You're working in the ED, caring for a 16-year-old girl who presents with a fever and chills. At first, your assessment is routine but after talking with the teenager and her parents, you discover that they recently returned from a vacation visiting family in Africa. You ask yourself: Could it be malaria?
Yes, it could. Testing soon confirms your suspicions, and the teenager is successfully treated. A patient's history tells its tale once again.
Malaria is a serious illness, affecting about 400 million people worldwide and killing 655,000 people annually. In the United States, millions of residents travel to countries where malaria is endemic. Every year, approximately 1,500 patients are diagnosed with malaria in the United States, mostly returning travelers. That's why you need to be aware of malaria and ask the right questions to uncover the clues.
One bite, big trouble
Malaria, which literally means bad air in Italian, was named because it was believed that the air from swamp gases was contaminated. However, in 1880 French physician Charles Laveran discovered that malaria is an infectious disease caused by a parasite that can be transmitted to a human host by a single mosquito bite. This female anopheles mosquito is found mostly in tropical areas of Asia, Africa, and Central and South America, where high humidity and warm temperatures provide a hospitable environment for mosquito larvae to thrive.
Malaria is caused by five species of the Plasmodium parasite. The most common and deadliest type is Plasmodium falciparum. Even with treatment, patients with this type of malaria have a poor prognosis. Other malaria-causing parasites are P. vivax, P. ovale, P. malariae, and P. knowlesi (zoonotic malaria). Although the prognosis is good for these types of malaria, treatment should never be delayed.
Symptoms generally begin 1 to 3 weeks after being bitten by the infected mosquito, but may take up to 8 to 10 months to appear. In some people, dormant parasites become reactivated years after the initial infection.
Who's at risk?
Malaria has made a significant impact on childhood mortality around the world. African children have the highest mortality from malaria due to many environmental factors, such as the extreme heat that lends itself to the inability to control the mosquito population and the lack of potable water in many areas. Age also plays a significant factor in the predisposition for contracting malaria: Children under age 6 months aren't as vulnerable to malaria because they receive acquired immunity from their mother; however, young children between ages 6 months and 5 years are especially vulnerable because their bodies haven't developed a formidable immune system.
Adults and teenagers are also vulnerable when traveling to countries with malaria. Noncompliance with preventive medication has been a serious barrier to eradicating this disease. All teens traveling to malaria-ridden countries must see their pediatrician for the most appropriate antimalarial treatment. Because teens may be noncompliant with the prescribed preventive course, emphasize the importance of antimalarial medications to this population.
Pregnant women should be particularly cautious when traveling to countries where malaria is endemic because pregnancy reduces a woman's resistance to malaria and puts her at risk for severe anemia and even death. For the unborn child, malaria increases the risk of spontaneous abortion, stillbirth, premature delivery, and low birth weight—a leading cause of child mortality.
Initial signs and symptoms of malaria are similar to those caused by influenza. You can assess for signs and symptoms of malaria by using the acronym FANS:
- Aches and pains
- Severe headache.
- For later signs and symptoms, use the acronym CASH:
- Cerebral ischemia
- Hepatomegaly and Hypoglycemia.
Because malaria's incubation period can be lengthy, your patient's history may provide the earliest clues to infection. Taking an accurate history involves carefully listening to your patient. Rather than diving in with a series of questions, give your patient enough time to tell you his or her story. Getting a valid account of what's troubling your patient and how it evolved over time is no easy task. It takes time, practice, patience, understanding, and concentration. An accurate history can sometimes mean the difference between life and death, so be vigilant and patient.
Tests and treatment
Rapid diagnosis of malaria is essential to ensure prompt and appropriate treatment. Tests to diagnose this disease may include microscopic diagnosis through serology and polymerase chain reaction (PCF) testing. Blood films allow for the identification of the parasite species and continue to be the most cost-effective way of diagnosing malaria. PCF tests are the most sensitive, but many countries where malaria is found don't have the economic means to conduct this test.
Treatment of malaria depends on many factors, including disease severity, the species of parasite causing the infection, and the part of the world in which the infection was acquired. The latter characteristics help determine the probability of whether the organism is resistant to certain antimalarial drugs. Additional factors, such as age, weight, and pregnancy status, may limit the options for malaria treatment.
Treatment should be initiated as soon as possible. Patients who have severe P. falciparum malaria or who can't take oral medications should be treated by I.V. infusion.
The prognosis for patients with malaria depends on the geographic location in which the patient was infected. Most patients with uncomplicated malaria exhibit marked improvement within 48 hours after initiation of treatment and are fever-free after 96 hours.
