Objective: To reveal the relationship between the biological characteristics of pathogen and the pig-to-human spread of the epidemic and infectious disease in 1998 in East China. Methods: Epidemiological survey, pathological examination of pigs and patients, and pathogen isolation were performed. Results: The disease had a character of quick onset, serious symptoms, short course and high mortality. The clinical manifestations and pathological changes of the disease were high fever, sometimes with nausea, vomiting and diarrhea, then might develop to myositis, fascitis, DIC, multiple organ failure, shock and usually died in 2-3 d. Among 25 patients, 16 manifested clinically as streptococcal toxic shock syndromes and 9 streptococcal meningiocephalitis syndrome. The mortality was 81.25% and 11.11% respectively. Pathogenic bacteria isolated from diseased pigs and patients were found to have some common characteristics in morphology, staining and biological characters. Conclusion: The pathogen isolated from the blood of patients and pigs were identified as streptococci.