930 DISEASES CAUSED BY FILTRABLE VIRUS 



days, and no case should be returned to ordinary life as long as 

 middle ear disease or any other open suppurative lesion persists. 



MUMPS 



Mumps is one of the most difficult infections to circumscribe 

 when once it has started in a crowded community. Mumps epidemics 

 in the army spread with speed and without yielding to ordinary 

 preventive measures. Ordinarily it is chiefly a disease of children 

 among whom it spreads in schools and institutions. 



Prevention is particularly difficult because the susceptibility 

 among children is practically universal and since exposure need not 

 be very close to give rise to infection. Also, difficulties are added 

 to by the fact that it may be passed on to others during the incuba- 

 tion time before actual symptoms have appeared. Our impression 

 from army experience is that there, may be carriers. 



Infection is direct, by the secretions of the mouth, nose and 

 throat, and it enters the new victim probably by the same route. 

 The incubation time after infection may be anywhere from five 

 days to three weeks. Martha Wollstein 22 has brought forward 

 evidence which indicates that the saliva and secretions from mumps 

 cases contain a filtrable virus. With such filtered secretions she 

 obtained pathological changes in the testicles and parotid glands of 

 cats which simulated human mumps. The most serious complications 

 are those occurring in the testes which in male adults may have 

 serious consequences. 



One attack usually protects, though not always. 



Prevention depends upon early recognition and isolation for two 

 weeks after all symptoms have disappeared. 



When the disease spreads in a group, it should be remembered 

 that it may be infectious for some time before symptoms occur and 

 that the incubation time may last as long as three weeks. Protective 

 measures, exclusion of contacts from school, and closure of schools 

 if found necessary, must cover this period. 



22 Wollstein, M., Jour. Exper. Med., 23, 1916, 265. 



