JUBA, South Sudan — Officials in South Sudan say the country has its first case of COVID-19, making it the 51st of Africa’s 54 countries to have the disease.

First Vice-President Riek Machar and the U.N. mission in South Sudan confirmed the positive case of a U.N. worker who arrived in the country from Netherlands on Feb. 28. The officials say the patient, a 29-year-old woman, is recovering.

South Sudan, with 11 million people, currently has four ventilators and wants to increase that number, said Machar, who emphasized that people should stay three to six feet apart from others.

“The only vaccine is social distancing,” said Machar.

The patient is under quarantine at U.N. premises and health workers are tracing the people who had been in contact with her, said David Shearer, head of the U.N. operations in South Sudan.

He said he hoped the measures would contain the case.

To prevent the spread of the virus in South Sudan, President Salva Kiir last week imposed a curfew from 8:00 p.m. to 6:00 a.m. for six weeks and closed borders, airports, schools, churches and mosques.

Maura Ajack, The Associated Press