Epidemiologist: Why I fear the coronavirus COVID-19 – Daily Memphian #coronavirus

The newly named and identified coronavirus, COVID-19, worries me. If the virus enters the general population in cities across the globe as it has done in Wuhan, China, then day-to-day lives in the affected cities will be greatly disrupted.

As an infectious disease doctor, I care for patients with illnesses like tuberculosis, HIV, influenza and the common cold, and as a public health epidemiologist, I track the movement of viruses and bacteria through large populations. I worry with the COVID-19 we are in uncharted territory.

With so much misinformation on the Internet, it is important to review four important facts about the virus. First, the symptoms of  COVID-19 — fever, cough and shortness of breath — are identical to the symptoms of flu or the common cold. So by clinical symptoms alone, doctors cannot tell if a patient is ill with the flu, common cold or COVID-19.

Second, the virus spreads among close contacts, those who are within 6 feet of an infected person. The basic reproductive number for COVID-19 is about 2.68, which means that one person with the virus infects three others on average. For the seasonal flu it is slightly above 1, varying during the summer and winter seasons.

Third, the virus has a doubling time of 6.4 days: If the virus enters a city, the number of infected cases doubles every week. One hundred cases turn into 1,600 cases in just a month. For the seasonal flu, the doubling time is about three days.

Fourth, and most concerning, the death rate from COVID-19 is presently reported as 2.8 percent. This means that about 30 of every 1,000 infected persons will die. This is 50 times greater than that of the seasonal flu which has a mortality rate of 0.05%. However, the COVID death rate will likely go down as more patients with a history of infection and lack of symptoms are identified. Also with early diagnosis and better medical care, the death rate will be lower.

So far, fortunately, there have been no cases of local transmission of the virus in any city in America. Our best strategy is aggressive local disease surveillance and vigilance on the part of doctors, nurses, hospital administrators and government health care leaders along with general awareness among the public.

Specifically, surveillance means that all patients with pneumonia or flu-like illness who come to a clinic or hospital need to be asked a simple question. “Have you traveled to China? Or have you been with anyone who has traveled to China in the past 14 days?” This question is the single most important epidemiological clue which will determine if a patient could have COVID-19. If the answer is yes, then they need to be placed in isolation and tested for COVID-19.

In addition to disease surveillance, we need to do death surveillance. In all major cities, hospital deaths that are due to community-acquired pneumonia, particularly viral pneumonia, need to have further investigations. The patient’s family needs to be asked again about any links to China and respiratory samples from the patient need to be tested for the COVID-19. 

Beyond disease and death surveillance, we need preparedness to act rapidly if a local transmission case or death from COVID-19 is identified. Like SWAT teams, active case-finding and contact-tracing teams must be ready and prepared at a day’s notice in each city to find as many as 500 to 1,000 potential cases that may be present by the time the first local case or death is identified.

The future disease course of the virus is unpredictable, and we still have a long journey ahead.

COVID-19 is not the first virus to appear on our watch as a global community, and it will not be the last. Each virus varies in how infectious and lethal it is. Swine flu (H1N1) in 2009 was highly infectious but less lethal. SARS in 2002 was less infectious but highly lethal. My concern about COVID-19 is that it is both highly infectious and mildly to moderately lethal. Such a combination was previously seen in the 1918 influenza pandemic which infected nearly a quarter of the world population and led to over 50 million deaths.

A century later, health care has changed with our understanding of disease epidemiology, prevention and modern respiratory-support treatment. Also, we have hopes for a vaccine and antiviral medicines. But until then, the best we can do is prepare through surveillance and active case finding because the COVID-19 virus is going ‘viral,’ not virtually, but actually.

Source : dailymemphian.com