Autumn in north-east NSW is likely to be wetter and warmer than usual - so mosquitoes may continue to be a nuisance and a health risk for the next 2-3 months

IMAGE: ABC News 28 March 2019

Rain was a constant feature in coastal north-east NSW last month.

Up to 27 February 2021 Yamba had recorded 242.2mm, Evans Head 296.8mm, Ballina 329.2mm, Cape Byron 247.4mm and Murwillumbah 299.4mm.

Autumn which begins on today, 1 March, is expected to bring more rain through to May.

Australian Bureau of Meteorology, 25 February 2021:

Autumn is likely to be wetter than average across Arnhem Land in the NT, southern and eastern Queensland, most of NSW, eastern SA, and eastern Tasmania. Chances greater than 70% are generally confined to small pockets of southern Queensland and north-east NSW.

Along with the rain Autumn is likely to be warm, with north-east NSW having a 60-70 per cent chance of exceeding median maximum and minimum temperatures.

This combination of a wetter and warmer March (beginning with median maximum temperatures on the coast from Clarence to the Tweed expected to be between 27-28 degrees Celsius) will likely see mosquitos remain active in our region, so locals need to remember to apply mosquito repellent when outdoors even though Summer has ended.

The incidence of aboroviral diseases, and Ross River Fever in particular, have been increasing since 2020.

ABC News, excerpt, 16 February 2021:

NSW Health says symptoms of Ross River infection include fever, rash and joint pains, and that prevention relies on avoiding mosquito bites.

"The majority of people recover completely in a few weeks. Others may experience symptoms such as joint pain and tiredness for many months."

Official figures show many regions experienced their worst year on record for the virus.

There were more than 640 cases in the Hunter-New England Local Health District, its highest number in the past 30 years.

About 400 cases were identified in the northern and mid north coast regions — the 30-year average for the Northern NSW Health District is 135 cases a year.

Cameron Webb, a researcher for NSW Health Pathology, said mosquito numbers exploded after heavy rain in February 2020.

"But it's incredibly difficult to predict ... even though you do get more cases of the disease when there are more mosquitoes about, it's a bit more complicated than that," Dr Webb said.

"Because mosquitoes don't hatch out of the wetland already infected with the virus, they have to bite native animals and those animals are typically kangaroos and wallabies.

"You will be at greater risk ... when you are outside some of the main urban areas, particularly when you are in that interface between the wetlands and areas where there is a lot of wildlife."

Council campaign

Councils on the far north coast, one of the worst-affected areas, recently launched the Tackling Mosquitoes Together campaign.

It was developed to raise awareness about risk factors, especially trouble spots around the home.

The Tweed Council's environmental health officer, Kelly Piazza, said mosquitoes would breed wherever there was still water.

"Anywhere and everywhere, and they will take any opportunity," she said.

"So anywhere the water can sit and be stagnant, that's where you're going to find that mosquitoes will come and lay their eggs."…...

Tackling Mosquitoes Together campaign runs through to end of April 2021. Details at https://www.tacklingmosquitoestogether.com.au/

Join our SMS program for helpful tips and reminders to protect yourself, your family and community from the disease risks and nuisance of mosquitoes.

Mosquitoes likely to remain a health hazard this winter

In January 1991 Ross River Fever became a notifiable disease in New South Wales and in that first year the Northern NSW local health district recorded 11 cases.

Up to the end of April in 2020 Northern NSW has recorded 156 cases. Only the Hunter New England local heath district is recording a higher figure at 183 cases.

By contrast Barmah Forest Virus, another notifiable disease, has only been recorded 25 times so far this year.

However, both are mosquito borne infections that are worth doing our best to avoid.

