Typing of Chlamydia trachomatis strains from urine samples by amplification and sequencing the major outer membrane protein gene (omp1).

OBJECTIVES: To develop a novel protocol for the extraction, amplification, and sequencing of Chlamydia trachomatis MOMP gene (omp1) from urine, a non-invasive source, and apply it to an epidemiological study on the distribution of C trachomatis strains in a population of pregnant women in Thailand. METHODS: The C trachomatis DNA was extracted from culture stocks and urine using a slightly modified commercially available kit, the High Pure PCR Template Preparation Kit (Roche Molecular Biochemicals, IN, USA). The PCR and sequencing primers used for the amplification and sequencing of the omp1 were designed based on the nucleotide sequence of multiple C trachomatis strains found in GenBank. The protocol for the extraction, amplification, and sequencing was tested on laboratory culture stocks of reference strains of all C trachomatis serovars and on urine samples collected in a cross sectional study designed to assess the prevalence of C trachomatis infections in the cities of Bangkok and Chiang Rai, Thailand. RESULTS: The omp1 gene was successfully amplified and sequenced from 18 laboratory C trachomatis reference strains and from 45 C trachomatis positive urine clinical samples collected from asymptomatic pregnant women. Among clinical samples, we found nine different C trachomatis genotypes: F (11, 25%), D (10, 22.6%), H (5, 11.7%), K (5, 11.7%), E (4, 9.3%), Ia (3, 7%), B (3, 7%), Ja (2, 4.5%), and G (1, 2.3%). One specimen generated an omp1 DNA sequence pattern indicating the presence of a mixed infection with at least two different serovars. CONCLUSIONS: Urine is a convenient and reliable source for genotyping C trachomatis strains. A clear advantage of urine over traditional samples, such as cervical swabs, is that urine is a non-invasive source which makes collection easier and thus facilitates the enrolment of patients in clinical and epidemiological studies. In addition to typing, urine is increasingly used for diagnosis of C trachomatis infection by several commercially available nucleic acid amplification assays which represents a distinct advantage for collecting, transport, storage, and laboratory handling of samples.

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

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 breast-fed, 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 HIV-seropositive 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.

HIV-infected women delivering without antenatal care in a large Bangkok hospital, 1997.

The aim was to estimate the proportion of HIV-infected women giving birth at a large Bangkok hospital who had not received antenatal care (ANC) and to identify predictors of not receiving ANC. At Rajavithi Hospital, Bangkok, women with ANC are routinely tested for HIV at their first antenatal visit; women without ANC are routinely tested at delivery. Hospital staff interview all HIV-infected women and record sociodemographic and HIV risk factor information in a delivery room log book. We abstracted and analyzed data recorded in this log book for all HIV-infected women who gave birth at Rajavithi Hospital in 1997. Of 303 HIV-infected women who gave birth, 75% had received ANC at Rajavithi Hospital, 10% had received ANC at other locations, and 15% had not received ANC. On multivariate analysis, HIV-infected women who had received ANC were more likely to work or have partners who worked in construction (25% vs 11%; adjusted odds ratio [AOR]; 2.6; p = 0.03) or have a history of injection drug use (4% vs 0.4%; AOR = 20.8; p = 0.02) than those who had not received ANC, but were less likely to report their current partner as a risk factor for acquiring HIV infection (22% vs. 40%; AOR = 0.4; p = 0.05). Because a substantial number of HIV-infected women give birth in this large Bangkok hospital without receiving ANC, interventions are needed to increase the number of HIV-infected women who receive ANC and to prevent perinatal HIV transmission from HIV-infected pregnant women who have not received ANC.

Lack of association between human immunodeficiency virus type 1 antibody in cervicovaginal lavage fluid and plasma and perinatal transmission, in Thailand.

