KATHMANDU, Nepal — Ram Singh Karki escaped the first wave of India’s pandemic by boarding a crowded bus and crossing the border home to Nepal. Months later, as the rate of new infections fell, he returned to his job at a printing press in New Delhi, which had sustained his family for two decades and helped pay the school fees of his three children.

Then India was swept by a second wave, and Mr. Karki wasn’t as lucky.

He was infected last month. Hospitals in New Delhi were overwhelmed. When his oxygen level dropped, his manager arranged for an ambulance to take him back to the border. He crossed into Nepal, carrying with him just the clothes on his back — and the virus.

Nepal is now considering declaring a health emergency as the virus rampages virtually unchecked across the impoverished nation of 30 million people. Carried by returning migrant workers and others, a vicious second wave has stretched the country’s medical system beyond its meager limits.

Nepal has recorded half a million Covid cases and 6,000 deaths, numbers that experts believe deeply undercount the toll. Testing remains limited. One figure could indicate the true severity: For weeks now, about 40 percent of the tests conducted have been positive.

A government in disarray has compounded the trouble. K.P. Sharma Oli, Nepal’s embattled prime minister, has been pushing for an election in November after the country’s Parliament was dissolved this month, an event that could worsen the spread.

This past week Hridyesh Tripathi, Nepal’s minister for health and population, said the government was considering declaring a health emergency as infections rise.

But such a declaration could be caught up in politics. The move would allow officials to limit people’s movements — a level of control that opposition groups worry could be used to quell dissent.

In the meantime, officials in Kathmandu, the capital, have urged people to store food for at least a week and stay home.

The impact is rippling beyond those infected. Remittances from migrant workers have slowed. Tourism and the economy have been damaged.

“Millions of people continue to feel the increasing pressure not just with the direct health impact of Covid-19, but also with food, jobs, medical bills, kids out of school, payback loans, mental pressure, and much more,” said Ayshanie Medagangoda Labe, the resident representative of the United Nations Development Program in Nepal.

Nepal’s close relationship with India helped make it vulnerable. India has long been its most important trade and transit partner. The two nations share a deep cultural bond across a porous 1,100-mile border. Nepal’s devastation mirrors that of its big neighbor — from patients spilling out into hospital corridors and onto lawns, to long lines at oxygen refilling facilities, to a government unprepared for crisis.

Officials say laborers like Mr. Karki who were forced to come home by the second wave brought the virus with them. Villages along the border are some of the worst hit. Nepal’s health ministry said about 97 percent of the cases sent for genome sequencing show the B.1.617.2 variant found in India, which the World Health Organization has classified as a “variant of global concern.”

Nepal’s leaders were unprepared. During India’s first wave last year, when about one million Nepali migrant workers returned home, Nepal instituted testing and quarantine measures at border crossings.

But during this spring’s second wave, those measures were too little too late. By the time Nepal shut two-thirds of its border crossings in early May, hundreds of thousands of laborers had made it back, trickling into their villages without proper testing or quarantine. Thousands continue to return daily.

The government’s attention had shifted elsewhere. In February, when the virus seemed to be in retreat, Mr. Oli held rallies of thousands of supporters in Kathmandu and other cities. Opposition parties held their own rallies. Last year, Mr. Oli said the health of the Nepali people would deter the disease.

The government’s defenders say that the pandemic is a global problem and that officials are doing the best they can with few resources or vaccines.

Mr. Oli has called for international aid, though it won’t be enough to meet Nepal’s needs. China has donated 800,000 vaccine doses, 20,000 oxygen cylinders and 100 ventilators. The United States and Spain have sent planeloads of medical equipment, including oxygen concentrators, antigen tests, face masks and surgical gloves. The United States provided $15 million this month to scale up Nepal’s Covid testing. Nepali migrant workers in Persian Gulf nations have arranged for oxygen cylinders to be sent home.

But Nepal can’t fight the pandemic without help from India. Already, an Indian vaccine manufacturer has told Nepal it can’t deliver a promised one million doses.

Nepal is also dependent on India for half of its medical equipment needs, according to the Chemical and Medical Suppliers Association of Nepal, but the latter country is keeping just about everything for its own urgent domestic needs. Equipment from China, already costly, has become more difficult to obtain because of Chinese pandemic restrictions.

“For a month now, India has stopped the supply of medical equipment and medicine also, not just vaccines,” said Suresh Ghimirey, the association’s president.

In some provinces that experienced the return of many migrant laborers in India, hospitals have run out of beds. In Surkhet district, the main provincial hospital said that it couldn’t admit more patients. Small outlying villages are quietly mourning their dead. Testing has been slow.

“Except a few villagers, many are unable to come out and do daily agricultural work,” said Jhupa Ram Lamsal, ward chief of the village of Gauri, where nine people died of Covid over 10 days earlier this month. “The worrying thing is that even symptomatic people aren’t ready for Covid tests.”

