Advantage of a two-dose versus one-dose varicella vaccine in healthy non-immune teenagers and young adults.

This study was undertaken to compare the immunogenicity and reactogenicity of two vaccines based on the attenuated Oka-strain of Varicella zoster virus (VZV), in adolescents and young adults. One hundred and eighty-six subjects, aged 13 to 29 years, were randomized to one of two groups to receive a one- or a two-dose VZV vaccine. Pre- and post-vaccination blood samples were assayed for VZV-specific IgG. Solicited local and general symptoms, as well as unsolicited symptoms, were recorded post-vaccination. Seroconversion rates were 94.9% in the one-dose, and 100% in the two-dose, regimen. The two-dose vaccine elicited significantly higher geometric mean antibody titer, 392.5 vs 86.8 pfu. Transient local injection site pain was the most frequently-reported symptom per dose in both groups (one dose: 48.9%; two-dose: 32.8%). The two-dose vaccine regimen afforded the advantage of higher antibody titers and potential increased protection from disease, without significantly increased reactogenicity.

Prevention of HIV transmission from mother-to-child in Srinagarind Hospital.

From January 1996 to December 1999, HIV infected pregnant women and their newborns were studied. Informed consent was obtained and HIV-tests were performed after counselling. ZDV for perinatal prophylaxis starting on week 14 to week 36 of gestation and continued throughout pregnancy was given following an ACTG 076 regimen except that during labour, intravenous ZDV was replaced by oral ZDV 300 mgs, given every 3-hours as a loading dose and ZDV syrup 2 mgs/kg every 6 hours for 7 days orally for the newborns. Newborn HIV-Ab and PCR were done at 6 weeks and 6 months after birth. Eighty-four HIV infected pregnant women were enrolled in the study, eighty-three of whom were delivered. The overall transmission rate was 5.2 per cent, with 3/58 children confirmed infected with HIV by at least two positive PCR test results.

Epidemiology of invasive meningococcal disease in 13 government hospitals in Thailand, 1994-1999.

This study was conducted to elucidate the magnitude of problem and the clinical course of invasive meningococcal infection from 13 government hospitals in Thailand between 1994 and 1999. Thirty-six strains of Neisseria meningitidis were isolated from 16 blood and 24 cerebrospinal fluid specimens; 4 patients had positive culture in both blood and CSF. Of the 16 strains, 9 (56.3%) were serogroup B. Seventy-one and eighty-four percent of the isolates were susceptible to penicillin and cefotaxime/ceftriaxone respectively. Five out of six penicillin-nonsusceptible strains were found to be relatively resistant to penicillin with the MIC of 0.125 microg/ml. Of 33 patients whose medical records were available, 21 were males and 12 were females, with a mean age of 11.2 years. Fifteen patients (45.5%) presented with meningococcemia and 18 patients (54.5%) presented with meningococcal meningitis. Hypotension and purpura were found in 24.2% and 33.3% of patients respectively. The overall mortality rate was 9.1%. In conclusion, meningococcal disease is not common in Thailand, meningococcemia is a life-threatening condition whereas meningococcal meningitis is much less severe. The prevalence of meningococci relatively resistant to penicillin seems to be increasing.

Survival of children with AIDS: experience in a university hospital in northeast Thailand.

The survival experience of pediatric AIDS patients from three points: birth, age at first symptom and age at AIDS diagnosis (by the WHO definition) was studied. We had 90 subjects, 46 males and 44 females. They were under 15 years of age and were diagnosed as having perinatally-acquired pediatric AIDS. The children came to Srinagarind Hospital between January, 1989 and December, 1997. They were followed-up until April 30, 1998. Patients who did not come to the hospital were traced by confidential mail. The two most common first symptoms were chronic diarrhea (36.7%) and persistent lower respiratory tract infection (34.4%). The median age at the first symptom was four months (95% CI = 3 to 5 months) and the median age at diagnosis was 13 months (95% CI = 11 to 15 months). Thirty-nine cases received antiretroviral treatment, either AZT, ddI or both. Forty-five cases died, 18 cases lived to the end of the study, 27 could not be followed-up. A survival curve was calculated according to the Kaplan and Meier method using SPSS version 6.0. The 1- and 2-year survival rates from the time of the first symptom were 75.3 per cent (95% CI = 65.8% to 84.7%) and 60.3 per cent (95% CI = 49.0% to 71.6%). The corresponding survival rates from AIDS diagnosis were 59.7 per cent (95% CI = 48.4% to 71.1%) and 42.8% (95% CI = 30.3% to 55.3%), respectively.

Seroepidemiology of hepatitis A virus antibody in primary school children in Khon Kaen Province, northeastern Thailand.

Hepatitis A is a disease commonly found in Thai children. Since 1984, there have been very few reports on the age specific prevalence of hepatitis A virus infection in the northeastern part of Thailand, which has the largest population and is the poorest area of the country. We studied the seroprevalence of hepatitis A virus (HAV) antibody in 3 primary school children in different areas of Khon Kaen Province, northeastern Thailand. Anti-HAV level was assayed by ELISA. Four hundred and forty-one children age 6-12 years were selected from one primary school in the urban area and two from rural areas. The highest prevalence was 22.6% at age 12 years and 0 at age 6 years. The seroprevalence was highest, 45%, in rural school children of the lowest socioeconomic status as compared to 10.8% and 2.6% in other urban school children. The overall prevalence was 12.7% and the age specific prevalence with 95% CI are presented. These data indicated a much lower seroepidemiological prevalence than previously reported and might be related to the level of socioeconomic and standard of public sanitation and living conditions.