Travel Guard® Health Advisory

What is Malaria?

Malaria is a potentially fatal tropical disease caused by a parasite known as Plasmodium. It spreads through the bite of an infected female Anopheles mosquito. These mosquitoes are most active between 9 p.m. and 5 a.m. There are four parasite species that cause malaria in humans:

• Plasmodium falciparum
• Plasmodium vivax
• Plasmodium malariae
• Plasmodium ovale

Plasmodium falciparum and Plasmodium vivax are the most common, while Plasmodium falciparum is the most deadly. In recent years, some human cases of malaria have also occurred with Plasmodium knowlesi–a speciesthat causes malaria among monkeys and occurs in certain forested areas of Southeast Asia.

The parasites develop in the intestine and salivary glands of the mosquito and can be passed onto humans the next time the mosquito bites. In humans, the parasite travels to the liver via the blood and then out into the bloodstream again, where it invades the red blood corpuscles (the cells that carry oxygen in the blood). Malaria can also be spread through blood transfusions, and the use of infected needles.

Symptoms

Typically 7 to 30 days pass between being infected and the onset of the disease. Symptoms include:

• Fever and shivering. The attack begins with fever, with the temperature rising as high as 40ºC (104 ºF) and falling again over a period of several hours.
• Feeling unwell
• Headaches
• Diarrhea, nausea and vomiting

Once their temperature drops, the patient often sweats profusely and feels much better. Further symptoms may occur within a day or two. The symptoms diminish over the course of several weeks if the patient develops the ability to resist the malaria parasite. If proper treatment is given, the fever and parasites may disappear within a few days. If a case develops into severe malaria, the classic symptoms may be coupled with increased drowsiness and other complications including:

• Low blood pressure (hypotension)
• Kidney failure
• Possible hemorrhage (bleeding)
• Effects on the liver (e.g. infectious jaundice)
• Shock and coma may also develop, and the condition may prove fatal
• Cerebral Malaria
• Anemia

Prevention of Malaria

Prevention requires A, B, C and D:

• Awareness of risk
• Bite avoidance
• Chemoprophylaxis (taking preventive medicines if you are traveling to or living in a malaria region)
• Diagnosis made promptly with early treatment of an infected case

Antiviral drugs are prescription medicines (pills, liquids or inhaled powders) and are not available for purchase over‐ the‐counter. These drugs should be used within the first two days of symptoms to treat people who are very sick (such as those who are hospitalized) or people with flu symptoms with an increased risk of severe flu illness (i.e., pregnant women, young children, people 65 and older and people with certain chronic health conditions).

Treatment

Early diagnosis and treatment of malaria reduces the disease and prevents deaths. It also contributes to reducing malaria transmission. WHO also recommends that all cases of suspected malaria be confirmed using parasite-based diagnostic testing (either microscopy or rapid diagnostic test) before administering treatment. Results of parasitological confirmation can be available in 15 minutes or less. Treatment solely on the basis of symptoms should only be considered when a parasitological diagnosis is not possible.

Preventive Medicines Include:

Mefloquine

• Recommended by the CDC as useful for last minute travelers since the drug starts working one to two days before travel
• Not recommended for people with certain cardiac conditions

Doxycycline

• Recommended by the CDC as good for last-minute travelers since the drug is started one to two days before travel
• Cannot be used by persons younger than 8 years old

Atovaquone/ proguanil (Malarone)

• Well-tolerated; side effects uncommon
• Cannot be taken by pregnant women or people with severe renal impairment

Chloroquine

• Recommended by the CDC as a good choice for long trips because it is taken weekly
• May exacerbate psoriasis

References

• http://www.who.int/malaria/en/
• https://www.cdc.gov/malaria/
• https://malariaworld.org/blog/2017-malaria-avalanche