This is the solution to the diagnostic mystery I posted Monday: http://www.boston.com/lifestyle/health/mysteries/2013/10/turning_yellow.html?comments=all
Dr. Edward Ryan, the director of Tropical Medicine at Massachusetts General Hospital, led the infectious disease team that consulted on Jean's case. After drawing his blood and preparing a smear on a glass slide, the team saw swarms of parasites had infected almost a third of his red blood cells (see figure in prior post).
Jean was diagnosed with severe malaria, caused by the parasite Plasmodium falciparum and spread by mosquitoes in many tropical countries. This disease moves rapidly, and if diagnosed late, can be fatal.
Several clues point to his diagnosis. The first is a high and recurrent fever. A patient returning from a malaria zone with fever should always be evaluated for this disease. American physicians frequently neglect to do so, especially since the disease may not announce itself until weeks after a person comes home from vacation.
The yellow color of the skin, called jaundice, occurs when the parasites destroy red blood cells and release a molecule called bilirubin, a bright yellow pigment that seeps from the circulation into the skin. The malaria parasite also causes tiny clots to form throughout the blood vessels; one by one, the organs may be starved of oxygen. The kidneys can fail. The brain, as it receives less oxygen, causes people to become drowsy and lethargic. The same tiny clots can shear platelets as they try to move through the circulation, causing their counts to fall, as they did in Jean.
Malaria kills 1 million people every year worldwide; the incidence of the disease in the United States is highest among travelers returning from abroad. Half of these travelers, like Jean, are visiting family and friends in a country they consider home. Although Jean's parents might have some immunity to the disease, their children may not. "This is not a case of bad parenting," Dr. Ryan says. "Instead, it's simply not on the radar screen for families or even primary care physicians. Families need to take appropriate precautions when traveling to malaria zones, which may include using mosquito netting, DEET-containing insect repellants, and medications."
The federal Centers for Disease Control and Prevention's website (http://wwwnc.cdc.gov/travel/destinations/list.htm) lists the necessary precautions people should consider before traveling to a particular country, even if it's a country that the family considers home.
Given Jean's progressive symptoms, the team had little time to waste. The doctors started Jean on intravenous quinidine, a drug that poisons the malaria parasite. They also called the CDC in Atlanta to ask for the most potent malaria medicine available in the United States - artemisinin. Unfortunately, because the Food and Drug Administration hasn't approved this drug, hospitals don't carry it. Instead, artemesinin is made by the military at Walter Reed National Military Medical Center and stockpiled by the CDC throughout the country.
In Jean's case, a shipment of the medicine was flown from JFK airport to Boston, reaching Jean when he most needed it. "In general, we try to get artemisinin to patients who need it within seven hours of the telephone call," says Paul Arguin, chief of the Domestic Response Unit in CDC's Malaria Branch. That's commendable for a drug that no company makes, that no hospital stocks, and that the FDA has not yet approved.
After receiving artemisinin, Jean's blood was cleared of the parasite. Had recognition or treatment of the disease been delayed longer, the outcome could have been far worse.
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