Hospital admissions from infectious diseases have leapt dramatically in the past 20 years, a trend out of line with developed countries and one which is costing New Zealand millions.
International experts say the findings in a new University of Otago study have enormous implications for New Zealand's health and social policy and have called for urgent action.
The study, published in international medical journal The Lancet, reveals that infectious diseases increased by 51 per cent in New Zealand between 1989 and 2008.
Lead investigator Otago University Associate professor Michael Baker said he was "taken aback" by the size of the increase in infectious diseases.
"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 ever of serious infectious diseases across an entire country and over an extended period. It was based on analysis of 5 million overnight admissions to New Zealand hospitals over a 20 year period.
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 included illnesses such as acute rheumatic fever, childhood pneumonia and meningococcal disease.
"All New Zealanders pay the price of rising infectious diseases. 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 hospitalisation a year and tens of millions of dollars in avoidable health care costs," Baker said.
The research also revealed ethnic and income inequalities in infectious diseases are large and increasing, with Maori and Pacific people more than twice as likely as the European population to be hospitalised with a serious infectious disease.
"Because Maori and Pacific populations tend to be over-represented in the poorest suburbs there is a multiplier effect regarding infectious disease risk. This has seen a 77 per cent increase in hospitalisation for Maori and a 112 per cent increase for Pacific peoples from the most deprived areas over the last two decades."
Infectious diseases accounted for 27 per cent of all acute hospital admissions in 2004-08 period.
University of Auckland Immunisation advisory centre director and senior lecturer Dr Nikki Turner said the consistent rise in rates of infectious disease in New Zealand appeared to contrast with other Western countries.
"What are the reasons for NZ being different? It appears to be particularly linked to the rise in socioeconomic 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.
"There is something very wrong in NZ with such a stark and growing inequity burden."
In an editorial accompanying the study in The Lancet journal, University of Washington Associate Professor Stephen Lim and Professor Ali Mokdad said the findings had "enormous implications" for health and social policy in New Zealand.
"The health of indigenous people in New Zealand has historically been poorer than the rest of the population and these findings suggest that a rising burden of infectious diseases may be leading to a widening of this gap. Urgent action must be taken to reverse this trend."
- The Dominion Post
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