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On Wednesday 23rd November I sat down with Paediatric Infectious Diseases Physician Dr Linny Kimly Phuong to answer all your questions on mozzies & associated diseases.
Heavy rains have caused mosquito numbers to explode in many parts of Australia and rightly many parents are concerned about associated diseases and how to best protect their family.
So how do you protect your family from mosquitoes and mosquito borne diseases?
The answer is tough because basically it’s ….”try not to get bitten” and in many parts of the country that’s nearly impossible but …
The four key aims are:
- Prevent mosquito bites
- Minimise exposure to mosquitoes where possible
- Reduce areas around your house where mosquitoes gather
- If you’re in a high risk area and eligible- consider vaccination against Japanese Encephalitis
Many parents wanted to go deep on repellents and active ingredients – Dr Linny had a lot of really handy information:
While we aim to avoid chemicals of any type on our babies and children, it’s a balancing act. In many parts of Australia, the risk of mosquito bites and mosquito borne illnesses is reasonably high and avoiding exposure can be near impossible – so a repellent may be needed from time to time.
Effective insect and mosquito repellents come in many forms with different % of active ingredient/application.
Repellents do not kill mosquitoes and other insects but they will help deter them from biting people. The recommended concentration of active ingredient depends on the level of risk of mosquito bites.
Here’s a breakdown of the most common mosquito repellent ingredients:
| Active Ingredient (other names) | Dr Linny’s 101 |
| DEET–
(Diethyltoluamide N,N-diethyl-3-methylbenzamide) |
Low-risk areas– 10% DEET provides approximately 90 min coverage
High risk areas– 15-30% DEET provides approximately 5-6 hours coverage Protection time provided by DEET depends on the strength/ percentage of DEET. Higher strengths do not improve effectiveness. DEET can be safely applied to cotton, wool and nylon, but may damage plastic, vinyl, spandex, rayon, acetate and pigmented leather. |
| Picaridin
(icardin, KBR3023, para-methane-3,8-diol) |
10% Picaridin is the usual concentration found in products
Odourless, less sticky. Can be used in young children > 3 months. Not long lasting, needs regular re-application. Doesn’t damage fabrics and finishes like other repellents. |
| Permethrin | Permethrin is not a repellent but is poisonous to insects (paralyses).
Safe for children. Used on clothing and bed/camping gear, not on skin. It can remain effective even after repeated laundering. Follow the label directions carefully when treating clothes or outer wear. |
| Plant based products
including melaleuca (tea tree) oil citronella
|
These plant based ingredients are often found in patches and wristbands you see advertised online for kids.
Citronella is often found in candles, torches, or coils that can be burned to produce a vapour or smoke that repels mosquitoes. These products are less effective than repellents applied to the body or permethrin applied to clothing. |
| Oil of lemon eucalyptus
(P-menthane diol (PMD)) |
Another plant based repellent with similar protection to low concentration DEET.
NOT recommended for kids under 3 years of age. |
5 TOP TIPS FOR MINIMISING MOSQUITOS
TIP 1: Cover up with loose, long and light coloured clothing
- Wear loose clothing, preferable with long sleeves and cover the legs. Mosquitoes can bite through tight fitting clothing.
- Wear light coloured clothing, as mosquitoes are attracted to dark colours
TIP 2: Avoid outdoor activities at dawn and dusk where possible
- Dawn and dusk are peak times for mosquito activity
- If unavoidable, wear repellants during these times outdoors
- Young children (< 3 months) cannot wear mosquito repellent- so cover strollers with insect netting if going for a walk during peak times
TIP 3: Remove or cover up any still water from around your house
- Cover any containers that store water (including swimming pools, cesspools and septic tanks).
- Empty or drain containers when they are not being used.
- Put sand in plates under flower pots and even holes in trees to absorb excess water.
- Change water in bird baths and watering troughs at least once a week.
- Remove excess vegetation from garden ponds and stock with fish.
- Do not over-water the garden.
TIP 4: Use barrier sprays to protect door and entry ways
- When using sprays, make sure children are kept away (during the spraying process and until the sprays have dried on surfaces)
TIP 5: Wear mosquito repellent if needed
- Repellent should only be used on exposed skin (which is not covered by clothing) but not on wounds or broken/ irritated skin (this is important in children with eczema or other skin conditions).
- Be sure to cover all exposed skin. A mosquito can find an unprotected spot the size of a five cent piece.
- When applying repellent to children, don’t spray directly onto them (we don’t want them to inhale or ingest repellents or get them into the eyes) simply spray into your hand away from them and rub into the exposed skin or use a roll on. Be careful about repellent on young children’s hands who may rub their eyes or put their hands/ fingers into mouths.
- Mosquito bands, patches and stickers are probably not be enough protection to ward against bites but may help deter mosquitoes.
- Repellent is still needed when clothing sprays containing permethrin are used.
- Follow directions carefully about how frequently to re-apply the product.
- If pregnant or breastfeeding, be sure to ask your GP for additional advice about the safe use of repellents.
- If you need to apply both sunscreen and repellent, apply the sunscreen first. Products combining sunscreen and insect repellent are not recommended, as sunscreen generally needs to be reapplied more often than insect repellent.
Mosquito Repellents and skin irritations
- Like any topical products, always be sure to test repellents on a small patch of skin first.
- Never apply to broken or irritated skin
- If you suspect a reaction to a product, wash product off skin and see your doctor if you’re really worried.
- Keep the repellent container, so that you can tell the doctor exactly what product you are using.
