Washington—It was a dirty job and nobody had to do it. But an international team of scientists did it anyway, testing dozens of sewage samples for simian virus 40 (SV40), which in the 1950s and 1960s contaminated millions of doses of polio vaccine. The unsavory task yielded compelling evidence of person-to-person transmission of SV40, evidence that complicates the contentious search for links between the monkey virus and human cancers.
During the past decade, an increasingly acrimonious debate over the issue has split researchers. One camp, mainly pathologists, reports finding the virus in human brain, bone, and lung tumors. The other, mainly epidemiologists, counters that cancer trends discount any link.