Response of extensively drug resistant Salmonella Typhi to treatment with meropenem and azithromycin, in Pakistan

INTRODUCTION: Salmonella Typhi is one of the leading health problems in Pakistan. With the emergence of extensively drug resistant (XDR) Salmonella Typhi, treatment options are limited. Here we report the clinical manifestations and the response to treatment of patients with XDR Typhoid fever. The patients were treated with either Meropenem or Azithromycin or a combination of both. METHODS: We reviewed the records of culture confirmed XDR typhoid who visited Aga Khan University Hospital (AKUH), Karachi and Aga Khan Secondary Care Hospital, Hyderabad from April 2017 to June 2018. Symptoms developed during disease, unplanned treatment extension and complications developed while on antimicrobials was recorded. Means with standard deviation were calculated for duration of treatment, time to defervescence, and cost of treatment. RESULTS: Records of 81 culture confirmed XDR typhoid patients admitted at the AKU hospitals were reviewed. Most, (n = 45; 56%) were male. Mean age of the cases was 8.03 years with range (1–40). About three quarter (n = 66) of the patients were treated as inpatient. Fever and vomiting were the most common symptoms at the time of presentation. Oral azithromycin alone (n = 22; 27%), intravenous meropenem alone (n = 20; 25%), or a combination of azithromycin and meropenem (n = 39; 48%) were the options used for treatment. Average (95% confidence interval) time to defervescence was 7.1(5.5–8.6), 6.7(4.7–8.7), and 6.7(5.5–7.9) days for each treatment option respectively whereas there were 1,0 and 3 treatment failures in each treatment option respectively. Average cost of treatment per day for azithromycin was US$5.87 whereas it was US$88.46 for meropenem. CONCLUSION: Patients treated with either Azithromycin, Meropenem alone or in combination showed similar time to defervescence. Because of the lower cost of azithromycin, it is preferable in lower socio-economic areas. Background estimates for power calculation can be made for more robust clinical trials using this observational data.