Intestinal microsporidiosis in HIV-infected children with acute and chronic diarrhea.

A prospective study of intestinal microsporidiosis in HIV-positive children was conducted at the Queen Sirikit National Institute of Child Health and Phramongkutklao Hospital, Bangkok, Thailand. Hospitalized HIV-positive children with and without diarrhea were enrolled in this study. Microsporidial spores identified by calcofluor fluorescent and gram-chromotrope stain were confirmed by electron microscopy. As well as Cryptosporidium parvum, Microsporidia was the most common protozoa found in the present study, each was 7.1%. Microsporidia was significantly more common in those who had diarrhea. Intestinal microsporidiosis was found in HIV-positive children with both acute and chronic diarrhea. This study emphasizes the importance of Microsporidia in HIV-infected children. Early detection of microsporidia could be of benefit for the patients, since the infection is treatable.

Response to JE vaccine among HIV-infected children, Bangkok, Thailand.

Since 1990, Japanese encephalitis (JE) vaccine has been part of EPI in northern Thailand, where there is a high prevalence of JE and HIV infection. To evaluate the immunogenicity and safety of JE vaccine among HIV-infected children, we conducted a retrospective study of HIV-infected and uninfected children who received 2 doses of JE vaccine at 12 months of age. Pre- and post-immunization plasma specimens were tested by plaque reduction neutralization for antibody levels to JE and dengue(1-4) viruses; titers of > or =10 were considered positive. Excluding 5 children with preimmunization antibodies, 5 of 14 (36%) HIV-infected children and 18 of 27 (67%) uninfected children had positive JE antibody titers after immunization [odds ratio (OR) 0.3, p=0.06]; 31% absolute difference [95% confidence interval (CI) 0-61.7%). The geometric mean titer of HIV-infected children with positive titers was lower than that of control children (15.1 vs, 23.8; p=0.17). No significant vaccine-associated adverse events were noted. We conclude that primary antibody response to JE vaccine was low among HIV-infected children and was approximately half of that seen among uninfected children. In endemic areas, HIV-infected children are likely to be at risk of acquiring JE despite routine immunization with 2 doses.

Knowledge, attitudes, and practices of senior high school students regarding human immunodeficiency virus infection.

A survey of knowledge, attitude and practice (KAP) regarding human immunodeficiency virus infection was performed on 899 students from 3 government-administered high schools located in the Bangkok Metropolitan area. Initially, all students completed a written questionnaire (pre-test) regarding HIV/AIDS. Following this, they attended a slide lecture presentation given by a specialist physician. The same test questionnaire was then completed by the same students six weeks (post-test) later for comparison of their previous KAP. The subjects composed of male to female ratio equal to that of the median age 15-16 years old. Sixty-seven per cent of the subjects were living with their parents, 16.3 per cent with relatives and 15 per cent with friends. Ninety nine per cent of the subjects had received information on HIV/AIDS before enrollment to this study. The source of knowledge ranged from television (89.1%), teachers (81.6%), pamphlets (80.2%), newspapers (75%), radio (55%), health care workers (53.4%), friends (38.6%) and only 32.5 per cent from their parents. The subjects' knowledge about HIV/AIDS and risk factors in the post-test questionnaire was significantly increased (P < 0.001) from the pre-test status. However, their attitudes to an HIV infected person were not significantly changed in the post-test questionnaire: only the "attending school" question showed significantly (P < 0.05) increased numbers of agreement. Similarly, the attitudes and practices to prevent HIV infection were not significantly (P > 0.05) different between pre-test and post-test questionnaires. The result of this study is to recommend regular school-based programs of education to increase awareness of preventive strategies for HIV/AIDS and sexually transmitted diseases.

Safety and immunogenicity of a Haemophilus influenzae type B polysaccharide-tetanus toxoid conjugate vaccine combined with diphtheria, tetanus and pertussis vaccines in Thai infants.

