Utility of terminal hemadsorption for detection of hemadsorbing respiratory viruses from conventional shell vial cultures for laboratories using R-Mix cultures.

ABSTRACT

BACKGROUND: Many laboratories using R-Mix cell lines inoculate other shell vial cultures to improve the recovery of viruses, and in particular, perform terminal hemadsorption (THad) following 10-14 days of incubation to improve detection of respiratory viruses. We explored the cost-effectiveness and added benefits of THad on conventional shell vial cultures from respiratory samples for laboratories using R-Mix cell lines. OBJECTIVES: To determine if eliminating the practice of THad from conventional shell vial culture when R-Mix cultures are negative, would result in a significant reduction in the number of hemadsorbing respiratory viruses detected. STUDY DESIGN: THad results were retrospectively reviewed for 41,129 respiratory shell vial cultures that were set up concurrently with R-Mix cultures. RESULTS: Greater than 95% of hemadsorbing respiratory viruses were recovered by R-Mix standard protocol within 24h of inoculation, and only 5% were detected by THad at 10-14 days. CONCLUSION: The practice of hemadsorption at days 10-14 for conventional shell vial cultures from respiratory specimens should be discontinued for laboratories using R-Mix due to its low yield, questionable clinical impact of delayed results and additional costs.