A returning migrant worker with avian influenza A (H7N9) virus infection in Guizhou, China: a case report

INTRODUCTION Human infection with avian influenza A (H7N9) virus was first reported on March, 2013 in the Yangtze River Delta region of China. The majority of human cases were detected in mainland China; other regions out of mainland China reported imported human cases, including Hong Kong SAR, Taiwan (the Republic of China) and Malaysia, due to human transportation. Here, we report the first human case of H7N9 infection imported into Guizhou Province during the Spring Festival travel season in January 2014. CASE PRESENTATION In early January 2014, a 38-year-old healthy Chinese man, a migrant worker returning from previously H7N9-affected Zhejiang Province, was identified as the first human case of infection with avian influenza A(H7N9) virus in Guizhou Province. He developed fever in Zhejiang at the beginning of January 2014, and returned to Guizhou for the Chinese New Year the next day. He went to seek medical care, but deteriorated rapidly and died on day 8 after his illness onset. The influenza virus A/Guizhou/01502/2014 isolated from the patient had 99% identity with viruses circulating in the Yangtze River Delta region. Selected amino acids substitutions, well-known to be associated with mammalian adaptation, viral replication and drug resistance were similar to other H7N9 viruses circulating in humans. CONCLUSIONS Epidemiology investigation and laboratory results confirmed it was the first imported case of H7N9 infection in Guizhou Province. This finding further indicated that more human H7N9 cases may be detected in other regions due to frequent travel both domestically and internationally.