The prevalence, the resistance pattern, the risk factors and the clinical profile of Multi Drug Resistant Typhoid Fever (MDRTF) and Nalidixic acid Resistant Salmonella Typhi (NARST) among culture positive typhoid fever in hospitalized children less than 12 years of age

AIM OF THE STUDY: 1. The prevalence and pattern of resistance in typhoid fever including MDRST and NARST. 2. Clinical presentation of drug resistant typhoid fever and risk factors for multidrug resistance. METHODOLOGY: Study Design: Descriptive study / Case control study. Study Place: All medical wards of Institute of Child Health and Hospital for Children. Study Period: February 2005 to August 2006. Sample Size: All those children who satisfy the inclusion criteria with in the study period. Target Population: All children admitted with clinical suspicion of typhoid fever. Study Population: All children with fever (38oC and above) for atleast three days, with a laboratory confirmed positive culture of S.typhi. (WHO definition for confirmed cases of typhoid fever). EXCLUSION CRITERIA: Associated infections (mixed infections) like UTI, malaria, leptospirosis, prior antibiotic usage. STATISTICAL ANALYSIS: 1. Proportion of MDRTF and NARST among culture proven typhoid fever was found. 2. To associate various features to drug resistance, univariate analysis was done to arrive at odds ratio (OR) with 95% confidence interval. 3. To associate how far individual factors contribute independently for drug resistance, multi variate analysis was done. RESULTS: Out of 186 samples of the enteric culture sent, 39 grew S.typhi with a culture positive rate of 21%. Only those with culture proven typhoid fever were included in the study (WHO definition of confirmed cases of typhoid). CONCLUSION: 1. Incidence of multidrug resistant and quinolone resistant typhoid fever was found to be 43.6% and 20.5% respectively which vary with time and place. Hence there is a constant need to monitor antibiotic sensitivity pattern of S.typhi and periodically review the antibiotic policy in the hospital and the community so as to effectively utilize these antibiotics. 2. Majority of S.typhi isolates were found to be resistant to cotrimoxazole (74.4 %) and ampicillin (59 %) and most strains were observed to be sensitive to ceftriaxone (89.7%) and amikacin (87.2%). 3. Though amikacin was found to be sensitive in as high as 87.2%, its usefulness in vivo need to assessed. 4. Chloramphenicol sensitivity was observed among 56.4% of the isolates. More importantly some of the quinolone resistant and ceftriaxone resistant strains were found to be sensitive to chloramphenicol. 5. Age less than five years, prolonged fever for more than seven days, hepatosplenomegaly, abnormal liver function test and thrombocytopenia are specific risk factors for multidrug resistant typhoid fever and need early and aggressive management for prevention of complications. 6. Quinolone resistance may be a problem in future in typhoid fever and specific risk factors and alternative therapeutic strategies need to be evaluated