As the number of COVID-19 coronavirus cases grows worldwide, the United States CDC has detailed the main ways in which SARS-like disease could spread and the routes that affect it most. The first person-to-person infection in the U.S. was confirmed in late January 2020, and the U.S. Centers for Disease Control and Prevention have since held several briefings to outline exactly what people should – and shouldn’t – be worried.
One of the most pressing questions is the mechanism of how that person-to-person dissemination could take place. COVID-19 has an incubation period of approximately fourteen days and one of the challenges facing healthcare professionals is that, if tested too early, current tests for infection can return a false negative.
“Based on what we know now, we believe that this virus spreads mainly from person to person, between close contact, which is defined as about one meter and eighty, through respiratory droplets produced when an infected person coughs or sneezes,” Nancy Messonnier, MD, director of the National Center for Immunizations and Respiratory Diseases said today during a CDC briefing. “People are thought to be more contagious when they are more symptomatic: that is, when they are the most sick.”
There are, however, two other ways in which coronavirus can be transmitted. “There may be some spread by touching the contaminated surfaces and then touching the eyes, nose and mouth,” added Dr. Messonnier. “But remember, we believe this virus doesn’t last long on surfaces. Some spread can occur before people show symptoms. There have been some reports of this with the new coronavirus, and it is compatible with what we know of other respiratory viruses, including seasonal flu. ”
In fact, it is the first concern to cough and sneeze. “At this time, we don’t believe that the latter two forms of transmission are the main spreading factor,” said Dr. Messonnier.
Disease surveillance is increasing in response
Five public health labs in the United States have already been brought online to add COVID-19 surveillance to their existing work. “We are looking into existing surveillance systems for both influenza and respiratory diseases,” explained Dr. Messonnier. “The results of this surveillance would be an early warning signal to trigger a change in our response strategy.”
The fear is that, although it is not currently a problem, coronavirus infection could become more widespread. While not guaranteed, it is something the CDC and other agencies are preparing for. “We must prepare for the possibility that at some point we may see a sustained spread of the community in other countries or in the United States, and this will bring about a change in our response strategy,” said Dr. Messonnier.
Current public health labs are located in Los Angeles, San Francisco, Seattle, Chicago and New York City. “This is only the starting point and we plan to expand into multiple sites in the weeks of the contest until we have national surveillance,” confirmed the director of NCIRD.
A delay in the test
One of the biggest steps already taken has been to expand the test of potentially infected samples, using an accelerated coronavirus assessment. This recently hit a problem when reports from external labs indicated that inconclusive results were being produced. Investigations conducted by these laboratories and CDCs identified problems in the reagents used as part of the test.
The CDC is currently reformulating these reagents, confirmed dr. Messonnier, although there is no time for when they might be ready for redistribution.
In the meantime, however, the greatest risk for most people is still not COVID-19. H1N1, also known as Influenza A, has seen a sudden increase in the number of infections in the United States this season, in line with the “serious” assessment of 2018. So far, there have been 250,000 hospitalizations and 14,000 deaths.