Which antibiotic is used to eliminate chronic leptospira infection?

• A. Doxycycline
• B. Amoxicillin
• C. Penicillin G
• D. Ciprofloxacin

Answer: (A)

Clearing chronic Leptospira carriage relies on an antibiotic that reaches the renal tubules where the bacteria hide and has proven activity against Leptospira. Doxycycline fits this role well: it has strong activity against Leptospira and excellent oral bioavailability with good penetration into renal tissue, enabling it to eradicate the chronic carrier state. It’s also commonly used for prophylaxis in exposed individuals, underscoring its effectiveness against persistent infection.

Penicillin G is highly effective for acute, severe leptospirosis due to rapid bactericidal activity in the bloodstream, but it’s not the preferred option for clearing chronic carriage. Amoxicillin can treat leptospirosis but is not as reliably used for long-term carriage eradication. Ciprofloxacin may treat leptospirosis in some scenarios, but it is not the standard choice for eliminating chronic infection.