A 6-year-old Yunnan province boy is the latest confirmed human case of avian influenza A(H5N1) on mainland China, according to the National Health and Family Planning Commission (NHFPC).

H5N1 avian influenza Image/Cynthia Goldsmith/ Jackie Katz
H5N1 avian influenza
Image/Cynthia Goldsmith/ Jackie Katz

This is the fifth human case of the serious bird flu in China this year and the third from Yunnan province in less than 2 weeks.

According to the NHFPC, the patient lives in Chuxiong and has presented with fever on March 23. He attended a local hospital on March 25 and has currently recovered after treatment.

His specimen, which was tested by the relevant authority, was positive for avian influenza A(H5N1).

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.

People mainly become infected with avian influenza through close contact with infected birds and poultry (live or dead) or their droppings. Human-to-human transmission is inefficient.

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.