Malaria Prophylaxis
Chemoprophylaxis is a strategy that uses medications before, during, and after the exposure period to prevent the disease caused by malaria parasites. The aim of prophylaxis is to prevent or suppress symptoms caused by blood-stage parasites. In addition, presumptive antirelapse therapy (also known as terminal prophylaxis) uses a medication (primaquine) toward the end of the exposure period (or immediately thereafter) to prevent relapses or delayed-onset clinical presentations of malaria caused by dormant liver stages of P vivax or P ovate.
In choosing an appropriate chemoprophylactic regimen, the traveler and the healthcare provider should consider several factors. The travel itinerary should be reviewed in detail to determine whether the traveler is actually at risk for acquiring malaria. The next step is to determine whether significant antimalarial drug resistance has been reported in that location. Resistance to antimalarial drugs has developed in many regions of the world. Healthcare providers should consult the latest information on resistance patterns before prescribing prophylaxis for their patients. Five medications are currently available and approved for malaria prophylaxis:
1. Chloroquine (or hydroxychloroqulne)-This drug is still effective for prophylaxis in Central America above the Panama Canal and in some areas of the Middle East, but should not be used for prophylaxis in other areas. Chloroquine is safe in pregnancy and breastfeeding. Prophylaxis should begin 1-2 weeks before arrival in a malaria-endemic area and should continue for 4 weeks after departure.
2. Mefloquine: This agent is effective for prophylaxis in most of the world, although P falciparum shows a patchy, but increasing. resistance to the drug in some areas. It is considered safe to use in pregnancy and breastfeeding, although small amounts are passed in breast milk. Prophylaxis should begin 2 weeks before arrival in a malaria area and continue for 4 weeks after departure.
3. Atovaquone/proguanil-This drug is effective and safe for children, but there is insufficient evidence to recommend it for use in pregnant women, children weighing <5 kg, or women breastfeeding infants weighing <5 kg. Prophylaxis should begin 1-2 days before arrival in a malaria-endemic area and continue for 7 days after departure.
4. Doxycycline- This agent is efficacious, safe, and the least expensive choice for prophylaxis. Prophylaxis should begin 1 day before arrival in a malaria-endemic area and continue for 4 weeks after departure.
5. Prlmaqulne-- Primaquine may be used as primary prophylaxis in areas with primarily P vivax. It is taken 1-2 days before travel to a malarial area and daily for 7 days after return. Terminal prophylaxis is not needed if primaquine is used as primary prophylaxis. When used as terminal prophylaxis, it is taken daily for 14 days after leaving the malarial area.