Description:
Changes in the inhibitory properties of human nasal mucus were found to be positively correlated with objective signs of influenza virus infection during the 1950 epidemic. In approximately 80% of the cases the inhibitor index was significantly increased during the acute stage of the disease, and reverted to normal during convalescence.Various respiratory diseases other than epidemic influenza did not cause similar changes.Examination of the inhibitory pattern of nasal mucus is proposed as a presumptive test for influenza virus infection, and its merits are discussed under the headings of reproducibility, specificity and sensitivity.