Evidence of a novel human coronavirus that is associated with respiratory tract disease in infants and young children.

The etiological agents responsible for a substantial proportion of respiratory tract diseases have not been identified. We sought to determine whether novel human coronaviruses (HCoVs) are circulating in New Haven, Connecticut, and, if so, whether they are associated with respiratory tract disease in infants and young children. We developed a polymerase chain reaction (PCR)-based approach for screening specimens from the respiratory tracts of symptomatic children. PCR probes that target regions of the replicase 1a gene that are conserved among genetically diverse animal CoVs and HCoVs were designed. Using these probes, we identified genomic sequences of a novel HCoV, designated "New Haven coronavirus" (HCoV-NH). Thereafter, we designed specific probes to screen respiratory specimens from children <5 years old for this novel HCoV. Clinical features associated with HCoV-NH infection were identified. Seventy-nine (8.8%) of 895 children tested positive for HCoV-NH. Cough, rhinorrhea, tachypnea, fever, abnormal breath sounds, and hypoxia were the most common findings associated with HCoV-NH infection. Sequence analysis revealed that HCoV-NH is closely related to a novel HCoV recently reported in The Netherlands. The novel HCoVs identified in New Haven and The Netherlands are similar and likely represent the same species. This newly discovered virus may have worldwide distribution and may account for a significant proportion of respiratory tract disease in infants and young children.