A Diagnostically Challenging Leptospirosis Case in a Serviceman in a Combat Zone

In recent years, the incidence of leptospirosis in Ukraine has been increasing because of a number of factors, such as climate change and the ongoing war. The aim of this case report is to present a case of challenging leptospirosis diagnosis in a serviceman. A 38-year-old male, although in a combat zone, repeatedly noted the presence of mice in his deployment locations. He experienced an acute onset of illness with fever, muscle pain, and pronounced general weakness. He self-administered an antibiotic. Subsequently, he developed a cough and shortness of breath upon exertion. He was hospitalized with a diagnosis of pneumonia. Klebsiella pneumoniae was isolated from his sputum. He was successively prescribed cefepime and meropenem, but no clinical improvement was observed: fever, cough, and CT changes were still present. As the infiltrative focus was localized in the right upper lobe, differential diagnosis with tuberculosis was performed. Sputum PCR and repeated CT allowed excluding tuberculosis. Because of persistent fever, myalgia, development of polyuria, and taking into account his epidemiological history, the patient was additionally tested for leptospirosis. The diagnosis of leptospirosis was verified by detecting specific serum antibodies by the microagglutination lysis reaction with a dynamic increase in their titer. The patient's condition improved after prescribing piperacillin-tazobactam, to which leptospiras were sensitive. This clinical case highlights that atypical clinical manifestations and their inadequate assessment can complicate the timely diagnosis of leptospirosis. Servicemen in field conditions are in a risk group for this infection.