Originally published in the Ottawa Citizen, July 19, 2004
Original Title: Preventing malaria when you travel
Hippocrates (460?-377 BC) described it in his written observations. Ancient Chinese, Egyptian and Middle Eastern cultures refer to this disease. Outbreaks often coincide with warfare, mass migrations and other societal disruptions. The British blamed “bad air” in the mid 1800’s India for a disease that killed many of their nationals. This mala aria (from the Italian) has killed more soldiers in the 20th century wars than bullets. The World health Organization reported 270 million worldwide cases and one million deaths in 1998.
Contrary to popular belief, malaria did exist in the Americas and arrived here as early as 1493. High risk areas for malaria include Central and South America, Haiti and the Dominican Republic, Southeast Asia, Africa, India, and the Middle East.
In 1638, Spanish Jesuit missionaries brought South American cinchona bark back to Europe. The bark, the first treatment for malaria contains quinine. Tonic water was used as means to make the drug more palatable.
Malaria spreads by the bite of an infected Anopheles mosquito. Once the parasite enters the blood stream it heads to the liver to reproduce. The red blood cells will carry the parasite that can infect more mosquitoes if you are bitten.
Over 80 percent of people with malaria will develop chills, sweats, headaches, fever, muscle aches and joint pain. Others in addition may experience a loss of appetite, nausea, vomiting and abdominal pain.
It can take ten to 28 days after the mosquito bite to develop symptoms. Indeed, malaria can appear in as little as eight days after a bite or one year later depending upon which of the four common types of malaria parasite is involved.
How can you assess your risk of contracting malaria?
Your doctor will need to know exactly where you will be traveling and your accommodations. This includes the specific cities or regions within the country. The destinations’ elevation is important because malaria transmission is rare 2,000 metres above sea level.
Many organizations monitor malaria. The country’s malaria risk can vary throughout the year and with the seasons. Some areas may be devoid of malaria while there may be pockets of severe infestation.
If you are a night owl and spend time outdoors, beware; the Anopheles mosquito feeds from dusk to dawn. Even as little as an hour of outdoor nighttime exposure can lead to infection.
People commonly wait too long before consulting their doctor for travel vaccines and malaria prevention. Certain vaccines and malaria medications must be given weeks to months before you travel so that they can provide maximum protection. Visit your doctor at least six weeks before your departure.
The choice of antimalarial medications will be linked to your destination and the latest information from travel medicine advisory centres. Although antimalarial drugs can significantly reduce the chance of infection, they are not foolproof. Furthermore, it is mandatory that the medications be taken exactly as prescribed. If not, it will provide an opportunity for the parasite to infect you even after you have returned home. Indeed, there are many endemic areas that have specific patterns of antimalarial drug resistance
Prudent malaria prevention actions include:
- Curtail nighttime activities. Wear long sleeve shirts and pants when outside at night.
- Insect repellents like DEET in concentrations of approximately 30 percent for adults and ten percent for children should be used on the hands and face and other exposed skin. Spray it on clothes as well. Reapply every three to four hours.
- Check your accommodations to make sure they have screens over their doors and windows or make sure they are shut tight at night. If possible choose a room that is air-conditioned since the mosquito likes heat.
- Drape the bed with mosquito netting permeated with the insect repellent permethrin. It can reduce the mosquito attack rate by 97 percent
- Stick to your medication schedule and complete the course even after you return home.
Consult your doctor immediately if you develop a fever after returning home.
For more information visit these sites:
CDC Travelers’ Health Information: www.cdc.gov/travel
Malaria Foundation International: www.malaria.org
International Association for Medical Assistance to Travellers: www.iamat.org