The influenza pandemic has gathered a lot of action, advice and coverage over the last few years. In 2009, an international H1N1 influenza pandemic led to concerns that there would be a repeat of the 1918 influenza pandemic which resulted in millions of deaths worldwide. The World Health Organization recorded over 37,000 cases of the H1N1 pandemic influenza in Australia and 193 confirmed deaths.
An additional concern was the appearance of a strain of H1N1 influenza that was resistant to one of the two most commonly used anti-viral medications, Tamiflu. The mutation of the virus to become resistant to anti-viral medications and also to be easily spread amongst the population was considered to pose a considerable threat.
This week the International Society for Infectious Diseases reported that over two dozen cases of Tamiflu-resistant H1N1 influenza had been reported in Newcastle - the largest outbreak of the drug-resistant strain.
Ian Barr, Deputy Director of the World health Organization’s Collaborating Centre for Influenza in Melbourne said, “As long as it's isolated to Newcastle and that region, it's not so much of a problem. If it spreads further, it might be a concern. Fortunately, we're heading toward the end of our flu season.”
Dr Craig Dalton, public health physician from Hunter New England Health and co-ordinator of the Flu-tracking project said, “It is likely that the strain will spread. The extent to which it replaces the normal H1N1 strain you can only speculate on, in the past it has done this very effectively and we'll wait to see if it happens again. Thankfully there are other anti-viral treatments available that this strain is not resistant to.”
“Fortunately for Australia there really are another two or three weeks in which we could get hit by a bad flu as far as an upswing in cases,” said Dr Dalton. “The question is, however, whether it then persists through and moves into the northern hemisphere's winter.”
Of 184 samples of H1N1 collected from patients in the Hunter New England region, 25 samples, or 14 per cent, exhibited highly reduced sensitivity to oseltamivir or Tamiflu. That compared with the previous average of about 1 per cent, Dr Dalton said. “If oseltamivir becomes less helpful then it will become more important for people to have the flu vaccination if they are immune-compromised,” Dr Dalton said.
The mutant strain was covered by the seasonal flu vaccine, Dr Dalton said, and it was now more important than ever for people who were immune compromised to have the vaccine. “The strain is covered by the vaccine and it should provide you good protection,” he said. The vaccination either led to no illness or less severe illness, he said.
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