The majority of cases presents with mild clinical manifestation and only 12% of cases has severe symptoms relating with underlying diseases such as chronic renal failure, cardiovascular diseases, diabetes, pregnancy or late hospitalization that require intensive therapy 92% of patients respond well with specific therapy within 7 days, 7% respond with the 10 days treatment course and only 1% of cases need to be prolonged the treatment course until 14 days. Conclusion: The characteristics of clinical, laboratory and epidemiological data of this study are similar with those announced from WHO.