A decrease in new HIV cases is usually a cause for celebration, but these aren’t normal times. Fewer people were diagnosed with HIV in Philadelphia last year—332 in 2020 compared with 446 in 2019, which brings the total number of people living with diagnosed HIV in the city to 18,621. But as health experts recently pointed out to WHYY.org, the 25.6% drop in new cases doesn’t necessarily mean the epidemic is dwindling. In fact, the opposite might be true.

That’s because HIV testing plummeted last year amid COVID-19 shutdowns and stay-at-home orders. For example, nearly 7,000 people were tested for HIV in Philadelphia in February 2020, a month before COVID-19 shutdowns began taking effect across the nation. By April 2020, the number of people getting tested for HIV in the city had sunk to just over 2,000.

If fewer people are getting screened, then some folks who are HIV positive aren’t being diagnosed. That means they’re not getting the HIV treatment that not only bolsters their own health but also lowers their viral load to an undetectable level, thus preventing them from transmitting the virus, a fact referred to as Undetectable Equals Untransmittable, or U=U.

In fact, viral load testing, which measures how well HIV meds are working, also decreased last year, reports The Philadelphia Inquirer. And of the people who did test positive for HIV last year, a greater proportion of them were also diagnosed with AIDS, which means they have been living with the virus for years and not taking treatment.

“We know that the majority of new HIV infections are acquired from people who have HIV but are unaware of their HIV status,” Kathleen Brady, MD, acting director of the Philadelphia Department of Public Health’s AIDS Activities Coordinating Office, told WHYY. “Our concern is that that proportion, and the size of that population, is now increasing, which certainly is concerning for ongoing HIV transmission and an increase in new HIV infections over time.”

Philadelphia’s 2020 HIV surveillance data report, issued today, offers a more detailed breakdown of HIV diagnoses:

Of the 332 Philadelphians newly diagnosed with HIV in 2020, the largest proportion of new diagnoses were among men (75.6%), non-Hispanic Blacks (66.8%), men who have sex with men (53.5%), and people age 30-39 (28.6%).

Of the 18,621 people living with diagnosed HIV in Philadelphia, 72.1% were assigned male sex at birth, 63.7% are non-Hispanic Black, 54.8% are aged 50 and older, and 38.9% are men who have sex with men.

Another concern among Philadelphia’s health experts and HIV advocates is that HIV rates among people who inject drugs had been increasing in recent years. Specifically, new HIV diagnoses among this population rose from 33 cases in 2016 to 83 in 2019. That trend reversed last year, at least on paper, with 36 cases in 2020.

“It’s very concerning to me that we don’t know what’s happening with that outbreak at this point in time,” Brady told WHYY, explaining that this lack of knowledge results from a drop in HIV screenings and other services for people who inject drugs. “I’m very concerned there could be ongoing HIV transmission in that community and very worried about a further increase in the outbreak.”

In related Philadelphia news, the city’s Department of Public Health launched a new HIV testing strategy in the summer of 2021 that shifted millions of dollars of public funding to the agencies and testing sites that reach populations at highest risk for HIV, including gay and bisexual men, transgender people, African Americans, Latinos and people who inject drugs.

HIV testing isn’t the only health screening to decline last year. For example, read “Hepatitis C Testing and Treatment Fell During First Year of the COVID Pandemic.”

To read a collection of articles about the intersection of COVID-10 and HIV, click #COVID-19, and for more content specific to the coronavirus, visit our sister publication COVIDHealth.com.