Antiviral activity in urine is attributable to ammonium salts

Urine exhibits antiviral activity in tissue culture against a number of viruses. We have characterized that antiviral activity in comparison with a number of antiviral substances which are known to be present in body fluids. We show here that the antiviral activity in urine cannot be due to the presence of contact-blocking virus inhibitor (CVI), or interferon. The findings support the conclusion that most of the antiviral activity in urine is qualitatively and quantitavely attributable to its content of ammonium salts.