Enhancing Diagnosis of Adenoviral Conjunctivitis: Silver-Amplified Lateral Flow Kits in Focus

A recent multicenter prospective study in Viruses shows that silver‑amplified lateral flow kits substantially improve point‑of‑care detection of adenoviral conjunctivitis, with sensitivity 86.0% versus 72.0% for non‑amplified kits and specificity of 100% for the silver‑amplified device. The sensitivity gain—statistically significant in paired testing—makes clinic‑level identification of cases that would otherwise be missed more achievable.

That improvement permits earlier case detection and fewer bedside false negatives. Silver amplification chemically enlarges metal nanoparticles at the test line to boost optical signal and analytical sensitivity, improving visibility of low‑antigen specimens. Versus non‑amplified lateral flow tests, amplification narrows the performance gap with laboratory qPCR when antigen levels approach the conventional strips' limit of detection.

In a blinded, prospective evaluation using tear fluid/conjunctival exudate from 200 patients with qPCR as the reference, the silver‑amplified kit outperformed the non‑amplified kit across paired comparisons and multiple sites. The authors report sensitivity 86.0% for the silver‑amplified lateral flow kit versus 72.0% for the non‑amplified kit, with specificity reported at 100% for the silver‑amplified device (and 98.1% for the non‑amplified comparator). The paper's confidence intervals and paired‑test statistics support the significance of these differences.

Performance was consistent across severity strata: the silver‑amplified kit maintained higher positivity in both mild/moderate and severe presentations and identified a greater proportion of cases at lower viral loads, although both kits failed to detect specimens at very low copy numbers (≤103 copies/test). The study used a small tear volume (≈25 μL) applied to each cartridge and an automated reader for binary outputs, supporting practical clinic workflows. The authors note limits in mild‑case numbers and single‑country sites as residual uncertainty and flag generalizability to other populations, platforms, and extreme early/late sampling times for further evaluation.

Broader use of silver‑amplified lateral flow tests could sharpen early detection and enable prompt infection‑control actions in outpatient and long‑term‑care settings.