Zika and West Nile: Protection against Mosquito Bite Infections

  

Summer is in full swing! With the season comes long hot days,

outdoor activities, and bugs!  It’s the time of year when people must

protect themselves against infections spread from bug bites. Especially

the viruses spread by mosquitoes – Zika and West Nile.

A common mosquito found in New Mexico, Culex quinquefasciatus

or southern house mosquito, is the carrier of the West Nile virus. Only

two mosquito species in NM are known to transmit the Zika virus: the

Aedes albopictus and the Aedes aegypti. The Aedes albopictus, also

known as the Asian tiger mosquito, is easily identified by its black and

white color pattern. To date, there are no confirmed reports finding the

common mosquito connected to spreading Zika. (Garvey, 2016). 

A common mosquito found in New Mexico, Culex quinquefasciatus

or southern house mosquito, is the carrier of the West Nile virus. Only

two mosquito species in NM are known to transmit the Zika virus: the

Aedes albopictus and the Aedes aegypti. The Aedes albopictus, also

known as the Asian tiger mosquito, is easily identified by its black and

white color pattern. To date, there are no confirmed reports finding the

common mosquito connected to spreading Zika. (Garvey, 2016). 

The Centers for Disease Control and Prevention (CDC) provide the estimated range of the potential
virus-carrying mosquitoes. As evidenced in the following graphic, NM is one of the states where the Aedes mosquitoes are found. However, just because the mosquitoes are found in NM does not imply that the Zika virus will be a health issue. The estimated range provides information to encourage proactive measures in protection and defensive measures at the individual, community, and state levels.

Characteristics of the Mosquitoes

All mosquitoes are attracted to dark clothing, perspiration, carbon dioxide and certain other odors. There are some differences between the mosquitoes that carry the West Nile and Zika viruses. (For more information on the West Nile Virus visit http://aces.nmsu.edu/pubs/_i/I102/)

Common Mosquitoes (West Nile)

·       Aggressive biters.

·       Lives in and around households.

·       Feeds on humans, mammals and birds during the evening hours (after sunset).

·       Lays eggs in wet areas and standing water, including ditches and marshes.

·       Flies short distances. Can also be blown by the wind.

Aedes Mosquitoes (Zika)

·       Aggressive daytime biters – can also bite at night.

·       Lays eggs in water-filled natural and artificial containers like cavities in trees and old tires and domestic water-holding containers (such as flower pots). They do not lay their eggs in ditches or marshes.

·       Does not fly more than about 1/2 mile from its breeding site – travels more in short hops.

·       Stays close to the ground so bites generally occur around the ankle area.

·       Lives on extremely small amounts of water – even on the undersides of plants.

·       The bite of the Asian tiger mosquito is not particularly irritating to most people, but they are persistent biters. Because they breed in nearly any sort of water-filled container, they often become very common and bothersome, even in neighborhoods where there are normally few mosquitoes.

Avoid Mosquitoes

·       Get rid of mosquito breeding sites by removing standing

water that can be found in unused farm equipment

o   Flower pots

o   Gutters

o   Barrels

o   Buckets

·       On a Weekly basis - Change/replace the water in

o   Pet dishes

o   Water troughs

o   Bird baths

·       Drill holes in tire swings so water drains out.

·       Keep children’s wading pools empty and place them on their

sides or upside down when not in use.

·       Wear insect repellent (DEET 10 – 30%). General guidelines follow in this article.

·       Wear clothing that covers the body – shoes, socks, long pants, and loose, long-sleeved shirts.

·       Limit time outside or stay inside during peak mosquito-biting hours.

·       Repair or install good screens on windows and doors around the home to keep mosquitoes out.

Effective Insect Repellants

No bug repellent or chemical-infused clothing
can credibly guarantee to fend off all mosquitoes (EWG, 2016).

The Environmental Working Group (EWG) – a nonprofit, non-partisan organization engaged in research dedicated to protecting human health and the environment – cautions against marketing claims that promise 100 percent protection from any mosquito infectious disease.  EWG scientists found that DEET (20-30 percent) is the most effective offering protection for up to four hours. In a fact sheet prepared for the general public, the CDC agreed that “Insect repellents that contain DEET offer the best protection against mosquito bites.” (http://www.cdc.gov/malaria/toolkit/DEET.pdf)

DEET, found in such popular products as OFF! Deep Woods, works by blocking scent receptors bugs use to find targets (Prevention, 2016 July).  After 5 years of research, DEET has been proven to have low toxicity when used at the 10 – 30% concentrations.

Used as directed most people do not experience any adverse reactions when using DEET. Skin rashes have been reported, but those are rare.

When using repellent with DEET, follow these recommendations:

·       Read and follow all directions and precautions on the product label.

·       Store DEET out of reach of children.

·       To apply to face, first spray product onto hands, then rub onto face.

·       Use only when outdoors and wash skin with soap and water after coming indoors.

·       Apply to clothing when appropriate.

·       Higher concentrations of DEET may have a longer repellent effect, however, concentrations over 50% provide no added protection.

·       Use just enough repellent to cover exposed skin and/or clothing. Avoid over-application of the product.

·       DEET may be used on adults, children, and infants older than 2 months of age. Protect infants from mosquito bites by using a carrier draped with mosquito netting with an elastic edge for a tight fit.

Sunscreen and Bug Spray

According to the CDC, when using both sunscreen and bug spray, you need to make sure they are applied in the right order.

Step 1: Apply the sunscreen.

Step 2: Apply the bug spray.

The reason for this is that as the bug spray evaporates, it creates the repellency. Therefore, you want the sunscreen directly applied to the skin with the bug spray over the top. (CDC, 2016)

Enjoy a safe and enjoyable summer!

 References available upon request.

By:Sonja Koukel, PhD

Community & Environmental Health Specialist