SEROPREVALENCE OF ANTIBODIES AGAINST TYPHOID FEVER IN A CANTON OF THE PROVINCE OF MANABÍ

SEROPREVALENCE OF TYPHOID FEVER

Abstract

Introduction: The diagnosis of typhoid fever represents a major clinical and laboratory challenge in resource-limited settings, where the Widal test remains the primary diagnostic method available. Objective:  To analyze the seroprevalence of antibodies against Salmonella typhi in the El Carmen canton. Methodology: An observational, descriptive, cross-sectional, and retrospective study was conducted, including 183 Widal test reports from afebrile patients processed between March and May 2024 at the Hospital del Día San Francisco. The data were collected through documentary analysis of anonymized clinical records and analyzed using descriptive statistics with SPSS software version 27. Results: The results showed an overall seroprevalence of 12.6%, using cut-off values of ≥1:80 for anti-O and ≥1:160 for anti-H antibodies. A higher frequency of anti-H antibodies (92.3%) compared to anti-O (88.5%) was observed, with predominant titers of 1:40 for anti-O and 1:80 for anti-H. A total of 10.4% of individuals had anti-O titers above 1:160, exceeding the internationally recommended 5% threshold for considering cutoff adjustments. These findings suggest that traditional thresholds may lead to false positives in this population. Conclusions: It is concluded that adjusting the diagnostic cutoff for anti-O to ≥1:160 would improve the specificity of the Widal test in this context, thereby optimizing the clinical management of patients suspected of having typhoid fever in El Carmen canton.