ORIGIN OF AIDS: Researchers Link Disease to 1930s
Scientists have pinpointed the beginning of the spread of AIDS to central west Africa in the 1930s -- decades earlier than other experts had determined, the Chicago Tribune reports. Dr. Beatrice Hahn of the University of Alabama-Birmingham included the finding -- from a still-unpublished study by researchers at Northwestern University, Alabama and the Los Alamos National Laboratory in New Mexico -- in her HIV research review article in the journal Science. The early date is "especially significant because the earliest known HIV infection was discovered in a stored blood plasma sample dating back to 1959," the Tribune reports. Researchers, however, cautioned that the 1930 estimate has a 20-year margin of error. Still, pinpointing HIV's origin will help vaccine makers forecast the virus' evolution and determine whether any additional epidemics might come from African primates. In the last year, findings have indicated that as many as 27 different primate species in Africa are naturally infected with simian viruses related to HIV. Dr. Steven Wolinsky, a researcher at Northwestern University Medical School who specializes in HIV evolution, said that although it might be impossible to determine the exact place or time when HIV first infected people, "narrowing the window of cross-species infection could bring insights into how the virus quietly evolved before it became an explosive epidemic in the 1980s." Wolinsky added, "Chances are that this was in the population for a long time, and then something made it really take hold."
Studying the Human-Chimp Connection
Since last year, when a team led by Hahn concluded that the virus was likely transmitted to humans from chimpanzees in the rainforests of West Africa, researchers have had trouble theorizing an historical account of the human-chimp contact. Now, some researchers have proposed a theory. When the French colonial government ruled West Africa in the early 20th Century, it used forced labor for large construction projects, including the Congo-Ocean railway, which was built between 1921 and 1934. During that railroad's construction, more than 20,000 workers are thought to have died, mostly because of malnutrition. Lack of food might have driven others to "desperate measures." Bruce Fetter, a social historian of colonial Africa at the University of Wisconsin-Milwaukee, said, "If they were underfed, they might have gone off and trapped animals in the forest because they were hungry. It was something they might not otherwise do." Researchers have pointed specifically to this railroad construction because of its location -- just across the Congo river from the city of Kinshasa, where the 1959 HIV-positive plasma sample was taken. Researchers also point to early 20th Century as a time when chimps were increasingly taken into captivity for use in zoos or circuses. Jim Moore, an anthropologist at the University of California-San Diego, said, "Zoos really took off in (the United States) around the turn of the century. It probably would have been the first time people were trying to capture chimps alive. And you're a lot more likely to get bitten by a live one." Additionally, some researchers have pointed to unsanitary vaccination campaigns in the early 1900s as opportunities for HIV to have been spread.
New Date Breeds Dissent
Other scientists disagreed with the 1930 date. Preston Marx, a virologist at the Tulane University primate center in New Orleans, said the virus' spread probably occurred closer to 1950, when vaccination programs in Africa saw a sharp increase. Similarly, Edward Hooper, author of The River, a book that connects the spread of AIDS to polio vaccination programs in Africa, said that "it's unlikely HIV would have left no traces between an emergence around 1930 and the first known case in 1959." Hooper added that such an occurrence would require the virus to be "hidden in a village somewhere, cooking slowly and silently." Defending the findings that she reported, Hahn said the 1930 estimate "tends to weaken" Hooper's theory because polio vaccinations started in central Africa around 1957 (Manier, Chicago Tribune, 1/31).