Indonesia stepped up an investigation into a possible cluster of bird flu cases in West Java province on Sunday after a young boy was hospitalised with symptoms of the disease, bringing the number of suspected cases to 10.
Laboratory tests have not been completed for the 5-year-old boy, who was rushed to Dr Slamet Hospital in Garut on Saturday after suffering from a high fever and respiratory problems.
His sister passed away two weeks ago before her illness could be determined. Both came from Cikelet, a West Java hamlet 150 kilometers (90 miles) southeast of Jakarta, where there have been eight other human cases of confirmed or suspected bird flu.
"Our team of health officials is collecting all data and information we can from the area," said Nyoman Kandun, the health ministry's director general of communicable disease control, who called the Cikelet case 'extraordinary'.
The H5N1 virus has killed at least 140 people worldwide since it began ravaging Asian poultry stocks in late 2003, 45 of them in Indonesia, the worst-affected country, according to the World Health Organisation.
Most people have been infected after coming into contact with sick birds, but experts fear the virus could mutate into a form that spreads easily among humans, potentially sparking a pandemic.