Human coronaviruses infection in patients with acute respiratory tract infection in Beijing, 2011-2012

Objective To understand the infection status of human coronaviruses (HCoVs) in patients with acute respiratory tract infection and epidemiological characteristics of HCoVs infection in Beijing. Methods From 2011 to 2012, throat swabs or sputum samples were collected from the patients with acute respiratory tract infection in 5 sentinel hospitals in Beijing, the patients' basic information were collected too. All the samples were tested with RT-PCR using specific primers to detect HCoV. The positive amplicons were sequenced to identify the virus type. The Results were analyzed with SPSS 17.0. Results Twenty samples were HCoV positive in 1619 samples (1.24%), including 9 from the patients with upper respiratory tract infection (1.11%) and 11 from the patients with lower respiratory tract infections (1.36%). Among 20 positive samples, 13 were OC43, 6 were 229E, 1 was NL63. The positive rate was higher in 2011 (1.82%,14/769)than in 2012(0.71%,6/850), the difference was statistically significant (2=4.112,P=0.043), but the differences in monthly positive rates had no statistical significance. The age specific positive rate in age group 25-59 years was highest (1.96%, 13/663), followed by age group 0-4 years (1.92%, 3/208) and other age groups (1%). The differences in age specific positive rates were statistically significant. The positive rates of OC43 in age groups 25-59 and 0-4 years were high, the difference had statistical significance (2=5.007, P=0.026). The difference in gender specific positive rate of HCoVs had no statistical significance. The differences in clinical symptoms caused by different types of HCoVs were not statistically significant. Conclusion During 2011-2012, HCoV-229E and HCoV-OC43 were the predominant HCoVs in Beijing. The circulating type and related intensity varied with year but had no obvious seasonality. Infants/young children and adults are the risk populations of HCoVs infection, especially HCoV-OC43 infection. The differences in clinical symptoms caused by different types of HCoVs are not statistically significant.