A randomized, open, multicenter trial was conducted to determine the safety and immunogenicity of a Haemophilus influenzae type b polysaccharide-tetanus toxoid (PRP-T) conjugate vaccine combined with tetanus, diphtheria and pertussis (DTP) vaccine in 271 Thai infants born to mothers immunized against tetanus during pregnancy. Infants were immunized at approximately 2, 4 and 6 months of age with these vaccines. To determine if elevated levels of anti-tetanus toxin antibodies suppressed the anti-PRP antibody response, a second group of infants were immunized with PRP complexed with outer membrane proteins of Neisseria meningitidis (Pedvax HIB) in one limb at 2 and 4 months of age and DTP vaccine in the other limb at 2, 4 and 6 months of age. A third group of infants received only DTP vaccine at 2, 4 and 6 months of age. The occurrence of both local and systemic adverse reactions were comparable in all 3 groups. The geometric mean anti-tetanus antibody titer was > 1 IU/ml at baseline. Approximately 1 month after the administration of the third dose of vaccine, 98.5%, 99.3% and 9.7% of the children immunized with DTP+Pedvax HIB, DTP-PRP-T or DTP possessed > or = 0.15 microgram of anti-PRP antibody per ml. No child in the DTP group achieved > or = 1 microgram/ml while 74.2% and 89.3% did so after immunization with DTP+Pedvax HIB, or DTP-PRP-T, respectively (p < 0.05). Immune responses to diphtheria, tetanus and pertussis antigens were similar in all vaccine groups. These results demonstrate that elevated tetanus antibody titers do not diminish the anti-PRP antibody response following immunization with a PRP-T conjugate combined with DTP vaccine.

Perinatal HIV infections in Thailand.

A collaborative study group of researchers from seven hospitals from all regions of Thailand was formed to collect information on children born to HIV-infected mothers since the beginning of the first hospital case until the end of June 1994. The study conducted to verify the status of perinatal transmission of HIV infection in Thailand showed a rapid increase in HIV seropositivity among Thai mothers with vertical transmission rates varying between 25% in Rayong and 42% in Chiang Rai Hospitals, respectively. The majority of children with symptomatic HIV infection had clinical presentations of delayed growth development, pneumonia, diarrhea, oral candidiasis, lymphadenopathy, hepato-splenomegaly. Cases of Penicillium marneffei infection were found only at Chiang Rai Prachanukroh Hospital. The ages at which diagnosis of HIV disease was made were mostly within the first year of life. One third of children with AIDS died during the period of study.

Bacterial meningitis in children: etiology and clinical features, an 11-year review of 618 cases.

During the period January 1980 to December 1990 (11 years) a retrospective study of patients with bacterial meningitis who were admitted to Bangkok Children's Hospital was carried out. There were 618 patients with 77 cases (12.5%) occurring below the age of one month (neonatal meningitis), and 541 cases (87.5%) between one month to 15 years (childhood meningitis). Pseudomonas aeruginosa was the most common pathogenic organism (16.9%) in neonatal meningitis; other causative agents in this age group included Klebsiella pneumoniae (13.0%), group B Streptococcus (11.7%), Escherichia coli and Enterobacter sp (10.4% each). In childhood meningitis, Haemophilus influenzae was the most common causative organism (42.3%), and followed by Streptococcus pneumoniae (22.2%) and Salmonella sp (12.4%). Excluding a 13 year-old leukemic patient, Salmonella meningitis occurred exclusively in infants, 87% of them were under six months, and 13% of them developed relapsing meningitis. Presenting symptoms and signs on admission of neonatal meningitis such as fever (81.8%), convulsions (45.4%), neck stiffness (22.5%), bulging fontanelle (33.3%) and Brudzinski sign (11.5%) were significantly less frequent than in the patients beyond the neonatal period (p < 0.05). The overall fatalities during 1980-1990 were 45.4% and 17.3% for neonatal meningitis and childhood meningitis, respectively. The fatalities of the two age groups declined significantly during 1987-1990 to 26.3% and 11.4% respectively.