Evaluation of a silver-amplified immunochromatography kit for adenoviral conjunctivitis

To compare and evaluate the sensitivity of a newly developed silver-amplified immunochromatography (SAI) kit with various immunochromatography (IC) kits for adenoviruses based on the detection limit (copies/test).

An SAI kit and four ophthalmic IC kits were evaluated. The detection limits of the five kits were determined using the limiting dilution method for 15 conjunctivitis-associated adenoviruses (adenoviruses 1, 2, 3, 4, 5, 7, 8, 11, 37, 53, 54, 56, 64, 81, and 85). The detection limits were presented as numerical values as determined by real-time polymerase chain reaction (PCR).

The detection limit of the SAI kit for the adenovirus types ranged from 1.0 × 10³ -5.0 × 10 ⁴  copies/test (geometric mean, 4.7 × 10 ³ ). SAI had a 10-250-fold lower detection limit than the four IC kits for all adenoviruses studied. There were also differences in detection limits among the adenovirus types for each kit.

The detection limit of the SAI kit was drastically reduced because the silver-amplification reaction increased the color development sensitivity. The results revealed the high sensitivity of SAI for detecting adenoviruses and suggested its usefulness for conjunctivitis examination.