Detection of seasonal and novel H1N1 influenza virus in cough-generated bioaerosols.
Blachere-FM; Lindsley-WG; Davis-KA; Thewlis-RE; Jackson-LG; Cao-G; Palmer-JE; Clark-KE; Fisher-MA; Khakoo-R; Davis-SM; Beezhold-DH
Abstracts of the 2010 American Society for Microbiology 110th General Meeting, May 23-27, 2010, San Diego, California. Washington, DC: American Society for Microbiology, 2010 May; :Q-898
Background: The importance of airborne transmission of influenza virus within indoor environments is controversial. In this study we examined the size distribution and concentration of viral RNA-containing particles produced directly by coughing from patients with influenza or influenza-like symptoms. Methods: Fifty-eight patients presenting to WVU Student Health with symptoms of upper respiratory infection during Oct and Nov, 2009 were asked to cough into a modified medical spirometer. The cough-generated aerosol was then collected using a NIOSH BC 251 two-stage sampler (48/58) or an SKC Biosampler (10/58). Quantitation of seasonal influenza virus matrix gene M1 copy number and detection of 2009 H1N1 influenza virus was performed using real-time PCR. Results: Analysis of nasal swab samples found that 12% of patients (7/58) were influenza A positive by Rapid Flu test while 74% were influenza A positive (33/56) and 42% 2009 H1N1 positive (24/55) by PCR. Based on the relative quantitative PCR results, we confirmed that influenza RNA-laden particles were present in the cough-generated aerosols. Airborne influenza A viral RNA was detected in 67% of the BC 251 samplers and 60% of the SKC samplers. Two BC 251 samplers from patients without PCR-confirmed influenza were weakly positive. Using the BC 251, which separates particles according to aerodynamic size, 35% of influenza A RNA was present in the first stage (> 4 Ám), 22% in the second stage (1-4 Ám) and 41% on the back-up filter (< 1 Ám) from PCR positive patients. Conclusions: Our results show that cough-generated aerosols from patients with influenza contain influenza viral RNA and that approximately 63% of the collected influenza-laden particles were within the respirable size range (< 4 Ám). These data concur with previous environmental studies looking at the presence of airborne influenza virus RNA. Future studies will further investigate the size distribution, concentration and viability of airborne particles produced by patients with influenza. These findings should significantly contribute towards the understanding of the routes of influenza virus transmission.
Airborne-particles; Bioaerosols; Biological-effects; Disease-transmission; Environmental-contamination; Exposure-assessment; Exposure-levels; Health-hazards; Indoor-environmental-quality; Infectious-diseases; Laboratory-techniques; Mathematical-models; Measurement-equipment; Microorganisms; Physiological-effects; Pulmonary-system; Quantitative-analysis; Respiratory-hypersensitivity; Respiratory-infections; Sampling-methods; Statistical-analysis; Viral-diseases; Viral-infections;
Author Keywords: Influenza; bioaerosol; transmission
Healthcare and Social Assistance
Abstracts of the 2010 American Society for Microbiology 110th General Meeting, May 23-27, 2010, San Diego, California