About border health

This section gives background information about how exotic diseases affect our health.

Border health is a term used to describe the health effects of public health threats from overseas. We focus on the impact of exotic infectious diseases. 

Our border health depends on two main environmental factors:

  • The movement of exotic disease-carrying pests (unwanted animals) across our borders.
  • The movement of people (international travellers) across our borders.

On this page 

What is the New Zealand border?
How does international travel and trade affect New Zealand health?
Which exotic diseases are we most worried about?
What disease-carrying pests are we most worried about?
Who is most at risk?
How is our border health protected?

What is the New Zealand Border?

The New Zealand border is made up of two main types of ports [1]:

  1. International airports: Auckland, Christchurch, Dunedin, Queenstown and Wellington (commercial airports); Whenuapai, Ohakea and Woodbourne (military airbases).  Most international travellers arrive in New Zealand by air. The vast majority enter through Auckland international airport [2].
  2. International seaports: Auckland, Bluff, Dunedin, Milford Sound, Gisborne, Lyttelton, Napier, Nelson, New Plymouth, Opua, Picton, Port Chalmers, Tauranga, Timaru, Wellington, Whangārei. Shipping is the major mode of entry for international cargo to New Zealand [3].

How does international travel and trade affect New Zealand health?

With increasing air travel, more and more people are moving between countries very quickly [2]. This means people carrying diseases can potentially spread them rapidly and widely.

There is a delay between being infected with a disease and developing the symptoms (the incubation period). People can easily cross international borders and spread diseases to other countries before they realise they are unwell. Some people may not develop symptoms at all, but can still transmit infections.

Travel is increasing and so is access to previously remote places. There are some parts of the world where new or rare diseases are more likely to develop due to environmental factors (e.g. warm tropical regions where humans and exotic animals more closely interact) [4]. Zoonotic diseases (i.e. diseases transmitted between animals and humans) are of particular concern because they are a major source of new, serious human diseases in the world [5]. Parts of the Asia-Pacific region pose a high risk for these diseases to develop. There is particular risk of exotic diseases being imported to New Zealand from the Asia-Pacific region because of close travel and trade relationships.

Global trade is increasing [3]. We import goods from all over the world. However, we need to ensure that unwanted exotic disease-carrying pests do not come in with this cargo. If pests, like exotic mosquitoes, are able to make New Zealand their home, the risk of exotic disease outbreaks will increase. This would have serious effects on our border health.

Global population growth and climate change will also increase the pressures on New Zealand border health [4]. Overcrowded conditions in poorer countries with fragile health systems can make it more likely for exotic disease outbreaks to occur. Mass movement of people (e.g. due to war or climate change making homes uninhabitable) is another pressure on international border health.

Which exotic diseases are we most worried about?

All exotic diseases are unwanted in New Zealand; they can be brought in by travellers, visitors and immigrants. High-risk exotic diseases are those which:

  • spread easily
  • New Zealand people may be particularly vulnerable to (e.g. non-immune)
  • can be severe and difficult to treat.

Exotic diseases of high-risk to New Zealand include:

  • Any disease alerted as a ‘Public Health Emergency of International Concern’:  A disease is given this classification (by the World Health Organization) if it poses a serious threat to global health. This alert calls for international action to prevent and control the disease.
  • Specific exotic respiratory diseases: New influenza (flu) viruses (e.g. Avian influenza or ‘Bird Flu’) are a particular concern because they cause serious, life-threatening lung infections, and can spread very quickly around the world. Symptoms often begin like normal, seasonal flu: e.g. fever, shortness of breath and cough.
  • Specific vector-borne diseases: Vectors are anything which can transfer diseases between humans, animals and/or plants. Mosquitoes are major human disease vectors. Each year thousands of people are infected overseas by mosquito-borne diseases. Common examples are diseases caused by viruses – e.g.  Dengue Fever, Zika, Chikungunya  – and diseases caused by parasites – e.g. Malaria. These diseases can cause fever, a rash, joint pains (e.g. Chikungunya, Zika), bleeding problems (e.g. Dengue and Yellow Fevers) and they can be fatal.

