NAIROBI, Kenya — When Valentine Ochogo arrived home in Kenya after being laid off from her job at a hot-air balloon business in Dubai, she was put in quarantine in a university dormitory with other travelers — one step in the government’s aggressive, often-lauded campaign to prevent the spread of the coronavirus.

But instead of the mandated 14-day quarantine period, she was confined for 32 days, often cold, hungry and so frightened that she said she blocked the door at night with an empty bed. Although she tested negative for the coronavirus three times, she said that government officials would not release her until she paid $ 434 in fees.

After she managed to negotiate the amount down to $ 65, Ms. Ochogo, 26, was freed.

“Am out,” a relieved Ms. Ochogo texted on April 24, saying later, “I got really lucky.”

Kenya’s government is now facing mounting criticism for its response to the pandemic — particularly its use of quarantine centers.

Citizens stopped by the police for violating curfew or not wearing masks have been sent not to police stations, but to quarantine, sometimes held in compounds with people known to be infected.

“During an emergency like this, you need to be persuading people to cooperate rather than coercing them, especially if your argument is that it is in their best interest,” said Dr. Lukoye Atwoli, associate professor at Moi University’s School of Medicine and the vice president of the Kenya Medical Association.

In interviews, seven people in quarantine or just released accused the government of putting them in unsanitary isolation units, holding them longer than 14 days, giving them inadequate food and water and failing to inform them of their coronavirus test results. Many say they were held until they paid hefty bills.

After 50 people broke out of a quarantine center in Nairobi last month, the government was forced to respond: on Wednesday, the Health Ministry announced that it would stop requiring people in quarantine to pay fees because the policy was deterring people from coming forward for testing.

Another policy change was announced last Sunday: officials will put curfew breakers in a designated “holding place” — not into quarantine.

Health Ministry officials, who initially agreed to an interview for this article, canceled and declined to answer questions.

Some citizens and health experts have praised Kenya for its response to the outbreak: it suspended international flights early, conducted tens of thousands of tests and imposed a partial lockdown on areas reporting high cases, like Nairobi.

The measures may have helped to suppress the number of cases in this East African nation: a country of about 47 million people has so far reported 607 cases, 29 fatalities and 197 recoveries.

But the government has also been accused of extremes. In the first 10 days of the curfew, Kenyan police officers killed at least six people while trying to enforce the lockdown, according to Human Rights Watch.

And the virus continues to spread. Officials on Wednesday imposed lockdowns on one neighborhood in Nairobi and another in Mombasa where the virus is said to be proliferating.

Even as the Health Ministry has urged citizens to come forward for testing, government officials elsewhere have said they would force residents to undergo mass testing.

But experts said the poor treatment of those held in quarantine centers could discourage people from reporting symptoms or volunteering for testing.

Those like Ms. Ochogo, who arrived back in Kenya in late March, said their problems began at the airport in Nairobi, with serpentine queues to get through immigration, passengers jostling one another and officials failing to enforce social distancing.

Many arrivals from the Middle East were blue-collar workers, like nannies and drivers.

Those who could pay were escorted to hotels, but others were taken to government facilities and told their stays would be free, several said.

Ms. Ochogo said that she and more than two dozen passengers boarded a bus, with no protective gear, and were first driven to a facility that was full. Around midnight, they finally arrived at the dormitories of Kenyatta University, where law enforcement officers with no masks, gloves or hand sanitizers helped unload their bags. Ms. Ochogo said no guidelines or instructions were provided.

She took her room keys and went to bed.

At another quarantine center in Nairobi, established at Mbagathi Hospital, Shabu Mwangi said he faced officials who berated him for having traveled to Italy — in mid-January. He had voluntarily gone to the quarantine center with flu symptoms a day after he arrived in Kenya in March.

Left to sit in his car for an hour, medics arrived. But, said Mr. Mwangi, a 35-year-old artist, “Their big concern was, ‘Why did you go to Europe?’”

For the three days he awaited test results, he said he was put in the same room with nine men where they freely mingled and even borrowed phone chargers from one another. Doctors gave him no medicine, he said. And while he tested negative, a Burundian in the room tested positive, he said.

Gospel musician Eko Dydda was among hundreds of people put in quarantine for defying the evening curfew. He said he was arrested while fetching medicine for his sick wife. After spending a night in jail and three days in quarantine, Mr. Dydda was released following a public uproar.

“Quarantine can’t be a response to people breaking the law,” said George Kegoro, the executive director of the Kenya Human Rights Commission, a nongovernmental organization, “because what it does, it exposes them to the possibility of infection, the very thing you are trying to fight.”

As more people were admitted into quarantine centers established in high school dorms and other government buildings, the chorus of disapproval in the country grew. People posted photos and videos on social media of dirty and broken toilets in overcrowded facilities, where some slept on the ground covered in flimsy sheets.

But even some people confined in hotels claimed they were denied food, because they had not paid fees. Others complained that they ran out of medications.

The Kenya Legal and Ethical Issues Network, a nongovernmental organization, and the nonprofit Katiba Institute along with seven people who say they were held in quarantine have filed a lawsuit against the government for violating the human rights of those held in mandatory quarantine.

Almost three weeks into her stay at Kenyatta University, Ms. Ochogo said she suffered an anxiety attack. As she cried for hours, she said she called and texted health officials for help. They promised to come, but no one did.

When officials presented people with bills sometimes totaling hundreds of dollars, demanding payment before they could leave, those in quarantine in places like Kenyatta University staged public protests.

“We left Dubai because we didn’t have jobs,” said Ms. Ochogo, who had $ 200 with her when she arrived.

She and others confronted health officials about the payments and the delays in their discharge.

“I was told I was rude and somehow, they wanted to deal with me,” she said. “They had told us they had marked us.”

When a threatening security officer in the center used a ruse to learn her full name, she pushed a spare bed in her room against the door at night: “I was afraid for my life.”

Kenya’s laws say that placing a person in quarantine should involve a doctor and a magistrate, said Mr. Kegoro of the Kenya Human Rights Commission. The cost of isolation, he added, should also by law be borne by the state.

“The government has a law. It has put it to one side,” Mr. Kegoro said of the recent decisions to make poor Kenyans pay. “We can’t tell where their powers are coming from.”

Days after returning home, Ms. Ochogo said she was still numb from her quarantine ordeal.

“I don’t even recognize myself,” she recently said over the phone. “I can’t do the things I used to do. I am still struggling to sleep at night.”