Mr. Lamsal said he had recently reached Gauri, which is remote and lacks health facilities, along with a team of doctors to conduct antigen tests. Locals turned down health professionals’ plea for Covid tests, he said, arguing they would be dispirited if they found out they were positive.

“The situation is out of control,” Mr. Lamsal said. “We are hopeless, helpless.”

Mr. Kakri, the printing press worker, hailed from a village in the Bhimdatta Municipality, in Nepal’s western corner. The area of 110,000 people has officially recorded 3,600 infections, according to the health chief there, Narendra Joshi. But lack of measures at the border mean that the data may not fully measure the severity.

“More than 38,000 people have returned from one of the two border points in the district since the second wave started in India,” said Mr. Joshi. “It’s hard to manage them.”

Mr. Karki was a high school dropout who went to India to work as a laborer when he was still a teenager, his wife, Harena Devi Karki, said. On his visits home twice a year, he was the life of gatherings — cracking jokes, making fun. The $350 a month he sent home covered his family’s household costs as well as the private school fees of their two teenage daughters and a 12-year-old son.

Even when the lockdown last year meant Mr. Karki was stuck at home for months with no earnings, he insisted the children continue with private school. He would repay the debts once the printing press opened again. He dreamed of seeing his eldest daughter — “she’s the most talented” — grow up to be a doctor.

“I couldn’t complete my studies,” Ms. Karki remembers her husband saying. “Let me eat less, but we should send them to a better school for their education.”

When Mr. Karki received her husband at the border around 2:30 a.m. on April 29, she said, he was frail and lacked the energy to even stand up. He was taken to a nearby hospital, where he died.

“‘Everything is OK. Go home,’” her husband told her, Ms. Karki said. “But he never came home.”

LONDON — Of all the unsavory ethical questions swirling around Prime Minister Boris Johnson these days, the one that has stuck is how he paid for the costly makeover of his apartment in Downing Street. And it has put his 33-year-old fiancée, Carrie Symonds, under a particularly scorching spotlight.

Mr. Johnson has been accused in news reports of secretly using funds from a Conservative Party donor to supplement his public budget for redecorating the apartment — a charge that, although Mr. Johnson says he has repaid the money, has prompted an investigation by Britain’s Electoral Commission. But it is Ms. Symonds and her purportedly expensive taste in wallpaper and designer furniture that has become a running theme on social media and in British tabloids.

“#CarrieAntoinette” is trending as a Twitter hashtag, while the leader of the Labour Party, Keir Starmer, had himself photographed studying wallpaper at the British department store John Lewis — a labored stunt meant to make light of reports that Ms. Symonds derided the Downing Street décor left by Mr. Johnson’s no-nonsense predecessor, Theresa May, as a “John Lewis furniture nightmare.”

Never mind that Ms. Symonds has not actually been quoted saying anything about John Lewis. The reference, in a profile of her in Tatler magazine, is attributed to an unnamed person who once visited her in the apartment. Tatler did report that Ms. Symonds oversaw the renovation project, and her involvement means she, too, may have to turn over evidence to the Electoral Commission.

For Ms. Symonds, a former Conservative Party communications chief who now works for an animal-rights group, it is the latest trial in a year overstuffed with dramatics: the near-fatal illness of Mr. Johnson after he contracted the coronavirus; the birth of their son, Wilfred; and the bitter purging of Mr. Johnson’s chief adviser, Dominic Cummings, in which she is reported to have played a behind-the-scenes role.

It all has put Ms. Symonds at the heart of a familiar narrative, one replete with sexism and double standards: the grasping, manipulative politician’s partner. She joins a parade of women, from Hillary Clinton to Cherie Blair, the wife of Prime Minister Tony Blair, whose murmurings to their men were the subject of fevered suspicion.

The fact that her relationship with Mr. Johnson coincided with the breakup of his 25-year marriage, and that she became the first unmarried partner to move into Downing Street, only adds to Ms. Symonds’ tabloid portrayal as a libertine Lady Macbeth or an upwardly mobile Marie Antoinette — choose your cliché.

“The outsized fascination with Carrie Symonds’ role in the prime minister’s circle reflects outdated sexist tropes that regard women in positions of influence as inherently devious,” said Sophia Gaston, director of the British Foreign Policy Group and a research fellow at the London School of Economics.

Her defenders say that as an accomplished political player in her own right, Ms. Symonds has no less right to offer advice to the prime minister than any other unpaid adviser — and he would be wise to take it.

And yet, others say, there are legitimate questions to ask about Ms. Symonds’ influence, which goes beyond the news media’s obsessive focus on home improvements at Downing Street. Her ardent defense of animal rights was reported to have contributed to the government’s decision to halt a cull of badgers in Derbyshire, which contradicted the advice of scientists and veterinarians.

Friends of Ms. Symonds have been installed in key positions in Downing Street and, in the telling of Mr. Cummings, protected by her even after evidence of wrongdoing. On his blog, he claimed that Mr. Johnson wanted to shut down a leak investigation after it became clear that the culprit was Henry Newman, a close adviser to Ms. Symonds.

