Earlier this week FluTrackers picked up a story about cats sick with influenza in New York City, which while not unheard of, is fairly uncommon. As we've discussed before (see Catch As Cats Can), felines have shown some susceptibility to both pandemic H1N1 and avian flu strains.
Last night it was announced that 45 cats at Manhattan shelter were infected with a low path avian H7N2 virus. How the virus was introduced into this feline cohort is unknown.
As the health department statement below mentions, there are only a couple of instances of H7N2 infection in humans on record in the United States - both were mild and both patients recovered.
In 2007, 4 people were presumed to have been infected by H7N2 in the UK following local outbreaks in poultry. From the Journal Eurosurveillance, we get the following summary:
Several cases of influenza-like-illness (ILI) and/or conjunctivitis in humans have been linked to an outbreak of avian influenza in poultry at a smallholding near Corwen in northern Wales in the United Kingdom (UK). Three of the cases were hospitalized . H7N2, a low pathogenic strain of avian influenza (LPAI), has been identified as the cause of the poultry outbreak by the Department for Environment, Food and Rural Affairs (DEFRA) . Four human cases (two in Wales and two in north-west England) have confirmed Influenza A infection and are closely linked in time and place to the discovery of the H7N2 avian influenza virus. Since there are currently very low levels of seasonal influenza in the UK, it is presumed that they are infected with influenza H7N2.
And, while little remembered today, live bird markets in the Northeastern United States were linked to the spread of, and heavy losses from, avian H7N2 in the mid-1990s (see Live-bird markets in the Northeastern United States: a source of avian influenza in commercial poultry by D.A. Senne, J.C. Pedersen, B. Panigrahy).
Here is the NYC Health Department statement, after which I'll return with a bit more on avian H7N2.
Health Department, Animal Care Centers of NYC Report Cases of Rare Influenza Virus Among Cats at ACC’s Manhattan Facility
H7N2 strain has caused mild illness in cats in Manhattan shelter and is thought to pose a low risk to humans
The Health Department is contacting persons who recently adopted Manhattan shelter cats
December 15, 2016 – The Health Department and the Animal Care Centers of NYC (ACC) today announced that a strain of influenza A virus, known as low pathogenic avian influenza H7N2, has been identified in 45 cats housed at the Manhattan shelter.
This is the first time this virus has been detected and transmitted among domestic cats. It is unknown how the cats contracted the virus. So far this virus causes mild illness in cats and is thought to pose a low risk to humans. There have been only two documented human cases of low pathogenic avian influenza H7N2 infection in the United States – one in a farmer who worked closely with chickens in 2002 and the other with an unknown source in 2003. Both of these patients recovered.
Based on recent testing data by the University of Wisconsin-Madison School of Veterinary Medicine, November 12, 2016 is the earliest date when this virus was likely introduced into the shelter. The Health Department is contacting all persons who have adopted cats from ACC’s Manhattan care center since November 12th. The Health Department is advising persons who adopted Manhattan shelter cats during this period to call the Department at 866-692-3641 for care instructions, including keeping their cat separated from other cats or animals, if their cat is showing signs of persistent cough, lip smacking, runny nose, and fever. The Health Department is also advising these pet owners to call 866-692-3641 if they develop fever with a sore throat, fever with a cough, or red, inflamed eyes.
This influenza virus is spreading from cat to cat and may be able to spread to other animals and possibly humans. No human infections have been identified to date. To date, ACC has tested 20 dogs at the shelter, and none have contracted this virus. Testing of other animals, including rabbits and guinea pigs, is ongoing. There have been no reported cases of this virus among cats outside of the ACC shelter system.
ACC will continue to distribute instructions to all new and recent cat adopters to monitor their cats, which includes guidance on checking animals for upper respiratory illness. The Health Department is coordinating closely with the Centers for Disease Control and Prevention (CDC), the US Department of Agriculture, the University of Wisconsin-Madison, and community partners.
“Although this strain of the avian flu has only resulted in mild to moderate illness in some cats located in one shelter, we have begun to test staff and people in close contact with the cats out of an abundance of caution,” said First Deputy Health Commissioner Dr. Oxiris Barbot. “We will continue to actively monitor all people involved and adapt our response accordingly.”
“While we are concerned about this new infection, the cats are experiencing only mild to moderate illness, other than one older cat who developed pneumonia,” said Sandra Newbury, clinical assistant professor at the University of Wisconsin School of Veterinary Medicine and director of the UW Shelter Medicine Program. “Many of the cats who were initially ill are already recovering. We do want people to be aware of what is happening, but influenza infection is unlikely in cats who have not had contact with cats from New York City’s Manhattan Animal Care Center."
Most of the infected cats have had a mild illness. One infected cat, who had underlying health problems and advanced age, died. The Health Department and ACC are working to identify a quarantine facility while the Manhattan shelter is disinfected. The cats will be monitored and released from quarantine once they have all fully recovered. To help contain the outbreak, the Health Department strongly discourages New Yorkers from dropping off cats at the ACC Manhattan shelter until all cats are quarantined.
While this influenza infection is unlikely in cats who have not had contact with cats from the ACC shelter, owners whose animals show signs of influenza should contact their veterinarian for care instructions and hand washing precautions should be taken to prevent spread of the virus on hands and clothing.
The Health Department will be coordinating testing and care for ACC employees and volunteers.
The Health Department will be releasing guidance to veterinarians about how to evaluate cats suspected of being infected with this virus and guidance to physicians about how to evaluate humans who have been exposed to cats suspected of having this virus.
The Wisconsin Veterinary Diagnostic Laboratory made the initial identification of the strain and the U.S. Department of Agriculture’s National Veterinary Services Laboratory confirmed the test results.
Kathy Toohey-Kurth, at The Wisconsin Veterinary Diagnostic Laboratory, working with the University of Wisconsin-Madison Shelter Medicine Program, made the initial identification of the strain and the U.S. Department of Agriculture’s National Veterinary Services Laboratory confirmed the test results. The University of Wisconsin-Madison Shelter Medicine Program continues to work with ACC Manhattan shelter to manage the illness.
While H7 viruses are generally considered less dangerous than H5 viruses (the exception being H7N9), we do keep a close eye on their spread and evolution.
A few H7N2 blogs include: