Scientists Seek Data on Cat Leukemia

Three researchers, including two microbiologists at the School of Public Health, have conducted a study on leukemia in cats leading them to recommend that more information be gathered on possible links between leukemia in domestic cats and incidence of the disease in humans.

In a study published in the September 15 issue of Nature, the researchers stated that the percentage of cats in which leukemia virus is present is "considerably higher" than the percentage of cats showing symptoms of leukemia, a cancer of the blood.

The article says past studies on transmission of feline leukemia have regularly overlooked those cats carrying the virus but not displaying the symptoms of leukemia.

The Harvard researchers are Donald T. Francis, research fellow in Pediatrics, and Myron E. Essex, associate professor of Virology. The third scientist involved in the study is W.D. Hardy, Jr. who works with the Memorial Sloan-Kettering Cancer Center in New York City.

Although a virus is known to carry leukemia among cats, no virus carrying leukemia in humans has been isolated.

Possible Link

But the study concludes, "It seems too early to rule out a link between any human disease and exposure to" feline leukemia virus.

Francis said this week the presence of feline leukemia virus in cats widely spread among the human population is still cause for concern. He said in the laboratory scientists handle the virus with the same safety precautions required for recombinant DNA work.

The virus is present in 1 to 2 per cent of the households in Boston, Francis said.

In their study the researchers also note that "as many as half of the domestic cats in free-roaming populations have evidence" of some infection with feline leukemia virus.

The study says feline leukemia virus is the only tumor-producing "RNA virus known to be widely disseminated in man's environment."

RNA is a material which normally transcribes the genetic code on DNA, but in some viruses RNA takes the place of DNA.