Are we seeing second wave of COVID-19?
Infectious disease experts, economists and politicians around the world are concerned about a second wave of COVID-19 globally that could worsen in the coming months, reported Reuters.
Here is an explanation of what is meant by the second wave.
WHY DESCRIBE DISEASE OUTBREAKS AS WAVES?
In infectious disease parlance, waves of infection describe the curve of an outbreak, reflecting a rise and fall in the number of cases. With viral infections such as influenza or the common cold, cases typically crest in the cold winter months and recede as warmer weather reappears.
Fears about the second wave of COVID-19, the respiratory disease, stem in part from the trajectory of the 1918-1919 Spanish flu pandemic that infected 500 million people worldwide and killed an estimated 20 to 50 million people. The virus first appeared in the spring of 1918 but appears to have mutated when it surged again in the fall, making for a deadlier second wave.
“It came back roaring and was much worse,” said epidemiologist Dr. William Hanage of Harvard University’s T.H. Chan School of Public Health.
Epidemiologists said there is no formal definition of the second wave, but they know it when they see it.
“It’s often quite clear. You’ll see a rise involving a second group of people after infections in a first group have diminished,” said epidemiologist Dr. Jessica Justman of Columbia University’s Mailman School of Public Health.
The United States government’s top infectious disease expert Anthony Fauci said it is too soon to discuss the second wave when the world has never emerged from the first wave in which more than 477,000 people have died and more than 9.2 million people have been infected with the novel coronavirus.
The U.S. is a prime example. COVID-19 cases here jumped in March and April and then edged downward in response to social-distancing policies aimed at slowing the transmission of the virus from person to person. But unlike several countries in Europe and Asia, the U.S. never experienced a dramatic drop in cases marking the clear end of the first wave. The country registers nearly 20,000 cases per day now.
Brazil surpassed several countries last week and became the second country with the biggest number of COVID-19 cases in the world after the U.S. According to Brazilian Health Ministry, 39,500 more people were infected with coronavirus in the last day, bringing the total number of cases to more than 1.1 million. The death toll during the outbreak exceeded 52,000.
Russia is the third country with the biggest number of nearly 600,000 coronavirus cases, followed by India with more than 456,000 cases and the United Kingdom with over 307,000 cases.