State public health authorities said they have strengthened surveillance over the spread of the new strain of bird flu, H7N9, after reporting Monday that a Beijing boy was found to be a carrier of the virus but had not fallen ill.

The capital's center for disease control and prevention said the 4-year-old boy, surnamed Zhu, was discovered to be a virus carrier during the screening of 24 farmers who sell live poultry in a village of Cuigezhuang township in the city's Chaoyang district.

The child, who remains under medical observation at Beijing Ditan Hospital, has so far not shown flu symptoms, the center said.

"We are taking the boy's temperature every four hours. If he shows any symptoms, we will immediately start treatment," Li Xingwang, director of the infectious diseases treatment center at Beijing Ditan Hospital, told the Global Times Monday.

While the boy's parents sell fish and live poultry, one of Zhu's neighbors also bought live poultry from the family of a 7-year-old girl who was the first person in Beijing to be sickened by the flu.

The girl's condition has improved and she was transferred to an ordinary medical ward at Beijing Ditan Hospital on Monday after her temperature returned to normal for 48 hours, China National Radio reported.

Jiangsu, Anhui and Zhejiang disease control officials each reported Monday one new case of human infection, bringing the total number of cases to 63. Jiangsu also reported one death, raising the death toll to 14 in the country.

"We have taken specific measures to strengthen surveillance in infected regions after the outbreak of the avian flu," a spokeswoman from the State Public Health and Family Planning Commission, who asked not be named, told the Global Times Monday.

The authority has also attached great importance to maintaining transparency in its updates on the avian flu outbreak, which is an effective way to prevent the spread of the virus, the spokeswoman added.

Beijing health authorities said Sunday it had established a disease surveillance system, ordering all of its branches and units to report outbreak-related information before 4 pm every day.

Information is also being released on the municipal health authority's website and its microblog on a daily basis, it said.

Some 30 million yuan ($4.85 million) has been allocated to the prevention of the virus and to treat those who have fallen ill. Previous media reports said the medical expenses of people who contract the flu will be fully covered by the government.

Many cities including Beijing, Hangzhou, Shanghai, Nanjing, Wuhan, Huzhou, Wuxi and Suzhou have banned all trade of live fowl in an effort to contain the spread of the virus.