Prevalence of multi-drug resistant Salmonella typhi among clinically diagnosed typhoid fever patients in Lagos, Nigeria

A total of 635 clinically diagnosed typhoid fever patients were bled from t hree 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 ra te of S. typhi among patients is 10.7%, with most isolates 45.9% found amon g the severely-ill young adults, age group 16-30 years. All isolates were s ubjected to anti-microbial susceptibility testing using 12 different antibi otics: chloramphenicol, ampicillin, cotrimoxazole, gentamicin, colistin sul fate, nalidixic acid, nitrofurantoin, cefotaxime, tetracycline, streptomyci n, ofloxacin and ciprofloxacin. All the S. typhi and S. paratyphi A isolate s showed resistance to two or more of the 10 of 12 antibiotics tested parti cularly the 3-first-line antibiotics commonly used (chloramphenicol, ampici llin and cotrimoxazole) in the treatment of typhoid fever in Nigeria. No is olate showed resistance to ofloxacin and ciprofloxacin, however, nalidixic acid and gentamicin showed a moderate and appreciable inhibition to most of our isolates.