Feasibility of an antiviral clinical trial requiring cross-country shipment of conjunctival adenovirus cultures and recovery of infectious virus

Abstract

Purpose. Accurate and timely laboratory diagnosis of adenovirus from conjunctival cultures is essential to ensure appropriate enrollment, and detection of residual infectious virus is essential to evaluate antiviral efficacy in any multicenter national clinical trial. As part of a feasibility study, we investigated those variables that might affect the successful recovery of infectious adenovirus from patient conjunctival cultures after cross-country shipment.Materials and methods. Simulated adenovirus conjunctival cultures were prepared in viral transport media to evaluate the effect of four variables (adenovirus serotype, initial concentration, initial storage temperature [−20°C, 0°C, 20°C], and preshipment storage times [1–5 days]) on the recovery of infectious adenovirus by a central laboratory in St. Paul, MN, following air shipment from Pittsburgh, PA. Upon arrival, the internal temperatures of the containers were recorded, and the samples were cultured on A549 cells using standard tube and/or shell vial culture.Results. Overall, adenovirus was recovered in 352/354 (99.4%) of the samples when the initial titer was greater than 1.0 PFU/ml. Adenovirus serotype, initial storage temperature, and preshipment storage times had no adverse effect on virus recovery.Conclusions. Simulated conjunctival samples could successfully be shipped cross-country at ambient temperatures to a commercial laboratory for adenovirus isolation by culture. Having demonstrated feasibility, a clinical trial was subsequently carried out that confirmed the ease of shipment and recovery of infectious adenovirus from conjunctival cultures.