Zoonotic diseases are infectious diseases that have jumped from an animal (non-human) to humans. Each week, this page is updated with the latest zoonotic news and articles from around the world, including COVID-19. Please send all comments or suggestions to email@example.com.
Pat Fricano is a One Health Collaborator that organizes and compiles a weekly list of zoonotic disease updates. He has in excess of 30 combined years of work experience in environmental protection and environmental public health between the Florida Department of Environmental Protection, the South Florida Water Management District and the Florida Department of Health. In his current capacity as the Zoonotic Diseases Coordinator at the Florida Department of Health in Palm Beach County, he tracks mosquito borne and other vector borne diseases.
Human Infection of Avian-Like Swine Influenza A(H1N1) in the Netherlands – 3/2021
We report a zoonotic infection of a pig farmer in the Netherlands with a Eurasian avian-like swine influenza A(H1N1) virus that was also detected in the farmed pigs. Both viruses were antigenically and genetically characterized. Continued surveillance of swine influenza A viruses is needed for risk assessment in humans and swine.
Eurasian avian-like swine influenza A(H1N1) viruses (IAVs) are entirely derived from a precursor virus of avian origin and have been enzootic in the swine population in Europe since 1979 and in Asia since 1993. Zoonotic infections with such viruses, which are then termed H1N1 variant (H1N1v) viruses, occur sporadically. Most cases occur in humans who have direct exposure to pigs. Since 1986, several human cases of Eurasian avian-like H1N1 swine IAV have been reported in Europe and China.
These events reflect the possibility of Eurasian avian-like H1N1 swine IAV transmission from swine to humans. In this study, we report an infection with a Eurasian avian-like H1N1 swine IAV in a pig farmer and his pigs in a herd in the Netherlands. We also conducted whole-genome characterization of viruses from the man and the pigs.
Study: Flu Shot Associated With Fewer, Less Severe COVID Cases – 3/24/2021
People who received a flu shot last flu season were significantly less likely to test positive for a COVID-19 infection when the pandemic hit, according to a new study. And those who did test positive for COVID-19 had fewer complications if they received their flu shot. These new findings mean senior author Marion Hofmann Bowman, M.D., is continuing to recommend the flu shot to her patients even as the flu season may be winding down.
“It’s particularly relevant for vaccine hesitance, and maybe taking the flu shot this year can ease some angst about the new COVID-19 vaccine,” says Hofmann, an associate professor of internal medicine and a cardiologist at the Michigan Medicine Frankel Cardiovascular Center. Michigan Medicine is the academic medical center of the University of Michigan.
Researchers reviewed medical charts for more than 27,000 patients who were tested for a COVID-19 infection at Michigan Medicine between March and mid-July of 2020. Of the nearly 13,000 who got a flu shot in the previous year, 4% tested positive for COVID-19. Of the 14,000 who hadn’t gotten a flu shot, nearly 5% tested positive for COVID-19. The association remained significant after controlling for other variables including ethnicity, race, gender, age, BMI, smoking status and many comorbid conditions, Hofmann says.
People who received their flu shot were also significantly less likely to require hospitalization, although the researchers didn’t find a significant difference in mortality between the two groups. No one in the study tested positive for both infections at the same time. The underlying mechanism behind the association isn’t yet clear, Hofmann says. “It is possible that patients who receive their flu vaccine are also people who are practicing more social distancing and following CDC guidelines. However, it is also plausible that there could be a direct biological effect of the flu vaccine on the immune system relevant for the fight against SARS-CoV-2 virus,” she says.
Prospective longitudinal studies to examine the effect of the flu vaccine on respiratory illness are ongoing, including the Household Influenza Vaccine Evaluation (HIVE) study through the University of Michigan’s School of Public Health. “It’s powerful to give providers another tool to encourage their patients to take advantage of available, effective, safe immunizations,” says co-first author Carmel Ashur, M.D., M.S., an assistant professor of internal medicine and a hospitalist at Michigan Medicine.
Months ago, Hofmann was concerned about misinformation she kept seeing online that connected the flu vaccine with a COVID-19 infection. Prominent media outlets like Reuters debunked this theory, and she knew her team’s data could also help address vaccine hesitancy. “Instead of a concerning connection between COVID-19 and the flu shot, our publication provides more confidence that getting your flu shot is associated with staying out of the hospital for COVID-19,” she says.
