Bat, the only flying mammal and count more than 20% of the extant mammals on earth, were recently identified as a natural reservoir of emerging and reemerging infectious pathogens. Astonishing amount (more than 70) and genetic diversity of viruses isolated from the bat have been identified in different populations throughout the world. Many studies focus on bat viruses that caused severe domestic and human diseases. However, many viruses were found in apparently healthy bats, suggesting that bats may have a specific immune system or antiviral activity against virus infections. Therefore, basic researches for bat immunology and virus-host interactions are important for understanding bat-derived infectious diseases.
Animals ; Chiroptera ; classification ; virology ; Communicable Diseases, Emerging ; virology ; Disease Reservoirs ; virology ; Genetic Variation ; Humans ; Viruses ; classification ; genetics ; isolation & purification

The annual seasonal epidemic of influenza caused serious disease burden around the world, and serious social panic and economic losses. Due to the high variability and uncertainty of influenza virus, prevention and control of influenza faces many challenges. Surveillance is a key strategy to prevent and control influenza, and influenza is the first infectious disease to be monitored globally. More than 60 years, influenza surveillance programs in China has made great contributions to the prevention and control of influenza in China and the world. Especially in the past 10 years, the influenza surveillance network has developed rapidly, the scale has been expanded significantly, the monitoring content and scope have been continuously improved, and the monitoring quality has been rapidly improved. The China Influenza Surveillance Network is one of the early detection systems for emerging infectious diseases in China and the world. It helps to improve the capacity of public health system in prevention and control and early warning of emerging infectious diseases.
Animals ; Birds ; China ; Communicable Diseases, Emerging/virology* ; Disease Outbreaks ; Global Health ; Humans ; Influenza in Birds/virology* ; Influenza, Human/virology* ; Population Surveillance/methods* ; Public Health ; Public Policy

Pandemic influenza has posed an increasing threat to public health worldwide in the last decade. In the 20th century, three human pandemic influenza outbreaks occurred in 1918, 1957 and 1968, causing significant mortality. A number of hypotheses have been proposed for the emergence and development of pandemic viruses, including direct introduction into humans from an avian origin and reassortment between avian and previously circulating human viruses, either directly in humans or via an intermediate mammalian host. However, the evolutionary history of the pandemic viruses has been controversial, largely due to the lack of background genetic information and rigorous phylogenetic analyses. The pandemic that emerged in early April 2009 in North America provides a unique opportunity to investigate its emergence and development both in human and animal aspects. Recent genetic analyses of data accumulated through long-term influenza surveillance provided insights into the emergence of this novel pandemic virus. In this review, we summarise the recent literature that describes the evolutionary pathway of the pandemic viruses. We also discuss the implications of these findings on the early detection and control of future pandemics.
Animals ; Birds ; virology ; Communicable Diseases, Emerging ; epidemiology ; history ; virology ; Evolution, Molecular ; History, 20th Century ; History, 21st Century ; Humans ; Influenza A Virus, H1N1 Subtype ; genetics ; Influenza A Virus, H3N2 Subtype ; genetics ; Influenza in Birds ; epidemiology ; history ; virology ; Influenza, Human ; epidemiology ; history ; virology ; Pandemics ; history

OBJECTIVETo understand the clinical and epidemiological aspects of avian influenza A (H7N9) virus infection in children.

METHODThe clinical data of the first confirmed pediatric case of avian influenza A(H7N9) virus infection were collected, and the epidemiological information, presenting symptoms, laboratory investigation, management and outcome were analyzed. The data of the pediatric cases were also compared with those of the adults cases.

RESULTThe case reported in this paper was a previously healthy 3.6-year-old boy residing in rural area of Shanghai. He had onset of fever and mild rhinorrhea on 31 March 2013 and he was afebrile and well since April 3. Influenza A (H7N9) virus was detected in his nasopharyngeal sample collected on 1 April through national Influenza-like Illness surveillance using real-time reverse transcriptase PCR and virus culture.His family raised domestic poultry with no apparent disease and there was no virological evidence of H7N9 infection. Monitoring and testing of 16 contacts had not found any secondary infection.

CONCLUSIONThe clinical course of H7N9 avian influenza virus infection in children was relatively mild as compared to adult cases. The source of infection and detail of exposure for children have not been known yet. Continued surveillance studies of mild and severe respiratory disease and subclinical infection are essential to further characterize the epidemiology and clinical spectrum of this emerging H7N9 virus infection in children.

Animals ; Child, Preschool ; China ; epidemiology ; Communicable Diseases, Emerging ; Humans ; Influenza A Virus, H7N9 Subtype ; genetics ; isolation & purification ; Influenza in Birds ; Influenza, Human ; diagnosis ; drug therapy ; virology ; Male ; Oseltamivir ; therapeutic use ; Poultry ; Real-Time Polymerase Chain Reaction ; Retrospective Studies ; Reverse Transcriptase Polymerase Chain Reaction