The second person who fell ill with H7N9 in Beijing was discharged from hospital at noon on Friday after negative results for three consecutive virus tests, said the city's health bureau.

The 6-year-old boy, surnamed Xu, visited hospital with a sore throat and a headache on May 21, and took antibiotic medication. He was put on venous transfusion for the next three days before his body temperature got back to normal.

On May 28, he was hospitalized for further observation in Ditan Hospital, one of the two hospitals to take in patients infected with H7N9 in Beijing, after a local center for disease control and prevention found the virus in his throat swab, though his symptoms had already disappeared.

He hadn’t shown flu-like symptoms during his observation.

The source of his infection was unknown, since his parents denied he was exposed to poultry or birds before he fell ill.

Fifty-eight people in close contact with him haven’t shown related symptoms.

Beijing has included the test for H7N9 into regular monitoring of flu-like symptoms, where hospitals and medical institutions test H7N9 along with seasonal flu viruses for suspicious flu-like cases they have detected.

In this case, Xu’s throat swab was collected and sent for tests by Peking University People’s Hospital, the first hospital he visited after falling ill, and one of the more than 140 local hospitals monitoring and reporting flu-like symptoms to the authorities of disease control and prevention.