A Covid-19 cluster is reported in Yemen, adding to its woes.
In Yemen, already mired in a devastating civil war, widespread hunger and a cholera outbreak, another threat was reported on Wednesday: the first confirmed expansion of the coronavirus in the country.
The authorities in the port city of Aden announced a cluster of five cases and immediately imposed a two-week lockdown that included the closing of shops and mosques.
Last month, the United Nations secretary general, António Guterres, appealed to Yemen’s warring parties to adopt an immediate humanitarian cease-fire to help stave off the threat from Covid-19.
Since then, the fighting has gotten worse.
A coronavirus outbreak, combined with a surge in fighting, could push the country to “the brink of a catastrophe,” warned Tamuna Sabadze, the Yemen director at the International Rescue Committee.
The virus has already worsened conflicts around the world. In Libya, for example, it has left some people wondering which fate might be worse: death by missile or death by pneumonia.
In the United States, concerns over the pandemic have forced the Defense Department to juggle two competing instincts: protecting troops from the virus and continuing its decades-old mission of patrolling the globe.
And in Yemen, the woes are only multiplying as the threat of a pandemic looms. A recent spate of torrential rains has exacerbated the cholera outbreak there, and flash floods in the south of the country last week washed away the homes of hundreds of people.
An urban exodus is convulsing Peru as city dwellers pour out to the countryside to live with their families.
In Lima, the capital, the bus terminals are so crowded with those waiting to escape that families are sleeping outside, side by side. Highways are lined with people on foot, laden with suitcases and children.
“We brought just a small suitcase,” said Wilson Granda, 28, an unemployed waiter, speaking from a bus terminal where his young family had been waiting for four days for a ride to his parents’ farm.
In all, at least 167,000 Peruvians in urban areas have registered with local governments, asking for help leaving cities and returning to their families.
Peru is emerging as one of the Latin American countries hardest hit by the pandemic, at least according to official counts. The country of about 30 million people is second only to Brazil, with about 30,000 confirmed cases, most of them in Lima.
Now, Peru is experiencing a reverse exodus of sorts.
For decades, rural families traveled from the countryside to Lima in search of work. That migration changed the face of the country, turning it into one of the more urbanized nations in the world.
The flow of people is part of larger virus-related migration patterns around the world that are raising alarm about the spread of contagion into rural areas, and worrying small-town officials who are ill-prepared to support large groups of new people.
With social distancing and virus testing policies in place for months in several countries, a few governments are now reporting remarkable milestones: Recording zero new domestically transmitted coronavirus cases, or any new cases at all.
South Korea on Thursday reported that for the first time since the virus’s Feb. 29 peak, it had no new domestic cases, and just four cases among people who came in from outside the country. The development marked a stark turnaround for a nation that was battered early on by the virus — with 909 cases on Feb. 29 alone — and quickly conducted widespread testing and contract tracing of new infections to halt the virus’s spread.
That progress has been mirrored in Hong Kong, which on Wednesday reported there had been no new cases in the semiautonomous territory for four straight days. The city has had more than 1,000 cases overall, and it saw a resurgence in infections in late March that prompted strict lockdowns on travel, including quarantining of foreign arrivals, social distancing measures and the widespread adoption of work-from-home policies.
Hong Kong residents overwhelmingly wear masks when going outside, even with the recent plunge in new cases.
Other countries are flirting with similar successes. Australia reported just nine new cases on Wednesday, and New Zealand had two days over the last week with just one new confirmed coronavirus infection.
The hunt for ventilators to keep alive people severely stricken by Covid-19 has taken a violent turn in Russia.
Russian law enforcement officers exchanged gunfire with a gang suspected of trafficking in the devices during a raid near Moscow, a Russian news outlet with close ties to the security services reported on Wednesday.
Life, an online journal, said that eight people had been detained, accused of trying to sell 100 ventilators for 70 million rubles, around $96,000. The official state news agency, Tass, also reported the raid but said the devices were all fake.
President Vladimir V. Putin and other officials have repeatedly warned against fraudsters trying to exploit the pandemic for profit.
The Moscow Times reported last month that wealthy Russians, wary of the health care offered by state hospitals, were buying ventilators for their own homes just in case family members fell ill with Covid-19.
Mr. Putin, seeking to calm fears of shortages, said in a televised address on Tuesday that Russia had ramped up domestic production of artificial breathing devices and now produces more than 800 a month. That is up from just 60 to 70 at the start of the year.
Dr. Anthony S. Fauci, the U.S. government’s leading epidemiologist, and President Trump on Wednesday hailed early trial results on the drug remdesivir, holding out hope that it can be effective against the new coronavirus.
The drug’s maker, Gilead Sciences, said on Wednesday that it “is aware of positive data” from the trial, sponsored by the National Institute of Allergy and Infectious Diseases — even as a new study reported that the drug offered no benefit to severely ill patients in China.
Neither Gilead nor the N.I.A.I.D. provided further details. In a statement, the company cautioned that remdesivir “has not yet been demonstrated to be safe or effective for the treatment of Covid-19.”
Stocks rallied on the news, as investors pinned their hopes on the gradual reopening of the world’s major economies. The S&P 500 gained nearly 3 percent, while shares in Europe were also sharply higher.
Meeting with reporters at the White House, Mr. Trump and Dr. Fauci, who heads the N.I.A.I.D., called the study encouraging. Dr. Fauci said the trial suggested that the drug could shorten the time to recovery by about a third, but he cautioned that it still needs to be properly peer reviewed.
“Although a 31 percent improvement doesn’t seem like a knockout 100 percent, it is a very important proof of concept because what it has proven is that a drug can block this virus,” Dr. Fauci said.
The other study, conducted in China and published in The Lancet, questioned the value of the drug for severely ill patients but left open the possibility that it might be useful for others. The research was incomplete, however, because not enough participants could be enrolled.
The Food and Drug Administration acknowledged that officials were discussing approval of remdesivir for treatment of Covid-19 patients, presumably under emergency use provisions.
Reporting was contributed by Gerry Mullany, Declan Walsh and Andrew Higgins