To determine the association between human immunodeficiency virus type 1 (HIV)-specific antibody and RNA levels in cervicovaginal lavage (CVL) samples and plasma, zidovudine treatment, and perinatal transmission, HIV subtype E gp160-specific IgG and IgA were serially measured in a subset of 74 HIV-infected women in a placebo-controlled trial of zidovudine, beginning at 36 weeks of gestation. HIV IgG was detected in 100% of plasma and 97% of CVL samples; HIV IgA was consistently detected in 62% of plasma and 31% of CVL samples. Antibody titers in CVL samples correlated better with the RNA level in CVL samples than with plasma antibody titers. Zidovudine did not affect antibody titers. Perinatal HIV transmission was not associated with antibody in CVL samples or plasma. HIV-specific antibody is present in the cervicovaginal canal of HIV-infected pregnant women; its correlation with the RNA level in CVL fluid suggests local antibody production. However, there was no evidence that these antibodies protected against perinatal HIV transmission.

Short-course antenatal zidovudine reduces both cervicovaginal human immunodeficiency virus type 1 RNA levels and risk of perinatal transmission. Bangkok Collaborative Perinatal HIV Transmission Study Group.

Human immunodeficiency virus (HIV) levels in cervicovaginal lavage (CVL) and plasma samples were evaluated in relation to perinatal transmission in a randomized placebo-controlled trial of brief antenatal zidovudine treatment. Samples were collected at 38 weeks' gestation from 310 women and more frequently from a subset of 74 women. At 38 weeks, after a 2-week treatment period, CVL HIV-1 was quantifiable in 23% and 52% of samples in the zidovudine and placebo groups, respectively (P<.001). The perinatal transmission rate was 28.7% among women with quantifiable CVL HIV-1 and high plasma virus levels (>10,000 copies/mL) and 1% among women without quantifiable CVL HIV-1 and with low plasma virus levels (P<.001). A 1-log increase in plasma HIV-1 increased the transmission odds 1.8 and 6.1 times (95% confidence interval, 0.9-3.5 vs. 2.4-15.4) for women with and without quantifiable CVL HIV-1, respectively (P=.03). CVL HIV-1 is an independent risk factor for perinatal HIV-1 transmission.

Determinants of depression and HIV-related worry among HIV-positive women who have recently given birth, Bangkok, Thailand.

HIV-infected pregnant women have been the focus of considerable research related to biomedical issues of mother-to-child transmission worldwide. However, there have been few reports on the psychological well-being of new mothers with HIV, either in developed or developing countries. As part of a perinatal HIV transmission and family impact study in Bangkok, predictors of psychological scales were evaluated from interview data (N = 129) collected 18-24 months postpartum. Standardised questionnaires were used to assess depressive symptoms and HIV-related worry. Depressive symptomatology and HIV-related worry were common amongst these women. Multivariate logistic regression analysis identified several factors that predicted these psychological outcomes. High depression scores were associated with women who were no longer in a relationship with their partner (odds ratio (OR) 5.72, confidence interval (CI) 2.18-14.97) and who used venting coping strategies (OR 2.15, CI 1.44-3.21). Higher levels of HIV-related worry were associated with women whose babies were HIV-infected (OR 3.51, CI 1.28-10.69), who had not disclosed their HIV status to others (OR 3.05, CI 1.29-7.24) and who reported that their HIV-infection was something about which their family would be ashamed (OR 3.44, CI 1.34-9.77). Based on the current findings, intervention strategies we propose are psychological interventions which address disclosure issues, feelings of shame and coping strategies as well as financial assistance for single mothers. Interventions that require few resources such as group counselling or support merit special consideration.

Short-course zidovudine for perinatal HIV-1 transmission in Bangkok, Thailand: a randomised controlled trial. Bangkok Collaborative Perinatal HIV Transmission Study Group.

