Similarities Between Pig Virus and AIDS Explored in ABC News Commentary
In an "exclusive" commentary piece, ABC News medical producer and author Nicholas Regush explores the possible link between porcine reproductive and respiratory syndrome and AIDS. PRRS, a "horrendous" disease caused by a virus and once known as "swine mystery disease," "blue abortion" and "swine infertility," has infected pigs in an estimated 75% of American herds, Regush writes. The virus primarily attacks pigs' immune systems, leaving the body vulnerable to secondary infections, particularly lung infections. The disease also causes infected pregnant sows to lose up to 10% of their pregnancies, either through spontaneous abortion or stillbirth. Of the surviving piglets, 20% to 30% die from respiratory ailments. Regush writes that PRRS has been a "nightmare" for pig farmers since "at least the mid-1980s." PRRS researcher Scott Dee of the University of Minnesota College of Veterinary Medicine said that the virus is the "most economically devastating swine disease there is," and that the problem is only "getting bigger."
Similarities with AIDS
Although there is no evidence that the disease puts humans at risk, Regush writes that PRRS and AIDS share several similar traits. Research by Monte McCaw of the North Carolina State University's College of Veterinary Medicine has found that both viruses replicate in macrophages, "front-line" immune cells. PRRS primarily reproduces in alveolar macrophages, immune cells in the lungs that when disabled leave pigs susceptible to opportunistic lung infections such as pneumonia, a common secondary infection in AIDS patients. In addition, once attacked by PRRS, lymphocytes, "[k]ey" white blood cells, go through "some of the same changes that occur in AIDS." McCaw adds that one "obvious difference" between the two diseases in terms of development is that PRRS-infected infant pigs can sometimes survive the "onslaught" of lung infections and "thriv[e]," unlike infant humans. Through his research, Dees discovered that PRRS can be transmitted from one pig to another through the "repetitive use" of needles during vaccination, as well as through blood, semen and saliva. Dees also learned that PRRS can "hide out" in lymph nodes, a claim also made about HIV.
Could There Be a Connection?
Beth Lautner, vice president of science and technology at the National Pork Producers Council, said PRRS is "complex" and acknowledged that some symptoms are "AIDS-like," but cautioned against further speculation because she fears "some people will jump to the wrong conclusion, that pigs gave AIDS to humans" (Regush, ABCNews.com, 3/30). However, a possible link between pig viruses and AIDS was proposed in 1986 when Harvard researcher Jane Teas published a letter in the Lancet, proposing a possible link between "African Swine Fever Virus" and AIDS. Teas and Boston University scientist John Beldekas reported that they had "found evidence of ASFV" in European AIDS patients. According to a summary in the book " America's Biggest Cover-Up," after the letter was published, however, a group of U.S. Department of Agriculture researchers stopped the trials investigating the link between the two diseases. Shortly following the cessation of the trials, two research groups that had corresponded with Teas and Beldekas "almost simultaneous[ly]" discovered a new virus, human herpes virus 6, in AIDS patients. The researchers reported that HHV-6 and ASFV are "very similar" viruses; they are the same size, they both attack the immune system and they both can mutate easily. At the time, a major argument against Teas and Beldakas' theory that ASFV was linked to AIDS was that pigs in the United States were not ill, but researchers now know that PRRS is present in much of the American swine population. The PRRS virus and HHV-6 have never been compared (Ostrom, "America's Biggest Cover-Up").
More Research Needed
All three researchers mentioned in Regush's article agree on the need for further research for "better understanding and controlling" of PRRS (ABCNews.com, 3/30). Charles Ortleb, a novelist and former editor of the New York Native, a newspaper that served the city's gay and lesbian community and that investigated a link between pigs and AIDS in the 1980s, said that although he does not believe that HIV causes AIDS, he does believe that HHV-6 causes AIDS and is "swine in origin." Ortleb believes that HHV-6, not HIV, is the "most important virus" in the development of AIDS. Although HHV-6 investigation "has a lot of catching up to do" with HIV research, he said it will "eventually win the debate with HIV" and be declared the root of AIDS. In his first novel, "Iron Peter," Ortleb included a section on the possible link between pigs and AIDS. He said that more research should be done, not only on HHV-6, but on pigs in general because they manifest diseases with similar traits to AIDS. In his new book, "The Closing Argument," which he calls "an essay about AIDS and a simultaneous dramatic interpretation of its threat to the African-American community," Ortleb questions the causes of AIDS using the closing argument of a fictional controversial court case as a platform. Ortleb said that more research is needed into "all possible causes" of AIDS before a definitive verdict can be rendered on AIDS, its cause and the best course of treatment (Schomann, Kaiser Daily HIV/AIDS Report, 3/30). To view the full text of "The Closing Argument" go to http://www.thegaycartoonsite.com/TheClosingArgument.pdf