leptospiros

Leptospires are slender, spiral-shaped bacteria of the genus Leptospira, members of the phylum Spirochaetes. They are Gram-negative and possess periplasmic flagella, which give them a distinctive corkscrew movement. Pathogenic leptospires are slow-growing and require specialized culture media, such as Ellinghausen-McCullough-Johnson-Harris (EMJH), for growth.

Ecology and transmission describe them as zoonotic pathogens found worldwide, with highest prevalence in tropical and subtropical regions. They colonize the renal tubules of reservoir animals, including rodents, livestock, and dogs, and are shed in urine. The bacterium survives in wet environments like stagnant water and damp soil. Humans acquire infection through skin abrasions or mucous membranes after contact with urine-contaminated water or soil, commonly during occupational or recreational activities.

Clinical features of leptospirosis range from mild, flu-like illness to severe disease. The early phase typically includes fever, myalgia (often in the calves), headache, and conjunctival suffusion. A second, immune-mediated phase can involve the liver, kidneys, lungs, and meninges. Weil disease is a severe form characterized by jaundice, renal failure, hemorrhage, and sometimes respiratory distress; fatalities occur mainly in cases with organ failure.

Diagnosis relies on serology (such as the microscopic agglutination test or IgM ELISA), polymerase chain reaction in early infection, and, in some settings, culture. Treatment is with antibiotics like doxycycline or penicillin, ideally started early; severe disease requires intravenous therapy and supportive care. Prevention focuses on minimizing exposure, rodent control, use of protective equipment for at-risk workers, and vaccination of animals, which reduces carriage and transmission. Human vaccines exist in limited settings but are not widely available.