Malaria in the United States: Highest number of cases in four decades
Malaria in the United States has seen its highest numbers in decades as reported in the Morbidity and Mortality Weekly Report (MMWR) released today by the Centers for Disease Control and Prevention (CDC).
In 2011, the federal health agency received 1,925 reported cases of malaria with an onset of symptoms in 2011 among persons in the United States, including 1,920 cases classified as imported, one laboratory-acquired case, one transfusion-related case, two congenital cases, and one cryptic case.
This number is the highest since 1971, more than 40 years ago, and represents a 14% increase since 2010 when 1,691 cases were reported.
More than two-thirds (69%) of the cases were imported from Africa, and nearly two-thirds (63%) of those were acquired in West Africa. For the first time, India was the country from which the most cases were imported.
According to the data, Plasmodium falciparum, P.vivax, P. malariae, and P. ovale were identified in 49%, 22%, 3%, and 3% of cases, respectively. Twenty-one (1%) patients were infected by two species.
“Malaria isn’t something many doctors see frequently in the United States thanks to successful malaria elimination efforts in the 1940s,” said CDC Director Tom Frieden, M.D, M.P.H. “The increase in malaria cases reminds us that Americans remain vulnerable and must be vigilant against diseases like malaria because our world is so interconnected by travel.”
Malaria is caused by a parasite transmitted by the bite of an infective female Anopheles mosquito. In 2010, it caused an estimated 660,000 deaths and 219 million cases globally. The signs and symptoms of malaria illness are varied, but the majority of patients have fever. Other common symptoms include headache, back pain, chills, increased sweating, muscle pain, nausea, vomiting, diarrhea, and cough. Untreated infections can rapidly progress to coma, kidney failure, respiratory distress, and death.
“Malaria is preventable. In most cases, these illnesses and deaths could have been avoided by taking recommended precautions,” said Laurence Slutsker, M.D., M.P.H., director of CDC’s Division of Parasitic Diseases and Malaria. “We have made great strides in preventing and controlling malaria around the world. However, malaria persists in many areas and the use of appropriate prevention measures by travelers is still very important.”
Travelers to areas with malaria transmission can prevent the disease by taking steps such as use of antimalarial drugs, insect repellent, insecticide-treated bed nets, and protective clothing.
Travelers in the United States should consult a health-care provider prior to international travel to receive needed information, medications, and vaccines.
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