Health & Safefy » Malaria

Malaria is caused by a parasitic infection transmitted to humans by a bite from the Anopheles mosquito, which unlike the Aedes aegypti mosquito, prefers to hunt at night. Malaria is common in the following states in Mexico: Campeche, Chiapas, Guerrero, Michoacan, Nayarit, Oaxaca, Quintana Roo, Sinaloa, and Tabasco. In addition, risk exists in the northern mountainous areas of Jalisco State. Fortunately, there is very little risk in major resort areas and along the United States-Mexico border. The vast majority of malaria cases in Mexico are due to infection by the P. vivax parasite. A bite rarely results in life-threatening Malaria. Malaria season is most common during or shortly after the rainy season.

Symptoms: Those ill with malaria experience symptoms when parasites, which have infected the liver, are intermittently released into the blood. This explains the on again/off again nature of symptoms, which include fevers (as high as 104° F), chills, headache, muscle aches and weakness, abdominal pain, vomiting, and diarrhea. A patient may experience a drenching sweat as the fever breaks. Symptoms often repeat every 48–72 hours or sooner. With rare exception, the pre-symptom, incubation period for malaria is typically seven days after being bitten. So, if you develop high fevers and you weren't in a high-risk area for at least the previous week, you likely don't have malaria.

Prevention: In addition to prevention by using DEET-containing insect repellents, you can prevent or control malaria infections with one of several drugs. Chloroquine (Aralen) is the drug we recommend for people traveling to at-risk areas in Mexico. For people who cannot take chloroquine, we recommend mefloquine (Lariam). It is important to note that preventive drugs do not provide 100 percent protection; you may still get malaria even while taking these medications. Also, a high number of cases of malaria have been attributed to the irregular use of preventive medications. Always take your medications; don't skip or put off doses!

Treatment: If you do develop fever and it has been seven days since you were in a malaria-risk zone, it is very important to initiate drug therapy within the first 24 hours. If you are traveling to remote regions lacking adequate health-care facilities, be prepared to initiate self-treatment until you can get a formal medical evaluation. The drugs you take for treatment will depend on the preventive drugs you took. Recommended regimens, reproduced from the World Health Organization (WHO), are listed in MedToGo's pharmaceutical guide.



Author; Robert H. Page, MD and Curtis P. Page, MD are authors of the MEXICO: Health and Safety Travel Guide and the Healthy Traveler Regional Series.