At least 73 countries are seeing surges in newly detected cases, and in regions where cold weather is approaching, worries are mounting.
It is a staggering toll, almost 200,000 people dead from the coronavirus in the United States, and nearly five times that many — close to 1 million people — around the world.
And the pandemic, which sent cases spiking skyward in many countries and then trending downward after lockdowns, has reached a precarious point. Will countries like the United States see the virus continue to slow in the months ahead? Or is a new surge on the way?
"What will happen, nobody knows," said Catherine Troisi, an infectious disease epidemiologist at The University of Texas Health Science Center at Houston. "This virus has surprised us on many fronts, and we may be surprised again."
In the US, fewer new coronavirus cases have been detected week by week since late July, following harrowing outbreaks first in the Northeast and then in the South and the West.
But in recent days, the nation's daily count of new cases is climbing again, fuelling worries of a resurgence of the virus as universities and schools reopen and as colder weather pushes people indoors ahead of what some epidemiologists fear could be a devastating winter.
The coronavirus death toll in the US is now roughly equal to the population of Akron, Ohio, or nearly 2 1/2 times the number of US service members who died in battle in the Vietnam and Korean wars combined, and about 800 people are still dying daily.
Around the world, at least 73 countries are seeing surges in newly detected cases, and worries are fast mounting.
In India, more than 90,000 new cases are now being detected daily, adding 1 million cases since the start of this month and sending the country's total cases soaring past 5 million.
In Europe, after lockdowns helped smother the crisis in the spring, the virus once again is burning its way across the continent as people proceed with their lives.
Israel, with nearly 1,200 deaths attributed to the virus, imposed a second lockdown last week, one of the few nations that has done so.
When the first wave of infections spread around the world, governments imposed sweeping restrictions on movement: more than 4 billion people were under some sort of stay-at-home order at one point. But most nations now are desperately trying to avoid resorting again to such intense measures.
"We have a very serious situation unfolding before us," Hans Kluge, the World Health Organisation's regional director for Europe, said last week. "Weekly cases have now exceeded those reported when the pandemic first peaked in Europe in March."
Across Latin America, the death toll stands at more than 310,000. Two-thirds of the total come from just two nations: Brazil with more than 132,000 reported deaths and Mexico with 72,000. Dr. Carissa F. Etienne, the director of the Pan American Health Organisation, warned that the threat remained.
"Latin America has begun to resume almost normal social and public life at a time when Covid-19 still requires major control interventions," she said last week. "We must be clear that opening up too early gives this virus more room to spread and puts our populations at greater risk. Look no further than Europe."
Deaths in the US from the coronavirus rose above 199,300 as of Sunday afternoon, leaving families across the country grieving. It was only four months ago, in late May, that the nation's death roll reached 100,000. Even the current tally may be a significant undercount of the toll in the US, analyses suggest, failing to include some people who die from Covid-19 as well as those who die from secondary causes that are also linked to the pandemic.
As the virus overtook the US this spring, deaths surged. In mid-April, more than 2,000 people were dying each day, on average. Deaths rose again this summer as cases spiked in the South and West. The pace has slowed considerably since.
Although the capabilities of health care systems vary widely across the globe, earlier detection of infections, efforts to keep the virus out of nursing homes and away from the most vulnerable groups, and better treatments have meant fewer people needing to be placed on ventilators and improved outcomes for those who fall seriously ill.
Still, as the race for a vaccine continues, there is no cure for Covid-19.
Each day, about 800 people with the virus are dying in the US on average. That's down from more than 1,200 deaths every day in early August. Yet even as some of the country's most populous states report vast improvements, and as Northeastern states have kept new infections low, deaths continue to trend upward in nine states and two territories.
Dr. Tom Inglesby, director of the Center for Health Security at the Johns Hopkins Bloomberg School of Public Health, said it was conceivable that the death toll in the US could reach 300,000 if the public let down its guard.
"There are many countries we might consider our economic peers, or that are far less developed in terms of economy or health care systems, that are having far less mortality," he said.
