Travel informed. Return well.

Dengue is a virus spread by mosquitoes that are mainly active during the day. Risk exists in tropical and subtropical regions, often in urban areas, near homes and in non-air-conditioned settings. Infection may be asymptomatic or cause high fever, headache, muscle and joint pain, rash, pain behind the eyes and fatigue that can last for weeks. There is no specific antiviral treatment. Vaccines are authorized in some countries, but none is currently authorized in Canada; bite prevention remains essential.

Zika virus is mainly spread by mosquitoes active during the day, especially in the early morning and late afternoon. It may also be transmitted through unprotected sex, from a pregnant woman to her fetus and, more rarely, through blood, cells or organs from an infected donor.

Risk exists in tropical and subtropical regions; the vector mosquito is not established in Canada. About 70 to 80% of infections cause no symptoms. When symptoms occur, they are generally mild and last 2 to 7 days: low fever, red eyes, joint and muscle pain, rash, fatigue and headache. There is no specific treatment or routinely available vaccine in Canada.

Japanese encephalitis is spread by mosquitoes active mainly in the evening and at night. It occurs across many parts of Asia and some areas of Oceania; risk rises in rural settings, rice-growing areas, rainy seasons and during longer stays. Risk is very low for most travellers, but disease can be severe: fever and headache, sometimes brain inflammation, permanent neurological effects or death. There is no specific treatment. Vaccination may be recommended based on destination, duration and style of travel.

Yellow Fever is spread by mosquitoes mainly active during the day in parts of South America and Africa. Many infections cause no symptoms; others initially resemble influenza, with fever, headache and significant muscle pain. About 15% of cases may progress to severe disease with a high risk of death. There is no specific treatment. The vaccine is highly effective and may be recommended for the itinerary; some countries require an international vaccination certificate for entry.

Chikungunya is spread by mosquitoes mainly active during the day. It usually causes sudden fever, feeling generally unwell, headache, muscle pain and especially joint pain, affecting larger joints such as ankles and wrists as well as fingers and toes. The acute phase often lasts a few days to about ten days, but joint pain can persist for months or longer. Chikungunya vaccines are now authorized in Canada for some travellers; suitability depends on age, health, destination and whether an outbreak is occurring.

Malaria is a serious disease caused by five parasite species spread by mosquitoes active mainly in the evening and at night. Some species are more dangerous and harder to treat. Symptoms may begin as early as 7 days after exposure, but sometimes months later. They vary greatly and can include fever, diarrhea, vomiting, muscle pain, dizziness or seizures. Symptoms alone cannot establish the diagnosis.

Seek care immediately for a sudden fever during or after travel to a risk area, even months after returning, and tell the clinician where you travelled. No malaria vaccine is routinely available to travellers. Preventive medication may be recommended based on destination and health; several options exist and should be chosen with a travel-health professional.

Rabies is a virus transmitted when saliva from an infected mammal contacts a mucous membrane or broken skin — through a bite, scratch or lick to the face or an existing wound. Dogs, cats, monkeys, bats and other mammals may carry it; dogs account for a large share of exposures worldwide. Once neurological symptoms such as paralysis and seizures appear, the disease is almost always fatal. Avoid animal contact and supervise children closely.

Congratulations! Travel during pregnancy calls for extra planning. Blood volume and cardiorespiratory workload rise; increased exhaled CO₂ may also make pregnant travellers more attractive to mosquitoes. Bite prevention is therefore essential. A 20% icaridin product may be an appropriate choice when used as directed.

At a spa, sauna, hammam or massage, avoid excessive heat, prolonged steam exposure and essential oils not recommended in pregnancy.

The first trimester often brings nausea and a higher miscarriage risk; the third carries a risk of preterm delivery. Many airlines restrict flying late in pregnancy, often around 36 weeks. Check the carrier’s rules. In an uncomplicated pregnancy, the second trimester is often the most comfortable time to travel.

The risk of deep-vein thrombosis is 5 to 10 times higher during pregnancy. Wear loose clothing and comfortable shoes, consider compression stockings if recommended and move regularly during the flight.

Be especially careful about foodborne infections such as listeriosis, toxoplasmosis and hepatitis E, which may lead to more serious complications for mother and fetus.

High altitude begins around 1,500 metres, but problems become more common above 2,500 metres. They relate to reduced oxygen, stronger UV radiation — about 4% per 300 metres — falling temperature — about 6.5°C per 1,000 metres — and dehydration. Altitude can worsen some heart and respiratory conditions, and there are absolute contraindications for some travellers.