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| Caring for Cats Infected With H7N2 - NYC 2016 |
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Prior to 2003, domestic cats were thought unlikely victims or vectors of influenza viruses. Feline respiratory viruses - sometimes dubbed `cat flu' - were generally due to various strains of calicivirus or feline herpes virus, not influenza.
That perception changed in 2003 when zoos in South-East Asia found out to their dismay what happens when you feed H5N1 infected chicken carcasses to tigers and leopards.The following comes from a World Health Organization GAR report from 2006.
H5N1 avian influenza in domestic cats
28 February 2006
(EXCERPTS)
Several published studies have demonstrated H5N1 infection in large cats kept in captivity. In December 2003, two tigers and two leopards, fed on fresh chicken carcasses, died unexpectedly at a zoo in Thailand. Subsequent investigation identified H5N1 in tissue samples.
In February 2004, the virus was detected in a clouded leopard that died at a zoo near Bangkok. A white tiger died from infection with the virus at the same zoo in March 2004.
In October 2004, captive tigers fed on fresh chicken carcasses began dying in large numbers at a zoo in Thailand. Altogether 147 tigers out of 441 died of infection or were euthanized. Subsequent investigation determined that at least some tiger-to-tiger transmission of the virus occurred.
(Continue . . . )In 2006, virologist C. A. Nidom of the Institute of Tropical Disease, Airlangga University demonstrated that of 500 cats he tested in and around Jakarta, 20% had antibodies for the H5N1 bird flu virus. Findings that prompted the FAO in 2007 to warn that: Avian influenza in cats should be closely monitored.
During the 2009 pandemic it became apparent that cats could contract human influenza viruses from humans as well (reverse zoonosis).
- We saw several reports of feline H1N1 infection, and in late 2010 we saw a study (see EID Journal: Pandemic H1N1 Infection In Cats) that looked at the pathogenesis of novel H1N1 in domestic felines.
- We revisited this topic earlier this year, in Connecticut: Two Cases Of Fatal H1N1 In Cats, after local vets announced two fatal H1N1 infections in cats from a single household. Reportedly, both cats had preexisting conditions, and the owner of the cats had recently been sick with a flu-like illness.
And in December of 2016, we saw just such an example when an H7N2 infected cat was taken into a New York City animal shelter, and the virus quickly spread to hundreds of other cats, and to one veterinarian (see NYC Health Dept Statement On Human H7N2 Infection).
Human infection with LPAI H7N2 has only rarely been reported, with a couple of cases on record in the United States (in 2002 and 2003), and 4 people who were presumed to have been infected in the UK in 2007 following local outbreaks in poultry. In all known cases, illness has been mild and self limiting.You'll find some follow up reports on this avian H7N2 virus outbreak in:
MAFRA's Quarantine division immediately announced plans to test stray cats in and around multiple areas that have been hit by avian influenza.Unlike avian H7N2, which has only produced mild illnesses in humans, HPAI H5N6 - which emerged in 2014 - has shown the ability to cause severe illness and even death in humans.
This was not the first time we'd seen reports of domestic cat infection with HPAI H5N6 (see 2015's H5N6 Rising: Infecting Birds, Humans, & Even Cats), but this was the first report of multiple cats infected.
Last year, in Arch. Of Virology: Novel Reassortant H5N6 Isolated From Cats - Eastern China, we again saw evidence of cats infected with avian H5N6.All of which brings us to a Dispatch, published yesterday in the EID Journal, which provides us the first in-depth details of South Korea's H5N6 outbreak in cats. Among the findings, cats displayed overt signs of neurotropic infection, including;
The histopathologic findings and the localization of H5N6 virus antigen to the lung and liver, but not to the brain, in cats have been reported (8). In this case, we observed meningoencephalitis. Moreover, the 3 cats showed neurologic symptoms such as salivation and convulsion, which may be related to necrosis and loss of neurons. The severity of the lesions was consistent with the number of cells that reacted with influenza viral antigen.We've also seen neurotropic effects described with infection by some clades of HPAI H5N1 (see CJ ID & MM: Case Study Of A Neurotropic H5N1 Infection - Canada) and other flu viruses as well (see JNeurosci: Another Study On The Neurocognitive Impact Of Influenza Infection).
I've only excerpted a portion of the study, so follow the link to read it in its entirety. When you return, I'll have a postscript.
Volume 24, Number 12—December 2018
Dispatch
Highly Pathogenic Avian Influenza A(H5N6) in Domestic Cats, South Korea KyungHyun Lee1, Eun-Kyoung Lee1, HyunKyoung Lee, Gyeong-Beom Heo, Yu-Na Lee, Ji-Youl Jung, You-chan Bae, ByungJae So, Youn-Jeong Lee, and Eun-Jin Choi
Author affiliations: Author affiliation: Animal and Plant Quarantine Agency, Gimcheon, South Korea
Abstract
In December 2016, highly pathogenic avian influenza (HPAI) infection with systemic pathological lesions was found in cats in South Korea. Genetic analyses indicated that the feline isolates were similar to HPAI H5N6 viruses isolated in chicken farms nearby. This finding highlights the need for monitoring of domestic mammals during HPAI outbreaks.
Highly pathogenic avian influenza (HPAI) H5N6 has spread across Asia, Europe, and Africa. Since a novel influenza A(H5N6) virus emerged in China in late 2013 (1), H5N6 viruses have been subsequently reported in Southeast Asia. In China, HPAI A(H5N6) virus caused the earliest reported human infection in 2014 and became one of the dominant subtypes in poultry farms and live poultry markets (2). These viruses caused a potential threat to other mammals, including pigs and cats (3,4). We report H5N6 virus infection in cats during 2016–17 HPAI outbreaks in domestic poultry in South Korea (5).
(SNIP)
Conclusions
Our results demonstrate that cats can be directly infected by HPAI H5N6 virus. Cats are companion animals and may act as a vector for influenza transmission to humans. Despite the low probability of H5N6 virus infection in companion animals, avian influenza surveillance will be needed for mammals, including cats, during H5N6 outbreaks.
Dr. KyungHyun Lee is a veterinary researcher at the Animal and Plant Quarantine Agency, South Korea. Her research interests include pathology and emerging infectious diseases in animals. Dr. Eun-Kyoung Lee is a veterinary researcher at the Animal and Plant Quarantine Agency. Her research interests include the molecular epidemiology and surveillance of avian influenza.(Continue . . . )
Some links to previous blogs on avian influenza in other domestic and peridomestic animals include:
HPAI H5Nx Clade 2.3.4.4. Shedding In Cottontail Rabbits
Study: Dogs As Potential `Mixing Vessels’ For Influenza
Influenza A(H6N1) In Dogs, Taiwan
Virology: Experimental Infection of Peridomestic Animals With Avian H7N9
Report: Skunks and Rabbits Can Catch And Shed Avian Flu
