Appendix 3 – Frequently asked questions about malaria: Canadian recommendations for the prevention and treatment of malaria
An Advisory Committee Statement (ACS) from the
Committee to Advise on Tropical Medicine and Travel (CATMAT)
The Committee to Advise on Tropical Medicine and Travel (CATMAT) provides the Public Health Agency of Canada (PHAC) with ongoing and timely medical, scientific, and public health advice relating to tropical infectious disease and health risks associated with international travel. PHAC acknowledges that the advice and recommendations set out in this statement are based upon the best current available scientific knowledge and medical practices, and is disseminating this document for information purposes to both travellers and the medical community caring for travellers.
Persons administering or using drugs, vaccines, or other products should also be aware of the contents of the product monograph(s) or other similarly approved standards or instructions for use. Recommendations for use and other information set out herein may differ from that set out in the product monograph(s) or other similarly approved standards or instructions for use by the licensed manufacturer(s). Manufacturers have sought approval and provided evidence as to the safety and efficacy of their products only when used in accordance with the product monographs or other similarly approved standards or instructions for use.
Appendix III: Frequently asked questions about malaria
* This document may be freely copied and distributed.
Is malaria a risk for Canadian travellers?
Yes. Malaria is a major killer worldwide and is the principal life-threatening infectious disease for Canadians travelling to malaria-endemic areas. Between 400 and 1,000 cases of malaria are reported among Canadian travellers annually, resulting in one to two deaths per year.
Where is malaria a risk?
Most malaria cases and deaths occur in sub-Saharan Africa. Transmission occurs in:
- Most of sub-Saharan Africa and limited areas in Northern Africa;
- Large areas of Southern Asia, Southeast Asia, and some parts of East Asia;
- Areas in Central America including the Dominican Republic, Haiti, parts of Mexico and much of South America;
- Papua New Guinea and other small islands in the South Pacific / Oceania region and in limited areas in the Middle East and Eastern Europe.
Please consult Appendix I: Malaria Risk and Recommended Chemoprophylaxis by Geographic Area for information about specific areas with risk of transmission.
What are the signs and symtoms of malaria infection?
Any individual who has travelled to a malaria-endemic area and subsequently developed fever should urgently seek medical advice and request testing to rule out malaria, even if the fever appears many months after returning to Canada. Early symptoms also include headache, muscle or joint aches, backache, fatigue, nausea and low appetite. The classic symptoms of malaria (a cyclical pattern of severe shaking chills, high fever and sweats) are often absent in mild or early cases. Symptoms may mimic other common diseases such as minor viral infections, influenza, gastroenteritis and pneumonia. As a result, it is easy to overlook malaria.
Does previous exposure to malaria offer any protection to travellers?
No. Canadian travellers who were born, grew up or used to live in malaria-endemic areas are not protected from malaria. They remain at risk regardless of past exposures or episodes of illness.
Do all travellers to the tropics need malaria chomoprophylaxis?
No. Some destinations in the tropics are free of malaria or have such a low risk that malaria chemoprophylaxis might not be indicated. In some countries, malaria chemoprophylaxis may only be required in particular regions (usually rural areas), during particular seasons or for longer stays. The boundaries of malaria-free zones within malaria-endemic countries can change rapidly, and all individuals (adults and children) travelling to areas with any risk of malaria should use personal protective measures, such as treated mosquito nets and insect repellents, to avoid mosquito bites. These also protect against other insect-borne disease like dengue.
Can travellers stop taking anti-malarial medications or using personal protective measures if they do not see any mosquitoes at their destination?
No. Even if travellers do not notice any mosquitoes, they should continue taking antimalarial medications. Malaria mosquitoes are different from the mosquitoes typically in Canada—they tend to bite when we sleep, and often are less aggressive.
Should pregnant women, babies and children travelling to malaria-endemic areas receive malaria chemoprophylaxis?
Yes. Pregnant women, babies and small children are at particular risk of acquiring malaria and of suffering severe complications from malaria. If they must go to high-risk areas, they should use the best available antimalarial medications (see Chapter 5), along with personal protective measures. Antimalarial medication taken by breastfeeding mothers will not provide protection for the breastfed child.
