Take measures to avoid mosquito bites this summer

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Summer is coming and rain is on the cards – so it’s time to start brushing up on measures to avoid mosquito bites.

Queensland Health’s Acting Deputy Director-General and Chief Medical Officer, Professor Keith McNeil, said as we head towards peak Ross River virus season, Queenslanders are reminded to protect themselves against mosquito bites as much as possible.

“Ross River virus infections account for the largest number of human mosquito-borne disease notifications in Queensland, and the summer months lead into the peak time for Ross River cases,” Professor McNeil said.

“If you’re enjoying the great outdoors this summer to play sport, go for bushwalks, catch up on gardening or even hosting a backyard barbecue, you need to be aware of mosquitoes. Biting can be experienced at any time of day, but some species are most active at dusk and dawn.

“Measures to prevent mosquito bites include regularly applying insect repellent, wearing loose, light-coloured clothing to cover up arms, legs and feet and using other insecticide-based mosquito control devices where possible.

“Around your home, you should empty containers holding water at least weekly and ensure flyscreens are in good order so mosquitoes can’t enter your home easily.

“There’s no vaccine or specific antiviral treatment available for Ross River virus, so it’s important you take steps to avoid infection as much as possible.

“Symptoms may include fever, swollen and painful joints and rash, which can be managed to ease discomfort. While most people recover in a few weeks, some people experience joint pain and fatigue for months after infection,” he said.

Ross River virus can be found in more than 40 different species of mosquitos across Australia.

The virus is spread from infected mosquitoes to humans, but it’s not directly contagious - it doesn’t spread from person to person. 

Mosquitoes get the virus from biting an infected animal. It is then spread to humans when they get bitten by an infected mosquito.

Professor McNeil said Ross River virus rates had fluctuated over the past two years, while malaria and dengue rates declined – in part due to public health measures introduced during the pandemic.

“The COVID-19 pandemic has had a varied impact on mosquito-borne disease epidemiology in Queensland, but the need for personal protective measures together with mosquito surveillance and control remains unchanged,” Professor McNeil said.

“Throughout the pandemic, Ross River virus rates acted differently to the malaria and dengue rates.

“Cases of malaria and dengue, which are generally imported from overseas, decreased over the last two years due to the decline in international arrivals, while cases of Ross River virus increased in 2020.

“Rates rose to the highest levels in five years last year, with the majority of cases occurring in South East Queensland,” he said.

Last year, there were 3,407 cases of Ross River virus recorded across the state. This year, there’s been 753 cases to date. At the same time last year, there was already 3,273 cases.

In 2018 and 2019, there were 1,739 and 1,649 cases recorded respectively annually.

“During 2020, there was an atypical late season outbreak of Ross River virus starting in March with the highest numbers of cases in April and May,” Professor McNeil said.

“The reasons for the fluctuating rates of Ross River virus in Queensland over the last two years is complex, but is understood to be influenced by environmental factors such as rainfall – with restrictions during the pandemic also potentially playing a role due to more people enjoying the great outdoors locally in 2020.

“We also know that we generally see an increase in Ross River virus every four years or so – and 2020 was right on target.

“While there has been a significant decrease in Ross River virus cases this year compared to the same time last year, there’s still a couple of months to go heading into peak season.

“Typically, Ross River virus cases begin to rise with the onset of rain and warm temperatures in December before peaking in February and March. Cases often occur following above average rainfall or king tides.

“Especially with recent rain, people need to be vigilant and protect themselves against mosquito bites," he said.

Ross River virus cases reported 2019 to 2021 by Hospital and Health Service
Data as of 1 November 2021

Hospital and Health Service

2021 (year to date)

2020 (annual total)

2019 (annual total)

Cairns and Hinterland

48

120

127

Central Queensland

74

189

133

Central West

4

9

18

Darling Downs

38

325

59

Gold Coast

41

259

118

Mackay

37

68

89

Metro North

110

724

280

Metro South

94

470

221

North West

5

17

27

South West

12

38

37

Sunshine Coast

151

523

259

Torres and Cape

8

15

27

Townsville

52

319

123

West Moreton

33

199

47

Wide Bay

46

132

83

Statewide

753

3407

1649

You can view Queensland Health’s Notifiable Conditions Annual Reporting data here.

ENDS