Human coronavirus NL63 infection in Canada

Abstract

The isolation of human coronavirus NL63 (HCoV-NL63) in The Netherlands raised questions about its contribution to respiratory illness. In this study, a total of 525 respiratory specimens, collected in Canada primarily during the winter months of 2001-2002, were tested for HCoV-NL63; 19 tested positive for HCoV-NL63, demonstrating virus activity during January-March 2002. Patients with HCoV-NL63 were 1 month-100 years old (median age, 37 years). The main clinical presentations were fever (15/19), sore throat (5/19), and cough (9/19), and 4 patients were hospitalized. These results provide evidence for the worldwide distribution of HCoV-NL63.

Figure 1.

Phylogenetic analysis of human coronavirus NL 63 (HCoV-NL63) isolates. Genetic sequences were determined for nucleotides 5856–6280 of the 1a gene. The corresponding sequences from previously reported Dutch HCoV-NL63 isolates were also included. Phylogenetic analysis was performed by use of the neighbor-joining method of the MEGA program. The Dutch reference strain is designated by “HCoV-NL63,” and the Dutch isolates are designated by “NDL” followed by an isolate number (i.e., NDL-246). The isolates detected in the present study are designated in terms of specimen number and the (2-digit) year of detection (i.e., 140-02).