Poliomyelitis: A Possible Relationship of Weather to the Gastrointestinal Route of Infection

Abstract

Lymphocytic choriomeningitis virus (fresh brain from infected mice) administered in tap water via stomach-tube (.2 cc) to mice, results usually in inapparent infections with the development of immunity. This device was employed to study the development of immunity in such inoculated mice by means of intracerebral challenge at varying intervals after intragastric inoculation. The results indicated that groups of mice receiving virus plus commercial mucin (concentration .5% to 2.%) or diluted fresh mucus from the human throat in tap water, delayed the development of immunity of a comparable degree to the control group by about 4 days. Encephalomyocarditis virus administered by the same method is readily absorbed but if it causes any infection, it is almost invariably fatal. When this virus was employed, the groups receiving virus plus mucin survived in significant numbers over the controls. These results suggest that the paucity of poliomyelitis and possibly other similarly transmitted virus infections in winter may be related to the necessarily increased mucous secretions from the upper respiratory tract, occasioned by the breathing of air of low absolute humidity, while its ability to spread in summer is related by the paucity of such secretion.