Evaluation of a commercial latex agglutination test for rapid detection of salmonella in fecal samples

A latex agglutination test for the detection of salmonella in feces was evaluated in comparison to direct culture and enriched culture using both artificially inoculated samples and clinical samples. In the samples inoculated artificially with different concentrations of salmonella (10¹ to 10⁵ per gram) the enriched culture performed better only at the 10² level in 0.4 g samples, whereas the latex test performed as well as the enriched culture at all levels in 4 g samples. In the tests using clinical samples, there was no significant difference between results of the latex test performed in 2283 samples and the enriched culture performed in 2072 samples. The sensitivity, specificity and negative and positive predictive values of the latex test were 88.2 %, 98 %, 97.5 % and 63 % respectively. The test provided results rapidly but yielded a number of false positive results.