. The Widal test is a serological test used to detect antibodies against Salmonella enterica serovars, specifically S. typhi and paratyphi A, B, and C, which cause typhoid and paratyphoid fever. These infections, collectively known as enteric fever.
. The disease is transmitted through the ingestion of contaminated food or water. The disease is prevalent in regions with poor sanitation and limited access to clean water.
. The Widal test measures the presence and concentration of antibodies (O and H) in the patient’s serum. A rising titer of antibodies or a single high-titer result may indicate recent or ongoing infection. However, due to cross-reactivity and false positives in endemic areas, clinical correlation and repeated testing are often recommended to improve diagnostic accuracy.