Neighboring Brazil has started to limit international travel amid concerns about the spread of a new coronavirus variant that experts say may be more contagious and fuel a second wave of infections.

RIO DE JANEIRO – Neighboring Brazil has begun to limit international travel amid concerns about the spread of a new coronavirus variant that experts say may be more contagious and fuel a second wave of infections.

The government of Guyana closed its border with South America’s largest country on Friday, two days after Colombia suspended passenger flights to and from Brazil; both countries cite the new variant as their reason. The Argentine government decided to cut the number of flights to Brazil in half from February 1, according to a January 27 report on state news agency Telam. And Peru on January 26 banned air traffic from Brazil; The governor of Peru’s Loreto department bordering Brazil asked the government to close land crossings as well.

The crackdown came as Manaus, the largest city in the Amazon rainforest and the location of a variant outbreak, suffered a brutal second wave of infections. Overflowing hospitals watched this month as their oxygen supplies ran out, leaving dozens of patients dying from asphyxiation. The government has rushed to replenish supplies with an ad hoc plan, but the situation remains touching and family members of the patient are still looking for oxygen cylinders on their own, although fewer than earlier this month.

There is speculation that Manaus may be just the first city to be destroyed by this new virus. Other cities in Brazil’s Amazon region have been destroyed since, including Porto Velho, the capital of the neighboring state of Rondonia. Like Manaus, Porto Velho has started transporting patients to hospitals outside the state. Former Brazilian health minister Luiz Henrique Mandetta told the O Globo newspaper on Thursday that the new strain could cause a “mega-epidemic” across Brazil within 60 days.

Alarms are growing, but science hasn’t caught up yet. Viruses keep mutating, and new versions – called variants – appear frequently, almost all of them no more dangerous than previous iterations.

The Brazilian variant was first identified in four travelers who had been in Brazil and tested at an airport outside Tokyo, Japan. It has also been found in patients living in Minneapolis-St. Paul Area, Minnesota Department of Health said in a statement this week. It contains a series of mutations that can affect their ability to be recognized by antibodies, according to the US Centers for Disease Control and Prevention. Health officials are also concerned about the variant first reported on great Britain and South Africa.

Felipe Naveca, a researcher at the state-owned institute Fiocruz Amazonia in Manaus, said in an interview with The Associated Press this week that the new strain accounted for two-thirds of the 90 samples taken between December and mid-January. Of those taken in January alone, new strains reached 91%. Naveca said it appeared that the variant was more transmissible, based on the frequency with which it was found, and on indications that the British and South African variants had a similar mutation.

Most of the samples his laboratory analyzes come from Manaus, but the new strain has also been found in cities deeper in the Amazon, including Sao Gabriel Cachoeira on the Colombian border.

Sylvain Aldighieri, deputy director of the Pan American Health Organization’s health emergencies department, said it was too early to determine whether the variant accelerated the spread of the virus and more genetic sequencing was needed. However, he asked the government to remain vigilant.

Speaking in an interview with the AP on Friday, Guyanese Health Minister Frank Anthony said local private laboratories had said they were equipped to test the new strain. The first 30 days of suspension were carried out with increased border patrols by army and police.

“We don’t have any evidence yet that a new strain of the COVID-19 virus is here, but we are just being careful,” he said.

Anthony acknowledged that the 1,606 kilometer (1,000 mile) border was practically impossible to patrol. Thousands of Guiana and Brazilians use the official Takatu River Bridge to cross into Guyana every day, while others cross several other small rivers that separate the two South American countries for trade, visit relatives, or work. Many from every country live in one country and work in another so crossing is normal for many people.

Officials in Bolivia and Venezuela, which share two of Brazil’s three longest borders, have not announced any changes to restrictions recently.

Jose Gregorio Díaz Mirabal, general coordinator of Indigenous Organizations in the Amazon Basin, warned this week that effective barriers have not been implemented.

“There is no guarantee it will not reach the (Brazilian) border with Venezuela, with Colombia, Suriname, Guyana,” said Díaz Mirabal, of the Wakuenai Kurripako ethnicity, in Zoom’s call to reporters. ——— AP author Bert Wilkinson reporting from Georgetown. AP author Melinda Ulloa contributed from Washington, Franklin Briceño from Lima, Almudena Calatrava from Buenos Aires, Regina García Cano from Bogota, and Scott Smith from Caracas.