COVID-19 IN HUMANS
COVID-19 causes flu-like symptoms in people, including mild to severe respiratory illness with fever, cough, and difficulty breathing. Person-to-person spread has been indicated in numerous countries, including the United States, and seems to occur when there is contact with an infected person’s bodily secretions, such as saliva or mucus droplets in a cough or sneeze. Transmission via touching a contaminated surface or object (i.e., a fomite) and then touching the mouth, nose, or possibly eye is also possible, but appears to be a secondary route. Smooth (non-porous) surfaces (e.g., countertops, door knobs) transmit viruses better than porous materials (e.g., paper money, pet fur) because porous, especially fibrous, materials absorb and trap the pathogen (virus), making it harder to contract through simple touch.
Time between infection and appearance of symptoms in people is not yet known with confidence, but initial estimates are approximately five to seven days. The COVID-19 quarantine period for people is 14 days. Cases of COVID-19 and instances of community spread are being reported in most states. People living in or traveling from places where ongoing community spread of SARS-CoV-2 is taking place appear to be at higher risk of exposure, with relative risk dependent on the location. Healthcare workers caring for patients with COVID-19 also have greater risk, as do close contacts of people with COVID-19. There are currently no antiviral drugs recommended or licensed by FDA to treat COVID-19, and there is no immunization available.
Awareness and prevention are important to reducing the spread of COVID-19:
- Avoid people who are sick.
- Call your physician if you experience a fever and respiratory issues.
- If you are ill, stay at home except to get medical care and call ahead before visiting your doctor. Minimize your contact with other people, including separating yourself from other members of your household who are not ill.
- Cover your mouth and nose when you cough or sneeze.
- Avoid touching your face, especially your eyes, nose, and mouth.
- Wash your hands often. Use soap and water, and wash for at least 20 seconds. If soap and water are not available, use hand sanitizer that contains at least 60% alcohol.
- Practice social distancing:
- CDC recommends keeping a distance of six to 10 feet from other people.
- Avoid gathering in public places, including attending or hosting large social gatherings. Postpone the latter, if at all possible.
- If considering a small gathering of friends, be careful that no one is showing symptoms of disease and/or is a close contact of someone who has.
- Shop for necessities at off-hours when there are likely to be fewer people in the store.
- As difficult as it may be, refrain from visiting people who are in assisted living and nursing facilities. They are among the most vulnerable population.
- Consider virtual visits with friends and the elderly.
- Regularly clean and disinfect objects and surfaces in your home and workplace. A list of products determined by the EPA to be effective for combatting viral pathogens is available from the American Chemistry Council Center for Biocide Chemistries (CBC).
- Those living in households with a person ill with COVID-19 should closely monitor their health and call their healthcare provider right away if they develop symptoms suggestive of COVID-19.
- The use of facemasks is not recommended for healthy members of the general public as a means of protection from COVID-19. Facemasks should be used by people with symptoms of COVID-19 to avoid spreading the disease to others and facemasks are also important for healthcare workers and people who are taking care of someone at home or in a healthcare facility.
Guidance is available from the CDC to help your household get ready for COVID-19 SARS-COV-2 AND DOMESTIC ANIMALS, INCLUDING PETS
On Thursday, February 27, Hong Kong’s Agriculture, Fisheries, and Conservation Department (AFCD) reported that samples obtained on February 26 from the nasal and oral cavities of a pet dog (a 17-year-old Pomeranian whose owner had been diagnosed with COVID-19) had tested “weak positive” for SARS-CoV-2, using a real-time reverse transcriptase-polymerase chain reaction (RT PCR) test. A fecal sample was negative. Testing was repeated on February 28, March 2, and March 5 with continued “weak positive” results (nasal and oral sample, nasal sample, nasal sample, respectively). The RT PCR test is sensitive, specific, and does not cross-react with other coronaviruses of dogs or cats. A “weak positive” result suggests a small quantity of SARSCoV-2 RNA was present in the samples, but does not distinguish between RNA detected from intact virus and fragments of RNA.
To better understand what this means, additional testing has been, and continues to be, conducted. Part of that testing is serology to see if the dog is mounting an immune response to the virus. An acute-phase sample was negative, indicating there are currently not measurable amounts of antibodies to the virus in the dog’s blood. This does not mean the dog is not infected with the virus, because it is not uncommon to have a negative result in earlier stages of infection. It can take 14 days or more for measurable levels of antibodies to be detected. A second “convalescent” phase sample will be obtained later for further testing. In addition, gene sequencing of the SARS-CoV-2 virus from the dog and its close human contacts has been done and the viral sequences are very similar.
Experts from the School of Public Health of the University of Hong Kong and the College of Veterinary Medicine and Life Sciences of the City University of Hong Kong believe the consistency and persistence of the results suggest the virus may have spread from the infected people to the dog in this particular case. Follow-up serology is pending. Testing has been conducted by the laboratories of the AFCD and the School of Public Health of the University of Hong Kong. The latter is an accredited reference laboratory for the WHO for the testing of SARS-COV-2. This pet dog is one of two pet dogs under quarantine in separate rooms in a facility at the Hong Kong Port of Hong Kong-Zhuhai Macao Bridge; the second pet dog has had negative results of tests for the virus. The pet dogs are being cared for and neither has shown any signs of being ill with COVID-19.
In other testing, IDEXX announced on March 13 that it had evaluated thousands of canine and feline specimens during validation of its new veterinary test system for the COVID-19 virus and had obtained no positive results. The specimens used for test development and validation were obtained from specimens submitted to IDEXX Reference Laboratories for PCR testing. Considering this information in total, infectious disease experts and multiple international and domestic human and animal health organizations (CDC, OIE, WHO) agree there is no evidence at this point to indicate that pets can spread COVID-19 to other animals, including people.
Although there have not been reports of pets becoming sick with COVID-19, out of an abundance of caution, it is recommended that those ill with COVID-19 limit contact with animals until more information is known about the virus. If you are ill with COVID-19, be sure to tell your physician and public health official that you have a pet or other animal in your home. Have another member of your household take care of walking, feeding, and playing with your pet. If you have a service animal or you must care for your pet, then wear a facemask; don’t share food, kiss, or hug them; and wash your hands before and after any contact with your pet or service animal. You should not share dishes, drinking glasses, cups, eating utensils, towels, or bedding with other people or pets in your home. Additional guidance on managing pets in homes where people are sick with COVID-19 is available from the CDC.
For responsible pet owners, preparing in advance is key. Make sure you have an emergency kit prepared, with at least two weeks’ worth of your pet’s food and any needed medications. Usually we think about emergency kits like this in terms of what might be needed for an evacuation, but it’s also good to have one prepared in the case of quarantine or self-isolation when you cannot leave your home. While we are recommending these as good practices, it is important to remember there is currently no evidence that pets can spread COVID-19 to other animals, including people.