H1N1介绍汇.pptVIP

Introduction to Epidemiology of Influenza A (HINI) Infection Dr. Tong Ka Io Center for Disease Control Prevention 4th May, 2009 Outline Situation update Characteristics of the disease Risk assessment Preventive measures Situation Update Influenza A (H1N1) human cases (2009.05.04) Situation in Mexico Jan to Mar 11: all samples reconfirmed to be negative Mar 15/17: 1st probable/confirmed case Apr 12: reported to WHO an ILI outbreak in a small community (Veracruz) Apr 17: Issued alert due to a case of “atypical pneumonia” (Oaxaca) and enhanced surveillance Apr 23: Canada HPA helped to confirm swine flu infection and reported to WHO Apr 27: School suspension in the whole country May 3: Epidemic easing Asia Pacific region Confirmed New Zealand...6 Hong Kong……1 Korea……1 Characteristics of Disease Virology H1N1 Same virus found in Mexico and US A new subtype not previously detected. A large part of the gene sequence is similar to that of the swine flu virus in US while a small part similar to that in Eurasia Resistant to amantadine and rimantidine but sensitive to oseltamivir (Tamiflu) and zanamivir (Relenza) Epidemiology Number of confirmed (N = 97) and probable (N = 260) cases of swine-origin influenza A (H1N1) virus (S-OIV) infectionby date of illness onsetMexico, March 15--April 26, 2009 Confirmed human cases of swine-origin influenza A (H1N1) infection with known dates of illness onsetUnited States, March 28--April 27, 2009 Epidemiology Epidemiology Number of patients and deaths from laboratory-confirmed infection with swine-origin influenza A (H1N1) virus (S-OIV) by age groupMexico, April 1--27, 2009 Places of transmission Families Medical establishments Schools Clinical manifestation Incubation: undefined at present, estimated to be 2-7 days by US. WHO adopts the longest incubation period of 14 days Manifestation: US: relatively mild self-limiting ILI. Vomiting and diarrhea are commonly seen Mexico: Mild cases are common, mostly with symptoms of fever, cough,