Epidemiology of an outbreak of leptospirosis in man and dog.

An outbreak of leptospirosis in man and dog occurred during the monsoon in Madras city, India. 48 (50.5%) of the 95 human sera tested were positive for leptospirosis. Of these, 32 showed the presence of agglutinin to serovar icterohaemorrhagiae. 20 (21.3%) of the 94 canine sera tested were positive for leptospirosis. Of these, 10 had agglutinins to serovar icterohaemorrhagiae and 9 to serovar canicola. Among murine reservoirs, 8 (25%) of 32 rat sera and 10 (41.6%) of 24 bandicoot sera were positive. Bandicoot and rat sera contained 70 and 50% of agglutinins to serovar icterohaemorrhagiae, respectively. Urine culture lead to isolate a icterohaemorrhagiae strain from a patient and a canicola one from a dog. The changing trends of epidemiology in the transmission of leptospirosis to man and dog has been discussed.