162 SUMMARY OF THE SYMPOSIUM

There was general agreement as to the identity, both clinical and serologic, of pharyngoconjunctival fever and the conjunc­tivitis described by Cockburn under the name "Greeley conjunctivitis." In connec­tion with the suggestion that the so-called "acute follicular conjunctivitis, Beal" might also be identical with pharyngoconjunctival fever, it was recalled that in about one-third of Beal's original cases there was associated upper respiratory disease. Beal made no reference to swimming-pool transmission but later observers have done so. The find­ing of corneal changes in Beal's conjunc­tivitis has not been reported, however, and further work must be done before certain identification of the two diseases can be made. It may be that corneal changes have not been reported because of incomplete slitlamp studies.

EPIDEMIOLOGY

All observers have noted apparent trans­mission of pharyngoconjunctival fever through swimming pools and the highest in­cidence of the disease in the summer months. In discussion, however, Huebner questioned the role of the swimming pool as a trans­mitter of the virus, suggesting rather that swimming tended to traumatize the con­junctiva and thus to favor infection which might otherwise be resisted. This factor, of importance in epidemiology, certainly needs further study, particularly as to the survival of adenovirus in chlorinated and unchlori-nated water. It is noteworthy that no one has reported the occurrence of office epi­demics of pharyngoconjunctival fever. This is in marked contrast to the high incidence of epidemics of epidemic keratoconjuncti­vitis in offices, hospitals, and dispensaries. This difference and the apparent predilection of pharyngoconjunctival fever for children could be explained by the high incidence of antibody to type 3 adenovirus in the general population and the low incidence of antibody to type 8.

ETIOLOGY

While it is clearly established that adeno­virus type 3 is the usual cause of epidemic pharyngoconjunctival fever in children, other types have been encountered in spo­radic cases and family outbreaks. These in­clude types 2, 3, 6, and 7. There was general agreement on the frequent association of certain types of adenovirus with certain dis­ease pictures, as well as on the ability of many types to produce similar pictures.

EPIDEMIC KERATOCONJUNCTIVITIS

CLINICAL PICTURE

There was general agreement among the symposium participants that the main fea­tures of epidemic keratoconjunctivitis con­sisted of (1) an acute follicular or pseudo-membranous conjunctivitis, depending on the severity of the disease, with ade-nopathy; and (2) a keratitis in the form of typical round subepithelial infiltrates, with onset a week or 10 days after the onset of the conjunctivitis, and of long duration. It was agreed that the conjunctival changes are usually much more severe and long lasting than those of pharyngoconjunctival fever; in the latter, for example, pseudomembranes never have been observed. In a paper con­tributed to the symposium by Pillat, epidemic keratoconjunctivitis is clearly differentiated from nummular keratitis, a disease common in Europe but seen rarely, if ever, in the United States.

It was maintained by the University of California group that the corneal changes of epidemic keratoconjunctivitis are readily dis­tinguishable from those of pharyngocon­junctival fever on the following grounds: (1) That the infiltrates of epidemic kerato­conjunctivitis are usually grossly visible while those of pharyngoconjunctival fever are usually visible only with the slitlamp; (2) that the lesions of epidemic keratocon­junctivitis are primarily subepithelial while

SUMMARY OF THE SYMPOSIUM 163

those of pharyngoconjunctival fever are pri­marily epithelial; and (3 ) that when corneal changes occur in pharyngoconjunctival fever they appear at the same time as the conjunc-tival changes, while in epidemic keratocon­junctivitis they are delayed from seven to 10 days. Another difference mentioned was that permanent visual damage is known to have been caused occasionally by epidemic kerato­conjunctivitis but never by pharyngoconjunc­tival fever.

It was agreed that an apparent predilec­tion for children has been shown by pharyn­goconjunctival fever but not by epidemic keratoconjunctivitis. It was further agreed that except in children epidemic keratocon­junctivitis is usually not associated with sys­temic signs of any kind. This is in marked contrast to pharyngoconjunctival fever which is regularly associated with systemic signs. According to Dr. Tanaka's report, however, epidemic keratoconjunctivitis in children has displayed severe systemic signs consisting of high fever, pharyngitis, otitis media, diar­rhea, and vomiting. She refers to Mitsui's experiments in which transmission of ma­terial from this infantile form of the disease produced typical epidemic keratoconjuncti­vitis without such systemic signs in adults. If this transmission experiment had not been made, one would be tempted to believe that the children had had primary herpetic kerato­conjunctivitis which is known to be ac­companied by severe systemic signs and in which the conjunctival signs are similar to those of epidemic keratoconjunctivitis. Some of these children have been shown to have rises in adenovirus type 8 antibody.

Noteworthy in Dr. Tanaka 's report is her statement that, until recently, epidemic keratoconjunctivitis and pharyngoconjuncti­val fever have been confused in Japan. This is reflected particularly in the reports of swimming-pool transmission. Further study is definitely indicated to determine how fre­quently epidemic keratoconjunctivitis spreads through swimming pools.

EPIDEMIOLOGY

All participants in the symposium agreed that epidemic keratoconjunctivitis is highly communicable and pharyngoconjunctival fever somewhat less so. It was brought out that in the United States, swimming-pool transmission has been typical of pharyngo­conjunctival fever but not of epidemic kerato­conjunctivitis, that transmission in hospitals, dispensaries, and private offices has been characteristic of epidemic keratoconjuncti­vitis but unknown with pharyngoconjunctival fever, and that epidemic keratoconjunctivitis has had a marked tendency to spread among professional personnel and pharyngoconjunc­tival fever has not. In the San Francisco Bay area, for example, two sporadic cases of pharyngoconjunctival fever in general physi­cians were studied, but in the course of two major epidemics of the disease, primarily among children, in this same area, no instance of its transmission to ophthalmologists or pe­diatricians was noted in spite of the many hundreds of cases that developed. Epidemic keratoconjunctivitis, on the other hand, spreads with ease through hospitals, and so forth, and has affected numerous ophthal­mologists. That it can be a serious public health problem was re-emphasized by Dr. Leopold's report of a recent hospital epi­demic among postoperative patients.

The role of trauma, particularly industrial trauma, and the connection between foreign-body removal and epidemic keratoconjuncti­vitis, were discussed at length. It was inter­esting that in the Schenectady epidemic Dr. Korns found no significant difference in the opacities or clinical severity of cases ap­parently contracted in the eye clinic after foreign-body removal, and of cases infected subsequently as a result of household con­tacts. In an unpublished study of 32 ophthal­mologists who contracted the disease while treating patients, it was found that all had corneal opacities and that the only conceiv­able trauma had been the simple rubbing of the eyes with the fingers. In a number of