From staff, wire reports
The US-based Centers for Disease Control has called on doctors not to use two of the four drugs previously prescribed to treat the main influenza strain circulating in the US.
This flu season, 91 per cent of samples of the main flu virus affecting the US, H3N2, have shown resistance to the two drugs, amantadine and rimantadine, CDC director Dr. Julie Gerberding said Saturday.
In comparison, she explained that last year, the proportion of viruses resistant to the two drugs was 11 per cent and less than 2 per cent two years ago.
She gave two possible reasons for the sharp increase: a mutation in the flu virus in the US or the importation of a virus that had already gained resistance.
The two newer drugs, Tamiflu and Relenza, have been gradually replacing the ineffective ones.
Dr. Kiran Kumar, Cayman Islands medical officer of health, explained that it is a known fact that amantadine and rimantadine were developing resistance.
‘But having been identified in the US that the current H3N2 virus is showing 91 per cent resistance, the CDC is recommending using only the newer drugs, Tamiflu and Relenza,’ he said.
He added that this is not an issue here.
‘In the Cayman Islands, it is Tamiflu mostly that is used. But, it is only effective if it is used within 48 hours after onset of symptoms,’ he said.
He stressed, however, that the issue remains not to use Tamiflu as a blanket protection against flu.
‘Indiscriminate use of any drug can cause resistance,’ he explained.