Prevalence of Multi-Drug Resistant Salmonella typhi among Clinically Diagnosed Typhoid Fever Patients in Lagos, Nigeria

Abstract

A total of 635 clinically diagnosed typhoid fever patients were bled from three different health institutions in the metropolis of Lagos, Nigeria over a period of 15 months, May 1997 to July 1998. Out of the total blood cultured, 101 (15.9% ) isolates of Salmonella species were isolated of which 68 (67.3% ) were S. typhi, 17 (16.8% ) and 16 (15.8% ) were S. paratyphi A and S. arizonae respectively. The overall isolation rate of S. typhi among patients is 10.7% , with most isolates 45.9% found among the severely-ill young adults, age group 1 6 -30 years. All isolates were subjected to anti-microbial susceptibility testing using 12 different antibiotics: chloramphenicol, ampicillin, cotrimoxazole, gentamicin, colistin sulfate, nalidixic acid, nitrofurantoin, cefotaxime, tetracycline, streptomycin, ofloxacin and ciprofloxacin. All the S. typhi and S. paratyphi A isolates showed resistance to two or more of the 10 of 12 antibiotics tested particularly the 3-first-line antibiotics commonly used (chloramphenicol, ampicillin and cotrim oxazole) in the treatment of typhoid fever in Nigeria. No isolate showed resistance to ofloxacin and ciprofloxacin, however, nalidixic acid and gentamicin showed a moderate and appreciable inhibition to most of our isolates.