after agreeing to join the study, your personal information is recorded and a unique study number is assigned. the study staff randomly assigns you to receive either a 3‑day or a 7‑day course of antibiotic treatment.

before starting medication, a brief medical history is taken, a physical examination is performed, and blood samples are collected to confirm mild leptospirosis and to evaluate kidney, liver and blood cell function.

on the first day you receive the assigned antibiotic:

doxycycline 200 mg given once daily either as an intravenous solution (vibraveineuse) or as an oral film‑coated tablet (doxycycline arrow 100 mg).

amoxicillin 3 g given once daily either as an intravenous solution (amoxiciline panpharma 1 g powder for injection) or as an oral dispersible tablet (clamoxyl 1 g).

ceftriaxone 1 g given once daily as an intravenous injection (rocephine 1 g/10 ml).

the specific antibiotic and route are chosen by the treating physician based on clinical judgment. you take the medication once each day for the assigned period of either 3 days or 7 days.

while you are receiving the antibiotic, nurses check your temperature, blood pressure, heart rate and any symptoms such as headache, muscle pain or nausea each day.

if you experience any side effects, such as rash, diarrhea or a sudden rise in temperature (known as a jarisch‑herxheimer reaction), the study staff records them and provides appropriate care.

at the end of the assigned 3‑day or 7‑day period, you stop taking the study antibiotic. you may be discharged from the hospital if your condition is stable and no complications are observed.

seven days after the first dose of antibiotic, you return for a follow‑up visit.

the study team measures your temperature, asks about any new symptoms, and repeats blood tests to check kidney, liver and blood cell function.

the visit determines whether treatment failure has occurred, which includes persistent fever, worsening organ function or other serious complications.

twenty‑one days after the start of antibiotic therapy, a second follow‑up visit is scheduled.

clinical signs such as jaundice, nausea, abdominal pain, muscle aches or joint pain are assessed, and laboratory results are reviewed to confirm return to normal.

you complete a quality‑of‑life questionnaire (eq5d) to evaluate how you feel overall.

after the day‑21 visit, all study data are entered into the trial database.

no further visits are required unless you develop new symptoms, in which case you should seek usual medical care.