Damp houses, poverty and a lack of primary healthcare are behind a dramatic rise in hospital admissions from infectious diseases that has left New Zealand out of step with the developed world, a study says.
Its lead author has called the findings a disgrace, and other medical experts have urged public health authorities to concentrate on improving housing quality and immunisation rates.
The University of Otago study, published in international medical journal The Lancet, shows hospital admissions for infectious diseases increased by 51 per cent in New Zealand between 1989 and 2008.
Lead investigator Michael Baker, an associate professor at the university's medical school in Wellington, said he was "taken aback" by the size of the increase.
"What we expected to see was a steady decline in serious infectious diseases and a rise in admissions for chronic diseases, such as cancer and diabetes, which is the expected pattern for a developed country.
"Instead we found infectious diseases had risen faster than chronic diseases. New Zealand now has the double burden of rising rates of both infectious and chronic diseases."
The study is the first into serious infectious diseases across a country and over an extended period. It was based on analysis of five million overnight admissions to New Zealand hospitals over 20 years.
It found that most categories of infectious disease have risen, with the main contributions coming from increases in respiratory, skin and gastrointestinal infections. Infectious diseases include such conditions as acute rheumatic fever, skin diseases, pneumonia, urinary tract infections and meningococcal disease.
Maori and Pacific people were more than twice as likely as Europeans to end up in hospital with a serious infectious disease.
"All New Zealanders pay the price of rising infectious diseases," Dr Baker said. "There are those who are directly affected by these infections. But these contagious diseases affect all sectors of society. The increased rates are adding 17,000 hospitalisations a year and tens of millions of dollars in avoidable healthcare costs."
Prime Minister John Key said he was concerned by the rise. "It's why the Government has put more money into rheumatic fever, it's why we've been insulating so many homes around New Zealand, it's why we're trying to lift people out of poverty and get them back into work ... and that's why we've established a ministerial committee on poverty. I think we're a First World country and we don't expect New Zealanders to be contracting Third World diseases."
University of Auckland immunisation advisory centre director and senior lecturer Nikki Turner said the consistent rise in rates of infectious disease in New Zealand differed from other Western countries.
"What are the reasons for New Zealand being different? It appears to be particularly linked to the rise in socio-economic inequalities in our society.
"The burden of disease is falling disproportionately on some groups in particular those from economically poorer environments and certain ethnic groups, with Maori and Pacific people carrying a heavy burden."
New Zealand needed to focus further on preventive strategies that include immunisation rates at a level that other Western countries were now routinely delivering, she said.
"Particularly varicella [chicken pox] vaccine to reduce skin infections, rotavirus vaccine to reduce diarrhoeal diseases, meningococcal vaccine.
"Other important preventive health strategies to continue to focus on are improving housing, heating, access to services and a stronger focus on family income for the very low income families all would be likely to have significant impact on our appalling rates of infectious disease."
Auckland University associate professor Cameron Grant, a paediatrician at Starship children's hospital, said improving the quality of homes and better nutrition during pregnancy and infancy would help limit infectious diseases in children. "Houses in New Zealand are cold, damp and mouldy ... smokers in the household and household crowding are factors that all increase the risk of young children being hospitalised with pneumonia."
Improving case management was another key area. It was recently shown that fewer than half the preschool-aged children with pneumonia had received antibiotics prior to hospital admission.
A RASH OF OUTBREAKS
The serious bacterial infection can damage breathing tubes. Babies are most at risk, and can die of complications. Outbreaks happen every three to five years. Between 2004 and 2005, more than 5000 cases were reported. A vaccine is free for children. Adults can get a booster, which also protects against tetanus, for $35-$45.
Often fatal bacterial disease causing meningitis (an infection of the brain membranes) or septicaemia (blood poisoning). It is spread through coughing, sneezing or sharing drinking vessels. The disease can progress in a matter of hours and can kill if not treated early with antibiotics. Since the decline of the meningococcal B epidemic, there have been about 100 cases a year. A vaccine is available for the C strain, but is not publicly funded.
Highly infectious virus spread by breathing, coughing and sneezing. Measles is a serious illness that puts one in 10 sufferers in hospital and kills 1-3 out of 1000. The last major epidemic was in 1997, when 2000 people, mostly babies and children, were infected and more than 300 needed hospital treatment. In a 1991 epidemic, seven died. Vaccination is free for children and for anyone under 42 who has not had the disease, or been previously immunised.
The disease, which develops from a streptococcal infection in the throat, causes sometimes fatal heart damage to 70 per cent of children who contract it. Each year about 450 people are admitted to hospital with rheumatic heart disease and about 200 die. It is prevalent in Maori and Pacific Island communities, who are 20 per cent and 37 per cent more likely to end up in hospital with acute cases. It is preventable if sore throats are treated properly and is almost unheard of in most developed countries. New Zealand's rate is 14 times higher than the Organisation for Economic Co-operation and Development average. The rate is nearly 250 times higher in Porirua East.
KIWIS SUSCEPTIBLE TO INFECTIOUS DISEASES
A dramatic increase in hospital admissions for infectious diseases has New Zealand out of step with the rest of the developed world.
While immunisation programmes in other Western countries have reduced infection rates, admissions have risen by 51 per cent in New Zealand between 1989 and 2008, according to an Otago University study. Maori and Pacific people are more than twice as likely as Europeans to end up in hospital with illnesses such as acute rheumatic fever, skin diseases, pneumonia, urinary tract infections and meningococcal disease.
Medical experts have blamed the rise on damp houses, poverty and a lack of primary healthcare.
Prime Minister John Key said he was concerned. "I think we're a First World country and we don't expect New Zealanders to be contracting Third World diseases."
- Fairfax Media