Epidemiology and characterization of leptospirosis at an urban and provincial site in Thailand

Patients with FUOs at the Children's Hospital in Bangkok and the Chao Phya Abhai Bhu Bejhr Hospital in Prachinburi were screened for leptospirosis by blood and urine culture in addition to microagglutination testing of their serum. Animal populations in urban and periurban areas of Bangkok were surveyed for evidence of leptospira infection. Three rural sites near the Prachinburi Provincial Hospital were also surveyed. The rodents' and domestic animals' blood, urine, and/or kidney cell samples were cultured for leptospira. Sera from these animals were also tested for leptospira antibody. The bataviae serovar was the most commonly detected leptospiral agent in both man and animals. Presenting symptoms varied with age with children showing primarily fever, vomiting, headache, abdominal and generalized muscle pain and diarrhea whereas adults had fever, headache, anorexia, muscle pain and constipation. Blood samples from patients suspected of having leptospirosis were tested for antibody by the MAT and cultured in EMJH media. The following serogroups were identified: bataviae, autumanalis, javanica, hebdomadis, and pyrogens. Leptospirosis incidence in humans was much higher in the rainy/flooding year of 1983 compared to the relatively dry year of 1984. Results of our animal surveillance studies indicate that in addition to rats, which have previously been mentioned, dogs, bandicoots, cattle and pigs could be the source of human leptospirosis infection in both urban and provincial locations in Thailand.