HIV-infected pregnant women enrolled in 3 studies of MTCT of HIV in Bangkok, Thailand (the studies were conducted from 1992-1994, 1996-1997, and 1999-2004, respectively). We tested plasma collected from pregnant women at delivery for GBV-C RNA, GBV-C antibody, and GBV-C viral genotype. If GBV-C RNA was detected in the maternal samples, the 4- or 6-month infant sample was tested for GBV-C RNA. The rates of MTCT of HIV among GBV-C-infected women and infants were compared with the rates among women and infants without GBV-C infection. RESULTS The prevalence of GBV-C RNA in maternal samples was 19%. Of 245 women who were GBV-C RNA positive, 101 (41%) transmitted GBV-C to their infants. Of 101 infants who were GBV-C RNA positive, 2 (2%) were infected with HIV, compared with 162 (13%) of 1232 infants who were GBV-C RNA negative (odds ratio [OR] adjusted for study, 0.13 [95% confidence interval {CI}, 0.03-0.54]). This association remained after adjustment for maternal HIV viral load, receipt of antiretroviral prophylaxis, CD4(+) count, and other covariates. MTCT of HIV was not associated with the presence of GBV-C RNA (adjusted OR [aOR], 0.94 [95% CI, 0.62-1.42]) or GBV-C antibody (aOR, 0.90 [95% CI, 0.54-1.50]) in maternal samples. CONCLUSIONS Reduced MTCT of HIV was significantly associated with infant acquisition of GBV-C but not with maternal GBV-C infection. The mechanism for this association remains unknown.

HIV seroconversion during pregnancy and risk for mother-to-infant transmission

Summary: Pregnant women infected with HIV‐1 were enrolled in a prospective mother‐to‐infant transmission study from 1992 through 1994 in Bangkok. In participating hospitals, voluntary HIV testing was routinely offered at the beginning of antenatal care and again in the middle of the third trimester of pregnancy. Women who seroconverted to HIV during pregnancy were compared with women who had tested positive on their first antenatal test. Maternal HIV RNA levels were determined during pregnancy, at delivery, and postpartum using RNA polymerase chain reaction (PCR), and infection status in infants was determined by DNA PCR. No infants were breastfed, but prophylactic antiretroviral therapy was not yet used in Thailand to prevent transmission from mother to infant. Among enrolled women, 16 who seroconverted during pregnancy and 279 who were HIV‐1‐seropositive at their first antenatal test gave birth. Median plasma RNA levels at delivery were similar for the two groups (17,505 and 20,845 copies/ml, respectively; p = .8). Two (13.3%) of 15 infants born to women who seroconverted and 66 (24.8%) of 266 infants born to previously HIVseropositive women were infected with HIV (p = .5). There was no increased risk for mother‐to‐infant HIV transmission and no significant difference in viral load at delivery between HIV‐infected women who seroconverted to HIV during pregnancy and those who were HIV‐seropositive when first tested.

Infection with Hepatitis C Virus among HIV-Infected Pregnant Women in Thailand

Objective. The purpose of this study was to describe the epidemiology of coinfection with hepatitis C virus (HCV) and HIV among a cohort of pregnant Thai women. Methods. Samples from 1771 pregnant women enrolled in three vertical transmission of HIV studies in Bangkok, Thailand, were tested for HCV. Results. Among HIV-infected pregnant women, HCV seroprevelance was 3.8% and the active HCV infection rate was 3.0%. Among HIV-uninfected pregnant women, 0.3% were HCV-infected. Intravenous drug use by the woman was the factor most strongly associated with HCV seropositivity. Among 48 infants tested for HCV who were born to HIV/HCV coinfected women, two infants were HCV infected for an HCV transmission rate of 4.2% (95% 0.51–14.25%). Conclusions. HCV seroprevalence and perinatal transmission rates were low among this Thai cohort of HIV-infected pregnant women.

