The Nelson Marlborough health area has the lowest rate of antibiotic-resistant MRSA bacteria in New Zealand, a study released this month shows.
Nelson Marlborough District Health Board medical microbiologist Richard Everts said his analysis of about 75 per cent of bacteria grown and tested in Marlborough and Nelson from 2010-12 "provides a beautiful picture of all the bugs in the region".
Bacteria causing urinary infections were the biggest group with 17,000 samples and gonorrhoea the smallest at 140 samples.
The reason for the low rate of this resistant bacteria was the small number of people living in this district compared with North Island cities which meant bugs were less likely to spread, he said. Also, Auckland had more links to Asia where antibiotic-resistance was more common.
Almost all bacteria were resistant to some antibiotics, Dr Everts said. However, some mutated a lot and became superbugs, resistant to so many antibiotics doctors could barely treat an infection.
"The superbugs of one decade become the ordinary bugs of the next."
Methicillin-resistant Staphylococcus aureus (MRSA) was once a superbug known as H-bug but had become quite common.
Another group of resistant bacteria were Extended Spectrum Beta Lactamases (ESBLs), widespread in Auckland but unusual in Marlborough and Nelson where affected hospital patients were isolated in their rooms and treated by staff wearing gloves and gowns.
"There are people walking around shops carrying and spreading ESBLs and MRSA who don't feel any different," Dr Everts said.
"It's on their skin, their clothes, their car keys . . . it's impossible to stop them spreading."
A 2008 Australian study found 20 to 30 per cent of people who returned from holidays in India, Southeast Asia and Africa brought back highly resistant ESBLs which were more common overseas, he said.
Healthy people in their homes seldom fell sick from resistant bacteria but residents of rest homes where there were people with catheter bags and existing health conditions were more vulnerable.
Despite this, in 10 years working in Marlborough and Nelson, Dr Everts could not remember any rest home resident whose infection was caused by bacteria resistant to multiple antibiotics.
"We have always been able to treat the bug but sometimes the patient has been too frail to survive," he said.
Only one true superbug was identified in Nelson during the two-year study, in a person with a connection to Southeast Asia who was treated and recovered. Of 20 antibiotics tested, only one proved effective, Dr Everts said.
The information he collected told doctors about which antibiotics to use to treat particular infections.
Before 1940, there were no antibiotics so people faced a high risk of dying from bacterial infections, Dr Everts said.
"If antibiotic-resistant bacteria continue to evolve faster than [we] can keep up, we may go back to that era," he said.
People could help slow the process of resistance by good hygiene practices such as washing hands after going to the toilet and before preparing food, good infection control in hospitals and not over-prescribing antibiotics, he said.
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