Efforts to persuade the Indonesian teenager to undergo treatment at a hospital in Bandung by health authorities proved unsuccessful as he resisted treatment.
Dr. Eka Sony, a Health Ministry official investigating the case said the teenager who was admitted to the hospital on Wednesday left the next day on the orders of his family who said they could treat him at home with a mixture of prayers and traditional remedies.
He said, "Our team felt very frustrated we were not able to persuade the family to let doctors take care of Umar."
Indonesia has recorded the highest number of human bird flu deaths in the world and this case highlights the problems of fighting avian influenza in the country where many are still ignorant about the disease and efforts to control the virus often meets with stiff resistance.
The country has been criticized for not doing enough to stamp out H5N1 as the virus is rampant among Indonesia's billions of backyard chickens, and the experts fear the virus, which remains hard for people to catch will mutate into a form that spreads easily among people, potentially sparking a pandemic.