NSW Health advises:

To protect against mosquitoes and reduce the risk of diseases they transmit:

• Cover-up with a loose-fitting long sleeved shirt and long pants when outside
•  Apply mosquito repellent to exposed skin
•  Take special care during peak mosquito biting hours, especially around dawn and dusk
•  Remove potential mosquito breeding sites from around the home and screen windows and doors
•  Take extra precautions when travelling or camping in areas with a higher risk of mosquito-borne diseases.
• For more detailed information on reducing the risk of mosquito bites at home and while travelling see the Mosquitoes are a Health Hazard fact sheet. This also includes more information on mosquito repellents.

As the Australian Bureau of Meteorology is predicting a 70% chance of wetter than average weather from July to September & warmer than average temperatures for coastal New South Wales in June to August this year, it is possible that infected mosquitoes will still be aound this winter so being aware of the mosquito load in your garden is advisable..

At the end of April Stratford Virus was detected in mosquitoes trapped in Yamba at the mouth of the Clarence River. This virus is not notifiable in New South Wales and infection usually presents as a mild fever with associated joint pain and lethagy.

North Coast Public Health Unit reminding Northern NSW residents to protect themselves against mosquitoes which remain in high numbers late in the season

Northern NSW Local Health District, media release, 27 April 2020:

The North Coast Public Health Unit is reminding residents of Northern NSW to protect themselves against mosquitoes which remain in high numbers late in the season.

“Mosquitoes have persisted in large numbers through to early autumn, along with the warm weather in recent weeks,” Paul Williamson, Senior Environmental Health Officer, said.

The NSW Arbovirus Surveillance and Mosquito Monitoring Program recently detected Barmah Forest virus and Ross River virus in mosquitoes in the Northern NSW area. Ross River and Barmah Forest viruses are common on the north coast and are transmitted by infected mosquitoes.

So far this year, 32 north coast residents have been diagnosed with Barmah Forest virus infection and 153 with Ross River virus infections, which is two and three times the number of infections, respectively, for the same period last year. One hundred and nineteen of these infections have been reported in the last four weeks, which is six times the number reported in the same period last year.

“These infections can cause symptoms including tiredness, rash, fever, and sore and swollen joints. The symptoms usually resolve after several days, but some people may experience these symptoms for weeks or even months,” Mr Williamson said.

Avoiding mosquito bites will be especially important until cooler weather brings an end to the mosquito-breeding season.

Whilst most people are at home due to current movement restrictions, many people are heading outdoors early or late in the day to get some exercise.

“Mosquitoes are very active at these times so protect yourself from being bitten by mosquitoes when out-and-about.”

Simple steps to avoid being bitten by mosquitoes include:

• Cover up as much as possible when outside with light-coloured, loose-fitting clothing and covered footwear.
• Use an effective insect repellent on exposed skin. Re-apply repellent within a few hours, as protection wears off with perspiration. The best mosquito repellents contain Diethyl Toluamide (DEET) or Picaridin. Botanical based products (e.g. eucalyptus, citronella etc.) provide only limited periods of protection.
• Use physical barriers such as netting on prams, cots and play areas for babies. Repellents should not be used on the skin of children under the age of three months.
• Check the product label of repellents for recommended age of use. Most skin repellents are safe to use for children over the age of 3 months or older. Some formulations are only suitable for children over 12 months.
• Use insecticide sprays, vapour dispensing units (indoors) and mosquito coils (outdoors) to clear rooms or repel mosquitoes from an area.
• Cover all windows, doors, vents and other entrances with insect screens.
• Remove and prevent mosquito breeding sites around the home, such as emptying containers that hold water.

“Preventing infection with these viruses depends on avoiding mosquito bites, especially as the mosquitoes have become active after recent rain, warm days and high tides,” Mr Williamson said.

Fact sheets are available from the NSW Health website: https://www.health.nsw.gov.au/Infectious/factsheets/Pages/mosquito.aspx

Weekly reports are available during the arbovirus season from the New South Wales Arbovirus Surveillance and Mosquito Monitoring Program: https://www.health.nsw.gov.au/environment/pests/vector/Pages/nswasp-weekly-report-2019-20.aspx