Only P. falciparum infection carries a poor prognosis, with high mortality if left untreated. However, if diagnosed early and treated appropriately, the prognosis improves dramatically.
Prevention is the best policy
Disease transmission can be reduced by preventing mosquito bites with the use of mosquito nets and insect repellents, or with mosquito-control measures such as spraying insecticides and draining standing water.
Prophylactic medications are indicated for people traveling to countries where malaria is endemic. The CDC recommends appropriate prophylaxis for specific countries; however, be aware that certain prophylactic medications can have adverse reactions, especially for children, pregnant women, and those who are immunocompromised.
Antimalarial medications include:
- chloroquine—a good choice for travelers taking long trips, but it can't be used in areas with chloroquine or mefloquine resistance. Exacerbation of psoriasis may occur when taking this drug.
- quinine—an antimalarial drug that also has antipyretic and analgesic properties. It's less expensive than chloroquine but it has more unpleasant adverse reactions, such as constipation, diarrhea, erectile dysfunction, and, in rare cases, pulmonary edema. Also note that this medication has a bitter taste when taken orally and may not be advisable for children.
- atovaquone/proguanil—the drug of choice for last-minute travelers, but it can't be used by pregnant or breastfeeding women. It's more expensive than some of the other drugs and shouldn't be used by people with severe renal impairment.
- mefloquine—a good choice for long trips because it can be taken weekly and for pregnant or breastfeeding women. This drug shouldn't be taken by people with seizure disorders or psychiatric conditions. It's also advised that individuals with cardiac conduction abnormalities shouldn't take this drug.
- doxycycline—this is a daily medication good for last-minute travelers. Those who are pregnant and children under age 8 can't take this medication. Yeast infections are a common adverse reaction, along with sun sensitivity.
Because several antimalarial drugs are available for prophylaxis, the healthcare provider needs to consider what works best for the traveler. Many drugs must be taken for several weeks before they're effective, but choices such as atovaquone/proguanil and doxycycline are available for last-minute travelers. For travelers who will be extending their visit for a long period, chloroquine and mefloquine are better choices.
Teach patients that no antimalarial drug is 100% protective; they must also take personal protective measures to prevent infection. Advise travelers to pack insect repellent, long-sleeve shirts, and long pants, and to make sure they'll be able to sleep in an insecticide-treated bed net.
Even careful and appropriate prophylaxis isn't always effective. In 2010, an undergraduate college student took her antimalarial drugs as prescribed for a trip to Ghana. Five days after her return to the United States, she was tired, feverish, and experiencing headaches; her healthcare provider thought she was exhibiting signs of jet lag, such as nausea and lethargy from the long flight and travel. But to everyone's surprise, she was infected with P. falciparum.
She experienced a high fever and hallucinations, and was admitted to the hospital where the triage nurse reviewed her recent travel history and recognized the telltale signs of malaria: fever, aches and pains, nausea, and headache. She was immediately transferred to the ICU and the medical team worked to determine the best course of treatment. Because her condition was rapidly deteriorating, 24 hours after being admitted, she received exchange blood transfusions and regained consciousness 3 hours later.
This story represents one of many from around the country and reminds us to be vigilant, take a thorough history of the patient's travels, and look out for signs and symptoms of malaria.
Ancient disease, contemporary threat
Malaria was first mentioned over 4,000 years ago. It was totally eradicated in the United States in 1951, but could global warming change this? Our concern now is those patients we see in the United States who've traveled to countries where they contracted malaria.
The good news is that the U.S. government has established an initiative that has eradicated malaria deaths by half in 70% of at-risk populations. The President's Malaria Initiative, which began in 2005, along with the support of the CDC and the U.S. Agency for International Development, is part of a continuing process of aiding areas where malaria is endemic focused on creating an environment in which there's potable drinking water and proper sanitary conditions. The fight to completely eradicate this disease continues, but significant progress and success give us hope for a future with no malaria.
did you know?
The CDC offers consultations for guidance on malaria diagnosis and treatment around the clock. For assistance, call the CDC hotline at 770-488-7788 or 855-856-4713 (toll-free Monday through Friday, 9 a.m. to 5 p.m. EST) or 770-488-7100 (after hours, weekends, and holidays).
Spell out the signs and symptoms of malaria. Use the FANS acronym to identify early signs and symptoms.
- Aches and pains
- Severe headache
Use the CASH acronym to identify later signs and symptoms.
- Cerebral ischemia
- Hepatomegaly and Hypoglycemia