As Medical Director at Remote Medical International®, I have worked on a wide variety of international and tropical medicine projects. While every region of the world poses unique risks for illness and disease, there are certain diseases that are common throughout much of the world.
Malaria is endemic in about 100 countries with approximately half of the world’s population at risk. It has been estimated that malaria has caused half of all human deaths.
When traveling in a malaria endemic area it is important to protect yourself against this potentially deadly infection. All travel is not created equally when it comes to risk of malaria. Risk varies significantly both among and within countries. There also may be seasonal variability due to the increase in mosquitoes after the rainy season. Risk also varies with the type of travel. For example, someone staying in a four-star hotel with air-conditioning and windows may be at lower risk than someone sleeping outdoors. In other words, it is important to determine the level of risk based on multiple factors including the country, location within the country, the time of year, and the type of travel.
The type of malaria prevention used will depend on the level of risk. This should be determined based on the factors listed above but must also include characteristics including the reason for travel, the general health or the traveler, and their individual risk acceptance.
It may be determined that the level of risk of malaria infection is low enough that mosquito avoidance is enough. This may be by simply sleeping in a closed, air-conditioned room and traveling in a closed, air-conditioned vehicle. If the level of risk is determined to be higher, it may be recommended that additional mosquito avoidance measures be utilized including light colored clothing, long sleeves, and insect repellant.
Finally, if the risk of malaria infection is significant, in addition to all the measures already listed, it may be recommended that one take medication to reduce the risk of malaria infection. This is called chemoprophylaxis. There are many options for chemoprophylaxis and the right one will depend on the area of travel and the preferences of the individual traveler. There are different recommendations depending on the specific species of malaria and the drug resistance patterns as drug resistance has become an enormous problem in some parts of the world.
For each medication there are two parameters that determine how often the medication should be taken and for how long the medication should be taken. Medications with a relatively long half-life such as chloroquine need to be started a week or two before entering a malaria endemic area and subsequently taken once a week. Those with a shorter half-life such as doxycycline need to be taken daily.
Medications that work on the blood form of the parasite need to be taken for one month after returning from a malaria endemic area to make sure all of the parasites have migrated from the liver to the blood stream where these medications are active. The vast majority of medications act on the blood form of the parasite.
For example, doxycycline has a short half-life and needs to be taken every day. Further, because it works on the blood form of the parasite, it needs to be taken for a month after leaving a malaria endemic area.
Malarone (atovaquone-proguanil) works on the liver form of the parasite. It works before the parasite migrates to the blood. Therefore malarone only needs to be taken for seven days after returning from a malaria endemic area. For many travelers Malarone is the chemoprophylaxis drug of choice as it may be started 1-2 days before travel, taken every day while in the malaria endemic area, but only taken for 7 days after leaving the malaria endemic area. This may be especially appealing to those making short trips for business and would otherwise have to take medication for a month after returning even from a short trip. Ultimately, it is a personal choice and there is no ‘one size fits all.’ The most important thing is to understand the risk and take the appropriate precautionary measures.
If you are in need of malaria medication or have any further questions about malarone, doxycycline or other options, please feel free to contact Remote Medical International.
Dr. David Townes is Medical Director for Remote Medical International. He received his medical degree from the University of Massachusetts and completed his internship and residency in emergency medicine. Dr. Townes completed a fellowship in international emergency medicine and earned his master’s degree in public health all at the University of Illinois at Chicago. He earned a diploma in tropical medicine and hygiene from the London School of Hygiene and Tropical Medicine. Dr. Townes is board certified in emergency medicine and has been a physician volunteer for the National Ski Patrol, the search and rescue team at Yosemite National Park, the Indian Health Service and is a former member of the Board of Directors of the Wilderness Medical Society.