Animals at risk of catching virus from humans

Is it a media frenzy? Maybe, maybe not. But the fact is, H1N1 among companion and production animals has hit the public’s radar screen.
H1N1 among ferrets, cats, dogs, poultry, swine and even a cheetah has been documented, and several animals have died because of it. While owners may be frightened of contracting the disease from their pets, the facts seem to indicate that the animals are the ones who should be afraid. That’s because at press time, the documented cases of H1N1 among animals almost exclusively involved transmission of the virus from humans to animals, not the other way around.
The impact on Veterinary Advantage readers remains to be seen. However, it is likely that, if anything, sales of hand hygiene and other personal-protective products may jump, as caregivers take special precautions not to spread the virus to the animals in their care.

Close contact with human illness
When Vet-Advantage spoke with her in late November, Kimberly Anne May, DVM, MS, DACVS, assistant director, department of professional and public affairs for the American Veterinary Medical Association, noted that the confirmed cases of H1N1 among animals primarily involved animals who had been in close contact with people who themselves had been affected by the virus.
Ferrets appear to be more susceptible to influenza A viruses in general, and H1N1 appeared to be no exception, said May. Most of the cats that had contracted H1N1 were older – generally older than 10 years old – and had had intensive contact with owners who had been ill, she added.

Recognizing the signs
Animals such as ferrets and cats typically present with sniffling, sneezing and runny noses, said May. Cats are more likely to show up with signs of pneumonia. While humans affected with H1N1 are treated with medications such as Tamiflu, no such recommendations are on the books for animals, according to May. In fact, there are no approved antiviral drugs for animals. “Realistically, the government is putting its emphasis on the human population,” she said.
“The majority of animals have recovered with supportive care,” said May. In most cases, that means making sure the animals are eating properly, even to the point of feeding them intravenously if necessary. Antibiotics may be necessary if a secondary infection, such as pneumonia, is present.

Confirming H1N1
Vets can make a presumptive diagnosis of H1N1 in their offices, said May. “If the animal presents with a respiratory problem, they need to do a thorough physical. It would also help to ask, ‘Has somebody in your house been sick with flu-like signs in the past week or two?’ If the answer is ‘Yes,’ that raises the index of suspicion.”
Thirty-six laboratories around the country are currently approved to conduct swine influenza virus diagnostics, says Dr. John R. Clifford, the U.S. Department of Agriculture’s chief veterinary officer. Together, these 36 state and university diagnostic laboratories form the National Animal Health Laboratory Network. A cooperative effort of the USDA’s Animal and Plant Inspection Service (APHIS), USDA’s National Institute of Food and Agriculture, and the American Association of Veterinary Laboratory Diagnosticians, NAHLN was formed over the past few years to provide the surge capacity needed for situations such as H1N1, says Clifford. (A listing of approved SIV laboratories appears at http://www.aphis.usda.gov/animal_health/nahln/downloads/siv_lab_list.pdf.?)
These 36 labs use standardized protocols provided by the National Veterinary Services Laboratories to conduct H1N1 testing. Once an approved lab identifies a positive H1N1 result, the sample is sent to NVSL for confirmatory testing. “Veterinarians should contact an approved NAHLN lab directly to find out how to submit samples to the lab,” says Clifford.
The AVMA recommends collecting an oropharyngeal, tracheal or nasal swab. Serum should also be collected. The samples should be collected on a dried polyester fiber swab (e.g., Dacron^TM) or flocked swab (e.g., Copan) and placed in a sterile tube with a few drops of viral transporting medium or saline. The association advises against using bacterial transport medium. The first cat (in Iowa) confirmed to be 2009 H1N1 influenza-positive was diagnosed based on testing of a sample obtained by bronchoalveolar lavage (BAL) during anesthesia, indicating that BAL samples are also sufficient for testing.
The National Veterinary Services Laboratories does not produce commercial diagnostic tests, said Clifford. That said, “the APHIS Center for Veterinary Biologics would provide licensing of commercial test kits if manufacturers determined there was a market for such a test,” he adds.
In December, IDEXX Reference Laboratories introduced its latest RealPCR™ test for canine and feline H1N1 influenza virus. Given the short shedding period of influenza viruses, samples should be submitted for testing to one of IDEXX’s 22 reference labs within seven days of onset of clinical signs to avoid false-negative results, according to the company. Test results are typically available within 72 hours.
Polymerase chain reaction, or PCR, is a laboratory process that enables the production of virtually unlimited copies of genetic material in the laboratory, according to IDEXX. A PCR diagnostic test indicates the presence of a virus, rickettsia, bacterium, parasite or fungal organism by detecting the organism’s amplified DNA in the patient sample.
IDEXX recommends that the H1N1 test be offered in conjunction with the feline upper respiratory disease and canine respiratory RealPCR panels so that the veterinarian can quickly identify and differentiate multiple causes of respiratory infection and begin timely and effective treatment.

Vaccinations
In June 2009, the USDA announced it would make the master seed virus for the novel H1N1 flu available to interested veterinary biologics manufacturers for development of a vaccine. The virus was sent to 10 veterinary biologics firms, not all of which intended to make vaccine, but rather, to do testing and reagent production associated with manufacture, says Clifford. As of early December, four firms were pursuing vaccine licensure, though Clifford would not say who they were.
When developed, the vaccine will be inactivated whole virus, as opposed to human vaccine for H1N1, which is either inactivated viral protein or a live attenuated virus given as a nasal mist, says Clifford. “Vaccination is advised for pregnant sow and gilts that develop maternal antibodies to protect nursing piglets,” he says. “It can also be useful to healthy swine three weeks of age or older, with specific recommendations by the attending veterinarian, dependent on production conditions.”
In Iowa, Hank Harris, professor of animal science at Iowa State University’s schools of agriculture and veterinary medicine, developed a swine vaccine and as of early December, had shipped more than 30,000 doses to a pork producer in Indiana, in whose herd H1N1 had been confirmed. The vaccine was developed by Harris’s start-up company, harrisvaccines Inc. (d/b/a Sirrah Bios), which came out of his Iowa State University lab. Sirrah Bios produces and sells vaccine strictly through veterinarians via 9 CFR 107.1 (veterinary/client/patient relationship), he says. Meanwhile, harrisvaccines Inc. was in the process of obtaining licenses to produce and sell vaccine via the USDA’s Center for Veterinary Biologics.
“For our products, produced by either harrisvaccines or Sirrah Bios, we do not require live viruses,” explains Harris. “We produce all our vaccines by sequencing and then synthesizing the critical genes of each virus.” For the novel H1N1 vaccine, “we pulled the hemagglutinin gene sequence off the [Centers for Disease Control and Prevention] Web page last April, had it synthesized, and then placed the gene in our replicon platform to produce the vaccine.” The results of Harris’s work were published online by the National Center for Biotechnology Information, at http://www.ncbi.nlm.nih.gov/rrn/articlerender.fcgi?acc=RRN1123.

Impact on sales
If H1N1 or other respiratory illnesses increase this season, it’s possible distributors may see a jump in the need for fluids or antibiotics, says May. In addition, any distributors that sell human influenza A point-of-care tests may see an increase in those as well.
It is also possible that distributors might see an increase in the demand for antiseptics, whether for veterinarians’ resale to clients, or simply for use in the office. “We do have to worry about workers in veterinary clinics,” says May. Often, staff come to work even when they’re sick. “They can potentially be a source of infection not only to the other staff, but to the animals. Ideally, people are increasing their vigilance and they’re staying home when sick.”