Alberto Zangrillo, director of the San Raffaele Hospital in Milan, upset the global public health community on Sunday when he told RAI national television that “the virus no longer exists clinically in Italy” and patients in tiny amounts of viruses have swabs on the nose. In a follow-up interview with the Washington Post, Zangrillo theorized that something else could occur “in the interaction between the virus and human respiratory receptors”.
He added: “We cannot demonstrate that the virus is mutated, but we cannot ignore that our clinical findings have improved dramatically.”
The comments, which received widespread attention after a Reuters report, triggered a violent rebound from a senior official from the World Health Organization, Michael Ryan, who said on Monday during an online press conference: “We have to be extremely careful not to get a feel for it Suddenly the virus made a decision to be less pathogenic. That is not the case at all. “
The consensus among other experts interviewed on Monday is that clinical evidence in Italy is unlikely to reflect a change in the virus itself.
Zangrillo’s clinical observations rather reflect the fact that with the peak of the outbreak in the past, fewer viruses are in circulation and there is less likelihood that people will be exposed to high doses of them. In addition, only seriously ill people were likely tested early, compared to the situation where even people with mild symptoms are wiped more often, experts say.
The pandemic is developing rapidly. In some severely affected areas of the world, including northern Italy and New York City, the number of new cases is decreasing, while it is increasing dramatically in Brazil, Peru and India. However, the virus is slowly mutating, experts say.
Some strains of the virus have become more dominant, but there is still no clear evidence that one of them is contagious or deadly, according to scientists who have reviewed recent genetic studies.
Vaughn Cooper, an infectious disease specialist at the University of Pittsburgh Medical School, said the new coronavirus is slowly mutating compared to influenza and other microbes, and its genetic changes appear to be “largely unimportant”.
“I think it is safe to say that the differences that doctors in Italy report are solely due to changes in medical treatment and human behavior that limit the transmission and number of new infections caused by large inocula – a larger one Virus dose appears to be worse than changes in the virus itself, ”he said.
All viruses develop over time, and many infectious disease experts believe the novel coronavirus will be less deadly to humans and, along with four other coronaviruses, will cause colds. So far, however, there is no solid evidence that it has changed significantly in the five months since it was first detected in patients in Wuhan, China.
“The virus has not lost its function on the two-month time scale,” said Andrew Noymer, epidemiologist at the University of California at Irvine. “Loss of function is something that I expect over a period of years.”
In the United States, the pandemic has adopted a patchwork pattern, with much of the northeast improving significantly. Some places in the south – such as Alabama, Texas and Virginia – as well as Wisconsin, California and the state of Washington show an increase in confirmed cases, according to the Johns Hopkins University coronavirus tracker.
“Every place has a different epidemic, and that’s not because of the virus,” said Jennifer Nuzzo, an epidemiologist at the Johns Hopkins Center for Health Security.
Minor changes in the microbe’s genome occur at various locations on the planet. Epidemiologists use these mutations to track the spread of the virus. These changes are similar to stickers that are stuck to a well-traveled suitcase – markings where the luggage is located that do not change functionality.
Researchers Harm van Bakel, Emilia Sordillo and Viviana Simon from the Icahn School of Medicine at Mount Sinai, who focused on the genetics of the novel coronavirus, said in an interview that they had seen no decrease in viral load in patients’ hospital system since March , they have not yet discovered any significant genetic changes to the virus in New York City.
Meanwhile, people in the United States are holding their breath together to see if there is an increase in response to the reopening of the economy, public holiday weekend gatherings on Memorial Day, and the outbreak of protests against police violence in U.S. cities last days.
Nuzzo pointed out that it usually takes about five days and up to 14 days for an infection to cause symptoms. Then there is another time delay before someone searches for a test and gets a result. There is also a delay between the onset of symptoms and the hospitalization of a person with a serious illness. It may take a few weeks for the reduction in social distance to lead to a demonstrable change in the course of a local epidemic, she said.
Uncertainty is compounded by the lack of a clear understanding of where and how the virus spreads, as the country has not done extensive testing and contact tracking to know where or how infections have occurred.
“We never knew where the broadcast was in the United States. And still don’t know, ”she said. “Is it risky to go to the grocery store?”
Caitlin Rivers, epidemiologist and senior scientist at Johns Hopkins, noted that it is difficult to say to what extent people practice recommended security measures, such as social distance, in communities that have made it easier to stay at home. It is most concerned about overcrowded institutions where social distancing is difficult or impossible.
“I think we will continue to see explosive institutional outbreaks,” said Rivers.
Of the 10 districts in the United States where the average of their seven-day new cases increased most from Friday May 22 to Friday May 29, at least nine have experienced outbreaks in a correctional facility, a detention center, or a food processing center. or long-term care facility.
“An outbreak begins in an institution, then begins to move in the community,” said Rivers. “We can’t just say,” It’s there in this place, it’s irrelevant to the rest of us. “That is not true.”