BACKGROUND: Many developing countries have not implemented the AIDS Clinical Trials Group 076 zidovudine regimen for prevention of perinatal HIV-1 transmission because of its complexity and cost. We investigated the safety and efficacy of short-course oral zidovudine administered during late pregnancy and labour. METHODS: In a randomised, double-blind, placebo-controlled trial, HIV-1-infected pregnant women at two Bangkok hospitals were randomly assigned placebo or one zidovudine 300 mg tablet twice daily from 36 weeks' gestation and every 3 h from onset of labour until delivery. Mothers were given infant formula and asked not to breastfeed. The main endpoint was babies' HIV-1-infection status, tested with HIV-1-DNA PCR at birth, 2 months, and 6 months. We measured maternal plasma viral concentrations by RNA PCR. FINDINGS: Between May, 1996, and December, 1997, 397 women were randomised; 393 gave birth to 395 live-born babies. Median duration of antenatal treatment was 25 days, and median number of doses during labour was three. 99% of women took at least 90% of scheduled antenatal doses. Adverse events were similar in the study groups. Of 392 babies with at least one PCR test, 55 tested positive: 18 in the zidovudine group and 37 in the placebo group. The estimated transmission risks were 9.4% (95% CI 5.2-13.5) on zidovudine and 18.9% (13.2-24.2) on placebo (p=0.006; efficacy 50.1% [15.4-70.6]). Between enrolment and delivery, women in the zidovudine group had a mean decrease in viral load of 0.56 log. About 80% of the treatment effect was explained by lowered maternal viral concentrations at delivery. INTERPRETATION: A short course of twice-daily oral zidovudine was safe and well tolerated and, in the absence of breastfeeding, can lessen the risk for mother-to-child HIV-1 transmission by half. This regimen could prevent many HIV-1 infections during late pregnancy and labour in less-developed countries unable to implement the full 076 regimen.

Maternal viral load and timing of mother-to-child HIV transmission, Bangkok, Thailand. Bangkok Collaborative Perinatal HIV Transmission Study Group.

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. Bangkok Collaborative Perinatal HIV Transmission Study Group.

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.

Rapid assessment of sexually transmitted diseases in a sentinel population in Thailand: prevalence of chlamydial infection, gonorrhoea, and syphilis among pregnant women--1996.

OBJECTIVE: To determine the prevalence of sexually transmitted diseases (STDs) among pregnant women in Thailand, where case reporting suggests a marked decrease in STDs following a campaign promoting condom use during commercial sex. DESIGN: Cross sectional study of women at their first visit to the study hospitals' antenatal clinics in Chiang Rai (n = 500) and Bangkok (n = 521). METHODS: First catch urine specimens were tested for Chlamydia trachomatis and Neisseria gonorrhoeae using the Amplicor CT/NG polymerase chain reaction assay. Syphilis and HIV serological testing were performed in the study hospitals' laboratories. RESULTS: The prevalence of chlamydial infection was 5.7%, gonorrhoea 0.2%, and syphilis 0.5% (all VDRL or RPR titres were < or = 1:4). The prevalence of HIV infection was 7.1% in Chiang Rai and 2.9% in Bangkok. In a multivariate logistic regression analysis, chlamydial infection was associated with younger age and with higher gestational age at first antenatal clinic visit, but was not associated with marital status, gravidity, city of enrollment, or HIV infection status. CONCLUSIONS: There was a low prevalence of gonorrhoea and syphilis among these pregnant women in Thailand. Chlamydial infection was detected at a higher prevalence, especially among younger women and women registering later for antenatal care. Testing of pregnant women using easily collected urine specimens and a sensitive nucleic acid amplification assay is a feasible method of rapidly assessing chlamydial and gonococcal prevalence.

HIV prevalence, risk, and partner serodiscordance among pregnant women in Bangkok. Bangkok Collaborative Perinatal HIV Transmission Study Group.

