Poor indoor and outdoor air quality increases the risk of lower respiratory tract infections among children
Lower respiratory tract infections (LRTI) refer to infections of the windpipe (trachea), lungs, and airways (bronchi, bronchioles). These include pneumonia, bronchitis and bronchiolitis. Household crowding  second-hand smoke exposure , indoor dampness and mould , and outdoor air pollution  increase the risk of lower respiratory tract infections in young children.
LRTI is responsible for a large burden of avoidable mortality and morbidity among young children under five years old globally. Compared with other developed countries, New Zealand has high rates of LRTI hospitalisation among young children . Each year, a small number of children in New Zealand die from lower respiratory tract infections. Between 2001 and 2018, 173 children under five years of age died from lower respiratory tract infections, an average of 10 deaths every year.
The COVID-19 pandemic
In March 2020, the New Zealand Government pursued an elimination strategy for COVID-19. New Zealand moved to Alert Level 4 (Lockdown) on 25 March 2020, along with temporary border closures, quarantine requirements, community testing, school closures, and contact tracing. These public health measures appeared to have affected lower respiratory tract infection (LRTI) hospitalisation rates in children 0–4 years in 2020.
Number of LRTI hospitalisations decreased dramatically in 2020
In 2020, there were 2856 LRTI hospitalisations in children under five years old, a 71% decrease since 2019 (9939 hospitalisations) (Figure 1).
Figure 1: Number of lower respiratory tract infection hospitalisations in children aged 0–4 years, 2001–2020
Usual winter LRTI hospitalisation peak was down by 85%
The number of LRTI hospitalisations during the 2020 winter season was very low compared to previous years since 2001. There were 272 hospitalisations in August 2020, down from 1817 in August 2019 (Figure 2). This dramatic decrease in LRTI hospitalisations is likely related to the strict public health measures implemented during the COVID-19 pandemic.
Figure 2: Number of lower respiratory tract infection hospitalisations in children aged 0–4 years, by month, 2018–20
Information about this data
Lower respiratory tract infection hospitalisations
Source: National Minimum Dataset, Ministry of Health
Definition: Acute and semi-acute hospitalisations with pneumonia (ICD-10AM J12–J16, J18), bronchitis (J20), bronchiolitis (J21) or unspecified acute lower respiratory tract infection (J22) as the primary diagnosis, for children aged 0–4 years. Analyses excluded overseas visitors and transfers within and between hospitals. Rates have been presented per 100,000 children.
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