Treatment of acute human leptospirosis

Treatment of acute human leptospirosis - professional guide

Treatment for leptospirosis is based on antibiotic therapy allied with supportive care and close monitoring of serology, renal, hepatic and cardiac function. Sequelae are treated without reference to their origin, and the bacterial growth checked by antibiotics almost independently of the patient's condition. Early antibiotic intervention is the most significant factor in recovery, and delays while awaiting test results can be critical. Antibiotic efficacy drops rapidly after day 5 of symptoms (S5) and can be of no benefit whatsoever after day S8. Ideally it should be initiated no later than 10 days after exposure (E10) although in many cases the patient does not request medical support until symptoms develop, and the incubation time of up to 21 days limits the ability to intervene before E10 in these cases.

Any patient with suspected leptospirosis should be placed on antibiotics immediately.

Do not wait for test results - they can take several weeks.

Choice of antibiotic

Severe infections should be managed with IV benzyl penicillin and will require hospital admission. Adult dose is 5MU to 8MU per day for five days although in some studies the doses have been routinely very much higher - up to 20MU. There is no evidence that doses over 8MU have an additional benefit, but doses below 5MU may be inadequate. In patients with penicillin allergy, a program of erythromycin can be used at 250mg QID for five days. In mild to moderate cases oral medication using amoxycillin, erythromycin, doxycycline or ampicillin can be used, subject to contraindications and age limits. Typical dosage for doxycycline is 100mg BID PO for ten days. 3G cephalosporins (cefotaxime, etc.) are known to be somewhat effective but the primary drug of choice is always penicillin. A Jarisch-Herxheimer reaction can occasionally be triggered by penicillin therapy, however the risk balance is acceptable and should not provoke discontinuance. Leptospires are usually resistant to vancomycin, chloramphenicol, rifampicin and metronidazole.

Multiple antibiotic therapy is not required - there are no clinical examples of in-vitro resistance developing and since human-to-human transmission is extremely rare, the potential for mutative selection of resistance is insignificant.

Supportive care

Severe illness required an aggressive regime of support, as the patient will rapidly alter their condition and multiple organs are involved. Fluid and electrolyte balance needs to be maintained and will require frequent adjustment, while patients with renal involvement can often require dialysis. ECG monitoring is also important as cardiac arrhythmias are common and can develop into fatal instabilities as the infection progresses.

Paychological manifestations are common, and patients may require sedation if they become aggressive or psychotic. These symptoms are temporary and would not normally require specific treatment, however longer-term depression, fatigue and other symptoms are to be expected, often lasting several years. These often appear to be unrelated to the efficacy of initial treatment.

The Leptospirosis Information Center