Bacterial enteric pathogens in children with acute dysentery in Thailand: increasing importance of quinolone-resistant Campylobacter.

Current data on pathogen prevalence and drug resistance patterns are important for treatment and vaccine-development strategies. An etiologic study of acute bacterial dysentery was conducted in children up to 12 years of age in 2 major hospitals in and around Bangkok. Stool samples or rectal swabs and clinical data were collected. Standard microbiological methods were used to detect Salmonella, Shigella, Campylobacter, Vibrio, Aeromonas and Plesiomonas. Pathogenic E. coli (ETEC, EIEC, STEC) was identified by digoxigenin-labeled probes. A total of 623 cases were enrolled: median age 11.0 months (range 1 month-12 years). At least one bacterial pathogen was isolated in 55% of cases. Campylobacter was the most common pathogen found (28%), whereas Salmonella, Shigella and ETEC were isolated from 18%, 9% and 6% respectively. EIEC, Vibrio and Plesiomonas were isolated from <1% and no STEC was detected. C. jejuni serotypes 36, 4 and 11 were the most common. The mean age of cases with Campylobacter was significantly lower than with Shigella (17.9 vs 52.8 months, p<0.001). Clinical presentations of Campylobacter and Shigella infections were compared: fever (28% vs 37%), abdominal colic (62% vs 80%, p<0.05), vomiting (38% vs 70%, p<0.001) and bloody stools (52% vs 48%). The Campylobacter isolates (80% C. jejuni, 20% C. coli) were 90% resistant to ciprofloxacin but sensitive to macrolides. All the Shigella isolates (70% S. sonnei) were sensitive to quinolones. Our study illustrates the increasing importance of quinolone-resistant Campylobacter and the decline of Shigella in the etiology of dysentery in Thailand. The clinical presentation of campylobacteriosis is similar to that of shigellosis, except that the patients may be younger and there may be less association with colic and vomiting; having fecal leukocytes will be >10/HPF. The use of macrolide antibiotics rather than quinolones would be reasonable in children <24 months of age; fluoroquinolones will be ineffective in at least half of culture-positive cases.

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.

Wilms' tumor with metastasis to duodenum - the first reported case in Thailand.

A case of Wilms' tumor with gastrointestinal tract metastasis of the duodenum was documented in a 22 month - old - child. She had been diagnosed with Wilms' tumor stage III, treated surgically and by radiation and chemotherapy about 1 year previously. While she was still on chemotherapy, she developed hematemesis and clinical signs of partial gut obstruction. Gastroscopy and upper gastrointestinal series showed an intraluminal vascular mass in the duodenal bulb and histologically proved to be Wilms' tumor. We believe this is the first report in the world of Wilms' tumor with gastrointestinal tract metastasis.

Effects of rice powder salt solution and milk-rice mixture on acute watery diarrhea in young children.

A randomized pilot study was carried out to compare the safety and effectiveness of rice powder salt solution (RPSS) in combination with milk-rice mixture (RPSS-MR group, n = 17) with other two regimens, glucose-based oral rehydration solution (ORS) combined with MR (ORS-MR group, n = 17) and ORS combined with formula milk (ORS-milk group, n = 14) in the treatment of acute watery diarrhea with mild to moderate dehydration in 48 boys younger than 2 years. Results showed that in the first 24 hours patients in the RPSS-MR group had significantly smaller amounts of stool weight (32.7 g/kg) than those in the ORS-MR group (67.5 g/kg) and ORS-milk group (59.2 g/kg) (p< 0.05 for both measurements). Patients in the RPSS-MR group also had significantly shorter duration of diarrhea (29.6 hours) than the other two groups (43.8 hours and 49.6 hours, respectively) (p < 0.05 for both measurements). The stool weight and duration of diarrhea between the ORS-MR group and the ORS-milk group were not significantly different. The positive effect of milk rice mixture was not demonstrated in the study due to the significantly more severe diarrhea in the ORS-MR group. The effectiveness of the RPSS-MR is therefore likely due to mainly RPSS.