A cross-sectional study of enteric fever among febrile patients at Ambo hospital: prevalence, risk factors, comparison of Widal test and stool culture and antimicrobials susceptibility pattern of isolates.

BACKGROUND

Enteric fever is one of the common infectious diseases of humans. The objectives of this study were to:1) estimate the prevalence of enteric fever among febrile patients visiting Ambo hospital; 2) comparison of Widal test and stool culture;3) evaluation of the antimicrobial susceptibility of isolates; and 4) assess potential risk factors to acquire enteric fever infection.

METHODS

Blood and stool samples were collected from 372 febrile patients with symptoms clinically similar to enteric fever. Widal test was used for testing sera while stool culturing and bacterial identification was done using WHO standard methods. Susceptibility testing was done using Kirby-Bauer disc diffusion method. Chi-Square test and Logistic Regression analysis were used to analyze the data.

RESULTS

The apparent and true prevalence of enteric fever were 56.2% (95% confidence interval [CI]: 50.97-61.29%) and 57.52% (95% CI: 52.3-62.6%) respectively, while, the culture prevalence was 2.7% (95% CI: 1.30-4.89%). Isolation rates of S. Typhi and S. Paratyphi were 0.8% (95% CI: 0.17-2.34%) and 1.9% (95% CI: 0.76-3.84%) respectively. The isolates showed 100% resistance to amoxicillin, bacitracin, erythromycin, 80%resistance to cefotaxime and streptomycin and 20% for chloramphenicol. The sensitivity, specificity, positive and negative predictive values of Widal test was 80.0, 44.5, 3.8 and 98.8% respectively. Multivariable logistic regression analysis revealed that age (adjusted odds ratio [aOR] = 2.45; 95% CI: 1.38-4.37; P = 0.002), religion (aOR = 15.57, 95% CI: 3.01-80.64; P = 0.001), level of education (aOR = 2.60, 95% CI: 1.27-5.28; P = 0.009), source of water (aOR = 2.20, 95% CI: 1.21-3.98; P = 0.009), raw milk (aOR =2.19, 95% CI:1.16-4.16; P = 0.016) and raw meat consumption (aOR = 1.80, 95% CI: 1.07-3.01; P = 0.026) are the predictors of enteric fever seropositivity.

CONCLUSIONS

Patients were wrongly diagnosed and treated for enteric fever by Widal test. Therefore, rapid tests with better sensitivity and specificity are needed for the diagnosis of enteric fever. Provision of safe water and health education are vital to bring behavioral change towards raw food consumption.