Zika Defense: Precautionary Steps to Minimize the Aedes aegypti Population

The prospect of contracting Zika has been terrorizing South American locals for several months now. Although the US has seen some Zika cases in travelers (and their partners) who had recently visited Zika-infested countries, there have not been any cases of locally-transmitted Zika infections within the Continental United States, as of yet. Nonetheless, it is essential to reiterate the precautionary steps that can prevent such a catastrophe.

The Centers for Disease Control and Prevention (CDC) outlined 10 tips to aid in Zika outbreak response planning, targeting three categories: public healthcare officials, healthcare professionals, and the general public. To help protect against an outbreak, it is imperative to take the necessary steps to minimize the population of the mosquito responsible for the spread of Zika, among other arboviruses, the Aedes aegypti.

Ae. aegypti mosquitos lay hundreds of eggs in natural and artificial water-filled containers, which hatch when completely covered with water and take only one week to become adults. These eggs stick to the walls of water containers and can only be removed when scrubbed off.

The CDC recommends that individuals should tightly cover all water containers in and around their homes. Once a week, these containers should be emptied and scrubbed. It is important to follow these procedures with unconventional water containers as well, such as: discarded tires, pet water bowls, rain barrels, pools, flowerpots, trash bins, fountains, bird baths, etc. Septic tanks should be covered at all times and cracks and gaps should be repaired to prevent mosquito entrance. In addition, all windows and doors should be covered with screens.

In th video below, Jason C. Gallagher, PharmD, FCCP, BCPS, Clinical Professor at the Temple University School of Pharmacy and a Clinical Pharmacy Specialist in Infectious Diseases at Temple University Hospital, shares the types of mosquito repellents individuals should use to help ward off mosquitos. Specifically, Dr. Gallagher recommends using any deet, picaridin, or lemon eucalyptus-based repellent since they defend against the greatest number of infection-carrying mosquitos.​

Be sure to follow the directions printed on the back label of any product, and reapply as recommended. In addition, the CDC advises the use of permethrin-treated clothing and gear, especially outdoors in areas with large mosquito populations. It is most important for those who are known to be Zika carriers to avoid being bitten by a mosquito, as this can spread infection, or even cause an outbreak.

Earlier this month, the CDC revised its Zika travel notice. Previously, individuals were advised not to travel to an entire country if local Zika transmission was confirmed by a local public health authority. However, a recent geospatial analysis of 16 countries with local Zika transmission has revealed that it is highly unlikely to find Ae. aegypti mosquitos at elevations exceeding 2,000 meters above sea level. This is because high elevations cause changes in ecological factors which are unsuitable for Ae. aegypti mosquitos. Currently, pregnant women are advised against traveling to countries that are less than 2,000 m above sea levels and have local Zika transmission. The CDC notes that it will continue to revise its travel notices as more data regarding the geographic conditions specific to Aedes aegypti become available.