The incubation period, fecal-oral transmission, hospital surge, internet scams, & the risk for pets.
There is so much news about the COVID-19 coming at us that it’s hard to know what a person should pay attention to.
Here are five pieces of news from this week’s torrent that we think are noteworthy.
1) People infected with virus that causes COVID-19 may be symptom-free for five days-and they may be able to transmit the virus during that period.
A team of researchers led by Stephen Lauer and Kyra Grantz of the John Hopkins Bloomberg School of Public Health used 181 confirmed cases from Hubei Province to model an estimate that the median incubation period COVID-19 is 5.1 days and that nearly all infected people will have symptoms within 12 days of infection. In their piece posted this week by the Annals of Internal Medicine, Lauer and Grantz et al said their estimate fits with others and supports the current active monitoring period (aka the quarantine period) of 14 days recommended by CDC.
But there are a couple of nuances to consider. The researchers note that while symptomatic disease is frequently associated with transmissibility, “given recent evidence of SARS-CoV-2 transmission by mildly symptomatic and asymptomatic persons we note that time from exposure to onset of infectiousness (latent period) may be shorter than the incubation period.” In other words, infected people may be able to transmit the virus during the incubation period when they don’t have symptoms.
The researchers also estimate that a small number of cases (101 out of 10,000) will develop symptoms after the 14-day period, so “…there may be high-risk scenarios (for example, a health care worker who cared for a COVID-19 patient while not wearing personal protective equipment) where it could be prudent to extend the period of active monitoring.
2) Fecal-oral may be a route of transmission, and some of the first symptoms may be gastrointestinal.
Two reports published in Gatroenterology suggest that RNA and proteins from the SARS-CoV-12 virus that causes COVID-19 are shed in feces. This is a preliminary finding, but the coronaviruses that caused the SARS and MERS epidemics were also shed in the stool, so this is not an outlandish finding. The mere possibility of fecal-oral route of transmission would be another reason to wash your hands.
The CDC says fever, cough, and shortness of breath are symptoms that may appear 2-14 days after exposure. But the case report published last week in the New England Journal of Medicine about the very first U.S. case of COVID-19 says the patient reported a 2-day history of nausea and vomiting as well as a dry cough.
3)Hospitals need to be ready for a surge of cases.
Reports suggest that COVID-19 is associated with severe disease that requires intensive care in about 5% of proven infections, according to Srinivas Murthy, of the University of British Columbia and his coauthors of a clinical update pubished in JAMA this week. They note that variability in the case-fatality rate in different parts of China underscores how important hospital capacity will be (that and whether social distancing can flatten the curve of new cases).
“Appreciating typical clinical features and disease course are crucial both to prepare for increasing numbers of patients and to determine how to best treat infected persons,” wrote Murthy and his colleagues, Charles Gomersall and Robert Fowler.
Murthy, Gomersall, and Fowler say the most documented reason for requiring intensive care has been respiratory support; two-thirds of those patients have met criteria for acute respiratory distress syndrome, they write. ARDS treatment includes conservative intravenous fluid strategies, empirical use of antibiotics, and consideration of extracorporeal membrane oxygenation. Their list of COVID-19 modifications to usual critical care includes private rooms for suspected cases if possible, keeping patients two meters apart, and N95 respirators and eye protection for clinicians performing aersol-generating procedures.
4) Beware of malicious COVID-19-related internet scams.
COVID-19 and coronavirus may be setting clickbait records because the interest-and fear-of the pandemic is running so high. Scammers know that the open rate of emails with coronavirus or COVID-19 in the subject line is going to be high. Some of that “phishing” email is designed to look like it came from the CDC or WHO. Rule one: Don’t open that link that promises more information.
One scam that is getting a lot of attention is a website that is a replica of a John Hopkins website that features a global map of coronavirus cases. The scammers' replica website has spyware that steals usernames, passwords, credit card numbers, and other data stored in browsers.
5) Can dogs and cats get COVID-19 and spread it? Doubtful but possible.
A Pomeranian in Hong Kong tested positive for the SARS-CoV-2 last week. As David Grimm reported in Science this week, that news stirred up worry that pets might contract COVID-19 from humans and end up being part of the chain of transmission. Hong Kong officials said the dog was “weakly positive,” according to Grimm’s reporting, but strongly advised that mammalian pets in households of quarantined people also be put under quarantine.
Grimm interviewed Shelley Rankin, a microbiologist at the University of Pennsylvania School of Veterinary Medicine, Philadelphia, whose lab is part of the FDA’s Veterinary Laboratory Investigation and Response Network. Rankin told Grimm that “samples from the Hong Kong dog had a small number of virus particles present, but added that “in an animal with no clinical signs of disease, it’s hard to say what this means.”
Rankin noted, though, that as mammals, the cats and dogs have cells with same kinds of receptors as humans, so the virus could theoretically attach to those receptors. She doubts, though, that it would enter the cells and replicate.
“Still, people infected with SARS-CoV-19 should limit contact with their pets,” Rankin told Grimm. “Wash your hands, and don’t let them lick you on the face. If the virus is in your secretions, and there’s any potential of transmission, these are ways it could be transmitted.”