Gu Jiang, director of the School of Basic Medical Sciences affiliated with Peking University, which led the study, said this does not mean that the bird flu virus can be transmitted from one person to another.
Gu said, "So far, no substantiated case of inter human transmission has been observed. It largely depends on how the virus further mutates," Xinhua news reports.
He said they studied the tissues taken from the body of a 24-year-old pregnant woman who died because of the bird flu virus. The virus, he said, was also found in the placenta and infected the fetus.
Gu added that the virus was also found in alimentary canal, brain, blood cells and respiratory tract of both the mother and the fetus. The unborn child's lungs and liver were also infected by the virus.
Gregory Hartl, World Health Organization spokesman, said this phenomenon of transfer does not prove that the virus can be transmitted from one human to another, as the mother and her unborn child are considered to function as one body.
Meanwhile, there are reports that bird flu outbreaks have occurred in Vietnam's northern Cao Bang Province.
The recent incidence of virus infections have raised the number of localities in Vietnam affected by the disease to three.
A total of 480 ducks and 80 chickens in 13 households in Trung Khanh district were reported to be infected with the bird flu virus strain H5N1.
Local veterinary agencies have reportedly collected all the infected birds and isolated the affected areas.
