By Adhityani Arga JAKARTA, June 6 (Reuters) - The H5N1 bird flu virus in Indonesia may have undergone a mutation that allows it to jump more easily from poultry to humans, the head of the country's commission on bird flu control said on Wednesday. Indonesia has recorded 79 human deaths from bird flu, the highest in the world, and the country has been struggling to contain the disease because millions of backyard chickens live in close proximity to humans across the archipelago. "In the past it took exposure of high intensity and density to the virus to get infected. There are now suspicions, early indications that this has become easier," Bayu Krisnamurthi told reporters. He said, however, that the suspicion had yet to be confirmed. A microbiologist at the bird flu commission said the suspicions were based on preliminary findings of molecular genetic tests conducted at laboratories in Indonesia. "Virus samples from poultry cases have increasingly shown a similarity in their amino acid structure to virus samples extracted from humans," Wayan Teguh Wibawan told Reuters. "This makes it easier for the virus to attach to human receptors," he said, referring to receptor cells lining the human throat and lungs. For the H5N1 virus to pass easily from bird to human, it would have to be able to readily attach itself to these special cells. For the moment, because H5N1 is a bird virus, it has evolved to easily attach to these receptors in poultry. Humans have a different type of receptor site, making it harder for people to become infected. Wayan said he had spotted "gradual changes" in the virus sample he receives every month. He did not give details on these gradual changes. Lo Wing-lok, an infectious disease expert in Hong Kong, said changes such as these demonstrated how important it was for Jakarta to share virus samples. "Are they going to share these samples with overseas labs? These must be confirmed and the world must be forewarned if there has been such an important change," Lo told Reuters in Hong Kong. "If there is such a change, it would not only mean that the virus can jump more easily from bird to man, but from human to human, too." Bird flu is endemic in poultry in many parts of Indonesia. Scientists are worried about the virus's persistence and ability to adapt to new environments and hosts, fearing this increases the chances of the virus mutating into a form that can jump easily between people, triggering a pandemic. Contact with sick fowl is the most common way humans become infected with bird flu. Krisnamurthi said lack of medical facilities and late intervention were to blame for a recent surge in deaths in Indonesia because new cases have mostly occurred in remote areas. Bird flu is often mistaken for seasonal influenza, which in most cases has led to delayed hospitalisation. There have been 188 deaths globally from H5N1 and 310 known infections in total, according to World Health Organisation data. Sharing samples is deemed vital to see if viruses have mutated, become drug resistant or grown more transmissible. The samples are also used to develop commercial vaccines. Indonesia said last month it had resumed sharing samples with the WHO after a five-month hiatus. Along with other developing nations, Indonesia has been demanding guarantees that they will have access to affordable vaccines in the event of a pandemic. (Additional reporting by Tan Ee Lyn in Hong Kong)