Before the pandemic hit, Hofmann and co-first author Anna Conlon, Ph.D., a U-M Medical School student, educated Frankel CVC patients about another encouraging association with the flu vaccine: cardiovascular protective effects. “There’s robust data that the flu shot prevents heart attack and hospitalizations for heart failure, which is an additional reason to get your vaccine every flu season,” Conlon says.
RHDV2 Kills Wild, Feral Rabbits in Oregon and Idaho – 3/26/2021
Rabbit hemorrhagic disease virus type 2 (RHDV2) was confirmed in a feral rabbit found dead in Milwaukie, Oregon and in two dead jackrabbits found near an airport in Boise, Idaho. The rabbit in Oregon was one of eight found dead in the Portland suburb, and state veterinarian Ryan Scholz believes the highly contagious virus killed all the rabbits.
Avian Influenza Events in Germany: No Sign of Ending – 3/27/2021
The risk of avian influenza is high in Germany, according to the Friedrich Loeffler Institute (FLI). The bird flu events have reached a second-high point in February; officials note saying the current epidemic in Germany have exceeded those of 2016/2017. In Germany, around 1,000 HPAIV H5 cases have been detected in wild birds and 133 outbreaks in poultry, six of them in birds kept in zoos or similar facilities, since October 30, 2020. In addition, a large number of European countries continue to report wild bird cases or outbreaks of HPAIV subtype H5 in kept birds on a daily basis.
The current spring migration of Nordic waterfowl can contribute to the supra-regional distribution. Therefore, the risk of spreading in waterfowl populations and entry into poultry holdings and bird populations (e.g. zoological facilities) continues to be classified as high. At present, there is also a high risk of entry through the spread of the virus between poultry holdings (secondary outbreaks). A high poultry density and (outpatient) live poultry trade pose particularly high risks. Biosafety in poultry keeping should continue to be checked and optimized.
Experts Review WHO Report on SARS-Cov-2 Origin – 3/29/2021
Scientists investigating the origin of SARS-CoV-2 on behalf of the World Health Organization do not believe the virus leaked from a lab and found it unlikely that the virus was spread on frozen food packaging, and they recommended more research on other possible sources, including transmission from bats directly or through another animal. "Seventeen experts, longstanding leaders from the field, including epidemiology, public health, clinical medicine, veterinary medicine, infectious disease, law, food security, biosafety, biosecurity ... will be reviewing this report intensively and quickly," said White House Press Secretary Jen Psaki.
Rescuing Dogs From Abroad Could Threaten Livestock – 3/29/2021
Dogs brought into the US for adoption from areas where African swine fever virus or other foreign animal diseases (FADs) are endemic could introduce those diseases into the US livestock industry, National Pork Producers Council Chief Veterinarian Liz Wagstrom wrote in a blog post. "While the dogs are not known to be susceptible to or carry FADs, there is the potential for bedding, crates or contamination of the dogs' coats to serve as disease carriers," she wrote.
Rabbit Hemorrhagic Disease Virus Found in Colorado – 3/30/2021
Rabbit hemorrhagic disease virus type 2 (RHDV-2) was found in North American cottontail rabbits and hares in Garfield and Saguache counties, Colorado, bringing the number of Colorado counties with confirmed RHDV-2 cases to 15. State wildlife officials are concerned the virus will spread to snowshoe hares and pikas, which could indirectly affect predatory species like the Canada lynx.
Unapproved Swine Fever Vaccines Reduced Hog Supply in China - 3/30/2021
Use of illegal African swine fever vaccines by some Chinese hog producers last year reduced output of hogs and will support prices in 2021, an executive from leading pork processor WH Group said on Tuesday. China has been trying to rebuild its massive hog herd since the deadly African swine fever virus ravaged the country’s farms during 2018 and 2019. But use of unapproved vaccines in a bid to protect against the disease had the opposite effect and ended up killing pigs, said Ma Xiangjie, president of Henan Shuanghui Investment and Development, WH Group’s domestic unit.
Pig prices rose significantly at the end of 2020, as supplies tightened, said Ma, defying expectations of growing hog output. “Since the second half of last year some pig producers in China, especially south of the Yangtze river, used some immature pig vaccines and caught African swine fever again,” said Ma, after the company released its annual earnings. The company has raised its forecast on pig prices this year due to the impact of “toxic vaccines”, he added, though said prices will still be on average lower than in 2020. The company said it processed 46% fewer hogs in China in 2020 compared with the prior year because of tight supply but lifted its imports to make up the shortfall.
