A new study reveals that most of the Covid-19 cases are linked with asymptomatic patients who are spreading the virus unintentionally. The research team from the University of Chicago finds that only 1 in 7 cases reported during the first wave in NYC were symptomatic and there is a greater chance that non-symptomatic transmission is behind the widespread of this pandemic.
According to this new study published in the Proceedings of the National Academy of Sciences, nearly 50% of all the cases are linked with asymptomatic Covid-19 patients.
When the virus was first spotted in the US, there was no understanding of how is it spreading so fast and how many people are infected. Typically, SARS-CoV-2 (novel coronavirus) causes specific signs but due to limited information, testing capacity, and widespread, it was impossible to identify the asymptomatic Covid-19 patients.
There is absolutely no way to find the origin of the infection without contact tracing and finding the source.
Without any information on the testing capacity, it is hard to estimate if the cases are unreported because of the unavailability of testing or they were actually asymptomatic cases. As New York was among the few cities which started testing earlier than the rest, this data was useful to find out the chances of asymptomatic Covid-19 spread.
There are some existing models that can help to determine the viral transmission rate but this current study is the first one to relate testing capacity with a daily number of cases trying to understand the symptomatic and asymptomatic spread of the pandemic.
Studying this data using the epidemiological model revealed that the number of symptomatic Covid-19 patients were between 13% to 18%”. Without adding other parameters to this analysis, it is clear that approximately 50% of Covid-19 transmissions are caused by people who have no signs of the disease (asymptomatic), including pre-symptomatic patients.
The study doesn’t talk about the infection level or severity of these asymptomatic Covid-19 patients. It also doesn’t add the mutated variants that are currently spreading everywhere in the world, including the US. This model just explains that the public health guidelines require more prompt actions to control community transmissions especially by asymptomatic patients as well as symptomatic patients.
If asymptomatic patients are not spreading the virus, they are still helping with infection spread. It is surprising to see how asymptomatic patients also comply with the preventive guidelines i.e., mask, social distancing, etc which is appreciable.
The research team suggests public health bodies improve the testing protocols and encourage asymptomatic testing to see how they may also be contributing to the transmission of the virus, unintentionally.
Collecting this data will help to understand the pandemic spread as it will remove the discrepancy that lies between the number of cases and types of sources. Once testing services are improved, transmission dynamics will be much more clear for further epidemiological modeling.