No, Hovering Covid-19 Instances Are Not Attributable to Extra Testing – They Present a Surging Pandemic
By Zoë McLaren, University of Maryland, Baltimore County
COVID-19 cases are on the rise in the US, reaching 100,000 daily cases for the first time on November 4, and 150,000 just eight days later. Some believe that this increase in reported cases is due to an increase in testing, as more than 1.5 million tests are performed daily in the US. However, it is clear that these high numbers reflect a real increase in the number of COVID-19 infections.
Hospital stays, deaths, and test positivity rates are increasing. Taken together, this means serious COVID-19 disease is on the rise and cases are being undercounted.
Steep increase in hospital stays and deaths
Rather than being an artifact of changes in testing policy, the rise in cases reflects ongoing transmission and serious illness.
Although COVID-19 treatments have improved and death rates have fallen, record-breaking hospital stays are already overwhelming intensive care units in many parts of the country. Hospital stays and deaths will continue to increase, although the increase subsides in new cases, as most cases are diagnosed before serious illness develops. Today’s new infections will increase the death toll in the coming weeks.
These hospital stays and deaths represent confirmed COVID-19 infections. A diagnosis of COVID-19 for hospital cases must be justified based on symptoms and test results. COVID-19 is simply the only plausible explanation for the persistently high hospital stays and death rates.
High and increasing test positivity
High and rising test positivity rates provide more evidence that COVID-19 is spreading uncontrollably across the country.
Test positivity can be calculated in two ways: as a percentage of all COVID-19 tests that come back positive, or as a percentage of people who have tested for active infection and give a positive result. For example, Iowa’s test positivity rate of 37.2% between October 26 and November 9 implies that out of 100 people who tested for COVID-19, 37 will be positive.
Test positivity tells public health officials whether a testing program casts a sufficiently wide net to capture the majority of COVID-19 cases.
A high test positivity rate indicates that the people tested are mostly people who have symptoms or think they may be exposed to someone with COVID-19. But people can be infected or contagious even when they don’t show symptoms. A low test positivity rate means that access to tests is wide enough to reach large numbers of people who may not know they have the coronavirus. This greatly increases the likelihood of diagnosing people with no symptoms or known exposure who may still be infected.
The World Health Organization recommends a target of 5% test positivity or less, but test positivity rates in many parts of the US are well above. As of Nov. 17, 44 states had test positivity rates above 5%, which means their testing programs did not have a sufficiently broad network and likely many undiagnosed cases were missing.
Overloaded test programs
The record spike in COVID-19 cases and hospital stays in the US means a real increase in infections and serious illnesses rather than an increase in testing. In fact, high test positivity rates indicate that cases are undercounted due to limited access to tests. Hospital stays and deaths will continue to increase in the coming weeks.
Overloaded testing programs remain a weak link in the US pandemic response. Diagnosing cases – and identifying them early – helps cut the chains of transmission of the deadly virus. Once people find out they are infected, they are more likely to take the necessary precautions to avoid exposing family, friends, and others to the virus. Contrary to what some ill-informed people have said, the US should expand access to testing to help contain the spread of COVID-19. Further testing would actually be a crucial step in finally bringing the virus under control.
This story has been updated to reflect differences in definitions of test positivity and a more accurate estimate of undiagnosed cases.
Zoë McLaren, Associate Professor of Public Policy, University of Maryland, Baltimore County
This article is republished by The Conversation under a Creative Commons license. Read the original article.