Clinical assessment of a generic DNA amplification assay for the identification of respiratory adenovirus infections.
BACKGROUND
respiratory adenoviruses are common, often resulting in serious sporadic and epidemic infections and impaired immunity can dramatically increase their severity. They are now thought capable of establishing latency. Diagnosis by culture is slow while direct antigen detection by immunofluorescence lacks sensitivity. Molecular diagnosis can be both rapid and sensitive but the genetic heterogeneity of adenoviruses poses problems.


OBJECTIVE
to design a generic adenovirus nested polymerase chain amplification assay designed to be capable of detecting all respiratory adenoviruses. This was achieved through optimised thermal cycling and the development of a generic degenerate primer set targeting the adenovirus hexon gene.


METHODS
this was a cross-sectional study on 172 respiratory specimens from hospital-based patients, and one from a general practice, in Northern Ireland. A comparison was made between the amplification assay, virus culture and immunofluorescence.


RESULTS
the nested polymerase chain reaction (nPCR) assay had a generic capacity for adenovirus detection and an analytical sensitivity of 6.4x10(2) copies/ml. Using an expanded gold standard (defined as a true positive or a true negative where a specimen was positive or negative by at least two of the study assays, respectively), PCR had a clinical sensitivity and specificity of 46/46 (100%) and 15/126 (91.3%), respectively. Patients with acute respiratory adenovirus infections were more likely to be male (chi(2), p=0.005) and to present with a fever (chi(2), p=0.02) than patients diagnosed with another respiratory virus. Co-infection was identified in 12/172 patients.


CONCLUSIONS
the nested amplification assay proved highly sensitive in both the analytical and clinical settings for the detection of respiratory adenovirus infections.
Mitchell
S
S
Regional Virus Laboratory, Kelvin Laboratories, Royal Victoria Hospital, Grosvenor Road, Belfast, BT 12 6BA, UK.
O'Neill
H J
HJ
Ong
G M
GM
Christie
S
S
Duprex
P
P
Wyatt
D E
DE
McCaughey
C
C
Armstrong
V J
VJ
Feeney
S
S
Metwally
L
L
Coyle
P V
PV
D000258:Adenovirus Infections, Human / Q000453:epidemiology / Q000821:virology*; D000260:Adenoviruses, Human / Q000145:classification* / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D036022:Capsid Proteins / Q000235:genetics; D002648:Child; D002675:Child, Preschool; D003428:Cross Infection / Q000453:epidemiology / Q000821:virology; D003430:Cross-Sectional Studies; D004279:DNA, Viral / Q000235:genetics / Q000302:isolation & purification*; D005240:Feasibility Studies; D005260:Female; D019085:Fluorescent Antibody Technique, Direct; D018740:Genetic Heterogeneity; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D009660:Northern Ireland / Q000453:epidemiology; D016133:Polymerase Chain Reaction / Q000379:methods*; D015203:Reproducibility of Results; D012141:Respiratory Tract Infections / Q000453:epidemiology / Q000821:virology*; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014776:Virus Cultivation
D036022:Capsid Proteins; D004279:DNA, Viral; C018315:hexon capsid protein, Adenovirus