In the 19th century public health operated at a local level with a focus on disease control. This was addressed through quarantine measures, sanitary reform and vaccination.
Quarantine – an enforced period of isolation – was the first and earliest line of defence against infectious diseases in the 19th century. All people onboard ships affected by disease were quarantined on islands. This occurred less frequently later in the century as large, spacious steamships replaced sailing ships, and screening before departure improved. However, quarantining did not officially cease until 1943.
The Public Health Act 1872 set up a central board of health for each province and smaller local boards (which were usually the borough and city councils) within the provinces. After the provinces were abolished in 1876, one country-wide board controlled by central government was established, while local boards were retained. Both were poorly funded and were neither very active nor effective.
The Christchurch Drainage Board (1876–85) was one exception. It employed a full-time medical officer and was responsible for significant sanitation improvements, including the first sewerage system in New Zealand (completed in 1882). This led to a reduction in deaths from infectious diseases such as typhoid.
From the 1880s doctors advocated a central department of health, which government was also considering. The (ultimately unrealised) threat of a bubonic plague pandemic reaching New Zealand provided the impetus government needed to establish the Department of Public Health in 1900.
The department (from 1922 called the Department of Health, and from 1992 the Ministry of Health) was responsible for the identification of public health issues and the development of preventative and promotional public health services, which were delivered by regional offices. This remained the case until the late 20th century.
In the 1990s the government concentrated on financial efficiency and health services for individuals. Resources were directed away from public health. An independent Public Health Commission was established in 1993 to conduct research, develop policy and contract out public health programmes, but it was disbanded in 1996.
In the 2000s the government made public health a priority. The Ministry of Health planned and managed public health services – such as immunisation, tobacco control and mental health promotion – on a national level, but they were delivered by the regional district health board public health units or non-governmental organisations. The Public Health Advisory Committee was established in 2001 to provide independent advice to the minister of health.
Particular aspects of public health previously administered by the ministry became overseen by separate government agencies. The New Zealand Food Safety Authority was responsible for food safety and the Department of Labour for occupational health.
Water, waste and sanitation services remained key local-government public health responsibilities. Other functions that had an impact on public health included the provision of recreational facilities and public transport. The Local Government Act 2002 conferred on local government a new, broader statutory responsibility to ‘promote the social, economic, environmental and cultural well-being of communities’.
The Public Health Act 1956 describes things that are offensive or potentially injurious to public health as ‘nuisances’. There are 17 separate nuisances. They are created, for example, ‘where any animal, or any carcass or part of a carcass, is so kept or allowed to remain as to be offensive or likely to be injurious to health’ or ‘where there exists on any land or premises any condition giving rise or capable of giving rise to the breeding of flies or mosquitoes or suitable for the breeding of other insects, or of mites or ticks, which are capable of causing or transmitting disease’.
Plunket (originally the Society for the Promotion of the Health of Women and Children), which from 1907 provided public health services for infants and children under five, was the earliest non-government public health organisation. By the 2000s about 50% of the public health section of the overall health budget went to non-governmental organisations to deliver services to the community.
In the 21st century general practitioners and other health professionals who grouped together as primary health organisations (PHOs) had a mandate to improve and maintain the health of the population through the delivery of national public health services such as immunisation. PHOs also had a limited role in health promotion.
Tertiary-education institutions provided postgraduate training in public health, while university-based research was an essential source of information for the public health sector. The Public Health Association, a voluntary organisation, promoted public health and assisted in policy development.