This report summarises NSW vector-borne disease (VBD) surveillance data for notifiable arboviruses (arthropod-borne viruses) and other notifiable arthropod-borne diseases in humans for 2019. The report notes changes in notifications over time and describes likely areas of disease acquisition for both local and exotic infections.

NSW Health undertakes VBD surveillance to monitor VBD trends with the aim of implementing control measures to prevent further illness within the community from endemic local VBDs (such as Ross River virus and Barmah Forest virus), and to inform appropriate prevention messages for travellers to areas of the world with exotic vector-borne diseases (such as dengue, chikungunya, malaria and Zika virus).

Key trends in 2019

  • Barmah Forest virus – a decrease in notifications compared to 2017 and continued low activity overall.
  • Chikungunya virus – a rise in notifications, with cases most commonly acquired in India, Thailand and Myanmar.
  • Dengue virus – a large increase in notifications compared to 2018, with cases most commonly acquired Indonesia, Thailand, India and Fiji.
  • Malaria – a similar number of notifications overall, with cases most commonly acquired in Papua New Guinea and India, and these were predominantly due to P. vivax. However, P. falciparum remains the most common malaria species reported overall, with these cases predominantly acquired in African countries.
  • Ross River virus – moderate RRV activity this year, similar to 2018. Activity highest in coastal and inland areas of the state known to be endemic for RRV.
  • Zika virus – there was only one notification, most likely acquired in Vanuatu.

Notified incidence of local and exotic vector-borne diseases in NSW

2019 count


5-Year count

Mean rate

% change from 2018#

Barmah Forest virus630.899.61.3-15%
Chikungunya virus320.431.60.4113%
Dengue virus4655.7324.64.261%
Ross River virus5697.0848.810.9-1%
Zika virus10.08.40.1-80%

* Cases per 100,000 population, NSW.
# Percentage change in condition case count in 2019 relative to the 2018 case count.

Further information

Further information on notifications for particular vector-borne diseases is available - see Infectious diseases data and select the condition of interest. Various data filters are available, including date range, age-group, gender and local health district.

Surveillance of VBD infections in humans is supported by local mosquito and sentinel chicken surveillance activities under the NSW Arbovirus and Vector Monitoring Surveillance Program. Annual arbovirus and vector monitoring surveillance reports are published by the Environmental Health Branch during the arbovirus season (from late spring to early autumn).

File Size: 691 kb
Type: Report
Date of Publication: 27 July 2020
SHPN: (HP NSW) 200275