Three years' experience in attempting to isolate viruses from conjunctival specimens from the autochthonous population of Eastern Saudi Arabia is described. From several thousand examinations, material for virus isolation was obtained from approximately 1000 individuals. Nine hundred forty-eight (948) specimens were tested in tissue culture and yielded two Coxsackie viruses, B1 and B2 and 65 adenovirus strains which fell into at least 13 different types. Of the 64 typed strains, the most common types were types 3, 8, 17 and strain BAR-2. Type 4 was isolated only three times and type 7 twice.
During the course of this study, several types of adenoviruses were isolated in Saudi Arabia which had not been encountered elsewhere. The new viruses are types 15, 16 and 17,9 and the strains designated 587, 931, 1645 and 2711, which have not been assigned type numbers as yet.
There was a marked seasonal incidence in the isolations of adenoviruses; 92 per cent of the 65 strains being obtained during the summer months of April through September. Only five strains were isolated from October through March, although more than half the specimens were obtained during this period. Despite the fact that over half the attempted isolations were in the age group 3 years and over, 81 per cent of the isolations came from children under 2 and 90 per cent from those under 3 years. No clear cut wide-spread epidemics due to types 3, 4 and 7, were encountered in this study of the agents recoverable from the conjunctivae of Saudi Arabs. Brief consideration is given to the possible role of adenovirus infection in the clinical complex which is diagnosed as trachoma in Eastern Saudi Arabia.