Malaria Prevention

If you are traveling to an area of the world where malaria occurs, you should read our chapter on malaria in pregnancy.  In this section we talk about the various methods to prevent malaria.

Most people, when they speak of malaria prevention, immediately think of spraying with insecticide or taking medicines.  The truth is that the first steps in malaria prevention are much more basic and consist of mosquito avoidance.

Remember that the mosquitoes that spread malaria typically breed in marshy or rural areas and bite at night.  Thus staying indoors or wearing long sleeves and long pants during the cool parts of the day are good ways to avoid malaria.  Similarly, keeping the mosquitoes out with window screens or a mosquito net helps tremendously, especially if the net is sprayed with Permethrin®.

The next step, discussed in a separate chapter, is the use of insect repellents.

Once you have done all this it is time to talk about taking preventive medicine.

Remember that malaria is a parasite that infects both the liver and the blood.  The various medicines to prevent the disease work on either the liver forms or the blood forms of the parasite.  Some combination medicines do both.

Chloroquine is the classic drug for malaria prevention.  It is slow in getting into your blood stream so you need to begin taking it one to two weeks before becoming exposed to malaria.  Also, as it kills only the blood forms you must take it for at least four weeks after exposure until the parasites in the liver die off.

Chloroquine has been around for many years and is of proven safety in pregnancy.  Unfortunately, malaria in most of the world is now resistant to this drug.  It is of little value outside of the Caribbean, Central America and the Middle East.

It has been largely replaced by mefloquine (Lariam®).  Like chloroquine, this drug is slow acting and affects only the parasites in the blood.  It, too, must be taken one to two weeks before exposure and four weeks after.

Unfortunately, Lariam® has gained an unwarranted bad reputation for serious side effects.  You will find this discussed much more thoroughly on our parent web site, The Travel Doctor (www.travdoc.com).   The truth is that its side effect profile is almost identical to chloroquine.  Mefloquine has now been studied extensively and found to be safe enough that its use in pregnancy is recommended by both the World Health Organization and the Centers for Disease Control (in the U.S.)  If your prescribing physician is unsure of this, he or she may contact us and we can supply over a dozen references on the subject.

A new and promising medicine for the prevention of malaria is Malarone®.  This is a combination of two drugs that hit both the blood and the liver forms of the parasite.  Also, it is absorbed rapidly so that it may be started just two days before exposure.  It must be taken daily, however, rather than weekly like chloroquine or mefloquine.  Because it kills all forms of the parasite, it need be taken only seven days after leaving the malaria area.

The two drugs that make up Malarone® have been around for a number of years and have been found to be safe in pregnancy when used individually.  It seems likely that the combination is also safe, and we do prescribe it for our pregnant patients going into high risk areas.  It remains to be proven, however, that the combination is as safe as the ingredients taken separately.

Another drug that has been used for a long time in Africa but is not available in the U.S. is Proguanil®.  Even though safe in pregnancy, this drug, too, has lost its effectiveness as most of the malaria parasites are now resistant to it.

For many years it has been the custom, when one returns from a malaria area, to follow up the preventive medicine with one specifically designed to kill the liver forms.  This is a drug called Primaquine®.  This drug is now also being used for prophylaxis in some areas.  Unfortunately, this medicine can cause life-threatening illness in individuals who lack a certain enzyme needed to metabolize it.  As we cannot test an unborn baby for this enzyme, we recommend against the use of this drug during pregnancy.

Finally, we need to point out that some of the medicines used for the prevention of malaria also use up you body’s supplies of folic acid.  As you may know, folic acid helps to prevent birth defects such as spina bifida.  For that reason, we recommend that pregnant women taking anti-malaria medicine also take at least two milligrams a day of folic acid (the equivalent of two prenatal vitamins.)

When a pregnant woman actually gets malaria the treatment is often simply higher doses of the same drugs mentioned above.  There are also other medicines that are used for treatment but not used for prevention.  They are beyond the scope of this discussion, however.