With the rise of at-home testing and no efficient method to report positive cases, experts and officials nationwide face difficulty capturing the true prevalence of COVID-19.

As a result of the underreporting with positive at-home test results, public health and vaccinology professor emeritus John Swartzberg has claimed the number of cases reported — 6.68% according to the city’s COVID-19 dashboard — probably only represents 8% to 10% of the actual number of positive cases. However, he emphasized there is no way to know for sure.

“The priority was getting those home tests out to people so they would have them,” Swartzberg said. “Now we are having to play catch up and try to develop systems among those.”

Campus University Health Services, or UHS, stopped offering free PCR testing at the Recreational Sports Facility in early May. However, according to UHS spokesperson Tami Cate, campus still offers limited PCR surveillance testing at the Tang Center and is in the process of exploring other options for the future.

Additionally, UHS continues to sell rapid antigen tests for students to take at home, increasing the amount of self-testing.

“We must learn to live with this new normal by responding to new waves and surges of COVID-19 and using the prevention strategies we have to help reduce our risk for infection and protect those with whom we come in contact,” Cate said in an email.

While at-home antigen testing can be administered within the comfort and safety of one’s own care, there remains no efficient system for patients to report self-testing results, according to Swartzberg.

Arthur Reingold, an epidemiology professor at the UC Berkeley School of Public Health, noted that this inaccurate capture of virus prevalence becomes a problem when public health agencies use positivity rates to make policy decisions.

For example, positivity rates are essential when discussing mask mandates, Reingold said.

“The setting up of policy like mask mandates by county or state or some other type of organization is a really challenging public health and epidemiologic issue,” Reingold said.

Even the collection of data on hospitalization and death rates is plagued by issues of its own, according to Swartzberg. Following case positivity rates, Swartzberg cites COVID-19 hospitalization rates as the next best early-warning indicator. However, he said the data can lag by at least two weeks, and COVID-19 hospitalizations can be overcounted because of misattribution.

Furthermore, Swartzberg said death rates — which are also the most accurate sources of data — often lag from case counts by at least four weeks, making it difficult to respond in a timely fashion.

“We are generally not prepared to be very strict about enforcing those kinds of things,” Reingold said.