Border Health In New Zealand

This section summarises how New Zealand health has been affected by exotic diseases which cross our international borders. For background see 'About Border Health'.

On this page:

No cases of a ‘Public Health Emergency of International Concern’ in New Zealand, 2011-15
No cases of severe respiratory disease of priority border health concern in New Zealand, 2011-15
Increasing mosquito-borne diseases in New Zealand, 2011-15
Differences in the characteristics of people who had priority border health diseases

No cases of a ‘Public Health Emergency of International Concern’ in New Zealand, 2011-15

During 2011-2015, there were two serious diseases alerted as a ‘Public Health Emergency of International Concern’ by the World Health Organization [1]:

  • Polio, and
  • Ebola Virus Disease.

Neither of these diseases were detected in New Zealand [2].

No cases of severe respiratory disease of priority border health concern in New Zealand, 2011-15

During 2011-2015, there were four severe respiratory diseases of border health concern detected in the world [1]. These included three influenza (flu) viruses (A(H5N1), A(H7N9), A(H3N2)) and one new coronavirus (Middle East Respiratory Syndrome Coronavirus). There were no cases of these diseases reported in New Zealand during this period [2].

Increasing mosquito-borne diseases in New Zealand, 2011-15

Five mosquito-borne diseases were diagnosed in New Zealanders, 2011-15 [2,3]:

  • Four mosquito-borne viruses: Chikungunya, Dengue Fever, Ross River Virus and Zika
  • One mosquito-borne parasitic disease: Malaria

The total number of yearly cases of mosquito-borne diseases is shown in Figure 1 and more than doubled from 2011 to 2015.

Figure 1

Differences in the characteristics of people who had priority border health diseases

In 2014-15, among people diagnosed with mosquito-borne diseases in New Zealand, there were [3]:

1. Differences in overseas travel 

All people diagnosed with mosquito-borne diseases in New Zealand, in 2014 and 2015, were thought to have acquired these diseases while travelling overseas.

The Asia-Pacific region was the major source of overseas infection.

2. Differences in gender:

Males were more than twice as likely to be diagnosed with Malaria (a mosquito-borne parasitic disease) as females in New Zealand, 2014-15. There were no differences in gender between people diagnosed with mosquito-borne viruses.

3. Differences in age:

In 2014-15, children and young people under 20 years old and older people (≥70 years) were less likely to be diagnosed with mosquito-borne viruses than other age groups (Figure 2).

There were very few children and older people diagnosed with Malaria. Young adults (20-29 years) were over twice as likely to be diagnosed with Malaria as other age groups.

Figure 2: Incidence rates of mosquito-borne virus diagnosis in New Zealand.

Figure2MosquitoBorneVirusDiagnosisInNZ201415 BorderHealthOutcomes released201611

Data Source: ESR, 2016. Data for years 2014 and 2015 have been aggregated to produce crude age-specific rates for 10 year age groups due to small counts. Age groups <10 and >79 years were excluded from analysis due to small (<5) or zero case numbers. 

4. Differences in ethnicity:

In 2014-15, people of Pacific ethnicity had a higher rate of mosquito-borne virus diagnosis than other groups. Pacific people in New Zealand had five and twelve-fold higher rates than people of European/other ethnicities, in 2014 and 2015, respectively. During this period, Asian people had higher rates of Malaria than other ethnicities.

5. No differences in socio-economic deprivation: 

In 2014-15, there were no differences in the rates of mosquito-borne disease diagnoses in New Zealand by different levels of socio-economic deprivation [3,4]. 

6. Differences by region: 

During 2014-15, people living in the Auckland region were more likely to be diagnosed with a mosquito-borne virus than people living in other areas (308 of 466 cases (66%) were in the Auckland region, 2014-15).  

In 2014-15, Auckland also had the highest number of Malaria cases diagnosed (43 cases in the region, including 19 cases in Auckland, 13 cases in Counties Manukau, and 11 cases in Waitemata District Health Boards (DHB)), followed by Canterbury DHB (9 cases). However, due to small case counts, incident rates between these top four DHBs were not statistically significantly different. All other DHBs had low or zero case numbers.

See the factsheet 'Border health in New Zealand' for more detail.

References

1. World Health Organization. Global Alert Response (GAR). [Accessed Jan 2016]. Available from: http://www.who.int/csr/resources/publications/HSE_GAR_ARO_2012_1/en/

2. Institute of Environmental Science and Research Limited (ESR). 2015. Notifiable Diseases in New Zealand: Annual Report 2014. Porirua: Institute of Environmental Science and Research Limited.

3. Institute of Environmental Science and Research Limited (ESR). Notifiable diseases EpiSurv data extraction. Porirua: Institute of Environmental Science and Research Limited. [2016 personal communication with ESR Senior Analysts]

4. Atkinson J, Salmond C and Crampton P. 2014. NZDep2013 Index of Deprivation. Wellington: University of Otago