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This what appeared in “sordid ..part 2”. One of the biggest publicity coups for the CDC’s war on AIDS was in the myth of the Florida woman who supposedly caught AIDS from her dentist. The story began in late 1986 with David Acer, a Florida dentist who discovered he was HIV-positive. He apparently frequented the homosexual bathhouse scene, including the poppers and other drugs so pervasive in that environment. Within another year, Acer had developed Kaposi’s sarcoma, his health slowly degenerating.

Meanwhile, Acer had pulled two teeth from college student Kimberly Bergalis, a business major. By 1989, more than a year later, Bergalis developed a mild yeast infection, a condition common to many women. A few months later she contracted a brief pneumonia, in the wake of emotional stress in studying for the state actuarial exam. Neither of these symptoms was serious or permanent, and both affect large numbers of people. But Bergalis was nevertheless tested for HIV, and turned out to be positive.

She denied any intravenous drug use or blood transfusions, and insisted she was a virgin. Because she seemed not to have caught HIV through any of the standard risks, her case attracted CDC attention within three months. The EIS network may have played a role, since several of its members worked in the Florida health department. Eager to find an excuse for imposing strict new regulations on the medical profession, the CDC sent in a team of investigators to find a plausible source of her infection. They soon came across David Acer, her dentist. Although Acer appeared to be conscientious and no route of HIV transmission could be found, the CDC investigators jumped to the conclusion that Bergalis must have caught the virus from the dentist. To reinforce this idea, a group of CDC researchers that included EIS members Harold Jaffe, Ruth Berkelman, and Carol Ciesielski compared the genetic sequences of HIV from dentist and patient, pronouncing them the same. The CDC experts even tested over a thousand of Acer’s clients, finding four others with HIV but no obvious risk factors.

The insurance company saw things differently, insisting that its own analysis showed that Bergalis received HIV from some other source. But the CDC ignored this evidence, rushing to publicize its own conclusions. The news leapt straight to the front pages and prime time television news broadcasts, terrifying the nation and swinging public opinion behind Congressional legislation to impose new CDC controls on medical workers. Ultimately the bill failed, though only after intense pressure from the medical profession.

In the meantime, an independent study out of Florida State University has concluded that Bergalis did not get HIV from her dentist after all. Other scientists have now pointed out that among Acer’s patients, five HIV positives add up to the same percentage as HIV positives in the general population — implying that these patients also caught the virus elsewhere. Where could Bergalis have contracted HIV? Apparently her mother has never been tested, opening the possibility that Kimberly may have carried the virus from birth — for twenty-three years — before she died.

Bergalis, moreover, did not die of HIV infection. She and her dentist suffered radically different diseases; he had Kaposi’s sarcoma, a cancer, while she first had a temporary yeast infection. Then Bergalis was prescribed the toxic and controversial AIDS drug AZT, a failed cancer chemotherapy that causes anemia, bone marrow loss, muscle wasting — and destruction of the immune system. Months of AZT treatment ravaged her body, leaving her open to opportunistic infections and forcing her into a wheelchair until her death.”
Myth? A noninfectous disease she caught from her mother 23 years before?
1) Law: A case of intentional HIV injection? In a highly publicized case in Lafayette, Louisiana in 1998, a woman claimed that her ex-lover (a physician) deliberately injected her with HIV-tainted blood (HIV is the virus that causes AIDS). She did not know whose tainted blood it was nor did she realize she had been injected with blood until she became sick with viral infections months later. Records showed that the physician had indeed drawn blood from an HIV+ patient on the day she was injected. There were no records of her injection and no witnesses. So how could her story be tested?
Evolutionary trees provide the best scientific evidence in a case like this. HIV picks up mutations very fast ñ even within a single individual. If one person gives the virus to another, there are few differences between the virus in the donor and the virus in the recipient. As the virus goes from person to person, it keeps changing and gets more and more different over time. Thus, the HIV sequences in two individuals who got the virus from two different people will be very different. Thus, if the woman’s story were true, her virus should be very similar to the virus in the person whose blood was drawn but should be very different from viruses taken from other people in Lafayette. That was exactly what the evolutionary trees showed; her virus appeared to have come from the patient’s virus but was unlike the virus taken from other people in town. Since there was no way to explain how she would have gotten THAT patient’s virus on her own, the evolutionary analysis supported her story. (Incidentally, this case was the first use of phylogenetics in U.S. criminal court.)

2) Did a Florida dentist with AIDS transmit the virus to his patients?
Kimberly Bergalis made national headlines and testified in congressional hearings as a heterosexual young woman who got AIDS. The only known potential source of her virus was her dentist, and over half a dozen of his other patients also had the disease. In this case, the initial evidence implicating the dentist was merely the statistical association of several people with AIDS whose only known exposure was the dentist. Again, evolutionary trees were created to see if the patients’ viruses appeared to have descended from the dentist virus. The dentist virus did appear to be closely related to many of the patient viruses, as if it was the source. However, two patients appeared to have gotten their virus elsewhere, and those two patients were the only two infected patients with other risk factors. So again, the evolutionary analysis provided a critical means of understanding HIV transmission. (see next box)
3) Other cases. Evolutionary trees have been used in many other cases of infectious disease transmission. They were used to identify deer mice as the source of hantavirus infections in the Four-Corners area in the early 1990s. They are routinely used to determine the source of rabies viruses in human cases, and they led to the discovery of a case in which rabies virus took at least 7 years to kill a person (a length of time far in excess of anything known previously). And trees have been used to determine whether recent cases of polio in North America were relict strains from the New World, were vaccine strains, or were introduced from Asia.
(From http://www.indiana.edu/~ensiweb/pap.apld.html, Applied Evolution: Technology for the 21st Century, James Bull, PhD, University of Texas at Austin, For the Symposium Presented, by the Society for the Study of Evolution, “Building the Web of Life: Evolution in Action” NABT Ft. Worth, 10/99)
Hillis, D. M., and J. P. Huelsenbeck. 1994. Support for dental HIV transmission. Nature 369:24-25.
SIR — On the basis of a phylogenetic analysis of HIV sequences, Ou et al. concluded that a Florida dentist infected five of his eight known HIV-1 seropositive patients. These authors used bootstrap resampling to test the reliability of their finding and found that the HIV sequences from the dentist and infected patients formed a monophyletic group in 79% of the replicates in parsimony analysis. DeBry et al. in Scientific Correspondence questioned the conclusion of dental transmission, however, because a bootstrap analysis (based on threshold parsimony) of independently sequenced HIV variants clustered only one of the patient sequences with a dental sequence in the majority-rule consensus tree. DeBry et al. concluded that their analyses “...show that the available data are consistent with both the dental transmission hypothesis and the null hypothesis (the patients were independently infected from the local community) and do not distinguish between the two.” But both studies used an analysis of the bootstrap results that may not be the most appropriate method for this case. We have reanalysed the two datasets, as well as sequences from new patients and new local controls, and find strong support for trees consistent with HIV transmission between the dentist and six of ten of his seropositive patients.”
carrot.mcb.uconn.edu/mcb372/class2-02.htm