The contrast with other rich industrialised countries is stark, reflecting how the virus is still tearing through parts of the US On one day last week, the US reported 849 new deaths. The same day, Italy, once the epicentre of the pandemic, had 13 deaths. Both Canada and Germany reported seven deaths that day.
The virus took off later in the US than in some other places, but cases were never fully reined in. Since the beginning of April, the country's average daily case total has not dropped below 20,000, and an essential question loomed at summer's end: Would a general trend downward in the nation's daily reports of new cases and deaths since August continue — or was a recent uptick in cases a sign of a new, concerning pattern?
Yvonne Maldonado, a paediatric infectious disease specialist at Stanford University, compared the country's current juncture with where California was weeks ago when a new surge of cases emerged.
"For those of us in California, we went through that period where we were really proud of the lockdown and our ability to really flatten the curve," Maldonado said. "We wound up becoming overconfident."
The pandemic could be protracted, she warned, like the influenza pandemic of a century ago. Then, the deadly flu churned through the US in three waves: one in the spring of 1918, another that fall, and yet another in the winter and spring of 1919. In that flu pandemic, about 675,000 Americans died.
New factors add to the uncertainties of the coronavirus's course. Cold weather is expected to test the risks of shared indoor air more than ever. An arriving flu season threatens to further stretch the health care system. And the success of efforts to prevent the virus from spreading through newly restarted schools and college campuses remains uncertain.
Many of the country's largest school districts are starting the year with remote instruction, but most states have at least some school districts, largely in rural or suburban areas, that have opened for in-person instruction.
Schools in states like Georgia and Indiana have already been open for a month, but experts say they cannot yet be sure what the effect will be on virus transmission in communities.
Bill Hanage, an associate professor of epidemiology at Harvard's T.H. Chan School of Public Health, said that because of the huge variation in how schools are reopening — with some schools strictly enforcing social distancing and mask requirements and others doing far less — "we expect there to be quite a wide range in terms of consequences."
Already, a return to colleges and universities, with widespread testing taking place on campuses, has driven an uptick in known cases. More than 88,000 cases of the coronavirus have been reported across more than 1,100 US colleges over the course of the pandemic, a New York Times survey shows.
Transmission on campuses would be expected to be less lethal among students, but experts fear that those cases could lead to wider, more dangerous outbreaks as young people interact with professors, family members and neighbours.
And indeed, metropolitan areas where the virus has been increasing the fastest included places with significant college outbreaks: La Crosse, Wisconsin, home of the University of Wisconsin-La Crosse, Viterbo University and Western Technical College; State College, Pennsylvania, home of Pennsylvania State University's main campus; and Gainesville, Florida, home to the University of Florida. Other college towns also reported staggering rises, including Provo, Utah, and Manhattan, Kansas.
"If this spike continues, it will strain our systems to the breaking point," Andrew P. Manion, the president of Edgewood College in Madison, Wisconsin, wrote in a letter imploring students to follow social distancing rules following a rise in cases. "The short-term gain of going to a party comes at the cost of making more people sick. If this trend continues I will make the painful but necessary decision to complete the semester via fully remote classes, and residence halls and offices will close for the semester.
The first months of the pandemic brought floods of cases into urban, coastal areas of the US., but the virus is spreading broadly now, through rural communities and to places that had seen few if any cases early on. States in the nation's middle, including Wisconsin, Montana and North Dakota, are seeing higher case numbers in recent days than ever.
The infection rate in North Dakota in the last week was twice that of Texas and more than quadruple that of California, both earlier hot spots. The infection rate measures virus cases per 100,000 people, and North Dakota, which has reported more than 17,000 cases and 190 deaths over the course of the pandemic, is home to only about 760,000 people.
Still, more than half of North Dakota's cases have been reported since the start of August.
"In the beginning, it was a big-city disease and we watched it on TV," said Sister Kathleen Atkinson, a Benedictine nun who is the director of a ministry in Bismarck, North Dakota's capital. "Now there isn't a single county that hasn't had positive cases, and it is part of everybody's life."
Written by: Simon Romero, Manny Fernandez and Marc Santora
Photographs by: Saul Martinez
© 2020 THE NEW YORK TIMES