Bacteria: Our Fellow Travellers
The deaths of three babies in Wellington highlighted how susceptible people are to common bugs despite medical advances. Can we ever win the war against bacteria? JOANNA DAVIS reports.
Dr Nicola Austin is proud of her new sinks. The clinical director of Christchurch Women’s Hospital shows off a pair of handbasins standing like sentries at the entrance to the new neonatal unit.
They feature elbow-operated taps, with wall-mounted soap dispensers and boxes of disposable gloves alongside. The sinks represent the unit’s first line of defence against infection.
When asked what the unit is doing to prevent an outbreak such as that rampaging through Wellington Hospital’s neonatal unit, Austin’s reply is mantra-like. “We wash our hands, we wash our hands, we wash our hands,” she says.
There are other measures, of course. Staff must not wear rings, watches or nail-polish, and must use gloves for nappy-changing and any other exposure to body fluids. Visitors to the tiny inpatients are limited, and staff are advised to stay home when they get colds.
This week, staff are being screened for the gentamicin- resistant strain of staphylococcus aureus that has been linked to the deaths of three babies in Wellington.
Austin says this move is a “simple precaution” since a baby transferred from Wellington to Christchurch Women’s Hospital’s Colombo Street site this year was found to be carrying a gentamicin- resistant organism.
With more than 100 staff to swab, Austin says the test results will not be back until Monday.
Despite all these preventive measures, infections remain a real risk in any neonatal unit. They are one of the three main reasons babies die in the unit, she says, alongside extreme prematurity (usually lung immaturity) and brain haemorrhages.
“Infection is common in a neonatal unit,” says Austin. “The premature babies don’t have the antibodies, so their immunity is significantly lower. The more premature in particular are very stressed. Their skin is fragile, and infections can get in through the tummy button and through the skin.”
These babies are obviously vulnerable, she says, otherwise they would not be in intensive care.
Austin says the Wellington situation has the potential to be drawn out. Is she concerned for her own unit?
“It doesn’t keep me awake at night,” she says. “We’re doing everything we can to monitor it.”
Such an outbreak does not reflect on the unit anyway, she says. “Ninety-five per cent of it is that the organisms are changing.”
Organisms changing — or mutating — is at the very heart of the superbug problem. Although health authorities steer away from the superbug label (“too emotive”, says Austin), there is certainly a level of community concern that has come with the increasing profile of MRSA.
MRSA, or methicillin-resistant staphylococcus aureus, was first reported in New Zealand in 1975. It remained uncommon until the 1990s, but its incidence has been increasing ever since.
Environmental Science and Research (ESR) figures, released in March, show 1788 reported cases of multi-resistant MRSA (resistant to two or more classes of antibiotics) last year.
The Ministry of Health is sufficiently concerned to issue guidelines for the control of MRSA and to require that all cases be reported to ESR’s nosocomial (hospital-acquired) infections lab in Porirua.
Although nearly three-quarters of cases are in hospital patients, some strains are now being found in the community.
Canterbury Health Laboratories clinical director Dr Mona Schousboe says she and colleagues are starting to see a community- based strain of MRSA that is resistant to Bactroban, a topical (skin) antibiotic. This means the treatment is now less effective when really needed. Bactroban’s former availability over the counter almost certainly contributed to its over-use.
Over-use of antibiotics is blamed for increasing bacterial resistance. With this in mind, Government drug-buying agency Pharmac has been running a campaign for seven years called Wise Use of Antibiotics.
Medical director Peter Moodie says this year’s campaign will be rolled out at the end of the month before the winter coughs and colds season. Patients visiting their GP are likely to see an A4 poster and leaflets reminding them that antibiotics are not the panacea some think and, particularly, are ineffective against viral infections.
Moodie says the campaign has decreased antibiotic use by about 15 per cent and made a “small but significant” improvement to patients’ understanding of proper antibiotic use.
He is quick to point out that the campaign is aimed at best medicine rather than cost-saving.
