Superbug spreads further in community

The study also found new strains of the virus were now circulating in New Zealand. Photo / Thinkstock

Cases of the superbug MRSA doubled in the six years to 2011, with the bug now infecting more people in the community than in hospitals, a new study shows.

New Zealand's rate of the antibiotic-resistant MRSA remains relatively low compared to other countries but a new study has found the specimens across the population increased from 8.6 to 18 per 100,000 people between 2005 and 2011.

The results of the first study to systematically track the spread and burden of MRSA in New Zealand have today been published in the international PLOS ONE scientific journal.

The findings show that while MRSA was first only thought to be a "hospital bug" when it arose globally about 20 years ago, it "now appears to have become more associated with infections with people in the community".

"The shift into the community has been accompanied by a rise in cases amongst younger age groups, especially in recent years," the study says.

It says the less rapid increase in hospital-associated MRSA may be the result of an increased focus on preventing outbreak of the infection in hospitals.

The rates of MRSA were significantly higher in Maori and Pacific Island populations.

The study also found new strains of the virus were now circulating in New Zealand.

Dr Deborah Williamson, who authored the report with ESR senior scientist Helen Heffernan, said the national surveillance of MRSA was important to "get a complete picture of this disease".

She said the research helped scientists make decisions on how to prevent MRSA's spread and treat those who became infected.

Over the last three years, the Institute of Environmental Science and Research has received dedicated funding from the Ministry of Health to increase the testing and surveillance of bacteria like MRSA.