Usefulness of dark field microscopy after differential centrifugation in the early diagnosis of leptospirosis in dog and its human contacts.

1. We found leptospira in the blood of two out of three police dogs by dark field microscopic examination after high speed centrifugation. One dog had fever and the other was asymptomatic. Leptospira could not be seen in the urine of one police dog which died of jaundice. 11 out of 21 human contacts were found to be positive for leptospira after low speed centrifugation and 5 after high speed centrifugation. One child had jaundice and an another child had fever. Others had mild symptoms of headache to none. Dark field microscopy after differential centrifugation is useful in the early diagnosis of leptospirosis and thereby could prevent later complications like jaundice.