Story: Epidemics

Nine thousand New Zealanders died in the 1918 influenza pandemic. Since the advent of vaccination, antibiotics and better sanitation, epidemics have been more readily controlled. However, the COVID-19 coronavirus outbreak which began in 2020 showed that the danger of widespread loss of life from epidemics was far from over.

Story by Geoff Rice
Main image: A girl receives a rubella vaccination in 1982

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What are epidemics and pandemics?

An epidemic occurs when many people in a country have the same disease at the same time. Epidemics are usually caused by infectious diseases, such as influenza (flu).

A pandemic occurs when an epidemic spreads between many countries.

How diseases are controlled

Many diseases that used to be common, such as polio, have been controlled by immunisation. This causes a person’s body to produce cells and antibodies that protect them from the disease. Other diseases have been controlled by better hygiene and sewerage systems, or by new drugs.

Early settlers and diseases

European settlers brought new diseases such as measles and flu to New Zealand. Māori lacked natural immunity to these diseases, so many died from them.

Early settlements usually did not have clean water and sewerage systems, which made diseases such as typhoid very common.

Influenza pandemics

Flu pandemics occurred in 1890–94 and 1918. The 1918 pandemic killed more than 50 million people worldwide and 9,000 in New Zealand.

Polio

Poliomyelitis (polio) was a common disease until the 1960s. It could cause paralysis and even death. Polio vaccines have removed the virus from New Zealand.

Epidemics since the 1970s

Meningococcal disease, which causes meningitis, reached epidemic proportions in the 1990s and early 21st century. Between 2004 and 2007, more than 1.1 million children and young adults in New Zealand were immunised against the meningococcal group B virus.

Better health services, immunisation and antibiotics have meant that epidemics have become less frequent. Despite this, more people have had to go to hospital with infectious diseases, and widespread air travel means diseases can now travel more easily between countries. In 2009, the ‘swine flu’ pandemic involved 3,000 cases in New Zealand, and 20 people died.

In 2020, the COVID-19 coronavirus pandemic posed an even more serious threat. The virus became a major cause of people being sent to hospital, and a leading cause of death. From the start of the pandemic until September 2022, when the last public health requirements were lifted, New Zealand recorded 1.7 million cases and more than 2,000 deaths.

Preventing epidemics

Immunisation (vaccination) is one of the best ways to reduce the spread of disease. Vaccines contain fragments of a disease germ or weakened germs. These encourage the body to produce cells and antibodies that protect the person from the disease. Vaccines to fight diphtheria, tetanus and pertussis/whooping cough (DTP) and the human papillomavirus (HPV) have been particularly effective.

Local health officials have special powers to fight outbreaks of disease, such as ordering schools to close. During the COVID-19 pandemic, a national state of emergency was declared and most people were told to work or study at home.

Doctors, health officials and government agencies look out for disease outbreaks and collect data on them. New Zealand works with the World Health Organization to prevent the spread of disease.

Mosquitos carrying tropical diseases may become established in New Zealand in future, as parts of the country become warmer and wetter due to climate change.

How to cite this page:

Geoff Rice, 'Epidemics', Te Ara - the Encyclopedia of New Zealand, http://www.TeAra.govt.nz/en/epidemics (accessed 20 March 2024)

Story by Geoff Rice, published 5 May 2011, reviewed & revised 8 February 2024