Human parainfluenza type 4 infections, Canada

Abstract

During the fall/winter season of 2004–05, we found 9 respiratory specimens positive for human parainfluenza virus type 4 (HPIV-4) in our laboratory (43% of all HPIVs) from patients with mild to moderate respiratory illnesses. Sequencing studies identified 8 different HPIV-4A strains and 1 HPIV-4B strain.

Figure 1

Seasonality of human parainfluenza virus type 4 (HPIV-4) infections during fall and winter of 4 consecutive years.

Figure 2

Phylogenetic analysis based on fusion (F) gene nucleotide sequences from clinical and reference human parainfluenza virus (HPIV) strains. The tree was built by using distance method and the neighbor-joining algorithm with Kimura 2 parameters. The topologic accuracy of the tree was evaluated by using 500 bootstrap replicates. Strains isolated at the Research Center in Infectious Diseases (Quebec, Canada) are indicated by a specific identification number (ccri) followed by the patient number in parentheses. Public sequences for HPIV-4A (GenBank accession no. d49821) and HPIV-4B (GenBank accession no. d49822) strains are also indicated in the tree.