Mosquitos and Other Bite Prevention


Over one million people die each year from a mosquito-borne illness. Malaria, Chikungunya, Dengue, Yellow Fever, West Nile Virus, and Zika are common illnesses transmitted to humans by mosquitos. While most of these are found in subtropical locations, many of them are becoming common in several areas around the world.

  • Use insect repellent. Repellents containing DEET, picaridin, IR3535, and some oil of lemon eucalyptus and para-menthane-diol products provide long-lasting protection.
  • If you use both sunscreen and insect repellent, apply the sunscreen first and then the repellent.
  • Do not spray insect repellent on the skin under your clothing.
  • Treat clothing with permethrin or purchase permethrin-treated clothing.
  • Always follow the label instructions when using insect repellent and/or sunscreen.
  • When weather permits, wear long-sleeve shirts and long pants. Spray the outside of clothing with insect repellent.
  • Select accommodations with well-screened windows and doors or air conditioning when possible. If unable to use screens or protect yourself indoors, sleep under a mosquito net.
  • Empty standing water from containers such as flowerpots or buckets.
  • Be aware of peak mosquito hours.
  • See a healthcare provider to discuss any concerns and to be evaluated as soon as any symptoms emerge.
  • Prior to trip departure, consult with a physician regarding vaccinations. 
  • Note: There is currently a global shortage of the Yellow Fever vaccine, which is required for entry to some countries. Stamaril, an alternate vaccine, is available in a limited number of clinics in the U.S., so plan ahead.

For more mosquito bite information and vaccines, see the Centers for Disease Control and Prevention.

Snakes, Scorpions, and Spiders

The most dangerous species of these animals are encountered in tropical, subtropical, and desert areas. Generally, the most venomous of these creatures are particularly active at night. Poison from snake and spider bites and from scorpion stings causes tissue damage around the wound. Venom can also have many serious effects throughout the body, such as affecting blood coagulation, leading to hemorrhage, and nerve damage.

If venom comes in contact with the eyes, it may cause severe damage, including blindness. Being bitten or stung by a venomous snake, scorpion, or spider is a medical emergency. It requires immediate attention in a medical facility. First aid measures include avoiding movement as much as possible and keeping calm. This can help limit the spread of the toxin through the body. Any rings or jewelry should be removed from the bitten limb.

For snakes, the wound should not be washed, as in some locations a swab of the venom can be taken to identify the snake and the correct anti-venom to use.  Many treatment methods made popular through movies and books should NOT be used as first-aid measures. Incisions, suction, tourniquets, and compression are all harmful to the patient. Anti-venom treatment should be administered only in a medical facility. 

Preventing bites/stings from snakes, scorpions, and spiders

  • Ask locals about the risks in the areas you will visit.
  • Wear close-toed shoes and long pants in areas where venomous snakes, scorpions, or spiders may be present. Do not overturn rocks or other materials without taking precautions as snakes, spiders, and scorpions (or other venomous insects/animals) could be hiding underneath. 
  • Sleep under a mosquito net to reduce the risk of scorpion exposure.
  • Check for animals in your clothing and shoes before getting dressed.
  • Do not try to handle or kill snakes.
  • Use insect repellents to deter scorpions or spiders.

Additional Information

  • Read about your destination and any animals or insects that you may come in contact with. Learn techniques about how to avoid being bitten or stung and what to do if you are. 
  • If bitten by an animal, call On Call International immediately. 
  • If you have any allergies to insect stings (such as bees and wasps), carry your medication with you at all times if in an area known for the insects you are allergic to. 
  • When you go outside, avoid wearing brightly-colored clothing or using sweet-smelling lotions, perfumes, and shampoos.
  • Always wear shoes, especially when going outside in areas with insects, snakes, or scorpions. Check the insides of your shoes before putting them on. Do not put your hand inside; instead, squish down the toe to the heel, then turn the shoe over a trashcan and shake and clear out anything in the shoe. 
  • Keep your food and trash tightly sealed.