Clinical and Molecular Epidemiological Features of Coronavirus HKU1–Associated Community-Acquired Pneumonia

Woo, Patrick C. Y.; Lau, Susanna K. P.; Tsoi, Hoi-wah; Huang, Yi; Poon, Rosana W. S.; Chu, Chung-ming; Lee, Rodney A.; Luk, Wei-kwang; Wong, Gilman K. M.; Wong, Beatrice H. L.; Cheng, Vincent C. C.; Tang, Bone S. F.; Wu, Alan K. L.; Yung, Raymond W. H.; Chen, Honglin; Guan, Yi; Chan, Kwok-hung; Yuen, Kwok-yung

BackgroundRecently, we described the discovery of a novel group 2 coronavirus, coronavirus HKU1 (CoV-HKU1), from a patient with pneumonia. However, the clinical and molecular epidemiological features of CoV-HKU1–associated pneumonia are unknown MethodsProspectively collected (during a 12-month period) nasopharyngeal aspirates (NPAs) from patients with community-acquired pneumonia from 4 hospitals were subjected to reverse-transcription polymerase chain reaction, for detection of CoV-HKU1. The epidemiological, clinical, and laboratory characteristics of patients with CoV-HKU1–associated pneumonia were analyzed. The pol spike (S), and nucleocapsid (N) genes were also sequenced ResultsNPAs from 10 (2.4%) of 418 patients with community-acquired pneumonia were found to be positive for CoV-HKU1. All 10 cases occurred in spring and winter. Nine of these patients were adults, and 4 had underlying diseases of the respiratory tract. In the 6 patients from whom serum samples were available, all had a 4-fold change in immunoglobulin (Ig) G titer and/or presence of IgM against CoV-HKU1. The 2 patients who died had significantly lower hemoglobin levels, monocyte counts, albumin levels, and oxygen saturation levels on admission and had more-extensive involvement visible on chest radiographs. Sequence analysis of the pol S, and N genes revealed 2 genotypes of CoV-HKU1 ConclusionsCoV-HKU1 accounts for 2.4% of community-acquired pneumonia, with 2 genotypes in the study population. Without performance of diagnostic tests, the illness was clinically indistinguishable from other community-acquired pneumonia illnesses