Over 100 members of Congress are calling on the Trump administration to collect information on the sexual orientations and gender identities of COVID-19 patients.

A letter addressed Wednesday to the Department of Health and Human Services said a failure to track demographic data about LGBTQ identities will "make it difficult for health care providers and policymakers to clearly identify and address the prevention and treatment needs" of the community during the pandemic. A lack of data on how COVID-19 affects LGBTQ people "will exacerbate the challenges that these populations are already experiencing during the COVID-19 public health emergency," it said.

"We know that LGBTQ people experience significant health disparities, and the coronavirus pandemic has the potential to disproportionately impact them as well."

"Like other marginalized groups, the LGBTQ community faces multiple health inequities," it read. "With scarce demographic information available about the LGBTQ population, it is difficult to provide quality care and solutions."

It is unknown how many of the 1.5 million people who have contracted the coronavirus in the U.S. and the 93,000 who have died are lesbian, gay, bisexual or transgender. Just one state, Pennsylvania, has begun tracking information on the LGBTQ identities of COVID-19 patients. A bill authored by openly gay state Sen. Scott Weiner, a Democrat from San Francisco, that would require LGBTQ data collection in California's pandemic response is still moving through the Legislature.

Sen. Bob Menendez, D-N.J., who organized Wednesday's letter with Sen. Tammy Baldwin, D-Wis., noted in an email to NBC News that the COVID-19 case report from the federal Centers for Disease Control and Prevention also does not ask about patients' LGBTQ identities. He said it is not clear whether "upcoming COVID-19 related surveys will include these questions."

"This contradicts the requirements of the Affordable Care Act, as well as HHS' Healthy People 2020 objectives to improve the collection of health data on LGBTQ populations," Menendez said.

The senator — who helped lead the effort this year urging the Food and Drug Administration to overhaul restrictions on gay blood donations — said having the information is critical in helping policymakers allocate crucial funding.

"Congress and governmental agencies rely on data to create better health programs, direct vital resources to communities, and better the health of all people," Menendez said.

Menendez and Baldwin were joined in the letter by 18 other senators and 81 members of the House, all of them Democrats except for independent Sen. Bernie Sanders of Vermont.

In an email to NBC News, Baldwin, the first out senator, said the letter is an important step in recognizing the unique vulnerabilities of LGBTQ people when it comes to COVID-19, the disease caused by the coronavirus. She and Menendez joined nine of their Senate colleagues in March to call on the White House to recognize risks for the 1.1 million people living with HIV, a chronic immune condition that disproportionately affects LGBTQ people.

"We know that LGBTQ people experience significant health disparities, and the coronavirus pandemic has the potential to disproportionately impact them as well," she said. "We must ensure that we have the data and information needed to better understand the full extent that this public health crisis is inflicting on our community."

A research brief released in March by the Human Rights Campaign indicated that LGBTQ individuals are 37 percent more likely to smoke than cisgender, heterosexual people and are 50 percent more likely to have asthma, which could increase the likelihood of severe illness from COVID-19. And HRC found that LGBTQ people are more likely to work in jobs in service industries like restaurants and bars that could put them into close contact with COVID-19. Seventeen percent of LGBTQ individuals lack health insurance, HRC said, making it more difficult to seek care if they become infected.

Wednesday's letter calls on HHS to ensure that federal health centers collect information on the LGBTQ identities of COVID-19 patients, explain the importance of the data to state agencies, work toward proper implementation of data collection and coordinate its efforts with LGBTQ community centers on the front lines of the public health crisis.

The letter emphasizes that HHS should stress that all information that is shared about a patient's sexual orientation and gender identity is "voluntary" and that federal agencies must offer "guidance to health care providers about how to ask these questions in a sensitive manner that emphasizes confidentiality."

"Data collection on sexual orientation and gender identity is an opportunity to eliminate barriers to culturally competent care," the letter said. "Questions about sexual orientation and gender identity allow individuals to disclose who they indeed are, if they so choose, and may allow individuals to feel safe sharing information that is relevant to their care. Inclusive and nondiscriminatory health care settings are urgently needed."