Name two malaria prophylaxis options commonly used in deployed settings.

• A. Doxycycline and atovaquone-proguanil.
• B. Mefloquine and chloroquine.
• C. Primaquine and doxycycline.
• D. Artemisinin-based combination therapy and quinine.

Answer: (A)

In deployed settings, malaria prophylaxis focuses on regimens that are effective against resistant parasites, safe and tolerable in the field, and easy to take consistently. Doxycycline and atovaquone-proguanil fit this need well.

Doxycycline is taken once daily and started a couple days before exposure, then continued daily during the deployment and for several weeks after returning. It provides good protection against blood-stage parasites, including chloroquine-resistant strains, and is affordable and widely available. Its downsides are photosensitivity and possible GI upset, and it isn’t used in pregnancy or in young children.

Atovaquone-proguanil is also a daily regimen, started just before travel and continued for a week after leaving the risk area. It has a favorable tolerability profile and is effective against resistant strains, with the practical advantage of a shorter post-travel tail compared to doxycycline. However, it’s more expensive and not suitable for certain populations (for example, it’s avoided in pregnancy in some guidelines).

Other options exist but are less commonly used in typical deployed scenarios for routine prevention: mefloquine is a weekly option but can have neuropsychiatric side effects that limit its use in some personnel; chloroquine is unreliable in many regions due to resistance; primaquine is reserved for specific situations and requires G6PD testing because of risk of hemolysis; ACTs and quinine are treatments, not prophylaxis.

So, the two commonly used malaria prophylaxis options in deployed settings are doxycycline and atovaquone-proguanil because they provide reliable protection with practical dosing and manageable safety profiles in field conditions.