An Efficacy Trial of Doxycycline Chemoprophylaxis against Leptospirosis

Abstract

Because leptospirosis has been an important cause of morbidity in U.S. soldiers training in the Republic of Panama, we conducted a randomized, double-blind, placebo-controlled field trial during the fall of 1982 to determine whether doxycycline was an effective chemoprophylactic agent against this infection. Doxycycline (200 mg) or placebo was administered orally on a weekly basis and at the completion of training to 940 volunteers from two U.S. Army units deployed in Panama for approximately three weeks of jungle training. Twenty cases of leptospirosis occurred in the placebo group (an attack rate of 4.2 per cent), as compared with only one case in the doxycycline group (attack rate, 0.2 per cent, P less than 0.001), yielding an efficacy of 95.0 per cent. This study demonstrated the value of doxycycline as a prophylactic drug against leptospirosis.

Increase of leptospirosis in dengue-negative patients after a hurricane in Puerto Rico in 1996 [correction of 1966].

“…Avoidance of exposure to flooding, use of protective boots, and chemoprophylaxis (doxycycline, 200 mg/week) in the event of exposure in rescue work should be recommended. 33 In our study, jaundice, eye pain, and diarrhea in dengue-negative patients were significantly associated with leptospirosis. In Barbados, patients who exhibit jaundice and accompanying thrombocytopenia are considered to have leptospirosis until proven otherwise.…”

Outbreak of Leptospirosis after a Race in the Tropical Forest of Martinique

“…3,4,7,8,22,23 In addition, several studies suggest that doxycycline could be used either as chemoprophylaxis or as post-exposure prophylaxis and post-exposure empirical treatment. 21,[24][25][26][27] Both a study of U.S. Army soldiers who participated in a 3-week training exercise in the jungles of Panama and another study in residents of a rural area of the Andaman Islands found preventive efficacy of doxycycline, administered 200 mg once weekly. 24,25 Administration of doxycycline, 100 mg daily, represent an alternative chemoprophylaxis, in areas where malaria and leptospirosis are endemic, as suggested by the preventive efficacy of such treatment during the race in Borneo.…”

“…21,[24][25][26][27] Both a study of U.S. Army soldiers who participated in a 3-week training exercise in the jungles of Panama and another study in residents of a rural area of the Andaman Islands found preventive efficacy of doxycycline, administered 200 mg once weekly. 24,25 Administration of doxycycline, 100 mg daily, represent an alternative chemoprophylaxis, in areas where malaria and leptospirosis are endemic, as suggested by the preventive efficacy of such treatment during the race in Borneo. 4 The Caribbean islands of Martinique and Guadeloupe are not an endemic area for malaria and none of the participants in our study reported taking such chemoprophylaxis.…”

Leptospirosis in the tropics and in travelers

“…A classic study showed that weekly doxycycline prevented leptospirosis in previously naïve soldiers undergoing jungle training in Panama [69]. Such findings were not replicated in an endemic setting in the Andaman Islands where exposure is likely ubiquitous in the course of activities of daily living [70].…”