Malaria Chemoprophlaxis

Chloroquine-sensitive regions

Chloroquine-sensitive regions are malaria-endemic areas where chloroquine resistance has not been documented or is not widely present. These include Haiti, the Dominican Republic, Central America north of the Panama Canal, parts of Mexico, parts of South America, north Africa, parts of the Middle East, and west/central China.

Drugs of choice: Chloroquine (Aralen®) is the drug of choice for travellers to areas with chloroquine-sensitive malaria. Hydroxychloroquine (Plaquenil®) is an acceptable equivalent alternative.

Chloroquine or hydroxychloroquine is taken once a week, beginning at least 1 week before entering a chloroquine-sensitive malaria-endemic region (or 2–3 weeks before to assess tolerability), during the period of exposure, and for 4 weeks after leaving the malaria-endemic region.

Alternatives: Individuals who are unable to tolerate chloroquine or hydroxychloroquine should use atovaquone–proguanil, doxycycline or mefloquine.

Chloroquine-resistant regions

Chloroquine-resistant regions are malaria-endemic areas where chloroquine resistance has been documented. Chloroquine-resistant regions include most of sub-Saharan Africa, South America, Oceania and Asia. Note that some border areas of Thailand, Myanmar (Burma), Laos and Cambodia, as well as southern Vietnam, are both chloroquine-resistant and mefloquine-resistant regions.

There are sufficient data in semi-immune and nonimmune hosts in various geographic locations to conclude that atovaquone–proguanil, doxycycline and mefloquine provide similar levels of protection against chloroquine-resistant malaria.

Drugs of choice: Atovaquone–proguanil, doxycycline or mefloquine.

Atovaquone–proguanilis taken daily, beginning at least 1 day before entering a malaria-endemic region (or 3–4 days before to test tolerability), during the period of exposure, and for 1 week after leaving the malaria-endemic region.

Doxycycline is taken daily, beginning at least 1 day before entering a malaria-endemic region (or 3–4 days before to test tolerability), during the period of exposure, and for 4 weeks after leaving the malaria-endemic region.

Mefloquineis taken weekly, beginning 1 week before entering a malaria-endemic region (or 3 weeks before, to assess tolerability), during the period of exposure, and for 4 weeks after leaving the malaria-endemic region.

Alternatives: If atovaquone–proguanil, doxycycline and mefloquine are not well tolerated, primaquine daily can be considered. Begin taking it at least 1 day before entering a malaria-endemic region (or 3–4 days before to ensure tolerability), during the period of exposure, and for 7 days after leaving the malaria-endemic region.

Note: Primaquine is contraindicatedin glucose-6-phosphate dehydrogenase (G6PD) deficiency and contraindicated in pregnancy.

Chloroquine-and mefloquine-resistant regions

Resistance to both chloroquine and mefloquine has been reported in various countries in Asia, Africa and the Amazon basin. However, it has not been found to be a significant problem except in rural, wooded regions where Thailand borders with Myanmar (Burma), Cambodia and Laos, as well as in southern Vietnam . While these areas are infrequently visited by travellers, use of PPM should be optimized for those travelling there.

Drugs of choice: Atovaquone–proguanil or doxycycline.

Atovaquone–proguanil is taken daily, beginning at least 1 day before entering a malaria-endemic region or 3–4 days before to ensure tolerability), during the period of exposure, and for 1 week after leaving the malaria-endemic region.

Doxycycline is taken daily, beginning at least 1 day before entering a malaria-endemic region (or 3–4 days before to ensure tolerability), during the period of exposure, and for 4 weeks after leaving the malaria-endemic region.

Alternatives: There are currently no alternatives for prevention in these regions.

NOTE: There are no approved drugs to prevent malaria in pregnant women or in children weighing less than 5 kg travelling to mefloquine-resistant regions. Atovaquone–proguanil (Malarone®) may be considered for women after the first trimester who cannot avoid travel to mefloquine-resistant areas (e.g. border areas between Thailand and Cambodia/Myanmar) after careful discussion of the benefits and risks.