Do most people who take malaria chemoprophylaxis have serious side effects?
No. The majority of people taking antimalarial medications (95% to 99%) have either no side effects or only mild, temporary ones. In most studies, only 1% to 6% of people change to an alternative medication because of side effects. Reactions to antimalarial medications are almost always reversible.
For travellers to high-risk areas, the risk of acquiring malaria and dying is significantly greater than the risk of experiencing a serious side effect from malaria chemoprophylaxis.
The final choice of which antimalarial medication to use should be based on an individual risk assessment performed by a knowledgeable travel health practitioner. The risk assessment should take into account the medication’s effectiveness, the traveller’s willingness to accept potential side effects, the convenience of dosing (weekly versus daily), the cost, and the traveller’s medical history, including contraindications to antimalarial medications.
If side effects are significant, then an alternative antimalarial medication should be chosen. Travellers who are concerned about their ability to tolerate medications may wish to consult a travel health practitioner well before travelling and consider a trial of antimalarial medication before leaving.
Are there safer and/or more effective anti-malarial medications available?
For high-risk regions of the world with chloroquine-resistant malaria, three equally effective medications are currently licensed in Canada: atovaquone-proguanil (Malarone®), doxycycline and mefloquine (Lariam®). Each has advantages and disadvantages. Cheaper medications available locally in destination countries may be ineffective, counterfeit, more toxic or inappropriate for high-risk individuals. These include chloroquine, proguanil (Paludrine®), amodiaquine (Camoquine®), pyrimethamine (Daraprim®), pyrimethamine plus sulfadoxine (Fansidar®) and pyrimethamine plus dapsone (Maloprim®).
Why do travellers need to continue taking medications after they leave the malaria-endemic area?
Most antimalarial medications do not actually prevent the initial stages of malaria infection when the parasites are in the liver. Rather, they work once the parasite has completed its development in the liver and entered the blood stream. The initial phase of infection in the liver can last from 8 days to several months, although the majority of malaria cases present within the first three months after leaving the malaria-endemic area. Most antimalarial medications (chloroquine, mefloquine and doxycycline) must be continued for four weeks after leaving a malaria-endemic area to prevent disease caused by the parasites that emerge from the liver. Some antimalarial medications (atovaquone-proguanil, primaquine) are effective against the liver stages of infection, and these medications may be discontinued several days to one week after leaving the malaria-endemic area.
What is the maximum length of time a traveller can safely use malaria chemoprophylaxis?
There is no absolute time limit on how long one can take antimalarial medication. The few individuals who experience significant side effects from antimalarial medications usually do so within the first few weeks of use. Many mild side effects tend to diminish over time, even with continued use of the medication. Long-term travellers should not discontinue a well-tolerated and effective antimalarial medication simply because they have been taking it for a long period of time.
For travellers using malaria chemoprophylaxis what is the risk of developing malaria?
Proper use of an effective antimalarial medication provides a high degree of protection and can reduce the risk of malaria illness by more than 90%, but no antimalarial medication is 100% effective. Therefore, even if travellers have taken chemoprophylaxis, malaria should be considered in febrile patients during or after travel to malaria-endemic areas.
Does the use of malaria chemoprophylaxis make it more difficult to diagnose malaria?
The use of malaria chemoprophylaxis may reduce the severity of symptoms and the number of parasites in the blood and could therefore rarely result in a minor delay in definitive diagnosis. However, properly used antimalarial medications will prevent the vast majority of malaria episodes and reduce the risk of severe disease, and will not prevent a definitive diagnosis if proper testing is done. The small risk of a slight delay in diagnosis must be balanced with the significant benefit of preventing disease and reducing the risk of severe disease.
Is it true that some malaria cannot be treated?
If identified early and treated appropriately, almost all malaria can be completely cured. However, even short delays in the diagnosis of malaria can make treatment more difficult and less successful, and can increase the risk of serious complications.
Once you are infected with malaria, are you infected for life?
No. Appropriate treatment and follow-up can cure malaria.
Further information on travel-related health issues is available on the Public Health Agency of Canada’s Travel Health website.
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