Related Experiment Videos
Polymerase chain reaction for rapid detection of ocular adenovirus infection
D J Morris1, A S Bailey, R J Cooper
1Clinical Virology Laboratory, University of Manchester, England.
Abstract:
Adenoviruses are associated with endemic and epidemic acute conjunctivitis, large nosocomial outbreaks reflecting virus transmission on unwashed hands or inadequately sterilised ophthalmic instruments. The polymerase chain reaction (PCR) proved more sensitive than antigen detection by immune dot-blot test for the rapid diagnosis of ocular adenovirus infection (sensitivities in a retrospective study 112/123 (91%) versus 72/123 (59%), P < 0.001). Indeed, in a prospective comparison, DNA amplification and virus isolation generated similar numbers of positive results (34 versus 32), though five PCR positive results were possibly false positives. The sensitivity of the PCR was largely independent of adenovirus subgenus or serotype, though reduced sensitivity with subgenus B strains could not be excluded. Specimen preparation for DNA amplification using a simple lysis buffer proved more effective than phenol-chloroform extraction. The immune dot-blot test gave unavoidable false positive results, but with the PCR this problem could be minimized by technical modifications. The PCR could replace antigen detection and virus isolation as the initial test for adenoviruses in conjunctival swabs, with cell culture only being retained for adenovirus serotyping in PCR positive specimens and for other viruses such as herpes simplex.
Insights
Polymerase chain reaction (PCR) is a more sensitive method for diagnosing adenovirus conjunctivitis than antigen detection. PCR offers rapid and reliable results for ocular adenovirus infections, improving diagnostic accuracy.
Area of Science:
- Ophthalmology
- Virology
- Molecular Diagnostics
Background:
- Adenoviruses are a common cause of endemic and epidemic acute conjunctivitis.
- Nosocomial outbreaks of conjunctivitis are frequently linked to poor hygiene and contaminated ophthalmic instruments.
- Rapid and accurate diagnosis is crucial for managing adenovirus outbreaks and patient care.
Purpose of the Study:
- To compare the diagnostic sensitivity and effectiveness of polymerase chain reaction (PCR) against antigen detection (immune dot-blot) and virus isolation for ocular adenovirus infections.
- To evaluate specimen preparation methods for DNA amplification.
- To determine the suitability of PCR as a primary diagnostic tool for adenoviral conjunctivitis.
Main Methods:
- Retrospective and prospective comparative study evaluating PCR, immune dot-blot, and virus isolation.
- Specimen preparation techniques included lysis buffer and phenol-chloroform extraction.
- Sensitivity analysis was performed across different adenovirus subgenera and serotypes.
Main Results:
- PCR demonstrated significantly higher sensitivity (91%) compared to immune dot-blot (59%) for adenovirus conjunctivitis diagnosis.
- DNA amplification and virus isolation yielded comparable numbers of positive results in prospective testing.
- A simple lysis buffer method for specimen preparation was more effective than phenol-chloroform extraction for DNA amplification.
Conclusions:
- Polymerase chain reaction (PCR) is a highly sensitive and effective method for the rapid diagnosis of ocular adenovirus infections.
- PCR can replace traditional antigen detection and virus isolation as the initial diagnostic test for adenoviruses in conjunctival swabs.
- Cell culture should be reserved for adenovirus serotyping in PCR-positive cases and detection of other viruses like herpes simplex.