Malaria is one of the leading diseases and major causes of death on this planet. Over a third of a billion people, i.e. 300,000,000 people, are infected with malaria every single year. Less than 1% of those infected actually die of it. So, are we leading a rather sheltered life when the entire southwardly traveling population decides to panic because a few returning travelers show malaria symptoms? Well over a thousand North Americans are diagnosed with malaria every year, after they return from tropical and sub-tropical destinations such as Africa, India, the Caribbean and South America. Malaria is caused by one of four types of Plasmodium parasites. These parasites live inside your red blood cells and some are worse than others. Malaria is transmitted into your blood by the females of certain mosquito species (Anopheles) when they feed on you. It can also be transmitted through blood transfusions or dirty needle use. This is the real worry and the main reason why cases need to be rapidly identified and treated, since we want to keep our blood supply clean.
The parasites tend to hide in the liver and produce infectious vectors called merozoites which enter red blood cells, mature, divide, and invade further. Within a week or two, you begin to develop flu-like symptoms including headache, chills, fatigue and muscle pains. Jaundice, nausea, abdominal pain, vomiting and diarrhea may also show up. The acute phase of the infection tends to be the worst part. The good news is that if properly diagnosed, malaria is treatable and most people survive. Diagnosis is by a malaria smear, performed by looking at a drop of blood under the microscope. It must be fully treated or else symptoms may recur several months later. This is because resistant forms of parasites exist, and are coupled with an ability to hide in the liver.
Malaria is found pretty well anywhere that mosquitoes can exist year round. In the natural cycle of things, if there are more mosquitoes around, you would expect more occurrences of malaria. In areas disrupted by hurricanes, such as the Caribbean for example, one would expect to see a rise in the mosquito population, as is the case in the Dominican Republic. The southern United States was a malaria-infested region at one time. Eradication efforts in the early part of the century changed this. The Anopheles species of mosquito does not exist in Canada. There are the extremely rare reports of transmission when mosquitoes hitching an accidental ride from an endemic area bite airport baggage handlers. We have also seen cases in which local mosquitoes bite an infected human and transmit malaria.
The best strategy to prevent malaria is not to get bitten by mosquitoes. Most bites occur between dusk and dawn. Wearing protective clothing and using DEET containing repellants on open skin areas is a great start. The next level of protection involves taking a medication that can destroy malaria parasites in the blood. These drugs do not prevent transmission or mosquitoes from biting, but rather destroy the parasites upon entry. It is essential therefore to pre-load the body before travel to accomplish this. Chloroquine is the most common agent used to prevent malaria. It is taken once weekly and is only effective in sensitive areas such as the Dominican Republic. Unfortunately, malaria has become resistant to chloroquine in many parts of the world, which is what makes it such a widespread health problem. In those areas, travelers are pre-treated with drugs like Malarone, Mefloquine, Primaquine or Doxycycline. These medications tend to be saddled with bothersome side effects. The best advice for pregnant travelers to areas infested with resistant parasite species is "Don't go, unless absolutely essential." After digesting all of this, perhaps spending Christmas immersed in family dynamics around the old fireplace with some good bottled cheer is not such a bad prospect after all. Just staying healthy may be one of the many things to be thankful for at Christmas!
● Malaria and Malaria: Fact Sheet from World Health Organization (WHO).
● Malaria from Wikipedia, the free encyclopedia.
● Malaria from Centres for Disease Control and Prevention CDC.
● Learn About Malaria from Malaria Foundation International.
● DDT and Malaria Control Interactive Video.
● Malaria: Frequently Asked Questions (FAQs) from CDC.
● Regional Malaria Information (Map) from CDC.
● Malaria from Directors of Health Promotion & Education (DHPE): Infectious Facts.
● Malaria - Causes from WebMD.
● Malaria by Dr. Charlie Easmon, specialist adviser in travel medicine, NetDoctor.co.uk.
● Malaria: Symptoms, Treatment and Prevention from Health Encyclopedia.