Single dosage of doxycycline for prophylaxis against leptospiral infection and leptospirosis during urban flooding in southern Thailand: a non-randomized controlled trial.

This study was conducted to investigate the protective efficacy of a single dosage of 200 mg doxycycline against leptospiral infection and leptospirosis and associated risk factors among residents exposed to flooding in southern Thailand. Of 641 participants, 600 received doxycycline while 41 did not. Twenty two participants were infected with Leptospira and six developed leptospirosis. Having a laceration wound was significantly associated with leptospiral infection (odds ratio [OR] = 37.20; P < 0.001) and leptospirosis (OR = 18.24; P = 0.003) whereas exposure to flood more than 3 h per day was associated with only leptospiral infection (OR = 3.70; P = 0.038). Seventeen participants who received doxycycline and five who did not, were infected with Leptospira, resulting a protective efficacy of 76.8% (95% confidence interval [CI] = 34.3%-92.0%). Four who received doxycycline and two who did not, developed leptospirosis, resulting a protective efficacy of 86.3% (CI = -9.8%-98.2%). Among the participants with laceration wound, the protective efficacy for leptospiral infection was 92.0% (CI = 81.2%-96.6%) and for leptospirosis was 95.6% (CI = 78.2%-99.3%). Among the participants exposed to flood water less than or equal to 3 h per day, the protective efficacy for leptospiral infection was 89.2% (95% CI 63.6%-96.67%). A single dosage of 200 mg doxycycline for prophylaxis might be effective for preventing leptospirosis among flood victims with laceration wound after recent flood exposure.

Leptospirosis among river water rafters in Satoon, southern Thailand.

OBJECTIVE: To assess epidemiology and risk factors for leptospirosis infection among the rafting participants in southern Thailand. MATERIAL AND METHOD: Prospective observation of the patients who participated in rafting in southern Thailand was conducted between January and December 2010. Demographic, clinical data as well as potential risk factors were collected Indirect immunofluorescent antibody test (IFAT) for specific leptospirosis IgG detection were examined immediately after rafting and two to three weeks after first samples. Microagglutination Test (MAT) was performed to confirm diagnosis in cases with seroconversion. RESULTS: One hundred fifty eight rafting participants enrolled to the present study of which 150 complied with the protocol and were analyzed Eleven patients had serological evidence of leptospirosis infection accounting for 7.3% while only three patients were symptomatic. Various serovars are responsible for infection while serovar Icterohemorrhagiae is most common. Persistence of abrasion wound/laceration wound were likely to be risk factors for infection with p < 0.05. CONCLUSION: The laboratory findings in the present study demonstrated that leptospirosis was associated with rafting and a contaminated environment.