If anyone is a seasoned traveller, it’s Nora Dunn. The self-proclaimed professional hobo and former financial planner has travelled full-time since 2006. And she’s seen a lot when it comes to travel-acquired illnesses.

Several years ago, she watched her ex-partner suffer through dengue fever on a trip to Thailand. There are four strains of the disease, two of which are more serious than the others. “It was one of the bad strains and it sent him to hospital for a week,” Dunn says. “It was very serious, with immediate risk of internal hemorrhaging, and doctors and nurses checking in on him every four hours to take blood and monitor his platelet count.”

“A few years later, I had dengue fever one week after landing on the Caribbean island of Grenada for a house-sitting job,” says Dunn. After suffering through a week of flu-like symptoms including high fever, severe headache, joint and muscle pain and nausea, Dunn made a full recovery.

Most recently, she came down with another illness, again in Grenada. This time she believes it was chikungunya, a mosquito-borne infection that is currently spreading throughout the Caribbean and into parts of Florida.

Still, getting sick hasn’t fazed her. Dunn says she doesn’t avoid travelling to areas where tropical diseases are widespread. “It hasn't necessarily changed my approach to travelling,” she says. “But I do certainly think twice about my attire – and the strength of DEET [in the insect repellent] I bring – when I visit mosquito-laden areas.”

Many tropical diseases on the rise

Whether it’s the result of global warming or an overall trend of urbanization, diseases such as valley fever as well as dengue fever and chikungunya are increasing. And infectious disease experts caution that the number of those infected will rise in coming years.

The trend has some travellers worried.

“I get calls all of the time asking me, “’Should I go?’” says Dr. Jay Keystone, medical director of Medisys Travel Health Clinics in Toronto and a staff physician in the tropical disease unit at Toronto General Hospital.

If you’re one of those concerned travellers, here is what you need to know about these three nasty bugs:


  • Symptoms: Late in 2013, chikungunya made big news. Spread by the Aedes aegypti mosquito, the illness causes severe joint pain, fever, headache, muscle pain, nausea and vomiting. And in some people, symptoms persist for weeks or months, causing an arthritis-like joint pain and neurological symptoms.
  • Why it’s noteworthy: In 2013, chikungunya infections began popping up in Aruba, San Maarten, the Virgin Islands, Martinique, Guyana -- and even southern Florida. It hasn’t stopped spreading since then. As of January 2015, there have been over one million suspected and confirmed cases, according to a Canadian government travel advisory. The disease is also being diagnosed in Pacific islands such as Samoa and New Caledonia.
  • Who’s most at risk: Keystone says immunosuppressed people, such as those with heart conditions or diabetes, or who are undergoing cancer treatment, are the most likely to contract the disease. Most people have a mild infection; more severe and prolonged joint pains occur in older individuals.
  • Prevention: Avoid mosquitos in the early morning and late afternoon, apply repellents containing DEET, wear long-sleeved shirts and long pants and choose resorts that fog for mosquitos. “We’ll have a vaccine for this within five years,” predicts Keystone. For now, there is no vaccine.

Dengue fever

  • Symptoms: High fever, joint pain, severe headache, rash, muscle pain, nausea and vomiting; possibility of internal bleeding.
  • Why it’s noteworthy: No vaccine or drug can protect you from dengue fever. And it’s on the increase. “In 2014, Malaysia and Singapore reported more cases when compared to the same time period in 2013,” according to the Public Health Agency of Canada. Dengue fever also broke out in Fiji in 2014, and the number of cases is expected to increase in countries affected by the rainy season.
  • Who’s most at risk: Those with health conditions, infants, children and the elderly. Severe dengue is a leading cause of serious illness and death among children in some Asian and Latin American countries, according to the World Health Organization.
  • Prevention: Avoid endemic areas. Avoid peak biting times such as dusk and dawn. Wear long-sleeved shirts and long pants and apply insect repellent.

Valley fever

  • Symptoms: Valley fever made headlines several years ago due to the higher number of cases reported in the southern U.S., although it exists in Mexico, Central America and South America as well. Caused by a microscopic fungus called Coccidioides that is inhaled into the lungs, valley fever leads to flu-like symptoms including fever, cough, headache, muscle aches, fatigue and joint pain in 60% of those infected. The other 40% have only mild symptoms.
  • Why it’s noteworthy: According to a fact sheet from the U.S. Centers for Disease Control and Prevention (CDC), valley fever cases in certain areas (California and Arizona) are dramatically on the rise -- from 2,265 in 1998 to 22,401 in 2011. Since 1990, more than 3,000 people have died. In 1% of cases, valley fever can spread from the lungs to other areas in the body or cause chronic pneumonia.
  • Who’s most at risk: People with underlying health issues, African Americans, Asians, pregnant women (particularly those in their third trimester) and people with weakened immune systems, such as those who have had an organ transplant or who have HIV/AIDS, chronic health conditions or cancer, says the CDC.
  • Prevention: Avoid travel when infections are at their highest, says Keystone: during the spring and fall in Arizona and summer in California. Avoid hiking after a dust storm when spores are more likely to be in the air and easily inhaled. If you’re undergoing chemotherapy or have a chronic respiratory illness, wear a N95 facemask outdoors in areas where infection rates are high, he says.

And as always, whenever and wherever you travel, be sure to have travel insurance to protect yourself against unexpected health care bills away from home.