Overseas infectious diseases are rapidly changing – new diseases can very quickly arise and become a threat to New Zealand border health. Therefore, it is important that diseases of priority concern to New Zealand are regularly reviewed and updated. The New Zealand Ministry of Health keeps a close eye on the overseas infectious diseases environment.

What disease-carrying pests are we most worried about?

Pests are unwanted animals (e.g. exotic insects) [6]. They have potential to damage New Zealand’s environment, our indigenous treasures (taonga), our economy, and our health.

Exotic mosquitoes are highly unwanted in New Zealand due to their ability to spread serious diseases (e.g. Dengue Fever, Malaria). These diseases cause a lot of illness globally (e.g. fever, joint pains, bleeding problems) and can be fatal.

Insects, especially mosquitoes, are experts at international hitch-hiking: e.g. hiding in aircraft holds, laying larvae in puddles on ships. Measures are in place to try to prevent their entry to New Zealand (see 'How is our border health protected?').

Who is most at risk?

Those most at risk from exotic diseases are our most vulnerable populations: children, elderly and people with chronic diseases (e.g. heart disease). For example, these groups of people are often worst affected by new influenza viruses if the viruses enter the country.

Those who are most affected can depend on the type of disease. People who tend to get mosquito-borne diseases in New Zealand are those who have travelled overseas and become infected there. Identifying how particular diseases affect our border health is important for targeting disease prevention and control measures (see indicator 'Border Health in New Zealand').

How is our border health protected?

New Zealand Border Health is protected by multiple agencies, led by the Ministry of Health [1]. They are primarily responsible for managing risks at the border which can most directly impact upon human health.

Biosecurity involves broader work at the border to protect New Zealand’s natural assets (agriculture and biodiversity).  Wider environmental, animal, economic and human benefits flow from that  [6]. Biosecurity is led by the Ministry for Primary Industries in New Zealand.

Border agencies (e.g. New Zealand Customs Service), biosecurity and border health officials work together to prevent pests and diseases entering New Zealand. Various legislation supports this work (link to MOH webpage).

Pest and disease prevention and control activities take place at three stages:

  • Pre-border (overseas/ before reaching New Zealand)
  • Border (at the border)
  • Post-border (within New Zealand).

Examples of prevention activities include inspecting imported cargo for pests, and spraying aircraft with insecticide. National mosquito surveillance takes place at New Zealand’s border to capture exotic mosquitoes and prevent them from becoming established in New Zealand.

References

1. Ministry of Health. Meeting core capacity requirements for international points of entry. Ministry of Health, New Zealand. [Website cited 18th Jan 2016]. Available from: www.health.govt.nz/our-work/border-health/meeting-core-capacity-requirements-international-points-entry

2. Statistics New Zealand. 2016. International visitor arrivals to New Zealand: April 2016. Overseas visitor arrivals to New Zealand by country of residence and selected characteristics. Wellington: Statistics New Zealand.

3. Statistics New Zealand. Infoshare. Overseas cargo statistics: Total imports by New Zealand port (Annual-Jun). (Accessed 8 June 2016). Available from: www.stats.govt.nz

4. Mackenzie JS. Responding to emerging diseases: reducing the risks through understanding the mechanisms of emergence. West Pac Surveill Response J 2011; 2(1):1-5.

5. Jones KE, Patel NG, Levy MA, Storeygard A, Balk D, Gittleman JL, et al. Global trends in emerging infectious diseases. Nature 2008; 451(7181): 990–3.

6. Ministry for Primary Industries. Protection and response. Ministry for Primary Industries, New Zealand. (Accessed 18th Jan 2016) Available from: http://www.mpi.govt.nz/protection-and-response/finding-and-reporting-pests-and-diseases/keeping-watch/