Preventing mosquito and tick bites: A Canadian update

Question 1

What are two potentially serious diseases acquired from biting arthropods in Canada?

Answer 1

1. West Nile virus

2. Lyme disease

Question 2

What are recommendations regarding avoidance?

Answer 2

1. Avoid going outdoors between dusk and dawn
2. Avoid shady places and standing water
3. Avoid woodland areas and tall grasses in the spring and fall

Question 3

What are some physical precautions against mosquito and tick bites?

Answer 3

1. Use screens on windows and doors at home and while camping, and keep them in good repair.
2. If biting insects are present, cover a child’s crib, playpen or stroller with a fine mesh netting.
   If biting insects and/or ticks are present, dress your child in long, loose-fitting clothes that cover the arms and legs, a hat and closed shoes (not sandals). Tucking shirts into pants and pants into socks are extra precautions.
3. Light-coloured clothes make it easier to see and remove ticks before they bite, and do not attract mosquitoes as much as dark clothing.
4. When residing in or visiting a tick habitat, inspect yourself and your children thoroughly at least daily: include the head, neck and behind the ears. If a tick is found, remove it as soon as possible. Ticks can stay attached to skin, feeding on blood and growing larger, for five or more days. However, removing a tick within 24 h to 48 h of starting to feed is likely to prevent Lyme disease because the bacteria will not yet have been transmitted from the tick to the individual.
   a) Use fine-tipped tweezers to grasp the tick close to the skin surface.
   b) Pull upward with steady, even pressure.
   c) Try not to twist or jerk, which can cause the mouthpart of the tick to break off and remain in the skin. If this happens and you are unable to remove the mouthpart easily with clean tweezers, leave it alone and let the skin heal.
   d) Clean the bite area and your hands with rubbing alcohol, an iodine scrub or soap and water

Question 4

What is the recommendations regarding repellents in infants <6mo?

Answer 4

Health Canada (PMRA) assume that non-chemical measures should be used to protect this population from bites

Question 5

What is the maximum safe amount of DEET for children <12yo?

Answer 5

10%

Question 6

What is the maximum safe amount of DEET for adults and children >12yo?

Answer 6

30%

Question 7

When should DEET be re-applied?

Answer 7

If the estimated protection period has passed and a significant risk of arthropod bites remain

Question 8

What is the recommended maximum exposure time when using 10% DEET?

Answer 8

1-2h

Question 9

What is the estimated protection time against mosquitoes for 5% DEET?

Answer 9

1.5-2.5h (mean 2h)

Question 10

What is the estimated protection time against mosquitoes for 10% DEET?

Answer 10

2.5-4.5h (mean 3.5h)

Question 11

What is the estimated protection time against mosquitoes for 15% DEET?

Answer 11

3.5-5.5h (mean 5h)

Question 12

What is the estimated protection time against mosquitoes for 20% DEET?

Answer 12

4-6.5h (mean 5.5h)

Question 13

What is the estimated protection time against mosquitoes for 30% DEET?

Answer 13

5-8h (mean 6.5h)

Question 14

What are the side effects for DEET?

Answer 14

1. Contact dermatitis (common)
2. Eye irritation (common)
3. Toxic encephalopathy (with prolonged or excessive use or DEET ingestion)

Question 15

What is the repellent of first choice by the PHAC Canadian Advisory Committee on Tropical Medicine and travellers six month to 12yo?

Answer 15

Icardin

Question 16

What is the estimated protection time against mosquitoes for 10% Icardin?

Answer 16

5h

Question 17

What is the estimated protection time against mosquitoes for 20% Icardin?

Answer 17

7h

Question 18

What is the recommendations regarding natural repellents?

Answer 18

“Natural’ repellents are not necessarily safer than DEET or icaridin.

Question 19

What is the estimated protection time against mosquitoes for 10% lemon eucalyptas oil or its synthetic derivative PMD?

Answer 19

2h

5h of black fly protection

Question 20

What is the age recommendation for PMD?

Answer 20

> 3yo

Question 21

How often can 10% lemon eucalyptas oil or PMD be applied?

Answer 21

BID

Question 22

What is the estimated protection time against mosquitoes for 2% soybean oil?

Answer 22

3.5h
up to 8h against black flies
May not protect against tick bites

Question 23

What is the age recommendation for soybean oil?

Answer 23

No restriction

Question 24

What are the limitations for frequency of use for soybean oil?

Answer 24

No restriction

Question 25

What is the estimated protection time against mosquitoes for citronella oil products?

Answer 25

30min-2h

May not protect against tick bites

Question 26

What is the age recommendation for citronella oil?

Answer 26

Should not be used on infants or toddlers

Question 27

What are the recommendations regarding repellent use?

Answer 27

1. Avoid products with a combination of repellent and sunscreen. Sunscreen typically needs to be reapplied more often than repellent. If repellent and sun screen are both required, apply the sunscreen first, allow to penetrate for 20 min, then apply repellent.
2. Apply the product lightly, just enough repellent to cover clothing and exposed skin.
3. Avoid applying repellent to a child’s hands so that they are less likely to get repellent in their mouth or eyes.
4. Do not apply aerosol or pump products directly to the face, and avoid contact with the eyes and mouth. If spray does get in a child’s eyes, rinse them well with water right away. For children <10 years of age, it is recommended that the child have their eyes closed and hold their breath while an adult sprays Do not apply repellent on cut, wounded, irritated or sunburned skin.
5. Do not apply repellent under clothing.
6. Do not apply repellent to clothing or mosquito netting that a child may suck or chew on.
7. If mosquitoes are biting, remove the child from the area or reapply repellent if sufficient time has passed.
8. Once indoors for the day, the repellent should be washed off with soap and water.
9. Spray repellents in open, ventilated areas (not in a tent), well away from food.
   Keep and store repellent safely out of the reach of children
10. If child experiences a local or general reaction to insect repellent wash the repellent off with soap and water and bring for medical assessment with the container of repellent

Question 28

What are the recommendations re: permethrin?

Answer 28

1. Not licensed as a topical repellent
2. Can be sprayed on clothing, bed nets, and camping gear
3. Permethrin retain its effects x 2 weeks or 6 washings
4. Outdoor clothing pretreated with permethrin is approved only for military in Canada

Question 29

What might provide the most effective protection overall against mosquito and tick bites?

Answer 29

Wearing protective clothing treated with the insecticide permethrin in addition to using DEET or icaridin on exposed skin as a repellent

Question 30

What products marketed as protective are not recommended as insufficient data on safety and efficacy?

Answer 30

1. Electronic (ultrasonic) devices
2. Electrocuting devices
3. Citrosa houseplant (geranium)
4. Vitamin B1
5. Skin moisturizer/insect repellent combinations