- The most commonly reported reaction is stinging when accidentally gets into the eyes. Flush eyes with cold water immediately if this occurs. This reaction can be minimised by spraying product into your hand and then applying onto your child.
- Skin reactions are rare and generally resolve quickly when the product is washed off. These reactions are not related to the concentration of the active ingredient in the product.
Managing Mozzie Bites – Common Symptoms
- A painful inflamed lump
- Swelling
- Itchiness
Relief from itching caused by mosquito bites:
- Wash the skin and apply a cold pack to reduce swelling.
- A cool bath may be soothing.
- Check with your GP or pharmacist if the following products may be helpful, and are safe:
- Antihistamine tablets or syrup
- Calamine lotion
- Menthol based antiseptic creams
- Gels and sprays with aluminium sulphate
- Mild steroid based cream, eg) containing hydrocortisone
- Take care with applying lotions or creams especially if there are areas of broken skin or wounds.
- Keep your child’s fingernails short. This can help to prevent infection if your child is scratching a lot.
- Distract your child with games or activities.
Medical help for mosquito bites: when do you need it?
Most mozzie bites and insect stings don’t need generally medical treatment, but see your GP if they:
- get blistering, widespread hives or ulcers
- have pain that doesn’t go away
- have signs of infection – for example, pus and increasing pain, redness and heat at the site
- have a non-healing bite area which is not improving
- start to feel unwell or have vomiting, stomach pain, fever, sweating or headache.
If your child has symptoms of anaphylaxis, you should lay your child flat, use an adrenaline injector & call 000.
Why do some people get bitten more by mosquitos than others?
There’s a lot of reasons why and no real straight answer from medicine that can help protect you (yet!). One of the most interesting things Dr Linny discussed was that everyone is probably getting bitten at some level, some people just react to the bites more – it’s important for everyone to protect themselves against mosquitoes even if they don’t get big itchy bites (LIKE ME!!)
Mosquito borne illnesses:
This is not an exhaustive list but just a note that the reason we want to avoid mosquitoes so much is because they carry some nasty diseases. In Australia there are many mosquito borne diseases you can get including Barmah Forest virus, Dengue fever, Murray Valley encephalitis, Ross River virus and more recently Japanese encephalitis (JEV). Many of these diseases do not have a vaccine- so avoidance is key.
What is Japanese Encephalitis?
Japanese encephalitis is a rare but serious illness caused by the Japanese encephalitis virus. It is spread to humans by infected mosquitoes.
Symptoms of Japanese encephalitis
Most people infected with JEV (about 99%) do not have any symptoms or have mild symptoms. Usually, symptoms develop 5 to 15 days after being bitten by an infected mosquito.
Less than 1% of people infected may experience symptoms that include fever, headache and vomiting.
People with severe infection may have symptoms of encephalitis such as:
- severe headache
- neck or back stiffness
- sensitivity to light
- confusion
- seizures
- paralysis
- coma.
Encephalitis can unfortunately lead to death or permanent disability. Anyone experiencing these symptoms should seek urgent medical attention.
Transmission of Japanese Encephalitis
- The current outbreaks in Victoria and areas of Australia are concentrated around piggeries
- JEV is spread to humans through the bite of an infected mosquito.
- The virus cannot be spread directly from person to person.
Is there a Japanese Encephalitis Vaccine?
There are two available vaccines in Australia.
- Imojev- live attenuated, single subcutaneous vaccine from 9 months of age.
- JEspect- inactivated, 2 doses intramuscular vaccine (28 days apart); from 2 months of age, pregnancy, immunocompromised.
Who should get the Japanese Encephalitis Vaccine?
Right now, there is limited Japanese Encephalitis vaccine available. It is suitable for anyone aged two months or older living or working in a high-risk priority local government area; or those travelling to at-risk countries. We recommend speaking with your GP and checking up-to-date government guidelines for vaccine eligibility.
Can pregnant women or those who are breastfeeding receive the JEV vaccine?
Yes, pregnant women can receive two doses of the inactivated JEspect vaccine. Pregnant women cannot receive the Imojev vaccine because it is a live attenuated vaccine, which means it cannot be given during pregnancy. Women should avoid pregnancy for 28 days after vaccination with Imojev. Women who are breastfeeding can have JEspect, however Imojev can be given. Please speak to your GP about suitability and other considerations.
Where can I get more information?
- Better Health Channel- Mosquitoes can carry diseases https://www.betterhealth.vic.gov.au/health/healthyliving/mosquitoes-can-carry-diseases
- Royal Children’s Hospital- insect bites and stings- https://www.rch.org.au/kidsinfo/fact_sheets/Insect_bites_and_stings/
- Royal Children’s Hospital- Insect repellents – guidelines for safe use https://www.rch.org.au/kidsinfo/fact_sheets/Insect_repellents_guidelines_for_safe_use/
- Department of Health- Japanese Encephalitis- https://www.health.vic.gov.au/infectious-diseases/japanese-encephalitis-virus
- ATAGI clinical guidance- https://www.health.gov.au/health-alerts/japanese-encephalitis-virus-jev/atagi-clinical-guidance-on-japanese-encephalitis-virus-vaccines
Meet Dr Linny Kimly Phuong
Dr Linny Kimly Phuong is a Paediatric Infectious Diseases Physician. Dr Linny currently holds appointments at the Royal Children’s, Royal Women’s, Austin Health, Cabrini and also works at Murdoch Children’s Research Institute. She is an active researcher in children’s infections, who is currently completing a PhD in invasive pneumococcal disease in children. Linny is also a proud mummy to a very active and inquisitive little three-year-old girl named Remy.
