Newer Treatment Options for Typhoid Fever

Abstract

Objectives: To test the newer antimicrobial agents, like third generation Cephalosporins, Carbapenems and Azithromycin against typhoid fever isolates. To compare their susceptibilities, by using disc diffusion technique and MIC testing, inorder to formulate new therapeutic options. Methodology: The study was conducted in Pakistan Institute of Medical Sciences from July 2011 to October 2012, yielding 141 Typhoid Salmonellae from blood cultures received from different departments. API and serological techniques were used for identification. Drug susceptibilities by Kirby-bauer disc diffusion and MIC’s of selected isolates were performed as per CLSI 2012 and BSAC 2012recom[1]mendation. Results: Susceptibility profiles of Typhoid Salmonellae on disc diffusion showed that, the conventional first line drugs were up to 70.9% sensitive, whereas the percentage sensitivity amongst the second line drugs i.e. Nalidixic acid and Ciprofloxacin was only 7.1%. The third line anti-typhoid drugs i.e. third generation Cephalosporins and Carbapenems were 100% sensitive, whereas Azithromycin was 10.6% sensitive only. The results of zone sizes and MIC of the Typhoid Salmonellae showed complete concordance except Azithromycin, having no positive parallel association of zone sizes and MIC, most probably due to lack of interpretive guidelines, which in future could be interpreted when guidelines become available. Conclusion: On the basis of culture and sensitivity, Third generation Cephalosporins and Carbapenems (100%) are the recommended drugs for empirical treatment for typhoid fever, whereas first line anti typhoid drugs are mainly 50% sensitive. Fluoroquinolones have no place in treatment of typhoid fever due to high alarming resistance in all age groups and Azithromycin can only be used based on culture results.