Mosquito-borne disease in New Zealand

This section presents information on how the health of New Zealanders is affected by exotic mosquito-borne diseases, including dengue, malaria, chikungunya, Zika virus, and Ross River virus. 

Mosquito-borne diseases pose a threat to New Zealand’s health

Mosquito-borne diseases such as dengue, malaria, chikungunya, Zika virus, and Ross River virus pose a greater risk to New Zealand because people have no natural immunity, vaccines are limited, they spread easily, and they can cause serious illness. Although New Zealand currently has no established populations of disease-carrying mosquitoes such as Aedes aegypti, Aedes albopictus, or Culex annulirostris (see Exotic mosquito species established in New Zealand), there is still a real risk that these mosquitoes could become established due to climate change.

Increase in mosquito-borne diseases following a decline in 2021

The number of mosquito-borne disease notifications in New Zealand increased from 46 in 2022 to 122 in 2023. In 2023, there were 55 cases of dengue, 54 of malaria, 9 of chikungunya, and 4 of Zika virus (Figure 1).

Figure 1: Number of notifications of mosquito-borne diseases, 2004–2023

All mosquito-borne disease cases acquired overseas

Between 2021 and 2023, all people diagnosed with a mosquito-borne disease in New Zealand were thought to have acquired it while travelling overseas. The most commonly visited regions prior to diagnosis were Asia, Southeast Asia, Pacific, and Africa (Figure 2).

Figure 2: Number of mosquito-borne disease notifications, by locations visited by New Zealand travellers prior to diagnosis, 2021–2023