Diagnosis of a critical respiratory illness caused by human metapneumovirus by use of a pan-virus microarray

Abstract

A pan-virus DNA microarray (Virochip) was used to detect a human metapneumovirus (hMPV) strain associated with a critical respiratory tract infection in an elderly adult with chronic lymphocytic leukemia. This infection had previously eluded diagnosis despite extensive microbiological testing for possible etiologic agents. The patient's hMPV strain did not grow in viral culture, and only one of five specific reverse transcription-PCR assays for hMPV was positive.

FIG. 1.

Chest imaging of the patient. A chest X ray taken on admission shows bilateral reticulonodular infiltrates and a right-lower-lobe consolidation (A), while a computed tomography scan (representative slice) (B) reveals in addition a bilateral “tree-in-bud” pattern consistent with a diffuse bronchiolitis.

FIG. 2.

Phylogenetic analysis of the patient's hMPV strain. Partial sequences of the highly conserved fusion genes (895 bp) and nucleocapsid genes (681 bp) from the patient's hMPV strain, the closest GenBank relative (JPS03-240), representative members from each of the four hMPV subgroups (CAN98-75, CAN97-92, 00-1, and CAN97-83), and avian pneumovirus type C (APV-C) were analyzed. For each sequence, the nucleotide percent identity to the patient's hMPV strain is shown in parentheses.