Local GP association Pegasus Health backs the campaign fully. Managing director Dr Paul McCormack says some patients still arrive with runny nose, colds or sore throats and expect to receive a script for antibiotics. The issue is one of patient education, he says. “Naturally enough, people are confused about which conditions are viral and which bacterial.”
Although some patients equate proper treatment with being given a prescription, McCormack says what they get for their consultation fee is reassurance.
“It’s a doctor’s role to let them know this is a nuisance problem,” he says. “It will get better by itself. If it’s a viral infection, you need temperature control (such as paracetamol), increased fluids, rest and the understanding that your body is having this fight with the virus.”
McCormack wants people to realise that antibiotics, like all drugs, have risks. “The goal with medication is always to take the smallest amount necessary.”
Despite the attention given to Wellington Hospital’s current outbreak and the wider incidence of MRSA, antibiotic resistance is hardly a new problem.
As long ago as 1955, local experts were calling for controls on antibiotic treatment.
In the spring of that year, nine babies died in Christchurch’s Calvary Hospital (now Southern Cross in Bealey Avenue) from “golden staph” — an infection that was resistant to the post-war “wonder drug”, penicillin. Earlier in 1955, surgery at Cashmere’s tuberculosis sanitorium had to be discontinued because of a similar outbreak.
A report to the North Canterbury Hospital Board, published in The Press on December 22, 1955, showed the antibiotic resistance problem was understood even then.
“It is the opinion of many medical men that the broad- spectrum antibiotics should be withdrawn and that they should be issued only over the signature of a specialist versed in their uses and dangers. No new antibiotic against staphylococcus should be issued for free use, but should be carefully husbanded and held in reserve against serious infections,” the report states.
A correspondent to the paper warned the public about their vociferous demands for antibiotic treatment. “Public pressure is undoubtedly brought to bear on doctors for the speedy relief of some not very serious illnesses. These examples should be grim warning of the necessity for conservative demands by patients.”
That outbreak was well before Schousboe’s time, but she has heard about it. Other local outbreaks include one in Christchurch Hospital’s spinal injuries unit in 1979. Like the current Wellington bug, that bacteria was a strain of the common staphylococcus. Both strains can be treated as normal with flucloxacillin.
Which is one reason Schousboe is reluctant to call the Wellington bacteria a superbug. Instead, the problem with it, she says, is its virulence and the fact it is blood- borne, rather than being confined to the skin, nose and throat as it is in about 20 to 30% of the healthy population.
“That’s why they’ve sat up and looked at it and said it’s not right,” she says.
Schousboe also throws cold water over the hysteria about MRSA, saying Canterbury, in particular, really does not have much of a problem.
“We’re different here. We’re tougher. Also, we have what they call a fortress policy here,” she says. That policy includes screening all staff for MRSA before they take up their positions, testing patients on transfer from other hospitals and screening any wounds for antibiotic-resistant bacteria.
Outbreaks could still occur, she says, and the important thing is to be vigilant.
Most people have a limited understanding of the role of bacteria and therefore the place of antibiotics. “We’ve got more bacterial cells than human cells, so we have to live in harmony with our fellow travellers,” she says.
“Antibiotics is a two-edged sword. You take them for saving people’s lives or for surgical procedures, for instance. But when you give them, you are declaring war on your fellow travellers.”
Her words echo those of the neonatal unit’s Austin: caution, vigilance, but never panic.
.
BACTERIA TO BUGS
While MRSA is the most common antibiotic- resistant bacteria, other comparatively rare bugs could also be of concern. They include:
* VRE, vancomycin-resistant enterococci.
* ESBLs, extended-spectrum beta-lactamases.
* PRSP, penicillin-resistant streptococcus pneumoniae. How do ordinary bacteria mutate into superbugs? Pharmac medical director Peter Moodie compares it to an atom bomb being dropped on New Zealand. “Most people would die, but there would be a few who would be resistant and they would breed children who are resistant themselves.” With superbugs and antibiotics, it is exactly the same logic, he says. The only difference is that bacteria “breed” a lot more quickly, so mutations become established faster.
——————–