British scientists rush to answer basic questions about the Covid-19 virus and its transmission before the lifting of the current national lock is approved by the government in the near future. Researchers say that relaxing social distancing should only happen once one understands why new infections of the disease are still diagnosed by the thousands every day.
Such a rate means that efforts to test and find infected contacts – a key element of the government’s anti-Covid strategy in the coming months – would be quickly overwhelmed. Much more information is needed on how the coronavirus is transmitted, they say. The new data will fuel the debate on the parameters in which the lock will be lifted first – for example, if it is relatively safe to organize outdoor events.
And last week, several groups launched studies aimed at providing answers. These include projects to analyze the behavior of aerosols loaded with viruses in the air in order to understand how the disease is transmitted between humans. In addition, other programs will target healthcare workers to study how the virus spreads to them from patients and then from others.
The importance of this latter approach has been revealed in recent figures for Covid-19 cases which have shown a decrease in the number of new cases in hospitals but reveal significant increases among health and social service workers.
This point was underlined by the epidemiologist Anne Johnson of the University College of London. She said reducing the transmission of Covid-19 to health and social services workers has now become a top priority. “Half of all new infections reported last week were by health professionals,” she said. Observer. “It has become the leading edge of the spread of the disease.”
Lack of protective equipment and the clothes may have made the situation worse, she added. “However, what is certain is that caregivers are still at risk from their patients from whom they can catch the virus and, in turn, pass it on to their colleagues, their own families and possibly other patients. We must focus on limiting the spread of Covid-19 among health and social service workers as a top priority if we are to have a chance of ending this epidemic. “
This opinion was supported by infectious disease expert Tom Wingfield of the Liverpool School of Tropical Medicine. “The figures show that the rate of decline in new cases is slower in the UK than in other European countries and that this is likely due to the transmission that occurs in health and social care settings, to the transmission in the community despite the social distancing and, to a lesser extent, the chains of transmission that still occur within households, in particular in larger households or in shared housing. “
Last week, researchers at the University of Bristol launched a major study to find out exactly how health workers are infected with the Covid-19 virus. “We have taken a group of 130 health workers and we will be testing them extensively over the next three months,” said project leader Professor Adam Finn.
“We will take swabs from them twice a week, take blood samples regularly and catalog their symptoms – until some of them are infected.” We will then be able to know when they were infected; how it relates to their symptoms at the time; and how it relates to their immune response. We will find out the details of the natural history of the disease as none of this information is known in detail. On the other hand, it is vitally important if we are to understand how this disease behaves. “
Finn said that the current modeling of the disease – although superb – was based on assumptions. “Basically, the models are conjectures about the behavior of the virus. To get rid of the guesswork, we need to provide evidence of how the virus actually behaves. “
Another approach is taken by another group at the University of Bristol, led by the chemist, Professor Jonathan Reid. Her team is studying how the Covid-19 virus is spread from person to person. This happens when fairly large droplets are spit or sneezed by infected people. However, it is also possible that viruses will spread through much smaller aerosol particles – although it is unclear whether they can carry enough viruses to be infectious.
“This is clearly important to know, because aerosols can travel much further than heavier droplets,” said Reid. His team has just built an automated high containment laboratory containing an apparatus in which clouds of aerosol particles loaded with viruses can be suspended while the researchers modify the temperature, the humidity, the ozone, the levels of sunlight and other variables.
“This way we can study how the infectivity of the virus changes,” added Reid. “It could tell us if he’s affected by the heat. If so, this epidemic could be seasonal. We might also have a better idea of how to operate air conditioning in hospitals, nursing homes and public spaces – in terms of temperature or humidity – in order to reduce the lifespan of the virus in order to reduce its exposure. “