Cold and damp conditions are adding to health problems faced by residents of overcrowded homes, an Auckland budgeting adviser says.
An Otago University study released today shows one in 10 hospital admissions for infectious diseases, including pneumonia, meningococcal disease and tuberculosis, were the result of overcrowded housing.
Darryl Evans, the head of Mangere Budgeting Services, says health problems included other respiratory illnesses.
He said said he had nine cases this year in which he'd helped clients move out of garages or overcrowded housing into better state houses or private rentals.
"In almost every case somebody in the household, whether it's the children or the adults is suffering from really bad chest infections," he said.
"Overcrowding has been a major issue for people - we are consistently seeing children present with respiratory infections, chest infections and asthma.
He said the quality of the housing was also to blame - cold and damp housing was leading to respiratory illnesses.
Mr Evans had helped a family of eight move out of a single room in a lodge in the last month.
He said there were 53 empty state houses in Mangere and 17 families he knew of in overcrowded housing and looking for a state house.
Mr Evans said more state houses needed to be built that were fully insulated and had a building warrant of fitness.
The Otago University study found children and Maori and Pacific people were particularly affected.
Lead researcher Professor Michael Baker said the findings highlighted the urgent need to address New Zealand's severe shortage of affordable housing.
The study showed crowding was an important risk factor for nine major types of disease, and estimated to cause more than 1300 hospital admissions a year, including some deaths.
"Most of the diseases in the study have especially high rates in children," Mr Baker said.
"Children are more susceptible to meningococcal disease, gastroenteritis, pneumonia and most other infectious diseases, and our analysis shows that their risk is strongly associated with exposure to household crowding."
He said the study also showed stark health inequalities between ethnic groups.
For Europeans, exposure to household crowding is estimated to cause 5 per cent of hospital admissions. For Asian peoples, the figure is 13 per cent, Maori 17 per cent, and Pacific 25 per cent.
"Fundamentally what it reveals is a very real and urgent need to lower household crowding as a first step to reducing these serious diseases among our most vulnerable populations," Mr Baker said.
He said Housing New Zealand programmes focused on overcrowding in Auckland, Northland and Wellington were having a positive effect.
But more needed to be done to address the severe shortage of affordable housing.
"New Zealand needs a large-scale programme to construct thousands of additional social and affordable houses if it wants to reduce household crowding and prevent many cases of serious infectious disease."