Ocular adenovirus (Ad)
infections occur throughout the world in both sporadic and epidemic forms. Accurate laboratory diagnosis of Ad in conjunctival samples is always valuable. The present study was carried out to explore the presence of Ad as a causative agent in clinically suspected
viral conjunctivitis and to compare the performance of conventional virus isolation on cell cultures, direct detection of Ad
antigens in conjunctival cells by a direct fluorescence assay, Ad
DNA detection by polymerase chain reaction (PCR), and specific
IgM measurement by ELISA. Samples included scrapes from conjunctiva. Scrapes were subjected to study by direct immunofluorescence
stain, culture on the Hep-2 cell line, and PCR for Ad detection. Blood samples were also taken and subjected to study for specific anti-Ad
IgM determination. The culture for Ad was positive in 77.8%, direct
antigen detection by fluorescent
stain was positive in 72.2%, PCR was positive in 83.3%, and serology was positive in 88.9% of patients. Both determination of
antibody IgM and PCR correctly identified a larger group of patients compared to cell culture. The most sensitive and specific method for diagnosis of Ad compared to culture was PCR (100%), followed by
IgM detection (92.9%) then direct
antigen detection by fluorescent
stain (85.8%). From this study, we conclude that Ad is a common pathogen in sporadic cases of
conjunctivitis. Screening of adenoviral
conjunctivitis is possible by using specific
IgM due to its high sensitivity. A confirmatory test can be done by PCR for diagnosis of Ad, as it is a rapid, specific, and accurate method.