English

Abstract

OBJECTIVE: To determine the titers of antibodies against O, H, AH & BH antigens of S.typhi & S. paratypi by Widal test over a 1 year study period among children in a tertiary level hospital. METHODS: This observational study was conducted in the Pediatric wards of a tertiary hospital at Bangalore, Karnataka from 1st January 2013 to December 31st 2013. Children who presented with a history of fever of =/> 7 days were included in the study. These children underwent a Widal test to rule out typhoid fever. A total of 1197 such patients were included in the study. Children with antibody titers more than 1:160 were considered to have enteric fever. RESULTS: Out of the 1197 children, 515 were females & 682 were males. Among females in the age group of /=1:160. Similarly, 5.97%, 6.9% & 7.41% of males in the age group of /=1:160.The titers were similar among the males & the females in all the 3 age groups that were studied. CONCLUSION: The level of antibody titers may vary with time. The highest level of Widal titers of 1:320 against both O & H antigen were found in 3.08%, 2.22% & 1.67% of females in the age group of <2yrs, 2-5 years & 5-18 yrs. Similarly, 1.49%, 3.45% & 1.4% of males in the age group of <2yrs, 2-5 years & 5-18 years had the highest level of titers of 1: 320 against both antigens . Thus there has been an increase in the level of baseline titers against Salmonella species, which needs to be considered while interpreting the results of Widal test for the diagnosis of enteric fever. INTRODUCTION: The term ‘Enteric fever’ covers both typhoid & paratyphoid fevers.(1) It is caused by S. typhi & S. Paratyphi belonging to the family Enterobacteriace. Typhoid & Paratyphoid fevers remain important public health problems globally & major causes of morbidity in the developing world.(2) One study ‘Typhoid fever & Paratyphoid fever: Systemic review to estimate global morbidity & mortality for 2010’ by Geoffrey C Buckle et al, suggests that in 2010, there were an estimated 13.5 million typhoid fever episodes globally & this estimate is comparable to the 2000 crude estimate of 10.8 million episodes published by Crump et al.(2) Lab detection methods for enteric fever include serological tests & cultures. The definitive diagnosis is based on the isolation of organisms on culture. Cultures are not easily available in all areas, especially in developing areas, where incidence of enteric fever is high. Its results are also affected by previous antibiotic usage. Although blood cultures remain gold standard for diagnosis, the poor sensitivity of this method has been acknowledged.(3) Culture positivity varied from 21-50% in a study ‘Enteric fever: a changing perspective’ by N Bismai et al. DOI: 10.14260/jemds/2014/3365