[The simple method of direct estimation of infectious process in mice and rats aerogenically infected with influenza...

Multiplication of influenza virus in laboratory animals (mice and rats) after aerogenic inoculation was recorded directly (by the agent accumulation in the lungs and trachea) and indirectly (by interferon concentration in the lungs of mice). Thermal inactivation of influenza virus in chick embryo allantoic fluid was observed (by 4.5-6 Ig within 48 h at 37 degrees C). The authors claim that influenza (strain A/Aichi/2/68) infection in the respiratory tract of mice and rats can be experimentally validated by inoculation of chick embryos with 10 and 20% mouse or rat lung homogenate (undiluted or diluted 10-fold) or with 1 and 5% mouse and rat trachea homogenate, respectively, 48 h after aerogenic inoculation of animals, and the virus AID50 be thus determined.