A new strain of bird flu, H7N9, has been discovered to be resistant to Tamiflu — the only treatment currently known for the disease. This wave of bird flu, declared to be “unusually dangerous” by the World Health Organization (WHO), appears to have mutated in a way that makes Tamiflu ineffective, Business Insider reports.
WHO’s influenza expert Keiji Fukuda said in a press conference in April that “this is definitely one of the most lethal influenza viruses that we have seen so far.” The resistance against Tamiflu was discovered in Shanghai after sampling 11 infected people.
The patients with the mutation that made antivirals ineffective rapidly got worse than their counterparts, ending up on breathing machines. The virus is believed to come from birds but has adapted to spread to mammals as well.
H7N9 has so far infected 133 people and killed 36. Out of those infected, only nine people have gotten well enough to be released from the hospital. Experts are considering this strain of flu nine times more deadly than the Spanish flu of 1918.