Results of a pilot study using self-collected mid-turbinate nasal swabs for detection of influenza virus infection among pregnant women

BackgroundWe evaluated the feasibility of asking pregnant women to self-collect and ship respiratory specimens. MethodsIn a preliminary laboratory study, we compared the RT-PCR cycle threshold (CT) values of influenza A and B viruses incubated at 4 storage temperatures (from 4 to 35 degrees C) for 6 time periods (8, 24, 48, 72, and 168hours and 30days), resulting in 24 conditions that were compared to an aliquot tested after standard freezing (-20 degrees C) (baseline condition). In a subsequent pilot study, during January-February, 2014, we delivered respiratory specimen collection kits to 53 pregnant women with a medically attended acute respiratory illness using three delivery methods. ResultsCT values were stableafter storage at temperatures <27 degrees C for up to 72hours for influenza A viruses and 48hours for influenza B viruses. Of 53 women who received kits during the pilot, 89% collected and shipped nasal swabs as requested. However, 30% (14/47) of the women took over 2days to collect and ship their specimen. The human control gene, ribonuclease P (RNase P), was detected in 100% of nasal swab specimens. However, the mean CT values for RNase P (265, 95% confidence interval [CI]=260-271) and for the 8 influenza A virus positives in our pilot (322, 95% CI=289-355) were significantly higher than the CTs observed in our 2010-2012 study using staff-collected nasal pharyngeal swabs (P-values<001). DiscussionSelf-collection of respiratory specimens is a promising research method, but further research is needed to quantify the sensitivity and specificity of the approach.