Antiretroviral resistance patterns and HIV-1 subtype in mother-infant pairs after the administration of combination short-course zidovudine plus single-dose nevirapine for the prevention of mother-to-child transmission of HIV.

BACKGROUND: World Health Organization guidelines for prevention of mother-to-child transmission of human immunodeficiency virus type 1 (HIV-1) recommend administration of zidovudine and single-dose nevirapine (NVP) for HIV-1-infected women who are not receiving treatment for their own health or if complex regimens are not available. This study assessed antiretroviral resistance patterns among HIV-infected women and infants receiving single-dose NVP in Thailand, where the predominant circulating HIV-1 strains are CRF01_AE recombinants and where the minority are subtype B. METHODS: Venous blood samples were obtained from (1) HIV-infected women who received zidovudine from 34 weeks' gestation and single-dose NVP plus oral zidovudine during labor and (2) HIV-infected infants who received single-dose NVP after birth plus zidovudine for 4 weeks after delivery. HIV-1 drug resistance testing was performed using the TruGene assay (Bayer HealthCare). RESULTS: Most mothers and infants were infected with CRF01_AE. NVP resistance was detected in 34 (18%) of 190 women and 2 (20%) of 10 infants. There was a significantly higher proportion of NVP mutations in women with delivery viral loads of >50,000 copies/mL (adjusted odds ratio, 8.5; 95% confidence interval, 2.2-32.8, P = .002 for linear trend) and in those with subtype B rather than CRF01_AE infections (38% vs. 16%; adjusted odds ratio, 3.6; 95% confidence interval, 1.1-11.8; P = .038). CONCLUSIONS: The lower frequency of NVP mutations among mothers infected with subtype CRF01_AE, compared with mothers infected with subtype B, suggests that individuals infected with subtype CRF01_AE may be less susceptible to the induction of NVP resistance than are individuals infected with subtype B.

Effect of perinatal short-course zidovudine on the clinical and virological manifestations of HIV-1 subtype E infection in infants.

BACKGROUND: The perinatal short-course zidovudine (ZDV) chemoprophylaxis that can reduce HIV-1 vertical transmission by 51% has been widely practiced in developing countries such as Thailand because of its simpler and less cost. OBJECTIVES: To investigate the effects of short-course regimen of oral ZDV for prophylaxis of HIV-1 subtype E vertical transmission among 'break-through' HIV-1 infected infants. STUDY DESIGN: The study analyzed clinical and virological outcomes of 80 infants, whose mothers received ZDV prophylaxis starting at 36 weeks gestation (group Z) and 37 infants whose mothers never received anti-retroviral drugs (group C), at the ages of 1-2, 4-6, and 12 months. RESULTS: Of the 12 HIV-1 infected infants, 5/7 (71.4%) from group Z and 1/5 (20%) from group C progressed to a symptomatic clinical stage by the age 4-6 months. The intersample nucleotide distance of HIV-1 pol reverse transcriptase (RT) sequences of isolates collected at age of 1-2 months from group Z was significantly higher than that from group C (3.34 and 2.92%, P=0.02). All twelve virus isolates from infected infants were non syncytium inducing (NSI) and macrophage tropic strains; and 5/6 (83.3%) viruses from symptomatic infants were also T-tropic viruses. The symptomatic infants also had significantly higher HIV-1 nucleic acid quantitation than asymptomatic infants. CONCLUSION: Our results preliminary suggested that infected infants who were perinatally exposed to ZDV may have a more rapid early disease progression with unfavorable viral manifestations than those without exposure to antiretroviral drug.

The outbreak of Serratia marcescens bacteremia in a pediatric ward, Siriraj Hospital 1997.

Between October 20 and November 11, 1997, Serratia marcescens bacteremia was identified in 8 patients in a pediatric ward at Siriraj Hospital. The organism was isolated from 17 blood and 3 bone marrow specimens. The only common associated factor in these patients was that they all had received an intravenous fluid infusion. In the attempt to investigate the source of S. marcescens implicated in the outbreak, 108 specimens of intravenous fluid, 3 intravenous fluid bottle caps, 4 specimens from intravenous fluid tubing sets, 21 specimens of antiseptics used on the ward, 28 specimens of rectal swabs from patients on the ward, 1 sample of blood culture media prepared by the hospital for routine use, and 62 environmental specimens including hand swabs of the medical personnel, refrigerator, air conditioning, milk samples, room air, water sink, wooden splint and adhesive tape used to immobilize the intravenous access. Of 227 specimens sent for culture, S. marcescens was isolated from only one specimen collected from the in-use intravenous fluid given to a patient with Serratia bacteremia. S. marcescens was not found in any other surveillance culture. The 8 patients were placed under quarantine in the same room with an exclusive nursing team. With the investigation and intervention including monitoring for meticulous hand washing of the ward staff, the outbreak was stopped within 7 days. Although the investigation failed to discover the environmental reservoir of S. marcescens in this outbreak, the data suggested that intravenous fluid was probably the route of transmission and the medical personnel played an important role in spreading the infection.

