COVID-19 cases and deaths among hardest hit countries worldwide as of Apr. 20, 2021

As of April 20, 2021, the United States had recorded almost 32 million cases of COVID-19. The country had also reported a total number of almost 568 thousand deaths from the disease.

COVID-19 testing remains important

The cumulative number of coronavirus cases worldwide exceeded 120 million by mid-March 2021. The United States marked its own heartbreaking milestone a month later when the death toll passed 500,000. Demand for test kits has at times exceeded production levels, but countries must continue to test citizens to detect any spikes in cases effectively. The U.S. has performed the most tests worldwide as of April 20, 2021.

The silent spread of the coronavirus

Widespread testing will also help to detect the hundreds of thousands of people who might be asymptomatic – showing few or no symptoms of the illness. These carriers are unwittingly transmitting the virus to others, and the threat of silent transmission is one reason why mass lockdowns have been imposed around the world. However, as asymptomatic carriers produce no symptoms, they may have developed some natural immunity to the illness. Viruses are not as easily spread in communities with high rates of immunity, which helps to protect more vulnerable groups of people. When an infection rate is less than one, a community has achieved herd immunity.