Tula Virus as Causative Agent of Hantavirus Disease in Germany – 4/1/2021
We report molecular evidence of Tula virus infection in an immunocompetent patient from Germany who had typical signs of hantavirus disease. Accumulating evidence indicates that Tula virus infection, although often considered nonpathogenic, represents a threat to human health.
Animal Reservoirs and Hosts for Emerging Coronaviruses – 4/2021
The ongoing global pandemic caused by coronavirus disease has once again demonstrated the role of the family Coronaviridae in causing human disease outbreaks. Because severe acute respiratory syndrome coronavirus 2 was first detected in December 2019, information on its tropism, host range, and clinical manifestations in animals is limited. Given the limited information, data from other coronaviruses might be useful for informing scientific inquiry, risk assessment, and decision-making. We reviewed endemic and emerging infections of alphacoronaviruses and betacoronaviruses in wildlife, livestock, and companion animals and provide information on the receptor use, known hosts, and clinical signs associated with each host for 15 coronaviruses detected in humans and animals. This information can be used to guide implementation of a One Health approach that involves human health, animal health, environmental, and other relevant partners in developing strategies for preparedness, response, and control to current and future coronavirus disease threats.
Coronaviruses are a family of RNA viruses whose large genomes, propensity for mutation, and frequent recombination events have resulted in a diversity of strains and species that are capable of rapid adaptation to new hosts and ecologic environments. This viral plasticity has garnered widespread concern because of zoonotic potential and the consequences of new emergence events in both human and animal populations. The emergence of a new strain of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which causes coronavirus disease (COVID-19) has once again demonstrated the role of the family Coronaviridae in causing human disease outbreaks. SARS-CoV-2, a novel betacoronavirus, was identified in human patients from Wuhan, China, during December 2019 and has resulted in a global pandemic, an unprecedented public health emergency, and untold economic and societal repercussions worldwide. Similar to the 2002–2003 severe acute respiratory syndrome (SARS) epidemic, a live animal market where hundreds of animal species were sold is suspected to be associated with the emergence or early spread of COVID-19 in humans.
Human Monkeypox and Declining Immunity in Nigeria – 4/2021
A monkeypox outbreak in Nigeria during 2017–2020 provides an illustrative case study for emerging zoonoses. We built a statistical model to simulate declining immunity from monkeypox at 2 levels: At the individual level, we used a constant rate of decline in immunity of 1.29% per year as smallpox vaccination rates fell. At the population level, the cohort of vaccinated residents decreased over time because of deaths and births. By 2016, only 10.1% of the total population in Nigeria was vaccinated against smallpox; the serologic immunity level was 25.7% among vaccinated persons and 2.6% in the overall population. The substantial resurgence of monkeypox in Nigeria in 2017 appears to have been driven by a combination of increased exposure and interactions with forest animals, driven by deforestation, armed conflicts and population migration; and population growth, accumulation of unvaccinated cohorts, and decline in smallpox vaccine immunity. The expanding unvaccinated population means that entire households, not just children, are now more susceptible to monkeypox, increasing risk of human-to-human transmission.
Fatal Crimean-Congo Hemorrhagic Fever Caused by Reassortant Virus, Spain - 4/2021
In August 2018, a fatal autochthonous case of Crimean-Congo hemorrhagic fever was confirmed in western Spain. The complete sequence of the viral genome revealed circulation of a new virus because the genotype differs from that of the virus responsible for another case in 2016. Practitioners should be alert to possible new cases.
A fatal case of Crimean-Congo hemorrhagic fever (CCHF) detected in Spain in 2018 was caused by a different genotype, a reassortant virus, than the genotype of a previous case detected in 2016. This unexpected variability contrasts with the situation in other CCHF-endemic countries. Because CCHF is a zoonotic disease and animal migratory routes between Europe and Africa usually pass through Spain, data about genetic sequences are crucial for monitoring infections in humans, developing suitable detection tools, and providing information about the dynamics of virus circulation and spread.
Low-Level MERS Coronavirus Among Camel Handlers, Kenya – 4/2021
Although seroprevalence of Middle East respiratory coronavirus syndrome (MERS) is high among camels in Africa, researchers have not detected zoonotic transmission in Kenya. We followed a cohort of 262 camel handlers in Kenya during April 2018–March 2020. We report PCR-confirmed Middle East respiratory coronavirus syndrome in 3 asymptomatic handlers.
