Leptospirosis in man, Israel, 1970-1979

In 1970-1979, the incidence of human leptospirosis in Israel was 0.7 per 100,000 population. The majority of the cases (62%) occurred in northeastern Israel (Upper Galilee). Prior to 1973 the main infecting serotypes were grippotyphosa (41%) and Hebdomadis szwajizak (31%). Following the first outbreak of Hebdomadis hardjo infection in 1973, a change occurred in the epidemiologic pattern of human leptospirosis, with hardjo becoming the most common serotype (59%). Hardjo infection outbreaks were sporadic and localized to dairy farms. The peak of incidence was during the summer months, June-September. All the patients with hardjo were dairy workers. The illness was relatively mild and mostly unicteric. Cattle seemed to be the principal source of hardjo infection for man.