CAIRO — A sharp spike in coronavirus cases in Egypt is threatening one of the largest economies in the Middle East, as the nation’s tourism sector reels from an outbreak on a Nile cruise ship that has affected more than a dozen American passengers.

Egypt reported its first death related to the virus on Sunday: a 60-year-old German tourist who had been in the country for seven days. He died in a hospital in the Red Sea city of Hurghada two days after traveling from Luxor.

The government announced that 45 passengers and crew were found infected on the cruise ship Asara, which traveled from Aswan to Luxor last week. Before that, the Arab world’s most populous nation had reported three cases of the virus. On Sunday evening, the Health Ministry announced seven more, for a total of 55.

Senior officials on Sunday visited the southern city of Luxor, where several dozen foreigners, including Americans, remain quarantined on the Asara. They tried to reassure travelers that the city, home to the famed Valley of the Kings and the Karnak Temple, remained safe to visit.

“We are here to respond to rumors saying that there are no tourists and people are afraid of coming,” Khaled al-Anani, the tourism and antiquities minister, told state television. “Thank God, people are here.”

But as officials played down the impact of the virus, there were signs the epidemic was burrowing into Egypt’s tourism dollars. Hossam el Shaer, the head of the chamber of tourism companies, told an Egyptian newspaper Sunday that foreign tourist bookings have fallen by as much as 80 percent from the same period last year. The news coincided with a sharp drop in the Egyptian stock market, forcing the suspension of trading in 25 hard-hit companies.

“The coronavirus is likely to seriously impact Egypt’s economy,” Timothy Kaldas, an analyst with the Washington-based Tahrir Institute for Middle East Policy, said in tweets on Sunday. “As fear of travel grows Egypt will likely witness [a] fall in tourism, a notoriously fragile, but valuable sector in its economy.”

Tourism, one of Egypt’s most important sources of foreign currency, was showing signs of a rebound after the political chaos that followed the 2011 Arab Spring revolts that ousted President Hosni Mubarak and a spate of terrorist attacks.

The outbreak is coinciding with a drop in the price of natural gas, a key Egyptian export. Falling oil prices could impact the livelihoods of several million Egyptians working in the Persian Gulf and elsewhere who send billions of dollars in remittances back to Egypt, Kaldas noted.

There were signs Sunday that those remittances could face more shocks. Large crowds of Egyptians planning to work in Saudi Arabia gathered outside a public laboratory in Cairo to take tests to prove they don’t have the coronavirus, under the kingdom’s new requirements.

The death of the German tourist was another blow. He tested positive at a hospital and was placed in intensive care after refusing to be quarantined at another medical facility, the health ministry said. His condition deteriorated Sunday.

It was unknown whether he sailed to Luxor last week on the Asara. Authorities struggled Sunday to prevent more infections on the cruise ship. More than two dozen Americans and other foreigners were on day three of a two-week quarantine.

American passengers interviewed by telephone and text message said about 50 of the roughly 80 remaining passengers, including French and Indian citizens, attended a morning briefing. “Still a little disorganized but getting better,” said Javier Parodi, 35, a building inspector from Miami. “We were told that if anyone tests positive that the 14-day clock starts again.”

Parodi said the U.S. Embassy in Cairo sent him a disclosure form, but he’s not been told anything of substance about his situation.

Embassy spokesman Sam Werberg said: “We are in the process of making contact with all American passengers, and will be providing appropriate assistance to the impacted U.S. citizens.” He said the embassy was aware of reports that Americans had tested positive for the virus and were taken to a quarantine hospital in Marsa Matrouh in northern Egypt.

“We are working closely with the Egyptian Government to ensure the safety and security of all U.S. citizens,” Werberg said.

Passengers on the Asara were advised to stay in their rooms, they told The Washington Post, but many, wearing masks, wandered through the ship’s common areas. In the ornate lobby, with wood-paneled walls and marble floors, blue cardboard boxes of bottled water were stacked nearly to the ceiling. A makeshift medical room was set up in the second-floor library.

Passengers were given pillows without cases, they said, and crew disinfected only their cabin floors. To Parodi, it seemed inadequate. “I was in the Air Force many years ago and I’m just used to cleanliness and organization,” he said.

Passengers were told their temperature would be checked twice a day, once in the morning and at night. They were given additional soap and towels. Despite his concerns about cleanliness, Parodi said the Egyptians were doing their best to assist the passengers.

“They did, in my opinion, mess up at first,” he said. “But they’ve done everything they can, as far as I know, to address our concerns and to make us feel as comfortable as possible.”

Heba Farouk Mahfouz in Cairo contributed to this report.