Concentration of enterovirus in air samples and exhaled samples

Pei-Shih Chen (1), CHIA YU CHEN (1)

(1) Kaohsiung Medical University, Taiwan

     Abstract Number: 474
     Last modified: May 12, 2010

Abstract
Enterovirus is a common pathogen, responsible for upper and lower respiratory tract infections in adults and infants. In 1998, 78 children died because of enterovirus infection in Taiwan. In 2008, enterovirus attacked Taiwan again leading to 14 children death. It was believed that all enterovirus serotypes except Coxsackievirus A21 (CA21) is fecal-oral transmission. However, high transmission rate among family members implicated the possibility of air transmission. So, the purpose of our study is to exam the hypothesis that enterovirus can be transmitted via air. Air concentration of enterovirus in pediatric department and in the exhaled air from infected children was evaluated.
We collected 14 air samples from June to August 2008 by using Teflon filter (Diameter 37mm, pore 1.0um) at 20L/min. Temperature, relative humidity, CO concentration, CO$_2 concentration and ventilation rate of the microenvironment were also collected. For exhaled samples, 24 samples were collected by using Teflon filter (Diameter 37mm, pore 2.0um). All samples were detected by real-time quantitative polymerase chain reaction (qPCR).
Enterovirus was detected in 64.3% (9/14) and 79.2% (19/24) for air samples and exhaled samples, respectively. In air samples, the concentration of enterovirus range from 4.6×10$^1 to 1.4×10$^8. In exhaled samples, the concentration of enterovirus range from 3.8×10$^5 to 1.6×10$^13. To our knowledge, it is the first study to detected enterovirus in air samples and exhaled air from patients. It revealed that enterovirus can be transmitted through the air. Exhaled CO was considered as an indicator of virus infection. By regression analysis, our data showed that exhaled CO concentration increased 1 ppm, air concentration of enterovirus increase 1.01×10$^13 copies/m$^3. It pointed out that exhaled CO may be the indicator of enterovirus infection. In conclusion, this study confirmed enterovirus other than CA21 can be transported by air.