Mindy Trieu sometimes feels the loneliness most acutely when she talks with her family back in Vietnam.

Everyone is together, while she is “stuck in the U.S.,” said the M.B.A. student at San Jose State University. Trieu’s dream was to study in America, and after five years here, she is used to being on her own. Still, the isolation of the Covid-19 pandemic and the uncertainty of when she will get to return home gnaw at her. She worries especially about her elderly grandparents and when — or if — she’ll be able to see them.

“I know my struggle is just emotional, and there are many people in a way worse situation,” Trieu said. “But I feel really sad that I can’t go back home.”

This fall, much of the focus on international students is on the ones Covid-19 has kept from American campuses. International undergraduate enrollments have fallen by nearly 14 percent, according to the most-recent data from the National Student Clearinghouse, while at the graduate level, they are down 8 percent. No other demographic group has experienced such steep enrollment declines.

But like Trieu, most international students who were enrolled when the pandemic began are still here. They never left, in fact. As many as nine in 10 international students remained in the United States, a survey this spring by the Institute of International Education found.

Some could not travel, while others chose not to. As the coronavirus spread, borders closed, and last-minute flights were hard to find or prohibitively expensive. Some students balked at the prospect of taking classes in the middle of the night because of time differences. Others worried that if they left the country, they might not be able to return.

In Vietnam, Trieu’s family was already in lockdown. “They were happy that I was in a safer place because at that time it was worse in Asia,” she said. “And no one thought it would be a lasting thing. We thought it would be just one month.”

One month has now stretched to eight; the spring semester has turned into fall. Yet, the pandemic shows little sign of abating.

Covid-19 affects all students, of course. But the American College Health Association has singled out international students as a vulnerable population. Far from family and longtime friends, they are at risk of isolation, and they are less likely than their American counterparts to seek counseling. Shifting student-visa policies and an uptick in racist and xenophobic incidents can add to their anxiety.

With international students making up a significant share of the student body on many campuses, colleges are seeking ways to support them through the pandemic. “Everyone was so caught up in triage,” said Keri Toma, international-programs manager at San Jose State. “Now the question is, how do we move forward?”

Isolated and Far From Home

Social distancing has been critical to reducing the coronavirus’s spread. But for many international students, it has weakened already shaky social networks.

With most classes online, many Michigan State University students stayed home this semester. Only about 2,000 students remain on campus, about 20 percent of them from overseas, said Krista McCallum Beatty, director of the Office for International Students and Scholars.

Avina Khiatani, a staff psychologist at the University of Oklahoma, said many of the international students who join a weekly Zoom meetup she runs feel distant not just from their families back home but from their American classmates, too. “The students and their families made huge sacrifices to come to the U.S., and this isn’t how they thought it would be,” Khiatani said. “They feel dejected, discouraged, hopeless.”

A generation ago, the majority of students from abroad came to the United States to study for graduate degrees, but today more than half are younger undergraduates, many away from home for the first time. With text messages and video calls their only connection to home, anxieties can run high on both sides.

In the early months of the pandemic, Haojun Song, a senior at San Jose State, said he feared for the safety of his family in Beijing. Now the tables have turned, and coronavirus cases have declined in China, while outbreaks are still strong in the United States. “At first I worried about my parents, then after a while, they worry about me,” he said.

For some families, Covid-19 has additionally been a source of conflict, with students and their parents disagreeing about whether to return home or to stay put, said Ayoung Phang, the “embedded” counselor with the Office of International Services at the University of Southern California. A median of just 15 percent of global respondents in a recent Pew Research Center poll said the United States had done a good job dealing with the outbreak.

The embedded program, meant to better connect traditionally underserved populations to the university’s mental-health services, predates the pandemic, but outreach has been essential now, Phang, who goes by Alice, said. A major challenge: Just getting students in the (virtual) front door.

Mental-health challenges are a taboo subject in many cultures, and going to therapy is stigmatized or seen as a sign of weakness. But even those students who want help don’t always know where to get it. They are unfamiliar with the American health-care system, Phang said, and “unfamiliarity leads to anxiety, and anxiety leads to avoidance.”

During the pandemic, Phang has tried to build greater awareness of and comfort with her services, offering workshops and holding weekly “let’s talk” nonclinical drop-in sessions, in addition to regular therapy appointments. “I try to show my face as much as I can. Knowing that there’s a therapist who looks like you makes them more open and willing to come,” said Phang, who is a former international student. She can hold therapy sessions in Korean; a colleague speaks both Mandarin and Cantonese.

