Coronavirus Symptoms Take About 5 Days to Appear, Study Says

The latest surveys of patients with confirmed cases of coronavirus (SARS-CoV-2) found that people exposed to the virus take about 5.1 days for symptoms of COVID-19 to appear, according to researchers at Johns Hopkins Bloomberg School of Public Health. (For reference, human coronaviruses that cause the common cold have roughly the incubation period of three days).

While analyzing public data of 181 cases from countries with confirmed cases before February 24, the study (published in the journal Annals of Internal Medicine on Tuesday) found that 97.5 percent of people who end up developing symptoms do it within 11.5 days of being exposed. They also believe that for every 10,000 people quarantined for the Center for Disease Control and Prevention’s (CDC) recommended 14-day period, only 101 of them will develop symptoms after being released.

“Based on our analysis of publicly available data, the current recommendation of 14 days for active monitoring or quarantine is reasonable, although with that period some cases would be missed over the long-term,” says study senior author Justin Lessler, an associate professor in the Bloomberg School’s Department of Epidemiology, in a statement.

According to experts, finding an accurate timeline between being exposed to the disease and developing symptoms helps epidemic experts estimate the impact and reach of the outbreak and help health officials determine the most effective ways to control community spread. And now, as more affected regions are recommending isolation and quarantine for individuals exposed to the virus and generally encouraging people to implement social distancing (avoiding large gathering or events and staying about six feet apart from other people) to slow — and ideally stop — it spreading.

What are the best practices for isolation and quarantine?

Per the CDC’s guidelines, “Isolation separates sick people with a contagious disease from people who are not sick. Quarantine separates and restricts the movement of people who were exposed to a contagious disease to see if they become sick.”

Lessler also added that there are concerns for the financial, personal and societal impact of quarantining individuals in a way that prevents them from working — particularly for people in health care and civil service positions.

Previously, Nancy Messonnier, M.D., Director of the National Center for Immunization and Respiratory Diseases said “for schools, options include dividing students into smaller groups or, in a severe pandemic, closing schools and using Internet-based teleschool to continue education. For adults, businesses can replace in person meetings with video or telephone conferences and increased teleworking options on a larger scale. Communities and cities may need to modify, postpone, or cancel mass gatherings. For healthcare settings. This might include triaging patients differently, looking at how to increase telehealth services and delaying elective surgery.”

What are the symptoms of COVID-19 to look out for?

According to the CDC, the symptoms for COVID-19 include:

  • Fever
  • Cough
  • Shortness of breath

They still encourage individuals who may have come in contact with the virus or have travelled to an area with documented cases of community spread to contact their doctor if they are experiencing symptoms.

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