First human case of avian influenza A (H5N6) in Yunnan province, China

OBJECTIVE: To report clinical, virological, and epidemiological features of the first death caused by a H5N6 avian influenza virus in Yunnan Province, China. METHOD: The case was described in clinical expression, chest radiography, blood test and treatment. Real-time RT-PCR was used to detect H5N6 virus RNA in clinical and environment samples. Epidemiological investigation was performed including case exposure history determinant, close contacts follow up, and environment sample collection. RESULTS: The patient initially developed sore throat and coughs on 27 January 2015. The disease progressed to severe pneumonia, multiple organ dysfunction syndrome, and acute respiratory distress syndrome. And the patient died on 6 February. A highly pathogenic avian influenza A H5N6 virus was isolated from the tracheal aspirate specimen of the patient. The viral genome analyses revealed that the H5 hemmagglutinin gene belongs to 2.3.4.4 clade. Epidemiological investigation showed that the patient had exposure to wild bird. All close contacts of the patient did not present the same disease in seven consecutive days. A high H5 positive rate was detected in environmental samples from local live poultry markets. CONCLUSION: The findings suggest that studies on the source of the virus, transmission models, serologic investigations, vaccines, and enhancing surveillance in both humans and birds are necessary.