Avian Flu H7N9 Spreads between Humans, Study Finds

A new study has found that the Avian influenza A (H7N9) virus can be transmitted between people. However, the virus is still incapable of effectively spreading among humans.

So far, 133 H7N9 infections and deaths have been reported from China. In most cases, the patients were living near or had visited a poultry farm. Until now, there were no reports of the virus being transmitted from an infected person to a healthy person.

In this case study, researchers found that the virus had spread from a father to the daughter. The man is about 60 years old and had visited a poultry farm before he contracted the infection. He was initially admitted to a hospital on March 11. As his condition deteriorated, he was shifted to the intensive care unit (ICU) on March 15, then to another ICU on 18 March. The man died on May 4.

The man's 32-year-old daughter contracted the virus at the hospital where he was admitted. She fell ill six days after she last visited him. The woman died of multi-organ failure on 24 April.

Researchers found that both the patients were infected with strains of virus that were genetically identical.

About 43 relatives of the two patients were tested for H7N9 infection and all but one had no infection. The person who had developed an infection was the man's son-in-law who had helped him at the hospital.

"Our findings reinforce that the novel virus possesses the potential for pandemic spread," they concluded.

According to Dr James Rudge, of the London School of Hygiene and Tropical Medicine, bird flu is known to pass between humans, BBC reported.

"It would be a worry if we start to see longer chains of transmission between people, when one person infects someone else, who in turn infects more people, and so on," Rudge added, "And particularly if each infected case goes on to infect, on average, more than one other person, this would be a strong warning sign that we might be in the early stages of an epidemic."

The study is published in the British Medical Journal (BMJ).