Song, the San Jose State senior, said he has been attending regular weekly group-therapy sessions for international students. It’s been helpful to hear from other students who face similar challenges, plus he has picked up tips for stress reduction, including meditation and working on online jigsaw puzzles.

Targets of Prejudice

Isolation isn’t the only issue facing international students. The first cases of Covid-19 were in the Chinese city of Wuhan, leading to a rise in anti-Asian sentiment worldwide. The group Stop AAPI Hate has tracked more than 2,500 reports of anti-Asian discrimination nationwide since the start of the pandemic, while an analysis of Twitter and other online message boards has shown a surge in Sinophobic slurs.

International students may be vulnerable to such racist attacks. The three countries that send the most students to the United States are all in Asia, and one-third of all international students here are from China. Some incidents have happened on college campuses. At Columbia University in February, someone posted an image in the library that said, “Wuhan virus isolation area” in Chinese.

Khiatani said fears of becoming a target of xenophobic behavior have led some students to stay close to home or to not go outside alone. “Some of them have experienced racism. Some of it subtle, but it’s felt,” she said. “And that fear is not subtle.”

Trieu said she was visiting a local Costco when a man, mistaking her for Chinese, began to scream at her. “Bring your virus back to your country,” she said he shouted. “I didn’t know what to do.”

The pandemic has also had serious financial repercussions for many students. Staying in the United States through the summer break, they incurred unexpected costs for housing and may have lost out on wages from summer jobs that they were counting on to help pay tuition. With the global economy in recession, students’ parents may have lost jobs or had to close businesses. When Congress approved emergency coronavirus relief for students, those from overseas were excluded.

Because of visa rules, international students are mainly limited to on-campus work. But with few students on campuses, those jobs — serving meals in the dining hall or taking tickets at football games — are drying up, too. Michigan State recently laid off 700 student workers, 100 of them international.

Students can apply for special permission for off-campus employment because of hardship, but the federal government approves few such authorizations, McCallum Beatty said. Her international office has started an emergency fund to help students in need with expenses such as rent and groceries, “but we can never meet demand,” she said.

Financial worries are a stressor that can take a toll on students’ mental health, Khiatani said. Visa concerns can also increase students’ unease. When the U.S. government said this summer that international students taking remote classes would have to leave the country, students’ anxiety shot up. Although the Trump administration quickly rescinded the policy, “it’s been such a roller coaster,” Khiatani said.

While the pandemic has given rise to new problems, in many ways it has exacerbated pre-existing ones. Building a sense of community is vital for international students, who can struggle to form deep connections in a foreign place.

When the pandemic abruptly shifted classes online, Anastasia Fynn, director of international student and scholar services at Embry-Riddle Aeronautical University in Daytona Beach, Fla., set out to telephone each of the campus’s 1,700 international students, enlisting staff members from other offices, professors, and even alumni as part of the effort. If students didn’t pick up, callers sent an email. Soon, students were emailing back, asking to set up a second call. “They were just hungry to talk,” Fynn said.

Her office began organizing regular online “chat and chill” sessions, sometimes bringing in speakers but often just playing games or organizing cooking demonstrations. At El Camino College, outside Los Angeles, Lindsey Ludwig and her international-student programs staff hold weekly town halls. “Everything is so up in the air that it’s sometimes just good that they can see us,” she said.

Even on campuses where some in-person instruction has resumed, it’s been important to nurture a sense of community amid Covid-19, administrators said. Troy University, in Alabama, holds regular “wellness” sessions for international students and has begun to organize socially distanced outdoor exercise classes in conjunction with the fitness center, said Kathleen Freed, an international-student adviser.

Collaborating with other groups, both on campus and off, can extend the international office’s reach, especially during the pandemic. Freed, for example, plans to ask area churches to help start up a food bank for international students.

And international students themselves have proved to be an important resource. At El Camino, they monitor the international office’s live chat during off hours so that their peers can get answers to their inquiries, no matter the time of day. San Jose State has a global-leaders program, a group of American and international students who work with the international-students office and mentor new students. Since the pandemic, they’ve taken on a far larger role, said Toma, the international-programs manager, helping plan events, such as Halloween and the Chinese Mid-Autumn Festival, organizing weekly peer chats, and acting as an early-alert system when issues arise.

By investing in their stranded international students, colleges may help them weather the storm. And eventually, the students may return the favor: When the pandemic finally lifts, the care colleges showed them could help attract new applicants from their communities abroad.