CONTEXT: Most prior studies of the human immunodeficiency virus (HIV) epidemic in Thailand have focused on commercial sex encounters; however, because the epidemic increasingly concerns stable heterosexual relationships, determining risk factors for this form of transmission is warranted. OBJECTIVES: To determine temporal trends in HIV prevalence, risk factors for HIV seropositivity, and rates of partner serodiscordance for pregnant women in Bangkok, Thailand. DESIGN: Retrospective review of hospital antenatal clinic HIV test results from 1991 through 1996. Baseline demographic and behavioral risk factors for HIV were assessed for subjects enrolled from November 1992 through March 1994. SETTING: Two Bangkok hospitals with routine antenatal clinic HIV counseling and testing. PARTICIPANTS: The HIV-positive pregnant women enrolled in a perinatal HIV transmission study and their partners and HIV-negative pregnant controls. RESULTS: From 1991 through 1996, antenatal clinic HIV seroprevalence increased from 1.0% to 2.3%. On multivariate analysis of data from 342 HIV-positive and 344 HIV-negative pregnant women, more than 1 lifetime sex partner, history of a sexually transmitted disease, and a high-risk sex partner were the most important factors for seropositivity (all P<.001). Twenty-six percent of partners of HIV-positive women were HIV negative. Women reporting more than 1 lifetime sex partner were more likely to have an HIV-negative partner than women reporting only 1 (45% vs 8%; relative risk, 5.5; 95% confidence interval, 3.2-9.5; P<.001); women reporting no high-risk behaviors were less likely to have an HIV-negative partner (10% vs 44%; relative risk, 0.2; 95% confidence interval, 0.1-0.4; P<.001). CONCLUSIONS: Prevalence of HIV in pregnant women has increased steadily in Bangkok from 1991 through 1996. Sex with current partners was the only identified risk exposure for about half (52%) of the HIV-positive women. Although few HIV-positive pregnant women reported high-risk behaviors, more than 1 lifetime partner and a partner with high-risk behavior were strong risk factors for seropositivity. Together with the unexpected finding that one fourth of partners of seropositive pregnant women were seronegative, these data emphasize that women in the general population are at risk for HIV because of the risk behavior of both current and previous partners.

Impact of HIV on families of HIV-infected women who have recently given birth, Bangkok, Thailand.

The objective of this study was to assess changes in the family situation of HIV-infected women who have recently given birth. As part of a prospective perinatal HIV transmission study, interviews were conducted with a subset of HIV-infected women at 18 to 24 months postpartum, and answers were compared with baseline information obtained during pregnancy. Standardized scales were used to assess levels of psychosocial functioning. A convenience sample of 129 HIV-infected women enrolled during pregnancy was interviewed at 18 to 24 months postpartum. At delivery, the women were young (median age, 22 years), primiparous (57%), and asymptomatic (93%). When baseline and follow-up data were compared, more women were living alone (1% versus 6%; p = 0.03), fewer women were living with their partners (98% versus 73%; p < 0.001), and 30% of families had reduced incomes. At follow-up, 10% of partners had died, and more partners than wives had become ill or died (21% versus 4%; p = 0.02). Most children (78%) were living with their mothers, but only 57% of the HIV-infected women were the primary caretakers. Fewer women had disclosed their HIV status to others (e.g., family, friends) than to their partners (34% versus 84%; p < 0.001), largely because of fear of disclosure. The women appeared to have high levels of depression and worry. The women's greatest worries were about their children's health and the family's future. Within 2 years after childbirth, substantial change within the families of HIV-infected women was evident. These were manifest by partner illness or death, family separation, reduced family income, shifting responsibilities for child care, and signs of depression and isolation. Providing family support is a major challenge in Thailand as the perinatal HIV epidemic progresses.

PIP: As part of a larger prospective perinatal HIV transmission study in Bangkok, Thailand (1992-94), interviews were conducted with a subset of 129 HIV-infected women 18-24 months after delivery and the results were compared with data obtained from these women during pregnancy. The median age of women at delivery was 22 years; 57% were primiparous and 93% were asymptomatic at delivery. 25 infants (19.4%) had confirmed HIV infection and 2 had died by the time of the follow-up interview. By follow up, 21% of male partners had died or developed HIV-related functional impairments. The proportion of women living alone rose from 1% at baseline to 6% at follow up, while the proportion living with their partner declined from 98% to 73%. 30% of families had reduced incomes at follow-up compared with baseline. Although 78% of infants were living with their mothers, they were the primary caretakers in only 57% of families. Only 34% of HIV-infected mothers had disclosed their HIV status to friends or family other than their partner. 43% of women scored above the cut-off on the depression scale. Mothers worried extensively about their child's health and their family's future. However, only 37% believed they could find someone to talk to about their feelings related to HIV. 58% were interested in joining a support group for women with HIV. These findings of family disruption, reduced family income, shifting responsibilities for child care, depression, and isolation indicate an urgent need for increased social support for HIV-infected mothers in Thailand.

Chlamydial and gonococcal cervicitis in HIV-seropositive and HIV-seronegative pregnant women in Bangkok: prevalence, risk factors, and relation to perinatal HIV transmission.