Mycobacterium avium complex in HIV-infected Thai children.

Of the 169 human immunodeficiency virus (HIV)-infected children being cared for at Siriraj Hospital from January 1998 to September 2000, 10 had Mycobacterium avium complex (MAC) infection; seven had disseminated disease and three had MAC pneumonia. Nine children were in the advanced stage of HIV disease at the time of diagnosis with the median CD4 count of 7 cells/mm3 and 127 cells/mm3 and the median age of 65 months and 63 months in disseminated MAC and MAC pneumonia respectively. None of these children had received prior chemoprophylaxis. Common clinical findings included prolonged fever, weight loss, lymphadenopathy, hepatosplenomegaly, diarrhea, anemia and leukopenia. The outcome of MAC infection was poor, with a mortality rate of 60 per cent. In in vitro susceptibility testing, clarithromycin was the least resistant drug. With the incidence rate of 2.15 per 100 person-years, the high rate of antimicrobial resistance, and the poor outcome, primary chemoprophylaxis for MAC infection in conjunction with effective antiretroviral therapy should be considered for Thai children in the advanced stage of HIV infection.

Appropriate time-interval application of alcohol hand gel on reducing influenza-like illness among preschool children: a randomized, controlled trial.

BACKGROUND: We studied the efficacy of different time-interval applications of alcohol hand gel as a strategy for the prevention of influenza-like illness (ILI) in preschool-age children. METHODS: We performed a classroom-based cluster randomization at a kindergarten school in Bangkok, Thailand. A total of 1437 children were placed into 3 test groups, based on the frequency of alcohol hand gel use for hand hygiene: only before lunch (q lunch), every 120 minutes (q 120), and every 60 minutes (q 60). The primary outcome was a change in the school absenteeism rate caused by ILI. RESULTS: The rates of absenteeism from confirmed ILI (sick days/present days) were 0.026 in the q lunch group, 0.025 in the q 120 group, and 0.017 in the q 60 group. Significant reductions in absenteeism rates were seen when comparing the q 60 group with the q 120 group (rate difference, 0.009; 95% confidence interval [CI], -0.002 to 0.015; P = .008) and comparing the q 60 group with the q lunch group (rate difference, 0.0096; 95% CI, 0.004-0.016; P = .002). No such differences were detected between the q 120 and q lunch groups (rate difference, 0.001; 95% CI, 0.005-0.007; P = .743). CONCLUSIONS: The compulsory hourly use of alcohol gel as classroom hand disinfection could significantly reduce the rate of absenteeism from ILI in preschool-age children.

Evaluating programs to prevent mother-to-child HIV transmission in two large Bangkok hospitals, 1999-2001.

The 2 largest maternity hospitals in Bangkok implemented comprehensive programs to prevent mother-to-child HIV transmission in 1998. We conducted a cross-sectional survey of post-partum HIV-infected women in 1999 through 2001 to evaluate these programs. Women were given structured interviews at 0 to 3 days, 1 month, and 2 months postpartum. Medical records of women and their newborns were reviewed. Of 488 enrolled women, 443 (91%) had antenatal care: 391 (88%) at study hospitals and 52 (12%) elsewhere. The HIV diagnosis was first known before pregnancy for 61 (13%) women, during pregnancy for 357 (73%) women, during labor for 22 (5%) women, and shortly after delivery for 48 (10%) women. Antenatal zidovudine (ZDV) was used by 347 (71%) women, and intrapartum ZDV was used by 372 (76%) women. Twelve (55%) of the 22 women who first learned of their HIV infection during labor took intrapartum ZDV. All 495 newborn infants started prophylactic ZDV; the first dose was given within 12 hours for 491 (99%) children. Ten (2%) children were breast-fed at least once by their mother, and 10 (2%) were breast-fed at least once by someone else. Although uptake of services was high, inconsistent antenatal care, fear of stigmatization, and difficulty in disclosing HIV status prevented some women from using services.