Emory Report

February 16, 1998

 Volume 50, No. 21

Nahmias' 14-year-old HIV
finding gains peer acceptance

The virtues of patience and persistence in scientific endeavor have never been more evident than in the case of Andre Nahmias, director of the Division of Pediatric Infectious Diseases, Epidemiology and Immunology at the School of Medicine. In 1984 Nahmias determined that a single blood plasma sample collected by scientists in Africa 38 years ago contained the HIV-1 virus. That sample has now been authenticated by molecular testing to be the earliest known case of HIV-1 infection in the world. This finding pushes the historical beginnings of AIDS in humans back to the late 1940s or 1950s-at least 10 years earlier than scientists previously believed.

Nahmias is co-author of an article in the Feb. 5 issue of Nature with David Ho, a physician-researcher at New York's Aaron Diamond AIDS Research Center. He also collaborated on a study describing the findings presented at the nation's largest annual AIDS research meeting, held last week in Chicago.

The blood sample is from an adult Bantu male who died in Leopoldville, Belgian Congo (Kinshasa in the present-day Democratic Republic of Congo) in 1959. It was part of a group of more than 2,000 blood samples collected by U.S. scientists studying genetic blood factors among different African populations. In 1984 Nahmias, who was the Emory scientist responsible for first identifying the virus that causes genital herpes, was studying genetic differences in herpes. He found out about the African samples, which had been sent to Atlanta.

He decided to examine the samples using then-new serological tests developed to identify the AIDS virus. After evaluating every sample, he found just one positive for HIV-1, and his results were confirmed at Duke, Harvard and the CDC.

Nahmias reported his findings at the "AIDS in Africa" conference in 1985 and again in a report in the British medical journal The Lancet in 1986. "At the time, there were a lot of nonbelievers who denied the importance of the sample, and political factors contributed to people ignoring the work or finding fault in the methodologies, although five separate tests were used," Nahmias recalled.

But the 1989 discovery of polymerase chain reaction (PCR), a very sensitive method of detecting the presence of small amounts of DNA, helped prove Nahmias' hypothesis. When Nahmias shared his sample with Ho and his colleagues, they found the sample to be closely related to viral subtypes in a certain group of HIV-1 viruses that are predominant in today's global epidemic. The sample predates the virus' mutation into the many varieties existent today and strongly suggests HIV spread from a single transmission to humans from animals in the late 1940s or 1950s.

The new information will undoubtedly lead to further research about the origins of HIV in humans and about how the virus mutated and spread so rapidly from Africa to Haiti and to the United States, Europe and beyond. Knowledge about how the virus evolved should help scientists as they search for effective vaccines for AIDS and try to identify the animal source of viral transmission to humans.

The HIV discovery is not the first time Nahmias' scientific patience has been tested. Although he first identified the genital herpes virus in 1965, his team had to wait 17 years for technology to catch up and allow them to develop the first serological test that distinguishes between non-genital and genital herpes antibodies. His application of this new test in the past 15 years has helped researchers gain much understanding about the prevalence of herpes virus in the United States and 25 other countries.

The test was used to establish a link between genital herpes and HIV, and Nahmias helped the CDC determine that a group of gay men in San Francisco who had been infected with genital herpes developed HIV more readily.

"What we learned from the African blood sample study is that it took about 30 years for the {AIDS} epidemic, mostly heterosexually spread, to take off to high rates in Zaire. The 1989-1994 National Health Survey indicates that young white Americans are acquiring a primarily heterosexually transmitted infection-genital herpes-in growing numbers, and recent CDC data indicate increasing rates of heterosexually transmitted HIV infections in young Americans. These old and new findings, including the more recent-and primarily heterosexually transmitted-HIV-1 epidemic in Southeast Asia, provide another call for greater education and concern in preventing this form of transmission in our country."

Last September Nahmias received the prestigious Bristol Award from the Infectious Diseases Society of America in recognition of his career contributions in infectious diseases. He still saves thousands of samples, including isolates of herpes simplex virus from all body sites, because, as he explained, "We don't yet know what questions the future may bring that may be answered by these frozen samples."

-Holly Korschun

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