OBJECTIVES: To determine the prevalence and risk factors associated with cervicitis caused by Chlamydia trachomatis and Neisseria gonorrhoeae in human immunodeficiency virus (HIV) type 1-seropositive and HIV-seronegative pregnant women in Bangkok, and the relation to perinatal HIV transmission. METHODS: As part of a multicenter perinatal HIV transmission study in an antenatal population with 2% HIV seroprevalence, endocervical swabs obtained at mid-pregnancy from a consecutive sample of 222 HIV-seropositive and 219 HIV-seronegative pregnant women at two large hospitals in Bangkok were tested for the presence of C. trachomatis and N. gonorrhoeae by DNA hybridization probe (Gen-Probe). Clinical risk factors and DNA probe results were analyzed in relation to the women's and newborns' HIV infection status. RESULTS: The prevalence of C. trachomatis was 16.2% in HIV-seropositive pregnant women and 9.1% in HIV-seronegative pregnant women (P = 0.03). The prevalence of N. gonorrhoeae was 2.7% in HIV-seropositive pregnant women and 1.4% in HIV-seronegative pregnant women (P = 0.5). The overall population prevalence estimate was 9.2% for C. trachomatis and 1.4% for N. gonorrhoeae. Women with gonococcal infection were more likely to be positive for C. trachomatis (RR(MH) = 5.2, P < 0.01). Young age (<21 years) and primigravid status were associated with C. trachomatis infection among HIV-seropositive women; history of multiple sex partners (>1) were associated with C. trachomatis infection among HIV-seronegative women. For HIV-seropositive women, primigravida status also was associated with C. trachomatis infection. The perinatal HIV transmission rates were similar for those with and without C. trachomatis (24.1% and 23.2%, P = 0.9) and among those with and without N. gonorrhoeae (20% and 23.5%, P = 1.0). CONCLUSIONS: Among pregnant women in Bangkok, C. trachomatis infection was considerably more common than N. gonorrhoeae infection and was associated with HIV infection, young age and first pregnancy (HIV-seropositive women), and multiple partners (HIV-seronegative women). Our data do not suggest an association between perinatal HIV transmission and maternal C. trachomatis or N. gonorrhoeae infection identified and treated during pregnancy. The high prevalence of C. trachomatis found using a test not readily available in Thailand emphasizes the need for improved, inexpensive ways to screen for and diagnose these sexually transmitted infections in developing countries.

PIP: Numerous studies have suggested that Chlamydia trachomatis and Neisseria gonorrhoeae facilitate heterosexual HIV transmission; the impact of these sexually transmitted diseases (STDs) on perinatal HIV transmission is unknown, however, due to the expense of routine screening for STDs during pregnancy in developing countries. As part of a multicenter perinatal HIV transmission study, 222 HIV-positive and 219 HIV-negative women presenting for prenatal care at 2 hospitals in Bangkok, Thailand, during 1993-94 were enrolled. At mid-pregnancy, endocervical swabs were obtained and tested for the presence of C. trachomatis and N. gonorrhoeae by DNA hybridization probe. There were 36 cases (16.2%) of C. trachomatis infection among HIV-positive women and 20 cases (9.1%) among HIV-negative women. There were 6 cases (2.7%) of N. gonorrhoeae among HIV-positive women and 3 cases (1.4%) among HIV-negative women. Based on an estimated antenatal HIV seroprevalence of 2%, these findings imply a general antenatal prevalence of 9.2% for C. trachomatis and 1.4% for N. gonorrhoeae. Women with gonococcal infection were more likely (relative risk, 5.2) to be positive for C. trachomatis as well. C. trachomatis infection among HIV-infected pregnant women was associated with age under 21 years and primigravidity. The overall perinatal HIV transmission rate was 24.2%, with no significant difference according to STD infection status. However, since all women diagnosed with STDs received treatment by the mid-third trimester of pregnancy, it remains possible that untreated STDs facilitate perinatal HIV transmission. The high prevalence of C. trachomatis detected in this study through use of a test not readily available in Thailand emphasizes the need for inexpensive, reliable methods to screen for STDs among pregnant women in developing countries.