Travel Bugs – Beware the Bite!

When considering traveling, working, or volunteering abroad, the responsible healthcare professional heads to the travel clinic to get updated on the typical vaccinations, such as tetanus, meningitis, and hepatitis. Depending where they'll wander, they may even get a yellow fever shot or a stock of malaria pills.

But what other bugs – whether rare or common – might one encounter, aside from the usual childhood diseases (e.g., mumps, measles, chicken pox) and other diseases familiar to North Americans (e.g., rabies, West Nile virus, Lyme disease, Norwalk virus, TB) …?

Today's bug to beware of is the mosquito!

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Dengue Fever & Dengue Hemorrhagic Fever (DHF)

• How do you get it? – Being bitten by infected Aedes mosquitoes.

• What causes it? – Any one of four flaviviruses, known as DEN-1 through DEN-4.

• What is it? – A viral disease characterized by sudden onset (after an incubation period of 3-14 days, but most commonly 4-7 days) of high fever, severe frontal headache, and joint and muscle pain. Many patients also have nausea, vomiting, and rash. It can present as a severe, sometimes fatal hemorrhagic disease called DHF.

• Where is it found? – It is endemic in most tropical countries of the South Pacific, Asia, the Caribbean, the Americas, and Africa.

• Prevention? – No vaccine is available. Use typical precautions to avoid mosquito bites, e.g., staying in well-screened or air-conditioned areas when possible, wearing clothing that covers the arms and legs, and using insect repellent containing a substance like DEET. Peak periods of biting activity are the morning for several hours after daybreak and in the late afternoon for several hours before dark. However, bites can occur at any time, especially indoors, in shady areas, or when it is overcast.

Encephalitis, Japanese

• How do you get it? – Being bitten by infected mosquitoes.

• What causes it? – A virus called Culex vishnui.

• What is it? – A viral encephalitis that is usually asymptomatic, but when clinical illness develops, the fatality rate can be as high as 30% and neuropsychiatric aftereffects are reported in 50% of survivors.

• Where is it found? – Asia and western Pacific countries, in generally rural, agricultural areas. Transmission is seasonal (and varies by country, e.g., occurring in the summer and autumn in the temperate regions of China, Japan, Korea, and eastern areas of Russia).

• Prevention? – A vaccine is available. However, since the risk is so low in urban areas, those traveling for short periods, or restricting travel to major urban areas generally don't need the vaccine.

Filiariasis, Lymphatic

• How do you get it? – By being bitten by infected mosquitoes.

• What causes it? – Microscopic worms (filariae), particularly Wuchereria bancrofti and Brugia malayi.

• What is it? – A lymphatic disease leading progressive lymphatic vessel dilation and dysfunction, which leads to secondary lymphedema of the leg, arm, scrotum, penis, or breast.

• Where is it found? – Tropical areas of the world, including sub-Saharan Africa, Egypt, southern Asia, the western Pacific islands, the northeastern coasts of South and Central America, and the Caribbean Islands.

• Prevention? – No vaccine is available. Typical mosquito precautions may be used (e.g., wearing clothing that covers the arms and legs, and using an insect repellent containing a substance like DEET).

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Check back for other items in our Travel Bugs series:

• Travel Bugs – Gotta "Fly"?

• Travel Bugs – This Will Bug You!

• Travel Bugs – Don't Drink the Water! (Part I)

• Travel Bugs – Don't Drink the Water! (Part II)

• Travel Bugs – Don't Drink the Water! (Part III)

• Travel Bugs – Fungus Among Us

• Travel Bugs – Miscellaneous Menaces

Want more information?

• World Health Organization's International Travel and Health page

• National Center for Infectious Diseases' Travelers' Health page