Rising mozzie numbers prompt virus safety warning as wet weather lingers

Murrumbidgee Local Health District has issued the call to action because the thriving insect populations can carry mosquito-borne viruses and spread them to humans.

The MLHD traps the insects to monitor the numbers and species of mosquitoes across the region - part of a surveillance program that also includes testing flocks of chickens.

The trapped mozzies can then be tested for viruses including Japanese encephalitis (JE), Ross River virus (RRV) and Murray Valley encephalitis (MVE).

RRV is the most common virus transmitted by mosquitoes and there have been 13 patients diagnosed with this virus in the health district since September.

Symptoms of Ross River virus include fever, chills, headache muscle and joint pain and fatigue. While most people make a full recovery in a few weeks, some people experience joint pain and tiredness for many months.

The MLHD says mosquito numbers are currently very high in Griffith and high in Grong Grong, Leeton, Temora and West Wyalong. Numbers in Wagga are rising.

Senior environmental health officer Tony Burns said the recent wet weather had led to an increase in mosquito numbers.

"With the rain we had over the last month to six weeks, our numbers are increasing," Mr Burns said.

"The amount of rain that's around can aid in the hatching process and then mosquitoes will come as a result."

The MLHD has not yet detected any viruses in the trapped mosquitoes, but Mr Burns warned the region's high water levels, climate and temperature made the area prone to viruses.

JE is the only virus which has a vaccine available.

"Some of these (viruses) can last for a long period of time, Ross River virus can be very debilitating and can take many, many months for people to recover," Mr Burns said.

"It's just a matter of getting over the illness."

Mr Burns said mosquitoes were attracted to light and carbon dioxide, and people should take safety precautions during summer.

"When we're outside this time of the year ... we're out there talking and we're exhaling carbon dioxide, that's one of the attractions that brings mosquitos around," he said.

The MLHD said the best prevention against viruses transmitted by mosquitoes was to avoid getting bitten - use repellent, avoid being outside at dawn or dusk, and cover up with a loose-fitting long-sleeve shirt and long pants.

The NSW Health sentinel chicken program also provides an early warning about the presence of serious mosquito-borne diseases. Blood samples are taken from the chickens once a week and sent for testing.

"We got a very extensive program, we've got in excess of 40 mosquito traps out weekly across the whole of Murrumbidgee LHD and eight sentinel flocks of chickens out," Mr Burns said.

"They're our early-warning device to see whether there is a virus in the area and it's enabled to get the message out to the public."

For more information, visit health.nsw.gov.au/Infectious/mosquito-borne.