ABSTRACT
OBJECTIVE: To evaluate SMART, Medicos Dip Stick and an Institut Pasteur (IP) cholera dipstick tests for accuracy and ease of use. METHOD: Every 50th patient presenting with diarrhoea at ICDDR,B between 1 April 2003 and 30 November 2003 was enrolled. The rapid diagnostic tests were performed by field and laboratory technicians, and sensitivity (Se), specificity (Sp), positive (PPV) and negative (NPV) predictive values calculated. RESULTS: We isolated Vibrio cholerae O1 from 116 (38%) of 304 patients. The Se, Sp, PPV and NPV of the SMART test were 58%, 95%, 84% and 84% for field technicians, and 83%, 88%, 83% and 88% for laboratory technicians. The Se, Sp, PPV and NPV of the IP dipstick test were 93%, 67%, 63% and 94% for field technicians, and 94%, 76%, 70% and 95% for laboratory technicians. The Se, Sp, PPV and NPV of the Medicos test were 84%, 79%, 71% and 90% for field technicians, and 88%, 80%, 72% and 92% for laboratory technicians. A high proportion of indeterminates (30%) hampered the performance of the SMART test. The IP dipstick had the highest Se, irrespective of technician skill level. CONCLUSION: The IP dipstick is the most appropriate rapid diagnostic assay for the detection of V. cholerae O1 in locations where the skill level of personnel may be low, such as remote areas or refugee camp settings. High cost may limit the utility of any diagnostic test in the developing world.
Subject(s)
Cholera/diagnosis , Clinical Competence , Diagnostic Tests, Routine/methods , Adolescent , Adult , Aged , Aged, 80 and over , Antibodies, Monoclonal/immunology , Antigens, Bacterial/immunology , Child , Child, Preschool , Cholera/immunology , Cholera/microbiology , Feces/microbiology , Female , Humans , Infant , Infant, Newborn , Male , Middle Aged , Predictive Value of Tests , Reproducibility of Results , Sensitivity and Specificity , Vibrio cholerae/isolation & purificationABSTRACT
Foodborne botulism is caused by potent neurotoxins of Clostridium botulinum. We investigated a large outbreak of foodborne botulism among church supper attendees in Texas. We conducted a cohort study of attendees and investigated the salvage store that sold the implicated foods. We identified 15 cases of botulism (40%) among 38 church supper attendees. Nine patients (60%) had botulinum toxin type A detected in stool specimens. The diagnosis was delayed in 3 cases. Fifteen (63%) of 24 attendees who ate a chili dish developed botulism (relative risk, undefined; P<.001). The chili dish was prepared with "brand X" or "brand Y" frozen chili, "brand Z" canned chili, and hot dogs. An unopened container of brand X chili yielded type A toxin. Brand X chili was purchased at a salvage store where perishable foods were inadequately refrigerated. Our investigation highlights the need to improve clinicians' awareness of botulism. More rigorous and more unannounced inspections may be necessary to detect food mishandling at salvage stores.
