Several months into the COVID-19 pandemic, researchers around the world are struggling to answer the most pressing question: how much risk does a person have in catching the disease? Recently, a research team said that the average risk is lower than perceived, but critics highlighted that the findings were flawed and oversimplified.
The risk of an average person to contract COVID-19 was unveiled by researchers at the University of California in Los Angeles (UCLA) and Stanford University. Their estimation has been one infection in 40,500 person contacts for an average person, while the hospitalization chance for adults aged 50 to 64 years was one in 709,900 person contacts. Although the risk was quantified, the numbers were questioned by critics due to observed flaws. The findings were published in the journal medRxiv.
The Known Facts on COVID-19
According to the World Health Organization (WHO) of the United Nations, the coronavirus disease or COVID-19 is an infectious disease caused by the newly discovered strain of coronavirus or SARS-CoV-2. Despite little knowledge about the pathogen and the disease it causes, biomedical scientists have found numerous insights like the common, uncommon, and serious symptoms. Unlike influenza, COVID-19 often triggers mild symptoms in most cases. But it does not mean that the novel disease cannot result in serious complications.
The notable symptoms of COVID-19 identified in actual cases are fever, dry cough, and tiredness. These are common signs of a person infected by the virus, provided they are symptomatic. Less common symptoms a person may develop include body aches, sore throat, diarrhea, headache, conjunctivitis, loss of smell or taste, and rashes on the skin or discoloration of fingers and toes. Serious symptoms from the infection include breathing difficulty, chest pain, and loss of speech or movement, all of which indicate the need for hospitalization.
If compared to the common cold, which can be caused by a different type of coronavirus, COVID-19 is not notably known to induce sneezing. However, people should make no mistake in catching someone's cough or sneeze because those expels can spread other pathogens in the air. For experts, sneezing is more correlated to allergic reactions, nasal irritants, or other viruses including influenza. So, sneezing as a symptom in this pandemic is unlikely induced by COVID-19.
To be on the safe side, people who may be experiencing one or more of those symptoms including sneezing are allowed to consult with a doctor. But they must prioritize telemedicine wherein contacting a healthcare professional remotely via voice or video calls. This enables initial diagnosis and ensures their protection at home. If the doctor tells them to go to a hospital, a set of instructions will be provided to prevent problems upon arrival.
The Chance of Contracting COVID-19 for an Average Individual
Clinical symptoms related and unrelated to COVID-19 are important details for public knowledge. But the ultimate detail everyone wants to know is the risk of a person catching the disease. This is something people can easily understand, especially for those living in cities with relaxed public quarantine protocols. The detail will play a part in their navigation in the new normal.
"Across the country, current probabilities of infection transmission, hospitalization, and death from COVID19 vary substantially, yet severe outcomes are still rare events. Individuals may be overestimating their risks of hospitalization and death and a moderate number and frequency of community contacts is unlikely to overwhelm hospital capacity in most U.S. settings," said the authors of the study, as quoted by The Mercury News, a US morning daily newspaper.
In the study, researchers Dr. Rajiv Bhatia, professor of primary and population health at Stanford, and Dr. Jeffrey Klauser, professor of epidemiology at UCLA, examined the publicly available records of COVID-19 in the US. A total of 100 US counties, the largest ones in the country, were identified in the analysis. The data included in this study had a date – the week ending May 30, 2020. They calculated the chance of confirmed infection, hospitalization, and death from a county-level person-contact.
Results in the submitted paper showed that the average estimate of a confirmed infection was one in 40,500 person contacts, at the county level. The average estimate of a confirmed hospitalization of a person aged 50 to 64 years was one in 709,000 person contacts, derived from the range between 177,000 and 10,200,000 person contacts. The average estimate of a confirmed death was one in 6,670,000 person contacts, derived from the range between 1,680,000 and 97,600,000.
The daily newspaper reported that a person in a large US county could have an average risk of one in 3,836 chances without social distancing, handwashing, and face mask. That risk referred to a random contact with another individual. For hospitalization, the average risk of an adult aged 50 to 64 years would be one in 852,000 chances after a random contact with someone else. And for fatality, the average risk would be one in 19.1 million chances after a random contact with another person.
A. Mark Kilpatrick, an infectious disease expert at the University of California – Santa Cruz, questioned the findings of the study. They claimed that the study was flawed in providing concrete COVID-19 risk. Dr. Jeff Smith, Santa Clara County Executive, commented that the study could be misleading and unhelpful. If the estimation in the study was perceived incorrectly by the public, some might underestimate the risk of getting sick when going outside unprotected, and it would lead to a new surge of cases.
According to the WHO, the global confirmed cases peaked at 11,125,245 as of July 5, 2020. The global confirmed deaths peaked at 528,204 as of the same date. The situation in the Region of the Americas continues to worsen as 5,697,954 confirmed cases and 262,538 deaths were reported to the WHO. The region with the least cases remained the Western Pacific at 223,915, while the region with the least deaths remained Africa at 6,746.
In the Americas, Brazil and the US had the highest confirmed cases and deaths than any other country in the region. As of July 5, 2020, the US reported a total of 2,776,366 cases and 129,226 deaths since the outbreak began. Brazil reported 1,539,081 cases and 63,174 deaths throughout the nation. Unless the community transmission in affected nations is stopped, COVID-19 will remain a major threat to health and the economy.
Despite the flaws in their study, researchers noted that the average risk assumes the same risk for everyone. But in truth, individual estimates of the chance to contract COVID-19 widely vary. They also said that the estimates have been limited by publicly available data, and if they had more access, they might have produced a more precise risk assessment.