Since the first human case of Middle East respiratory syndrome coronavirus (MERS-CoV) was identified in 2012, the World Health Organization has reported 2,494 infections and 858 deaths (case-fatality ratio 34.4%) in persons across 27 countries in the Middle East, Europe, Asia, and North America. Dromedary camels (Camelus dromedarius) are the known reservoirs of the virus. Most human cases result from direct or indirect transmission of virus from camels or human-to-human transmission in healthcare settings; researchers have also documented limited secondary transmission to household contacts. Occupational direct contact with camels is a risk factor for primary MERS-CoV infection. Camel workers and herders have a 0%–50% seroprevalence of MERS-CoV, generally higher than that of the general population in Saudi Arabia.
Although infection is widespread among dromedary camels, zoonotic transmission from camels to humans is sporadic, and disease prevalence among humans is not directly proportional to potential exposure to infected camels. Although >65% of the world’s dromedary camels live in Africa, on that continent MERS-CoV seroprevalence in humans is low (0.2%), with no documented cases of acute human infection. Furthermore, studies in the Africa region have identified MERS-CoV RNA in 11%–16% of camels and in 80%–95% of seropositive camels. To determine whether MERS-CoV infections occur in humans in a region with high seroprevalence among camels, we studied a cohort of 262 camel handlers in Kenya.
February 2020: First dog tests positive in Hong Kong. Pomeranian, 17-year-old, owner diagnosed with COVID-19, PCR positive followed by antibody positive status. Dog later died of causes likely related to age and other known health issues, NOT COVID-191.
March 2020: A 2-year-old German shepherd in Hong Kong is PCR positive after the owner was diagnosed with COVID-192.
April 2020: False PCR positive in a pug in North Carolina, antibody negative, family was COVID-19 positive3.
May 2020: An 8-year-old American bulldog from the Netherlands was antibody positive and owner had COVID-19. The dog was euthanized due to worsening breathing problems, but it is unknown if the breathing issues were caused by COVID-19 or if they were unrelated4.
June 2020: First confirmed PCR positive in the United States. The German shepherd from COVID-19 positive household had respiratory illness. The other dog in the household was antibody positive5.
October 2020: Canada reported its first case of a positive, asymptomatic dog that was identified as a part of a research study. People in the household were diagnosed with COVID-19 and likely transmitted the virus to the dog13.
Other dogs have been confirmed by the USDA to have had the infection via antibody testing as a part of targeted, active surveillance: 2 in Utah, 2 in Wisconsin, 1 in North Carolina, and 9 in Texas9.
April 2020: The United States confirmed its first two cases in pet cats in two different areas of New York state. Both cats had mild respiratory illness3.
Other cats have been confirmed by the USDA to have had the infection via PCR or antibody testing as a part of targeted, active surveillance: 4 in Utah, 2 in New York, 8 in Texas, and 1 in Louisiana12.
While there have NOT been any documented cases of naturally infected rabbits, ferrets, or hamsters, early and unpublished studies have shown that they are possibly susceptible to infection, and precautions should be considered if you are ill and have these animals in the household1–3. There is some evidence that while rabbits and ferrets can become infected, they seem to require closer contact for transmission, may be asymptomatic, and may not be able to spread it easily to others4,5.
In the United States, IDEXX, a veterinary testing service, announced that they have developed a test for COVID-19 in pets. In the process of validating this new test, thousands of samples (collected for other reasons) were tested from the U.S.; all tests for COVID-19 in those cats and dogs were negative1.
The USDA has begun tracking positive animal cases in the United States that have been confirmed by USDA’s National Veterinary Services Laboratories, and are reporting them on their website: https://www.aphis.usda.gov/aphis/ourfocus/animalhealth/SA_One_Health/sars-cov-2-animals-us
All information to date indicates that some animals are able to be infected by the COVID-19 virus, but it appears to be an infrequent occurrence. In Hong Kong, at least 30 dogs and 17 cats have been tested from homes with owners that were either confirmed COVID-19 cases or were close contacts to a COVID-19 patient, and only 2 dogs and 1 cat have tested positive.
Recently, there has been strong evidence of at least two humans becoming infected after exposure to infected mink at farms in the Netherlands1,2. It is suspected that a human initially infected the mink at the farm, and then the infection spread back to other humans from these infected minks. In November, Denmark reported proof of human to mink to human transmission, as well as evidence of viral mutation during this infection cycle3.
