August 13, 2009
Swine influenza, or ‘swine flu’, is a highly contagious acute respiratory disease of pigs, caused by one of several swine influenza A viruses that cause regular outbreaks in pigs.
Outbreaks in pigs occur year round, with an increased incidence in autumn and winter in temperate zones. Many countries routinely vaccinate swine populations against swine influenza.
Swine influenza viruses are most commonly of the H1N1 subtype, but other subtypes are also circulating in pigs (e.g., H1N2, H3N1, H3N2). Pigs can also be infected with avian influenza viruses and human seasonal influenza viruses as well as swine influenza viruses.
The H3N2 swine virus was thought to have been originally introduced into pigs by humans.
Recent outbreak due to
Recent outbreak due to the new strain of influenza virus A (H1N1) has had cases reported from North America, Mexico, Spain and UK. Suspect cases have been reported from New Zealand and France and these are being investigated.
April 28, 2009
CliniciansClinicians should consider the possibility of swine influenza virus infections in patients presenting with febrile respiratory illness.
If swine flu is suspected, clinicians should obtain a respiratory swab for swine influenza testing and place it in a refrigerator (not a freezer). Once collected, the clinician should contact their state or local health department to facilitate transport and timely diagnosis at a state public health laboratory.
State Public Health Laboratories
Laboratories should send all unsubtypable influenza A specimens as soon as possible to the Viral Surveillance and Diagnostic Branch of the CDC’s Influenza Division for further diagnostic testing.
Public Health and Animal Health Officials
Officials should conduct thorough case and contact investigations to determine the source of the swine influenza virus, extent of community illness and the need for timely control measures.
Source: Centers for Disease Control and Prevention