[Report on first finding an epidemic of Scrub typhus in north rural areas]

In the autumn of 1989 and 1990, an epidemic of Scrub typhus occurred in north rural areas in Tianjin. The authors investigated the epidemic on clinical, epidemiological, serological and etiological features, 44 patients were diagnosed serologically or clinically as Scrub typhus and 42 of them (95.5%) were diagnosed serologically by IFA method. 10 sera specimens collected from the patients were determined distinctively by CF method, 8 of them were > or = 1:20 titre to Gilliam type antigen of tsutsugamushi. The try for isolating pathogens failed of success. The epidemic areas is situated in 39.45'-40.05' north latitudes and showed it was the new epidemic area in the north of China.