Epidemiology and HIV’s Physical Properties

OCT.19 '95 7:34AM 310-446-1664 LAYNE @ UCLA. [phone]MME 'RY
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these questions may permit us to understand the operations of the worst offenders in the viral
world and devise new strategies of intervention.
Interdisciplinary effort
Surveying the physical properties of HIV will require coordinated efforts that extend far beyond
the confines of biohazard laboratories. Such ambitious efforts must necessarily involve specialized
contributions from epidemiologists, virologists and engineers, with support from governments and
international agencies alike.
Epidemiologists arc using increasingly convenient tools to conduct rapid field surveys of
HIV prevalence and the incidence of new infections. Newer methods use body fluids such as
saliva (instead of blood) to determine whether individuals are HIV infected. This not only reduces
the physical invasiveness of sample collection but often increases the willingness of individuals to
participate in epidemiologic surveys,. These innovations, together with various types of
mathematical models20, permit epidemiologists to track and analyze the IIIV epidemic with
increasing accuracy. The necessary tools arc available for conducting repeated estimates of
person-to-person transmissibility and matching them with the physical properties of IIIV isolates.
Virologists have developed reliable and quantitative assays of HIV's physical properties.
These assays arc rather labor intensive, though, posing a major obstacle to their widespread use.
For instance, measuring HIV's spontaneous decay requires the collection of data around the clock
for several days on end14,21.22. Decay assays must then be analyzed and repeated several times,
amounting to quite a bit of work for just one viral isolate. Conventional biohazard laboratories are
technique rich yet, in certain respects, labor and time poor. To survey larger numbers of HIV
isolates, virologists will have to reach beyond their customary set of tools.
Sophisticated robotic systems, developed by engineers and computer scientists to carry out
intelligent and automated tasks, may serve as one new resource. For example, computer guided
systems are under development for exploring life on the ocean floor and for disposing of forgotten
land mines that maim innocent people. Biologists are already familiar with the more mundane

aspects of this technology via commercial instruments that sequence DNA and analyze microscopic
images. This same technology can also help to revolutionize IIIV research in the biohazard
laboratory. Assays for quantifying HIV's physical properties are composed of elemental
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