Aasian dating related 32 txt 32
During the fifth epidemic, LPAI Asian H7N9 viruses acquired an HPAI mutation that causes increased morbidity and mortality in poultry.Ten of 33 provinces, regions, and municipalities in China reported HPAI Asian H7N9 viruses in poultry and environmental samples: Fujian, Guangdong, Guangxi, Hebei, Heilongjiang, Henan, Hunan, Inner Mongolia, Shaanxi, and Tianjin.Throughout the first four epidemics of Asian H7N9 infections, only low pathogenic avian influenza (LPAI) viruses were detected among human, poultry, and environmental specimens and samples.During the fifth epidemic, mutations were detected among some Asian H7N9 viruses, identifying the emergence of high pathogenic avian influenza (HPAI) viruses as well as viruses with reduced susceptibility to influenza antiviral medications recommended for treatment.What are the implications for public health practice?These candidate vaccine viruses, as well as others being developed by other World Health Organization Collaborating Centers for Influenza, could be used for vaccine production, clinical trials, stockpiling, and other pandemic preparedness purposes, based on ongoing public health risk assessment.Furthermore, the fifth-epidemic viruses diverged genetically into two separate lineages (Pearl River Delta lineage and Yangtze River Delta lineage), with Yangtze River Delta lineage viruses emerging as antigenically different compared with those from earlier epidemics.
All 166 viruses had the S31N mutation in the M2 protein, indicating resistance to amantadine and rimantadine, as was observed in previous Asian H7N9 epidemics (7).All infections were either detected in mainland China, Hong Kong, and Macao, or associated with travel from mainland China (29 cases were exported to Malaysia, Canada, Hong Kong, Macao, and Taiwan).Infections were reported from more provinces, regions, and municipalities in China during the fifth epidemic (30) than during the first four epidemics combined (21) (Figure 2).Similar to epidemics 1–4, 70% of infections during the fifth epidemic occurred in men, and the median age was 57 years (range = 4–93 years); most occurred among persons with recent poultry exposure (90%) and resulted in severe respiratory illness (90%)** (2).Among the 759 reported infections during the fifth epidemic, 14 clusters of two or three persons with Asian H7N9 virus infections were reported to WHO, compared with an average of nine clusters in each of the previous epidemics (range = 4–11 clusters).
The current Asian lineage avian influenza A(H7N9) virus (Asian H7N9) epidemic in China is the fifth and largest epidemic on record. Human infections with Asian H7N9 virus were reported from more provinces, regions, and municipalities in China during the fifth epidemic than in the previous four epidemics combined.