Although Ebola is dominating news coverage in every form, we are reminded that other outbreaks of exotic viral diseases continue and new cases pop up from time to time.


Whether it be MERS, dengue fever or chikungunya, there is so much disease circulating in the world, including avian influenza.

Today, the Hong Kong Centre for Health Protection (CHP) of the Department of Health (DH) received notification from the National Health and Family Planning Commission (NHFPC) of two cases of human infection of avian influenza A(H7N9) affecting a woman aged 44 in Xinjiang Uygur Autonomous Region and a girl aged 7 in Beijing. The 44-year-old woman passed away last month.

This brings the total to 440 cases confirmed on the Mainland. The breakdown of cases by province is as follows:  including Zhejiang (139 cases), Guangdong (109 cases), Jiangsu (56 cases), Shanghai (41 cases), Hunan (24 cases), Fujian (22 cases), Anhui (17 cases), Jiangxi (eight cases), Shandong (five cases), Beijing (five cases), Henan (four cases), Guangxi (three cases), Xinjiang Uygur Autonomous Region (three cases), Jilin (two cases), Guizhou (one case) and Hebei (one case).

According to the CHP, there are various types of influenza viruses. Apart from the influenza viruses which can circulate among humans and cause seasonal influenza, many other influenza A viruses are found in birds and other animal species. These viruses are distinct from human seasonal influenza viruses and do not easily transmit to humans.  However, some of these animal viruses may, occasionally infect humans. These are known as novel influenza viruses and avian influenza viruses are one example.

Avian influenza is caused by those influenza viruses that mainly affect birds and poultry, such as chickens or ducks. Since the virus does not commonly infect humans, there is little or no immune protection against it in the human population. However, if an avian influenza virus acquired the capacity to spread easily from person to person, either through adaptation or acquisition of certain genes from human viruses, an influenza pandemic can occur.  Human cases infected with avian influenza A (H5N1, H7N9 and H9N2) viruses have been identified in Hong Kong, Mainland China and other parts of the world, while human infections due to H10N8 and H6N1 viruses have been first reported in Mainland China and Taiwan respectively since 2013.

Clinical presentation of avian influenza in humans includes eye infection (conjunctivitis), flu-like symptoms (e.g. fever, cough, sore throat, muscle aches) or severe respiratory illness (e.g. chest infection). The more virulent forms [e.g. infection by avian influenza A (H5N1, H7N9 or H10N8) viruses] can result in respiratory failure, multi-organ failure and even death. For more infectious disease news and information, visit and “like” the Infectious Disease News Facebook page