TMSS Medical College Journal

Background: Enteric fever is an important multisystem infectious disease caused by Salmonella typhi. It is a major public health problem in developing countries including Bangladesh. A changing antimicrobial sensitivity pattern of Salmonella typhi and emergence of resistance has increased to a great concern. Objective: To investigate the antimicrobial sensitivity pattern of Salmonella typhi and selection of appropriate antimicrobial therapy to avoid multidrug-resistance. Materials and Methods: This cross-sectional descriptive study was conducted at MH Samorita Hospital and Medical College, Dhaka, Bangladesh from January 2021 to December 2021. Blood culture samples were collected aseptically and cultured in Microbiology laboratory. A total of 100 laboratory reports were collected during this period. Simple random sampling technique was applied for selection of culture positive Salmonella typhi patients laboratory reports. Specimens from the blood culture were identified by standard procedures as needed. Antimicrobial sensitivity testing was performed by disk diffusion method according to ‘The Clinical Laboratory Standard Institute’ guidelines. Results: Among the culture positive cases, Salmonella typhi was sensitive to ceftriaxone and gentamicin 100% followed by Ceftazidime 99%,Imipenem 98%, Cefixime 93%, Cotrimoxazole 79%, and least sensitive antibiotic was azithromycin 21% and Ciprofloxacin 23%. The incidence rate was high in male 63% and the age group 0-10 years 35%. Conclusion: The antimicrobial sensitivity testing showed that the Salmonella typhi were highly sensitive (>88%) to most of the drugs used in this study, whereas azithromycin showed only 21% sensitivity. So this study indicates that Ceftriaxone, Gentamicin, Ceftazidime, Imipenem and Cefixime can be used as a first line therapy and Azithromycin, Ciprofloxacin should be avoided for treatment.

Enteric fever is a febrile illness caused by infection with the Gram-negative bacterium Salmonella enterica serovar Typhi (S. Typhi)." It is an endemic disease in many developing countries including Bangladesh. World Health Organization (WHO) estimates the global enteric fever disease burden roughly 21.6 million people annually, resulting in about 223,000 deaths per year.’ The pathogens are transmitted by the faeco oral route with poor hygienic practices resulting in high morbidity and mortality. More than 90% of this morbidity and mortality occurred in Asia.* Antimicrobial therapy is the mainstay of managing enteric fever. If not treated properly, enteric fever carries a mortality rate of 30 %. Prompt institution of appropriate antimicrobial therapy can reduce the mortality and morbidity of this illness.’ Since 1948, chloramphenicol had been the mainstay of treatment of enteric fever until 1972. Then chloramphenicol resistant enteric fever became a problem. Extensive and irrational use of antimicrobial drugs have led to the emergence and spread of drug-resistance, often referred as multidrug resistance (MDR) in the pathogenic strains of Salmonella.® The early emergence of drug resistance among Salmonella isolates dates back to late 1980s when the traditional first-line drugs (chloramphenicol, ampicillin and co-trimoxazole) became ineffective due to antibiotic resistance, which compelled clinicians to rely upon fluoroquinolones, especially ciprofloxacin.” Recent global surge in resistance to fluoroquinolones could lead to a disastrous increase in global infectious diseases." However, several findings suggest the increasing burden of nalidixic acid resistant S. typhi (NARST) strains with reduced susceptibilities to fluoroquinolones, which subsequently has led to the introduction of third generation cephalosporins like Cefixime, Ceftazidime, Ceftriaxone and Macrolieds like Azithromycin.” But with their increasing usage in clinical settings the resistance against these antibiotics is increasing reported. Multidrug-resistance (MDR) has been emerging rapidly and consistently in enteric fever pathogens driven by selection pressure due to irrational drug therapy. This has resulted in treatment failures leading to extended hospital stay, health complications and leading to rise in morbidity and mortality."