Frequency and characteristics of selected enteropathogens in fecal and rectal specimens from childhood diarrhea in Trinidad, 1998-2000.

Objective: To determine the prevalence and characteristics of selected enteric pathogens in diarrheic children in six counties of the island of Trinidad.

Methods: This cross-sectional study was conducted from April 1998 through March 2000. Fecal or rectal swab specimens from children (<12 years) were collected and then processed, using standard methods, to detect Salmonella spp., Shigella spp., enteropathogenic Escherichia coli (EPEC), Campylobacter spp., Yersinia spp., Cryptosporidium parvum, and parasite ova. The antibiograms of the enteropathogens were determined using the disk diffusion method.

Results: A total of 236 samples were processed; 86 samples originated directly from 17 heath centers in two counties (St. George East and St. George West), while 150 samples were obtained from the Trinidad Public Health Laboratory, having been submitted by private practitioners and personnel from six counties in Trinidad. Of the 236 samples, 33 (14.0%) were positive for Shigella, 4 (1.7%) for Salmonella, and 1 (0.4%) for EPEC. Two of the samples (0.8%) were positive for Campylobacter jejuni, while 1 sample (0.4%) was positive for hookworm ova. All the samples were negative for Cryptosporidium parvum and Yersinia spp. With the 86 samples collected directly from the health centers, in St. George East County the frequency of Shigella was 20.0% (12 of 60), compared with 26.9% (7 of 26) for samples from St. George West County, but the difference was not statistically significant (P>0.05 with the chi-square test). For the 150 samples from the six counties that had been submitted directly to the Trinidad Public Health Laboratory, 14 of them (9.3%) were positive for Shigella, a figure statistically significantly lower than that found with the samples sampled directly from the health centers (P<0.05 with the chi-square test). Sh. sonnei was the predominant serotype detected, accounting for 28 of the 33 Shigella isolates (84.8%) recovered from the 236 samples. Overall, the frequency of detection of enteropathogens had no seasonal pattern nor relationship to the county of origin. Of the 37 isolates of Salmonella and Shigella tested for antimicrobial sensitivity, all of them were sensitive to ciprofloxacin, gentamicin, and cefotaxime. In terms of resistance, 3 of the 37 isolates (8.1%) exhibited resistance to ampicillin, 1 (2.7%) to chloramphenicol, and 1 (2.7%) to sulfamethoxazole/ trimethoprim.

Conclusion: Of the enteropathogens for which assays were done, Shigella sonnei was the most prevalent, and it has the highest probability of being an important etiological agent of childhood diarrhea in Trinidad.