The Centers for Disease Control disputes a study by the Hudson Institute that the number of Americans infected with the deadly AIDS virus is actually twice the official estimate. In a study released Friday, the Hudson Institute said that up to 3 million Americans are infected by the AIDS virus, an estimate that is far above the calculation by CDC, the primary federal agency monitoring the spread of AIDS. Kevin R. Hopkins, a Hudson mathematician, said his study uses ``realistic'' assumptions not used by the CDC and, as a result, his estimate is closer to the true number of Americans infected by the human immunodeficiency virus which causes AIDS. ``The actual number of people carrying the HIV virus in the United States (at the end of 1987) was not the 900,000 to 1.4 million the official sources estimate, but probably more than twice that number,'' the Hudson report said. ``There were between 2 and 3 million people infected with the AIDS virus, with the most likely total of infections probably close to 2.4 million,'' the report said. Dr. Timothy Dondero, chief of a CDC branch studying the spread of AIDS, quickly disputed the claim, however. In a telephone interview from the CDC headquarters in Atlanta, Dondero said he and his staff reviewed the Hudson study and the methods used and said, ``We do not feel a change in our data is appropriate.'' He said that for the Hudson model to be correct, about 2 percent of the young adult population in the United States would have to be infected with HIV. Yet, he said, ``their figures are inconsistently high within segments of populations for which there are test results.'' Dondero said tests from hospital patients, military recruits and prisoners show HIV infection rates of less than 1 percent _ 0.2 percent to 0.66 percent _ among young adults. Hopkins admitted, ``We're all in a guessing game'' when it comes to estimating the number of people infected with the AIDS virus. Nonetheless, he said he believed the Hudson method is a more realistic model or mathematical estimate of the situation. ``The CDC may be right and we may be wrong,'' Hopkins said. ``Until a national seroprevalence test is conducted, we will not know. ... The main conclusion is that we cannot be complacent about this disease.'' The study by Hudson, a privately financed public policy research organization with headquarters in Indianapolis, used basic CDC data on the number of AIDS cases. But Hopkins said Hudson used different computer models and more sophisticated statistical analysis techniques to estimate the rate of HIV infections. Acquired Immune Deficiency Syndrome, which is caused by the HIV virus, is the end stage of the disease and may not develop for years after a person is infected with the virus. But an infected person can spread the virus before developing AIDS. For this reason, experts are attempting to estimate the rate of infection in order to gauge the future extent of the epidemic. HIV infection is determined by a blood test which identifies antibodies in blood serum. A person with such antibodies is known as seropositive. Hopkins said the Hudson study also estimated that the number of heterosexuals infected by the virus may be three times higher than CDC estimates. The CDC says the chief victims of AIDS, a contagious disease that attacks the body's immune system, have been homosexual men and intravenous drug users. The Hudson study estimates that of the 850,000 to 1.4 million heterosexuals infected with the HIV virus, between 200,000 and 500,000 are those who do not use drugs. ``There are vastly more heterosexuals infected today,'' said Hopkins. ``A breakout into the non-monogamous population is unavoidable.'' The CDC has estimated that the AIDS virus has infected only 80,000 to 165,000 of the non-drug-using heterosexual population. The Hudson report said about 118,000 of the heterosexuals infected are ``mainstream'' population members. ``They are not poor, and they are not IV drug users,'' Hudson said. ``But they are nonetheless carriers of the virus and, through their sexual contacts, can proceed to spread the disease to others of their same class.'' The CDC says that as of Aug. 15, 1988, AIDS had been diagnosed in 70,702 Americans, of whom more than half, or 39,898, have died since June 1, 1981. No one is known to have recovered from AIDS.
