How to deal with close encounters with Christmas critters

Associate Professor Cameron Webb from the Faculty of Medicine and Health said mosquitoes thrive in wet and warm weather, with Eastern Australia seeing plenty of opportunities for mosquitoes after recent rainfall and floods.

“It is important to remember that mosquitoes are more than just a nuisance, their bites can spread pathogens that make people and pets sick.”

Webb says when outdoors, the best way to avoid a mosquito bite is to cover up with long-sleeved shirt, long pants, and covered shoes.

“You should apply insect repellent to all exposed areas of skin. Most formulations containing ‘deet’, ‘picaridin’ or ‘oil of lemon eucalyptus’ will provide the longest lasting protection but you must apply to all exposed skin.”

“If you get bitten, the best thing is to use a cold pack to reduce swelling and keep the bite site clean so there is no secondary infection.”

Despite the diversity of mosquitoes in Australia, no more than a dozen or so are serious threats to public health.

“Unfortunately, there is a range of pathogens spread by many mosquitoes including Ross River virus, that infects over 5,000 people across the country every year, and Japanese encephalitis virus, a recent discovery in Australia that can result in potentially fatal illness,” said Associate Professor Webb.

“While there is a safe and effective vaccine for Japanese encephalitis virus, there isn't any for other mosquito-borne diseases in Australia.”

Tick bites are common in many areas of Australia, especially along the east coast of Australia including Tasmania and offshore islands.

“The best prevention to avoid tick bite is to avoid places with ticks”, said Dr Bernard Hudson, clinical microbiologist and infectious diseases physician at the University of Sydney.

“If you do frequent places such as bushy areas that are favourable for ticks, you need to dress appropriately to protect your body and wear a hat.”

Ticks can inject toxins that generate local or mild irritation, with most tick bites causing little or no symptoms. But according to Dr Hudson some are the source of tick-borne infections such as spotted fever and possibly other as yet unidentified infections.

“If you are bitten, you can remove the parasite safely by freezing it with five squirts of a freeze spray. It kills the tick and causes it to drop off. You must not handle the tick - do not try to pull it out with fingers or household tweezers because these usually just encourage the tick to inject substances including toxins and other substances that may cause allergic and other harmful reactions.”

There are two main Australian spider species venomous to humans to be watchful of - the redback spider and the funnel-web spider.

“In summer, these critters are more active and can pop up around your home including in the swimming pool”, says Associate Professor and toxicologist Naren Gunja.

Redback spiders cause an intensely painful bite, sweating and other symptoms.

Funnel-web spiders can look like any other big black spiders and cause severe envenoming requiring prompt medical attention.

“If you are bitten by a big black spider, apply a pressure bandage, keep still and call 000 to get to a hospital. Patients may need anti-venom and intensive care. A photo of the spider might help identification but be careful not to get bitten again.” 

Australia has some of the most venomous snakes in the world, both on land and the sea snakes in our northern shores.

Brown, Tiger and Taipan snakes can cause profound coagulopathy, where the body’s ability to clot is diminished, and life-threatening bleeding occurs. Death adders are known for their neurotoxicity, which can cause muscle paralysis.

“Remember to carry elastic bandages when bushwalking. If you are bitten by a snake, keep still, apply a pressure bandage, and call 000”, said Associate Professor Gunja. 

Urgent medical attention with anti-venom could be lifesaving. 

Australian waters are home to several harmful jellyfish - from the tiny Irukandji that causes a painful sting to the deadly Chironex box jellyfish.

“These species are mainly encountered in Queensland. Vinegar is the standard first aid for box jellyfish, though its effectiveness has recently been questioned,” said Associate Professor Gunja.

“But New South Wales beachgoers can come across Physalia species, commonly known as blue bottles, or other stinging marine creatures.”

“If you are stung by a blue bottle, immerse the limb, or take a shower, in hot water; ice packs can also help if you can’t get to hot water.”