There is no vaccine or antiviral treatment available for Zika virus. Treatment includes supportive care of symptoms… but “prevention is better than cure”. The best way to prevent a Zika virus infection is to avoid being bitten by its vector, the mosquito (the Aedes species of mosquito). Avoiding bites involves a combination of efforts like wearing clothes that cover most of the body, destroying potential habitats that will promote mosquito breeding, using insecticide in ones environment and using insect repellants on the body.
Let’s talk about the natural sources of mosquito repellants and insecticides. For a homemade insect repellant, one part of an effective essential oil is often mixed with 10 parts of a base/cooking oil like coconut oil or olive oil. The base oil acts as the diluting agent.
There are many kinds of Eucalyptus trees which we can extract oil from, but the most popular Eucalyptus essential oil has been from Lemon Eucalyptus (Eucalyptus citriodora) since it was approved by the CDC as an effective mosquito repellent. A 2003 study reported that burning of leaves of Lemon Eucalyptus provides a cost-effective method of household protection against mosquitoes in Africa. Other studies have shown that a mixture of 32 percent lemon eucalyptus oil gave more than 95 percent protection against mosquitoes for three hours.
You can create your own repellent mixture with one part lemon eucalyptus oil to ten parts sunflower oil or witch hazel. You can also create your own sunscreen with a mixture of lemon eucalyptus oil and extra virgin coconut oil. Be mindful of the oils’ odours when making homemade mixtures. Lemon Eucalyptus has a strong citrusy smell and EV coconut oil is sweet smelling. Please note that University of Florida researchers caution against using lemon eucalyptus oil on children under three years old.
The main active component of Lemon Eucalyptus insect repellent is p-menthane 3,8-diol also called PMD. It has been found to be more effective than DEET, the active ingredient in synthetic bug spray. Another common eucalyptus essential oil is from Eulcalyptus globulus or the Bluegum tree. The major constituent of Bluegum is 1,8-Cineole. The duration of repelling effect of the Eucalyptus oils depend on concentration and method of extraction of the oils.
Neem tree (Azadirachta indica) has a wide range of medicinal properties. More than 140 compounds have been isolated from different parts of neem. All parts of the neem tree- leaves, flowers, seeds, fruits, roots and bark have been used traditionally in herbal medicine. According to a 1995 study in India which evaluated repellant action of neem essential oil (from neem leaves) against different mosquito species: 2% neem oil mixed in coconut oil provided 96-100% protection from anophelines, 85% from Aedes species, 37.5% from Armigeres species, whereas it showed wide range of efficacy from 61-94% against Culex species.
Mix ten (or so) drops of neem essential oil with a quarter cup coconut oil for a DIY bug spray. Note that neem is irritating to broken skin. Burning neem candles is also effective at mosquito repelling.
Crushing or grinding leaves, placing them in a bottle of water and oil or alcohol then spraying the mixture on one’s skin and in environment is a common practice. Of course the leaf crushing method is not as effective, as we would have to apply the spray more frequently. Also, the mixture is less stable and so has a shorter shelf life and may require storage in a cool environment.
Repellent activity of thyme (Thymus vulgaris) essential oil has been reported for Aedes and Anopheles mosquito species. In another study, hairless mice had 5 percent thyme oil applied to the skin, with a 91 percent protection rate.
For a homemade preparation, combine four drops of thyme oil to every teaspoon of base oil, such as olive or jojoba oil. For a spray, mix five drops of thyme oil with 2 ounces of water. To make the oil, simply crush a small stem or two of thyme leaves and add it to a comparably larger portion of base oil then heat the mixture for 5 to 10 minutes until it bubbles and allow it to cool.
Thyme essential oil should only be used on the skin. If taken internally it can cause negative side effects such as nausea, dizziness, vomiting, diarrhoea and muscle problems. It may also stimulate the thyroid gland, which is why this oil is not recommended for people with hyperthyroidism.
Greek catnip (Nepeta parnassica) also known as greek catmint is a potent mosquito repellant. Studies have shown Greek Catnip essential oil is 10 times more effective than DEET and at certain concentrations can effectively provide protection for 6 hours. Unfortunately, Greek catnip oil may be hard to find in the Caribbean.
Dilutions of the essential oils mentioned above may be safe to use for pest control on animals. I haven’t found any studies indicating negative effects from use of these essential oils on animals. Neem oil is the most versatile of the essential oils mentioned. Neem is currently used in many pet products and has been found to have a variety of biological activities including biocidal activity against nearly 200 arthropod pests without any adverse effects on most non-target organisms. Not enough studies have been done on each of the oils’ uses in a wide range of animal species. Please note: Zika Virus is not known to affect any domestic animal species.
The synthetic compound DEET also known as diethyl-3-methyl-benzamide or diethyl-toluamide has long been the main repellent used on human skin against blood-feeding arthropods, and it also has been identified as effective against ticks. According to studies, there have been rare reports about severe reactions, including encephalopathy in humans, to DEET. Moreover, DEET does not readily degrade by hydrolysis at environmental pHs and is a common pollutant in aquatic ecosystems. Furthermore, it damages hard plastics and we all know products that damage plastic aren’t that great for human use. Insect repellants that have DEET as their main ingredient include: Repello Wristband, Gone Original Wristband and most of the OFF! products (eg. OFF! Deep Woods, OFF! Skintastic). There are many natural alternatives that are more effective and safer than DEET we just have to search.
Blogged by Gabrielle Beckford.
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