Mr. Cummings quoted Mr. Johnson as saying to him, “If Newman is confirmed as the leaker, then I will have to fire him, and this will cause me very serious problems with Carrie, as they’re best friends.”

Downing Street has denied that Mr. Johnson tried to shut down the investigation, but it did not comment about Ms. Symonds’ role.

Her defenders say she has a savvy political sense and could well have aspired to a seat in Parliament if she hadn’t begun a relationship with Mr. Johnson. To the extent that she is giving him advice, some say, it is helpful: cutting loose Mr. Cummings and other hard-core Brexiteers softened the prime minister’s image and improved his popularity before the recent ethics issues pulled him back to his more familiar role as a political scalawag.

“She was fantastic — she is very loyal and was hugely supportive,” said John Whittingdale, a former culture secretary for whom Ms. Symonds served as a special adviser. He described her as “a strongly committed Conservative” and a “very strong Brexit supporter” at a time when that was a less popular position.

“The people who are attacking Carrie clearly see a route to damage the prime minister by attacking her,” he said.

Ms. Symonds labors under a few handicaps, one of which is the lack of a job description for a prime minister’s partner. The role has no constitutional status, and unlike that of first lady in the United States, little administrative support. Successful spouses have usually had strong identities outside Downing Street.

Margaret Thatcher’s husband, Denis, was a businessman, as is Mrs. May’s husband, Philip. David Cameron’s wife, Samantha, ran a fashion company, while Ms. Blair, who once had her own political ambitions, worked as a high-level barrister during her husband’s decade in office. Though Ms. Blair’s influence came under criticism early on, the scrutiny subsided as she built a flourishing legal career.

“She always knew she could go back to her job at the bar, which made it less demeaning to be the appendage,” said Fiona Millar, a journalist and onetime aide to Ms. Blair. Ms. Symonds, she said, “doesn’t seem to have that life outside politics, which the people who’ve been successful at it did have.”

The daughter of Matthew Symonds, a co-founder of The Independent newspaper, and a lawyer for the paper, Josephine McAfee, Ms. Symonds was raised by her mother (both parents were married to other people at the time).

Her young adulthood was deeply affected by an incident in 2007 when she was targeted by a taxi driver who served her spiked drinks while driving her home. Ms. Symonds testified against the man, John Worboys, who was jailed as a serial sexual predator.

Well connected and social, Ms. Symonds became a public relations aide for the Conservative Party, eventually rising to chief communications officer, where she encountered Mr. Johnson. The couple had hoped to get married last summer, after his divorce from Marina Wheeler became final, but delayed the date because of coronavirus restrictions.

Life in Downing Street is less glamorous than it might appear, Ms. Millar said. While the job comes with a spacious Westminster apartment, a baronial weekend home, Chequers, and an annual decorating budget of £30,000 ($41,600), the government does not pay for food or household staff. Outside of public occasions, the couple are expected to cook for themselves or get takeout.

Living above the office, as Mr. Johnson struggled with the pandemic and his own illness, was challenging, people who know Ms. Symonds said. She contracted Covid herself, while pregnant, and then cared for their baby while Mr. Johnson, 56, was still shaking off his illness.

“There were times last week that were very dark indeed,” Ms. Symonds tweeted after he was released from an intensive care unit. Despite that, she retained her interest in environmental protection.

“Since having Wilf & not being able to get to the shops during lockdown,” she posted four months later, “I’ve relied on Amazon for lots of baby essentials, but I’ve been dismayed at the amount of plastic packaging. Please sign this petition to ask Amazon to give us plastic-free options too.”

Political commentators say they see Ms. Symonds’ fingerprints in Mr. Johnson’s embrace of green policies. They say she has played to his pragmatic instincts by nudging him toward a more conciliatory politics.

Few prime ministerial partners have been so deeply immersed in politics. Not only does she know the Conservative Party well, she also has strong contacts among its lawmakers, political journalists and the special advisers who play a powerful role in Downing Street and elsewhere in the government.

Steven Fielding, professor of political history at the University of Nottingham, said people have questioned Ms. Symonds’ influence “because of her specific insights and connections and background as a political operative and because of Boris Johnson’s malleability, and the fact that no one is sure what in his head.”

Some of the uneasiness about Ms. Symonds is as much about Mr. Johnson as her. With few fixed positions and a lack of ideological moorings, he leaves the impression that his decisions can be swayed by those with greatest access to him. During a year of lockdowns, that circle sometimes shrank to Ms. Symonds.

“The reason we’re fussing over this is that we think we have an inadequate figure as prime minister,” said Jill Rutter, a former civil servant who is a senior research fellow at the U.K. in a Changing Europe, a London think tank. “If we thought we had a really good prime minister, would we really care who his spouse is, beyond hoping he has a happy personal life?”