Use of polymerase chain reaction as a sensitive method for detection of human adenovirus during epidemic keratokonjunctivitis
R. Kiel1, P. Schnitzler2, K. Rohrschneider1, S. Ebner1, F. von Weyhe1, F. E. Kruse1
The initial phase of epidemic keratoconjunctivitis (EKC) is characterized by unspecific symptoms which often preclude a secure diagnosis. Aim of this study was to evaluate the use of polymerase chain reaction (PCR) for the initial diagnosis of EKC
Methods: For PCR, conjunctive swabs were performed from the palpebral conjunctiva of patients with presumed EKC. Samples were taken on the day of the initial visit and 7, 14 and 21 days there after. To detect human adenovirus a 800 bp sequence of hexon gene was amplified by the use of PCR. Consecutive swabs were also tested with cell culture and immunfluorescence. The diagnosis of EKC was confirmed when at least one of the tests showed positive results.
Results: 65 patients with clinical diagnosis EKC were examined. 33 (51%) showed subepithelial corneal infiltrates in the follow-up, which were visible around day 13 (range 8.-21. day). In 94 % of patients with subepithelial infiltrates an acute infection with adenovirus was confirmed. Examination of the house keeping gene showed insufficient sample in one patient. In comparison with the cell culture (50%) and antigen detection (53%) PCR examinations (94%) showed the highest sensitivity for human adenovirus detection.
Summary: PCR is a sensitive, specific and rapid tool for the confirmation of EKC caused by adenovirus in swab samples. An improvement of the sensitivity could be achieved by improvement of the technique by which the samples are obtained.
Augenklinik1 und Abt. Virologie2, Hygiene Institut der Universität Heidelberg, INF 400, D-69120 Heidelberg.
1Universitäts-Augenklinik Heidelberg, INF 400, 69120 Heidelberg und 2Klinik Dardenne, Friedrich-Ebert-Str.23-25, 53177 Bonn