February 5, 1998
MEDIA CONTACT: Marc Kusinitz
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A Johns Hopkins physician has discovered that a 74-year-old woman originally diagnosed with a blood cell cancer actually had a very mild case of malaria that lasted for as many as 70 years. Once he nailed down the cause of her symptoms, he cured her within three days.
"This appears to be the longest documented case of malaria on record," says Joseph Vinetz, M.D. The Hopkins physician, is now at the Laboratory of Parasitic Diseases at the National Institute of Allergy and Infectious Diseases. A report on the case appears in the Feb. 5 issue of the New England Journal of Medicine. The work was supported by a Physician Postdoctoral Fellow Award from the Howard Hughes Medical Institute.
Using a technique developed by his collaborators at the National Institutes of Health, the group used a novel test to greatly amplify the genetic material of malarial ribosomes -- the tiny protein-making factories in all living things. Using the ribosomal RNA as a guide, he made large quantities of the genes that code for ribosomal RNA, then applied genetic "probes" that sought out and highlighted only genes that occur in one type of malarial parasite known as Plasmodium malariae. He suspected that P. malariae was the culprit, because it is known to cause very mild cases that last for years.
The tale of misdiagnosed malaria began in 1994, when the woman, from the Greek island of Karpathos, was found by a newly minted young medical graduate to have an enlarged spleen during a routine physical in a rural clinic.
Following a diagnosis of lymphoma, the woman began treatment with the anti-cancer drug methotrexate. But she developed severe headaches and a cyclical fever called a quartan fever that occurred every 72 hours. After doctors took her off methotrexate, she recovered from her symptoms but still had an enlarged spleen.
In 1996, the woman came to Baltimore, where her daughter lives, to be examined at Johns Hopkins, infectious disease clinic. There, Vinetz, who was also then working at the Laboratory of Parasitic Diseases, suspected the fever and large spleen might be caused by malaria. In only three days, using five doses of anti-malaria medicine, she was cured.
Vinetz, who has a reputation for tackling difficult research problems, noted that the ancient Greek physician Hippocrates characterized quartan fevers as the mildest fevers. "He was right then and he was right now," Vinetz says of his patient.
Greece has been free of malaria since about 1950, so the patient, who had never left the country until she came to Hopkins, could not have been infected after that year, Vinetz says. "We learned from her sister that she had been infected with malaria when she was about 3 years old, but was thought to have recovered without being treated. She clearly was never really cured until now."
Vinetz is known for his research into rat-borne diseases in Baltimore and his success in scouring alleyways to trap and test rodents for testing.
Other authors of the paper include Jun Li, Thomas F. McCutchan and David C. Kaslow (National Institute of Allergy and Infectious Diseases).