Attack of the mosquitoes - Dengue and JE | Dr Joann Child Specialist

Dengue and JE cases in Malaysia

Earlier this month (June 2020), we just heard the news that the number of dengue cases has shown an upward trend of 8% for 6 consecutive weeks and this trend is likely to continue until September. This was followed by reports of two cases of Japanese Encephalitis (JE) in Sungai Bakap, Penang. Now, we have an outbreak of malaria in Ampang involving 14 cases of workers at a construction site. What do all these diseases have in common? All are examples of zoonotic diseases brought about by bites of infected mosquitoes.

For the next few days, I will be elaborating on these three diseases individually. But what is more pressing right now is to focus on how to protect your family and yourself from getting these diseases.

As all of these diseases are spread by the bites of infected mosquitoes. Hence, it only makes sense that to break the chain of infection, the focus should be on how to avoid being bitten and how to reduce the population of mosquitoes.

What can you do to prevent mosquito bites?

✔️ Use an insect repellent

Some important facts to note:
– Insect repellents of any kind are discouraged for children younger than 2 months old.
– Use insect repellants in open spaces to avoid breathing it in.
– Never apply insect repellent on a child’s hand. This is to avoid accidental ingestion and to prevent eye irritation if they touch them.
– After coming back home, make sure your child takes a bath and changes his or her clothing.

☢️ The insect repellent that you choose should contain one of the following active ingredients.
DEET (N,N-diethyl-m-toluamide)
Picaridin (KBR 3023)
IR3535
Oil of lemon eucalyptus (OLE) or Para-menthane-diol (PMD) – not recommended for children < 3 years
2-undecanone

Some precautions for DEET❗️
– For children, choose a repellent with no more than 10%-30% of DEET.
– Generally, DEET should not be applied more than once a day.
– DEET should not be used on a child’s face, under clothing, on cuts or irritated skin, or the hands of young children.

mosquito repellant contains DEET

✔️Cover up
If you intend to bring your children out to the park, let them wear long-sleeved shirts or long pants with socks to reduce their exposed skin surface.

✔️ Keep mosquitoes outside
– Turn on the air conditioning or use window or door screens to prevent mosquitoes from entering your home.
– Mosquito repellents in the form of vape, coil, or liquid can be used while you are sleeping, however, do ensure that your room is well ventilated and keep the windows open so that you do not breathe in the fumes.
– Another alternative is to sleep under a mosquito net.

✔️ Know your enemy well
– Aedes mosquito tends to come out at dusk (6-8 am) and dawn (6-8 pm) –>vector for dengue infection.
– Female Anopheles mosquito starts biting late evening with the peak activity during midnight and early hours of the morning –> vector for malaria.
– Culex mosquitoes are far more likely to bite from midnight till 5 am –> vector for JE (Japanese Encephalitis).
So try not to go out or take extra precautions during this specific period of time.

✔️ Special precautions
– For those who are at higher risks of getting mosquito bites, for example, those participating in jungle trekking or loggers, treat clothing and gear with permethrin. Use 0.5% permethrin on boots, pants, socks and tents. Permethrin is an insecticide that kills or repels mosquitoes. Permethrin-treated clothing provides protection even after multiple washing.

– Travellers or visitors to malaria-endemic areas can take antimalarial drugs as a preventive measure. However, no antimalarial drug is 100% effective without taking other preventive measures.

Steps to mosquito-free living

✔️ Get rid of standing water that allows mosquitoes to lay eggs.
– Empty, turn over, cover or throw items that hold water like tires, buckets, planters, toys, birdbaths, flowerpot saucers, or trash containers.
– Tightly cover or place a wire mesh over water storage containers for example buckets to prevent mosquitoes from laying eggs.

✔️ Put larvicides (Abate aka Temefos) into stagnant water if it is not feasible for the water to be removed for example ponds.

✔️ Kill mosquitoes at their resting place using an insect spray.
– Mosquitoes love to rest in dark, humid areas like under furniture, behind curtains, in closets, under the sink, or in garage/storeroom. Always remember to read the instructions on the insect spray before using it.

✔️ Using household mosquito traps may be helpful to kill mosquitoes by air drying and dehydrating them.

Prevention is always better than cure. Let us continue to keep these pesky pests at bay! ?

References:
1. Prevent mosquito bites cdc.gov
2. Controlling mosquitoes at home cdc.gov
3. Are insect repellents with DEET safe for kids? kidshealth.org