Effect of polychlorinated biphenyl on viral infections in mice.

Mice that were fed a diet containing 400, 200 or 100 microgram of polychlorinated biphenyls (PCB) per g were significantly more susceptible to Herpes simplex virus than mice that were fed a PCB-free diet. The mortality of mice that were fed a diet containing 400 or 200 microgram of PCB per g and infected with ectromelia virus was higher than that of normal control mice infected with virus. There was no significant difference in inducibility of interferon by polyinosinic acid-polycytoidylic acid between PCB-fed mice and control mice.