WHO: initial analysis of Pakistani H5N1 suggests no dangerous mutations

Link: CIDRAP >> WHO: initial analysis of Pakistani H5N1 suggests no dangerous mutations.

An official from the World Health Organization (WHO) today shared results of initial genetic sequencing tests on H5N1 avian influenza samples from a man who died of the disease in Pakistan that suggest the strain doesn't have the capacity for widespread transmission. John Rainford, a WHO spokesman in Geneva, told CIDRAP News that the genetic sequencing involved two clinical samples from a 25-year-old man from the Peshawar area who was recently announced as the first confirmed human H5N1 case-patient and fatality in Pakistan. The man was part of a family cluster of suspected H5N1 cases which sparked global concern that the virus had mutated into a form that could enable widespread human-to-human transmission. However, the WHO said in a previous statement that while the Pakistani cases suggest a rare instance of human-to-human transmission, the virus did not spread beyond the family. Rainford said preliminary sequencing of the hemagglutinin and neuraminidase genes from the specimens was performed at the WHO collaborating center in London. Tests completed so far show the hemagglutinin amino acid sequence is identical to some of the recent clade 2.2 viruses that have been isolated from chickens in other outbreaks in the region, he said. WHO virologists say the findings, along with recent field investigations, suggest that the H5N1 viruses in Pakistan have not gained the capacity for widespread human-to-human transmission, reported Rainford.