Rare mosquito borne diseases detected in Townsville

Two Townsville residents have tested positive for rare mosquito-borne diseases, including the first case of locally acquired dengue virus in the city in five years. 

Townsville Public Health Unit Director Dr Steven Donohue said a resident was being treated in Townsville University Hospital for Japanese encephalitis virus (JEV), most likely infected outside Townsville, while another is being treated in the community for dengue virus after being bitten by a mosquito capable of transmitting dengue virus.

“Since the Eliminate Dengue project started almost 15 years ago, which released mosquitos carrying dengue-resistant Wolbachia bacteria into the community, the disease has been almost non-existent,” he said.

“Both cases are breakthrough cases and are not outbreaks. The cases are not linked,” he said.

“The chances of further cases in the community are low.”

JEV is a rare virus which came into Australia a few years ago, related to Murray Valley encephalitis and Kunjun virus, and is spread through bush mosquitoes leading to brain swelling with a sudden headache, high fever, and disorientation.

“This is the first case of JEV that we have seen in Townsville, and it is very unlikely the patient got the disease here as they had been holidaying in southern Queensland where the virus has been present,” Dr Donohue said.

“The resident with Japanese encephalitis is in a stable condition in hospital.”

This is the first human JEV case in Queensland since May 2022.

Dr Donohue said it was a timely reminder to residents to protect themselves and their families by limiting exposure to mosquito bites in and around the home.

“Mosquitoes breed in small quantities of water which can be found in items like tyres, buckets, toys, or pot plant bases,” he said.

“Tip out the water and limit the chances of them breeding in your own backyard.

“When you are outside or in the bush, wear long, loose, light-coloured clothing and cover your feet.

“Also use insect repellent with DEET or picaridin as well as electric zappers or mosquito coils.”

“The mosquitoes that could transmit dengue fever are stealthy. They bite people during the day and are most likely found indoors with some people often not knowing they have been bitten,” he said.

“The risk to residents is low but anyone with a sudden fever, intense headache, muscle and joint pain, extreme tiredness or a rash should contact their GP,” he said.