Worldwide, foodborne illness is often associated with consumption of meats and poultry products sold at retail markets. A cross-sectional retail food study was conducted in Bangkok, Thailand to assess the prevalence of bacterial pathogens on retail food samples. Raw chicken, beef, pork, and chicken eggs were purchased from fresh markets and supermarkets and tested for Salmonella spp., Campylobacter spp., Arcobacter spp., and Enterococcus spp. Suspect bacterial pathogens were isolated by differential culture and Salmonella species were serotyped. A total of 200 samples were collected from 50 markets between May and August 2003. Of the 200 samples tested, 121 (61%) were positive for at least one Salmonella spp. serogroup. A total of 175 Salmonella spp. were isolated. The most common serotype was Salmonella Anatum, followed by S. Corvallis and S. Derby. Campylobacter spp. were found in 31 (15.5%) of 200 samples. C. jejuni was isolated from 15% of fresh market chicken samples and 35% of supermarket chicken samples. Arcobacter spp. were isolated from 42 (21%) samples; fresh market chicken had significantly higher A. butzleri contamination than supermarket chicken. The presence of Enterococcus spp., an indication of fecal contamination, was detected in 188 (94%) samples, including 100% of the beef and pork sources. Few studies have examined retail food contamination in Thailand. In particular, the high prevalence of samples with Arcobacter spp. warrants further study to determine pathogenicity.

This study was conducted to investigate the presence of intestinal parasites among pre-school children (aged 3 months to 5 years) in Sangkhlaburi, a rural district in the west of Thailand along the Thai-Myanmar border. Stool specimens were collected from October 2001 through October 2002. A total of 472 pre-school children, 233 males and 239 females, 236 children with diarrhea and 236 asymptomatic children were recruited for the study. Each specimen was processed and examined by direct wet smear, modified acid fast stain, formalin-ethylacetate sedimentation concentration technique, and trichrome stain. In detecting Giardia lamblia and Cryptosporidium species ProSpecT Microplate assays (Alexon-Trend, Lenexa, KS) were performed. There were 107 individuals (22.7%), 41 diarrheal and 66 asymptomatic children, infected with intestinal parasites. The most frequent parasites identified in cases and controls were G. lamblia and Cryptosporidium spp. Eighteen specimens (3.8%) showed mixed parasite infections. Highest proportion of intestinal parasites occurred during the rainy season (June-October).

Background We conducted a comprehensive investigation to update our knowledge of traveler’s diarrhea (TD) etiology and antimicrobial resistance (AMR) in Nepal. Methods A case–control study of TD etiology was conducted at the CIWEC Clinic Travel Medicine Center in Kathmandu from 2012 to 2014. Stool samples were tested by microscopy, culture and molecular techniques for identification of bacterial, viral and parasitic enteric pathogens, and AMR. We analysed patient demographic data, pre-treatment information and clinical outcomes. Results We enrolled 433 TD cases and 209 non-diarrhea controls. At least one of enteric pathogens was identified among 82% of cases and 44% of controls (P < 0.001). Multiple pathogens were observed among 35% of cases and 10% of controls. The most common pathogens significantly identified among cases in comparison with controls were Campylobacter (20%), norovirus (17%), enterotoxigenic E. coli (ETEC) (12%), rotavirus (9%) and Shigella (8%) (P < 0.001). We noted Campylobacter, Shigella and ETEC resistance to azithromycin at 8, 39 and 22% and to ciprofloxacin at 97, 78 and 23%, respectively. Conclusion Among travellers to Nepal with TD, viral pathogens were commonly found and norovirus was the second most common pathogen after campylobacter. We noted increased AMR to fluoroquinolones (FQs) and azithromycin (AZM). There is heightened concern for AZM treatment failures, though this continues to remain the drug of choice for TD treatment in our setting where FQs should not be used.

Shigellosis is a worldwide disease, characterized by abdominal pain, fever, vomiting and the passage of blood- and mucus-streaked stools. Rhesus monkeys and other primates are the only animals that are naturally susceptible to shigellosis. A suitable animal model is required for the pre-clinical evaluation of vaccines candidates. In this study the minimal dose of S. dysenteriae1 1617 strain required to produce dysentery in 4 of 5 (80% attack rate) monkeys using an escalating dose range for three groups (2×108, 2× 109 and 2× 1010 CFU) was determined. In addition, the monkeys were re-infected. The identified optimal challenge dose is 2× 109 CFU, this dose elicited 60% protection in monkeys when they were re-challenged with a one log higher dose (2× 1010 CFU). The challenge dose, 2× 1010 CFU, produced severe dysentery in all monkeys, with 1 monkey dying within 24 h, elicited 100% protection when re-challenged with the same dose. All monkeys exhibited immune responses. This study concludes that the rhesus monkey model closely mimics the disease and immune response seen in humans and is a suitable animal model for the pre-clinical evaluation of Shigella vaccine candidates. Prior infection with the 1617 strain can protect monkeys against subsequent re-challenges with homologous strains.