In response to this evidence, the OIE released a statement acknowledging concerns about animals becoming reservoirs for the virus, and the possibility of future spillover events from animals to humans. In light of this public health concern, the OIE recommends the following: 1) implementing national risk reduction strategies and a One Health approach to prevent the transmission of the virus between humans and susceptible animals, 2) monitor susceptible animals and humans in contact with these animals, 3) report cases to the OIE, and 4) share genetic sequences and other research findings and data4.
A study out of the University of Minnesota and University of North Carolina looked at which animals have the most similar receptors to the virus when compared to humans. These receptors are used by the virus to enter the cell and cause infection. The study observed cats, ferrets, pigs, and non-human primates have the most similar receptors to human receptors1.
A small study (not peer reviewed or published at this time, which means it has not been evaluated by other scientists for validity and suitability for publication) out of an OIE collaborating research center in China investigated the ability of ferrets, dogs, cats, pigs, chickens, and ducks to become infected with the COVID-19 virus. Both ferrets and cats were able to be infected through direct exposure (placing virus into the nose). One cat became infected through close contact alone, which suggests that cats can spread the virus through respiratory droplets to other cats. Dogs were able to become infected with direct exposure, but did not become infected through close contact, and none of the dogs had symptoms. The pigs, chickens, and ducks did not become infected2.
Another very small study (not peer reviewed or published at this time) found that cats are highly susceptible to subclinical SARS-CoV-2 infection. This means they can become infected from humans or other cats, but typically do not have clinical signs or do not appear ill. While they are infected, however, they can spread the virus to other cats. Dogs were able to become infected but did not shed virus during infection. Therefore, dogs were unable to spread the virus3. Another small study (not peer reviewed or published at this time) demonstrated similar findings with cats: infected cats in the study were asymptomatic but were able to spread the virus to other cats in just a few days4.
A study performed in Hong Kong found evidence that human to cat transmission is possible but not common, with 6 out of 50 cats in COVID-19 positive households testing positive for the virus. One of the cats that tested positive had the identical viral genome sequence, providing more evidence that the infection was almost certainly acquired by the humans in the household5.
A small study with 7 cats and 3 dogs observed that dogs can become infected and mount an immune response to SARS-CoV-2, but do not shed virus; cats are susceptible to productive SARS-CoV-2 infection but are unlikely to develop clinical disease (signs and symptoms). Cats in this study also were resistant to reinfection, meaning cats could be useful to study further for vaccine development in humans6.
Researchers at the University College London published a study7 in Scientific Reports (Nature) showing that dozens of animals have the ACE2 spike protein, which allows the virus to infect the host. The study also reported that most birds, fish, and reptiles do not appear susceptible. This study highlights the importance of surveilling and monitoring farmed and wildlife species to detect possible reservoirs and prevent future outbreaks8.
In August, the Wildlife Health Specialist Group (WHSG) of the International Union for Conservation of Nature and the World Animal Health Organization created guidelines centered on SARS-CoV-2 transmission risk to free-ranging wild mammals. In this document, the risk of reverse zoonosis and the possibility of the wildlife population to become a reservoir for the virus is discussed in detail. Click here for the guidelines.
A study in Germany evaluated raccoon dogs as a potential intermediate host. The study found that raccoon dogs are susceptible to infection and are able to transmit the virus to other raccoon dogs in close proximity9.
Because this virus is new and we are still learning, as a precaution you should restrict contact with your pets if you are diagnosed with COVID-19. If this is not possible, wash your hands before touching your pet, avoid snuggling and other close contact, and wear a facemask or something to cover your nose and mouth.
There are no specific recommendations or guidelines at this time. However, in general, monitor your pet for any signs of illness (coughing, sneezing, excessive sleepiness, vomiting, diarrhea, difficulty breathing). Contact your veterinarian if these occur, particularly if your pet has been exposed to someone diagnosed with COVID-19.
No. Currently, there are shortages of supplies such as facemasks, and medical personnel and those sick with COVID-19 should have first access to these masks. Additionally, especially in certain breeds, masks can cause breathing difficulty.
There is currently no vaccine for the SARS-CoV-2 virus that causes COVID-19. The canine coronavirus vaccine is not effective for preventing COVID-19, it is only effective for preventing canine coronavirus, which is a virus that causes severe diarrhea. They are two different coronaviruses.
In September, a vaccine candidate to protect cats from the virus that causes COVID-19 began clinical trials1. If successful, it will likely not be available until 2021 at the earliest.