An intracerebral assay procedure in mice for chemical inactivation of rabies virus.

An intracerebral assay technique in mice is described for testing chemical disinfectants acting on the rabies virus. The assay determines whether more than 99% of 10 000 mouse intracerebral LD(50) of virus are inactivated within 1-2(1/2) minutes. By this test, several substances usually available for the treatment of animal bite wounds were found to be effective. They are: 1%-20% soap solutions; 43%-70% alcohol; 1:1000 (0.1%) or lower dilutions of two quaternary ammonium compounds, benzalkonium chloride and cetrimonium bromide; 1:10 000 or lower dilutions of iodine; acetone; and ether.Several other substances tested for possible use in environmental disinfection were also found to be virucidal. They were: 3% caustic soda and commercial preparations of organic phenols, iodine, and a mixture of trisodium phosphate and sodium hypochlorite. No virucidal effect was exerted by a 2% aqueous solution of mercurochrome, a 1:1000 aqueous solution of thiomersal, or 3% formalin (1% formaldehyde).A number of substances that inactivate rabies virus have thus become available for local treatment of bite wounds and for environmental disinfection. The assay procedure described may be useful in testing other disinfectants and chemical substances.