Ash-Pacific JournaI of Public Health Leptospirosis: A Newly Identified Disease in Korea

A new clinical syndrome, epidemic pulmonary haemorrhagic fever, which is characterized by malaise, fever, myalgia and nausea or vomiting at the onset of the illness and chest pain, haemoptysis and dyspnoea with pneumonia-like X-ray shadow in the later stage, has been occurring sporadically in Korea since October 1975 as a disease of unknown aetiology. Upon the massive occurrence of the same syndrome again in the autumn of 1984 afler a flood, the government commissioned an analytic epidemiological investigation that was conducted by the author. The objective of the investigation was to identify the aetiological agent of the syndrome by testing the hypothesis that the cause of the new syndrome is leptospiral infection, which had been formulated by the author on the basis of 1975 materials, a few years prior to the 1984 epidemic. Patients with a diagnosis of the syndrome (cases) and patients ' families and/or villagers (controls) were interviewed and specimens to isolate leptospires, ie blood and urine, were collected. In addition, rodents and water from the paddy fields in the same areas that the patients came from were collected to be examined for leptospiral organisms. Spiral organisms were isolated from most of the specimens inoculated, from guinea pigs and mice. These organisms were reported by the microbiologists to have characteristics of Leptospira intemgans in every aspect examined. Subsequent community studies on a healthy population revealed 2 3 1 6 % subcfinical IeptospiraI infection rates on whole blood cultures in artificial media. Over 90 % of rodents examined harboured leptospires. The results of this study served to confirm the endemicity of leptospirosis in Korea.-: A disease of unknown aetiology