HKU1

Human coronavirus HKU1 (HCoV-HKU1) is a virus that belongs to the genus Betacoronavirus. It was identified in 2005 in Hong Kong by researchers at the University of Hong Kong, after which it was named. HKU1 is one of the several endemic human coronaviruses that circulate in the population, alongside other common cold viruses.

HKU1 has a positive-sense RNA genome of about 29 kilobases and shares the characteristic coronavirus genome organization, including the replicase genes ORF1a/1b and the structural genes encoding spike (S), envelope (E), membrane (M), and nucleocapsid (N) proteins, with additional accessory proteins. Like other coronaviruses, HKU1 uses its spike protein to enter host cells, but the specific cellular receptor for HKU1 has not been definitively identified. The virus is transmitted primarily through respiratory droplets and close contact.

Clinically, HCoV-HKU1 infection can cause a range of respiratory symptoms from mild upper respiratory illness to more significant disease. In many cases, infections are indistinguishable from those caused by other common cold viruses. In older adults, young children, or immunocompromised individuals, HKU1 can contribute to more severe respiratory conditions, including pneumonia, especially in the context of co-infections with other pathogens.

Epidemiologically, HCoV-HKU1 is distributed worldwide and tends to show seasonal activity, with higher incidence in winter months in temperate regions. Diagnosis is typically by molecular methods such as reverse-transcription polymerase chain reaction (RT-PCR) on respiratory samples; serology is used mainly in research settings. There are no vaccines or specific antivirals for HKU1, and treatment is supportive. Infection control measures help reduce transmission.