Modification of otitis media in chinchillas rechallenged with nontypable Haemophilus influenzae and serological response to outer membrane antigens.

Otitis media was produced in chinchillas by right-sided intrabullar inoculation with nontypable Haemophilus influenzae, and susceptibility to reinfection was investigated. After resolution of initial right-sided infection, animals underwent ipsilateral or contralateral intrabullar rechallenge with the same strain. After ipsilateral rechallenge right ears were completely protected against reinfection; previously uninfected left ears were similarly protected on contralateral rechallenge. Previously infected ears remained fully susceptible to infection with a heterologous strain of nontypable H. influenzae. Using an enzyme-linked immunosorbent assay, we measured the serological response to outer membrane protein and lipopolysaccharide antigens during initial infection. A greater than or equal to 10-fold rise in titer of antibody to homologous outer membrane proteins was observed in all 11 animals tested. Most animals exhibited a minimal serological response to lipopolysaccharide. Thus experimental otitis media due to nontypable H. influenzae induces strain-specific protective immunity and a concomitant serological response to outer membrane proteins.

Management of communicable diseases in day care centers.

In this article, we have focused on specific communicable diseases in day care centers, and have provided guidelines for prevention and control of outbreaks, and management of contacts. Given the growing number of working mothers in the United States and the related increase in child care outside the home, it is inevitable that physicians caring for children will encounter illnesses acquired in the day care setting. Only by understanding the unique epidemiologic characteristics of day care centers will practitioners be able to recognize potential outbreaks and help prevent the further spread of communicable diseases.