After a period of decreased testing and treatment during the pandemic, the number of persons living with HIV in the U.S. is likely to climb.

According to data from the National Syndromic Surveillance Program, there were roughly 670,000 fewer HIV screening tests completed between Mar. 13, 2020 and Sept. 30, 2020, compared to the same time in 2019.

The U.S. Centers for Disease Control and Prevention says that the human immunodeficiency virus, or HIV, affects the immune system. It can progress to AIDS, or acquired immunodeficiency syndrome if left untreated.

The number of individuals living with HIV in the world climbed from 30.7 million in 2010 to 38 million in 2019, based on data from the Kaiser Family Foundation.

Because testing is the only method to find out whether you have HIV, Deborah Gold, chief executive of the National AIDS Trust in the United Kingdom, told CNN that lower testing numbers could mean more people are inadvertently transferring the virus.

Gold noted that the sooner you find out if you have the virus, the better.

The Joint United Nations Programme on HIV/AIDS (UNAIDS) states the virus can be communicated through a variety of routes, including penetrative sex, needle-sharing, and blood transfusions. It can also be passed from mother to child during pregnancy and breastfeeding.

According to UNAIDS, the greatest strategy to prevent HIV transmission is to practice safer sex. This includes using protection like condoms and testing for infections on a regular basis.

It's important to know if you're infected so you can take the appropriate precautions to avoid infecting others, according to Charlotte Sector, UNAIDS spokesperson.

HIV patients should start therapy as soon as possible, according to Sector.

Anti-retroviral therapy is one of the most frequent treatments, she added, because it reduces the viral load to an undetectable level, making it impossible for someone to spread the virus.

"For example, a woman living with HIV who takes her treatment daily can have a baby that is born without HIV," Sector said.

Experts suggest that if you do become sick, your symptoms will stay longer and you will not recover as quickly.

HIV can be fatal if not treated.

Even if you are in a committed relationship, physicians recommend being tested at least once a year if you have a higher chance of developing the virus. People aged 13 to 64 should be tested once as part of normal health care, and more frequently if they have additional risk factors such as having been diagnosed with another sexually transmitted disease.

For more information about U.S. testing sites, go to the CDC's testing center website.