Expats know that the best protection against mosquitoes is a commercial preparation containing DEET. They may not know that there are associated health concerns, and U.S. health agencies urge that users of these commercial mosquito repellents wash it off if they are not going to be exposed to the insects.
There have been a few bad reactions to the chemicals, particularly when it is at 100 percent strength, even though that provides the longest protection.
Some expats may not like DEET because they are opposed to such products philosophically. And the chemicals have been known to damage some fabrics.
The U.S. Centers for Disease Control and Prevention says that repellents containing picaridin that is found in products like Cutter, a product with the trade name of IR3535 reflecting its chemical makeup, and some oil of lemon eucalyptus and para-menthane-diol products provide protection, too.
Still, hardly any chemical provides protection more than 12 hours. And mosquitoes have a way of finding the skin that has not been protected. In addition, some mosquitoes learn to hold their little proboscis and drill DEET-covered skin anyway, according to some studies.
A survey of the literature available on the Web shows that there can be some limited protection by using certain foods like garlic or by continual doses of vinegar. But a lot of the folk knowledge does not stand up to scientific scrutiny.
The issue is important in Costa Rica because of the current outbreak of the mosquito-borne zika virus in some areas. In the
north, there is concern about other diseases, like West Nile virus. The best protection appears to be a combination.
The Centers for Disease Control suggests wearing plenty of clothing for protection. But that is not the best remedy for beachgoers. The Centers also encourage mosquito-proofing homes and other sleeping areas.
There are hotels in Costa Rica that do not have screens and other protective devices on the windows and doors of the guest’s rooms. In the past that was acceptable because mosquitoes are constricted by climate and also altitude. But tourists might consider the security that screens bring.
There also is value on the little creatures that scurry up the walls, chirp to each other and have a diet heavy in mosquitoes and other bugs.
The Ministerio de Salud also is directing a number of campaigns to clean up trash where mosquitoes may breed. Zika outbreaks generally have been in blue-collar areas where there are a lot of mosquito breeding spots, like spare tires and even junk cars.
Potted plants, household drains, gutters, bird baths and even water pockets in vegetation can host mosquito larvae.
The health ministry and the Federación de Municipalidades de Guanacaste said Friday that they are working together to eliminate breeding spots in trash. Municipal representatives met to discuss actions against the Aedes aegypti, which carries dengue, chikungunya and zika and trash management in general.
The arrival of the rainy season signals the likely increase in mosquitoes.