Gonococcal urethritis diagnosed from enzyme immunoassay of urine sediment

First-catch urine specimens were obtained before clinical examination from 101 sexually active men who attended a sexually transmitted diseases clinic with a complaint of urethral discharge. Urethral swab specimens were used for preparation of smears and were then cultured on Martin-Lewis medium. Enzyme immunoassay (EIA) tests were performed on (1) uncentrifuged urine, (2) urine sediment, and (3) urine sediment diluted 1:6 with detergent buffer. Urethral cultures from 65 (64%) of the 101 men were positive for N. gonorrhoeae. EIA performed on urine sediment diluted 1:6 yielded the highest sensitivity: 98.5% (64/65). Sensitivity of EIA for uncentrifuged urine was only 66% (43/65). Specificity of all samples tested exceeded 97.2%. Overall agreement between results of EIA on diluted urine sediment and culture was 98% (99/101). Discordant culture and EIA results were unrelated to urine volume, time since prior urination, quantity of gonococcal growth on Martin-Lewis medium, duration of urine storage (less than 72 hours) before testing, or immunotype. EIA tests using urine sediment are highly sensitive and specific, and they offer an alternative means of diagnosing gonorrhea in men who refuse urethral manipulation. They also provide a means of screening men at high risk for gonorrhea who have submitted a urine specimen for other reasons.

Prevalence and correlates of GB virus C infection in HIV‐infected and HIV‐uninfected pregnant women in Bangkok, Thailand

GB virus C (GBV‐C) is an apathogenic virus that has been shown to inhibit HIV replication. This study examined the prevalence and correlates of GBV‐C infection and clearance in three cohorts of pregnant women in Thailand. The study population consisted of 1,719 (1,387 HIV‐infected and 332 HIV‐uninfected) women from three Bangkok perinatal HIV transmission studies. Stored blood was tested for GBV‐C RNA, GBV‐C antibody, and if RNA‐positive, genotype. Risk factors associated with the prevalence of GBV‐C infection (defined as presence of GBV‐C RNA and/or antibody) and viral clearance (defined as presence of GBV‐C antibody in the absence of RNA) among women with GBV‐C infection were examined using multiple logistic regression. The prevalence of GBV‐C infection was 33% among HIV‐infected women and 15% among HIV‐uninfected women. GBV‐C infection was independently associated (AOR, 95% CI) with an increasing number of lifetime sexual partners (referent—1 partner, 2 partners [1.60, 1.22–2.08], 3–10 partners [1.92, 1.39–2.67], >10 partners [2.19, 1.33–3.62]); injection drug use (5.50, 2.12–14.2); and HIV infection (3.79, 2.58–5.59). Clearance of GBV‐C RNA among women with evidence of GBV‐C infection was independently associated with increasing age in years (referent <20, 20–29 [2.01, 1.06–3.79] and ≥30 [3.18, 1.53–6.60]), more than 10 lifetime sexual partners (3.05, 1.38–6.75), and HIV infection (0.29, 0.14–0.59). This study found that GBV‐C infection is a common infection among Thai women and is associated with HIV infection and both sexual and parenteral risk behaviors. J. Med. Virol. 83:33–44, 2011.

Early Postpartum Pharmacokinetics of Lopinavir Initiated Intrapartum in Thai Women

ABSTRACT Lopinavir (LPV) exposure is reduced during the third trimester of pregnancy. We report the pharmacokinetics of standard LPV-ritonavir dosing (400/100 mg twice daily) in the immediate and early postpartum period when initiated during labor. In 16 human immunodeficiency virus-infected Thai women, the median (range) LPV area under the concentration-time curve and maximum and minimum concentrations in plasma were 99.7 (66.1 to 180.5) μg·h/ml, 11.2 (8.0 to 17.5) μg/ml, and 4.6 (1.7 to 12.5) μg/ml, respectively, at 41 (12 to 74) h after delivery. All of the women attained adequate LPV levels through 30 days postpartum. No serious adverse events were reported.