First Case Report of Salmonella enterica Serovar Haifa in a Patient from Mysore, Karnataka, India

Background: Salmonellosis is a major global public health concern, commonly caused by serovars such as Salmonella enterica serovar Typhimurium and Salmonella enterica serovar Enteritidis. Rare serovars, however, may represent underrecognized links between environmental reservoirs and human infection. Salmonella enterica serovar Haifa is a sporadic serotype primarily associated with livestock and environmental sources and has previously been reported in Indian poultry but not in human clinical cases to date. Case Presentation: A 70-year-old male with a history of type 2 diabetes, presented with acute watery diarrhea and dehydration. One week prior to symptom onset, the patient reported direct contact with cattle and poultry in a rural setting. Laboratory investigations revealed leucopenia and elevated procalcitonin (3.73 ng/mL). Stool culture yielded non-lactose fermenting colonies on MacConkey agar and H2S-producing colonies on Hektoen enteric agar. The isolate was identified via VITEK 2 and confirmed as Salmonella enterica serovar Haifa by the National Institute for Research in Bacterial Infections (NIRBI). Antimicrobial susceptibility testing (AST) revealed that the isolate showed resistance to ampicillin, ceftriaxone, and ciprofloxacin. The patient was successfully treated with a three-day course of intravenous Azithromycin (1 g) and achieved rapid clinical recovery. Conclusions: To the best of our knowledge, this case represents the first reported human infection caused by S. Haifa in India. The finding highlights the potential zoonotic risk of rare non-typhoidal Salmonella serovars and emphasizes the importance of surveillance, routine serotyping, and antimicrobial resistance monitoring within a One Health framework.