NSW Vector-Borne Diseases Annual Report - 2016

Summary

This report summarises NSW vector-borne disease (VBD) surveillance data for notifiable arboviruses (arthropod-borne viruses) and other notifiable arthropod-borne diseases for 2016. The report notes changes in notifications over time and describes likely areas of disease acquisition for both local and exotic infections.

Key trends in 2016

Barmah Forest virus – a marked decrease in notifications, likely reflecting both low activity in the community and stricter laboratory case definitions for surveillance.
Chikungunya virus – 74% of cases acquired in India. Almost half of cases were residents of Western Sydney LHD.
Dengue virus – increasing trend in notifications; 56% acquired in Indonesia, predominantly Bali.
Ross River virus – decreased notifications overall. Notable increase in notifications in December, predominantly in western and southern NSW west of the ranges following heavy rains and flooding in inland NSW. Overall trend also influenced by stricter laboratory case definitions for surveillance.
Malaria – 25% decrease in notifications compared to 5-year annual mean. India and Papua New Guinea were the countries where malaria was most commonly acquired.
Zika virus – a marked increase in notifications but no cases of congenital Zika infection. The increase in cases likely reflects increased exposure of travellers in areas with Zika outbreaks, as well as increased awareness and testing.

There were no reports of human infection due to MVE virus, Kunjin virus, Japanese encephalitis virus, or yellow fever virus. All reports of infection with exotic vector-borne infections were believed to have been acquired overseas.