Table 2 Common and uncommon community-acquired respiratory viruses that may cause severe respiratory viral infection
Virus Epidemiologic and clinical features Additional infection control precautionsa
Common respiratory viruses
Influenza A and influenza B Only influenza type A viruses are known to have caused pandemics
Currently circulating seasonal influenza A viruses in humans: subtype A(H1N1)pdm09 and A(H3N2) strains
Currently circulating influenza B viruses: A/Victoria-like, A/Yamagata-like strains
May be associated with acute myocardial infarction, myocarditis, rhabdomyolysis, acute renal failure, encephalopathy/encephalitis, and other non-pulmonary complications Droplet
Picornaviruses (rhinovirus, enterovirus) Frequently detected in critically ill patients with severe acute respiratory infection.
May cause severe illness in the elderly, persons with co-morbidities including immunosuppression. Droplet
Human coronaviruses (229E, NL63, OC43, HKU1) Contact
Respiratory syncytial virus Contact
Human metapneumovirus Contact
Parainfluenza (1-4) Contact
Adenoviruses Droplet + contact
Uncommon and emerging viruses
Avian influenza A/H5N1, A/H5N6, A/H7N9 and other subtypes Residence in or travel to Southeast and East Asia
Exposure to poultry or visit to poultry market Airborne + contact
MERS-CoV Residence in or travel to the Arabian Peninsula
Exposure to dromedary camel (in endemic areas)
Nosocomial transmission risk to other patients and to healthcare workers Airborne + contact
SARS-CoV No cases have been reported since 2004
Nosocomial transmission risk to other patients and to healthcare workers Airborne + contact
2019 Novel coronavirus (2019 nCoV) As of February 4, 2020, 20630 cases were reported from China and 23 other countries Droplet + contact and wherever possible airborneb
Measlesc Incomplete vaccination
Characteristic rash. Progressive giant cell pneumonia without rash may occur in immunocompromised (Hecht’s pneumonia) Airborne
Hantaviruses (e.g., Sin Nombre, Andes)c Residence in or travel to affected areas of North, Central, or South America
Exposure to rodent excretions particularly when cleaning buildings Standard
Varicella-zoster virusc Incomplete vaccination, pregnancy
Often with characteristic rash Airborne + contact
Please refer to the online supplement for references
Infection control precautions are based on the Centers for Disease Control and Prevention at: https://www.cdc.gov/infectioncontrol/guidelines/isolation/appendix/type-duration-precautions.html#M, https://www.cdc.gov/coronavirus/mers/infection-prevention-control.html, https://www.cdc.gov/infectioncontrol/guidelines/isolation/appendix/standard-precautions.html, https://www.cdc.gov/flu/professionals/infectioncontrol/healthcaresettings.htm (all accessed on Dec 10-2019)
aAll suspected or confirmed RVIs require minimum of standard precautions. Eye protection is a reasonable addition to droplet isolation as the ocular route of infection has been documented for several common respiratory viruses
bData on the novel coronavirus are based on the WHO interim report as of February 4, 2020
cOther viral pathogens with respiratory routes of acquisition