Health and household crowding

This section presents statistics on health conditions related to household crowding. These conditions include lower respiratory tract infections, gastroenteritis, meningococcal disease, serious skin infections, and rheumatic fever. 

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Household crowding and health
Bronchiolitis
Pneumonia
Gastroenteritis
Meningococcal disease
Serious skin infections
Rheumatic fever
Burden of disease due to household crowding

Household crowding and health

Household crowding can increase the spread of infectious diseases. In particular, household crowding is a risk factor for [1]:

  • pneumonia / lower respiratory tract infections
  • gastroenteritis
  • RSV bronchiolitis
  • Haemophilus influenza (Hib) disease
  • meningococcal disease
  • Hepatitis A
  • Helicobacter pylori infection
  • tuberculosis
  • trachoma (eye infection).

Evidence also suggests that household crowding may be linked to serious skin infections and acute rheumatic fever. 

Children are more at risk from these diseases. Some children are disproportionately affected by these diseases: infants, Māori and Pacific children, and children living in the most socioeconomically deprived areas.   

Bronchiolitis

Bronchiolitis is a common respiratory infection in infants, and is mostly caused by the respiratory syncytial virus (RSV). Household crowding increases the risk of lower respiratory tract infections such as bronchiolitis.

  • In infants under 1 year, there were about 4,800 hospital admissions and 1 death each year for bronchiolitis [2].
  • In 2006–2010, bronchiolitis hospitalisation rates for children under 1 year old were much higher than the national rate (75 per 1000) in Pacific infants (169 per 1000), Māori infants (115 per 1000), and infants living in the most deprived decile (163 per 1000).

Pneumonia

Pneumonia is an inflammation of the air sacs (alveoli) in the lungs. Household crowding increases the risk of lower respiratory tract infections such as pneumonia.

  • On average, there were 3,400 hospital admissions for pneumonia each year in children aged 0–14 years (a rate of 4 per 1000) [2].
  • Hospital admission rates for pneumonia gradually dropped from 2000 to 2010 in New Zealand children.
  • Children aged 0–2 years had the highest pneumonia hospitalisation rates in 2006–2010.
  • Rates were twice as high among Māori children, and over four times as high among Pacific children, as in European children. 
  • Rates were three times as high in more deprived areas than in less deprived areas.
  • Each year, 10–11 children or young people die from pneumonia.

Gastroenteritis

Gastroenteritis has symptoms of diarrhoea, nausea, fever, abdominal pain and vomiting. Household crowding is a risk factor for gastroenteritis. 

  • Each year, there was an average of 5,400 hospital admissions for gastroenteritis in children aged 0–14 years (a rate of 6 per 1000) [2].
  • Hospital admissions for gastroenteritis were higher among Pacific children and children in the most deprived areas. 
  • Rates were relatively stable from 2006–07 to 2010. 

Meningococcal disease

Household crowding increases the risk of meningococcal disease. Meningococcal disease is a serious bacterial infection, affecting mostly children and young people.

  • Rates of meningococcal disease are now the lowest in two decades. In 2014, 46 cases of meningococcal disease were notified, a rate of 1.0 per 100,000 people [3]. The rate had decreased since 2013 (68 cases, 1.5 per 100,000 people). 
  • Infants under 1 year had the highest rates of meningococcal disease.
  • Rates of meningococcal disease were about three times higher in Māori and Pacific people than in European/Other people.
  • In 2008, 7 children and young people died from meningococcal disease. 

Serious skin infections

Serious skin infections include cellulitis, abscesses and boils. Evidence suggests that household crowding is a risk factor for these infections. 

  • Rates of hospital admissions for serious skin infections increased from 2000 to 2010 among 0–14 year olds [2].
  • In 2006–2010, the highest rates were among young children, particularly infants under 1 year.
  • Hospital admission rates were also higher than the national average (7.2 per 1000) in Pacific children (17.5 per 1000), Māori children (11.8 per 1000), and children living in the most deprived areas (13.6 per 1000).

Figure 1

Rheumatic fever

Rheumatic fever can be caused by an untreated sore throat, and can lead to rheumatic heart disease. Studies suggest that rheumatic fever is associated with dampness and household crowding.

New Zealand has some of the highest rates of rheumatic fever in the developed world. Reducing the incidence of rheumatic fever is a current government target. 

  • In 2013, there were 205 notifications of acute rheumatic fever, including 194 initial attack cases [3]. 
  • From 2005 to 2013, the notification rate increased from 2.1 to 4.6 per 100,000.
  • Children were most affected, particularly those aged 10–14 years.
  • Māori and Pacific were disproportionately affected by rheumatic fever, with most cases occurring in these ethnic groups.

Burden of disease due to household crowding

Each year, an estimated 1,343 hospital admissions for infectious disease are caused by household crowding in New Zealand [1].

Crowded households were a particularly important risk factor for Māori and Pacific, and especially for meningococcal disease. 

The main conditions contributing to attributable hospital admissions were: bronchiolitis from respiratory syncytial virus, pneumonia/ lower respiratory tract infections, upper respiratory tract infections, helicobacter pylori, gastroenteritis, tuberculosis, meningococcal disease, Haemophilus influenza (Hib) disease, and Hepatitis A. 

References

1. Baker MG, McDonald A, Zhang J, Howden-Chapman P. 2013. Infectious Diseases Attributable to Household Crowding in New Zealand: A systematic review and burden of disease estimate. Wellington: He Kainga Oranga/ Housing and Health Research Programme, University of Otago. Available online: http://www.healthyhousing.org.nz/publications/

2. Craig E, Adams J, Oben G, Reddington A, Wicken A, Simpson J. 2013. The Health Status of Children and Young People in New Zealand. Dunedin: Dunedin School of Medicine, University of Otago. Available online: http://dnmeds.otago.ac.nz/departments/womens/paediatrics/research/nzcyes/nz_reports.html

3. ESR. 2015. Notifiable and Other Diseases in New Zealand: Annual Report 2014. Porirua: The Institute of Environmental Science and Research Ltd. Available online: https://surv.esr.cri.nz/surveillance/annual_surveillance.php