Global health officials warned on Tuesday that the number of people infected in an Ebola outbreak in central Africa could be much higher than reported and that the outbreak could last for months.
The suspected death toll stood Tuesday at more than 130 people.
The outbreak is centered in the east of the Democratic Republic of Congo, where people, including migrant laborers working in gold mines, move across borders. The area is also in the grip of a conflict that has displaced more than a million people, gutted health clinics and slowed the public health response, officials said.
“The last outbreak in this area took two years,” to contain, Dr. Anne Ancia, a representative for the World Health Organization in Congo, said in a phone interview from Bunia, the capital of Ituri province, where the first cases were identified.
“We hope it won’t be that long, but I’m foreseeing several months,” she added.
Her comments followed a news conference by Congo’s health minister, Dr. Samuel-Roger Kamba. He reported 131 suspected deaths and 513 suspected cases linked to the virus.
Tedros Adhanom Ghebreyesus, the director-general of the W.H.O., said at a meeting of the organization in Geneva that he was “deeply concerned” about the scale and speed of the outbreak.
Laboratory testing has confirmed 30 cases so far. Experts have expressed alarm that the virus, a relatively rare species called Bundibugyo, appears to have been spreading unchecked for several weeks in an area where contact tracing is likely to be very difficult.
A model of the outbreak published on Monday by the MRC Centre for Global Infectious Disease Analysis, at Imperial College in London, found that the current number of cases could be well over 1,000.
“Our analyses suggest that the true number of cases may be substantially higher than those confirmed to date,” said Dr. Anne Cori, an associate professor in infectious disease modeling and one of the scientists who created the model.
Dr. Ancia said W.H.O. officials had been in Bunia since Sunday and that while medical equipment, disinfectant and protective gear had arrived, it was not enough.
“We need more people, more hands on the ground,” she said. Moving equipment to the region was made more difficult since rebels took over the city of Goma, home to the region’s main airport, she added.
Dr. Tedros said the deaths of health care workers and the absence of vaccines or therapeutics to treat the Bundibugyo species raised fears that the outbreak would spread further. Cases have already been reported in urban areas, including in Kampala, the capital of Uganda, and in Goma.
The W.H.O. supplies that were flown in since Sunday included diagnostic kits capable of identifying the Bundibugyo species, Dr. Ancia told reporters at a briefing on Tuesday. Additional laboratory equipment are expected this week, she said.
Health authorities have not yet identified a ‘patient zero’ marking the start of the outbreak, Dr. Ancia said.
A technical advisory group meeting in Geneva on Tuesday to weigh which vaccines would be prioritized for clinical trials.
On Tuesday, the State Department said it “strongly urges” Americans not to travel to the Democratic Republic of Congo, South Sudan, or Uganda, and to reconsider travel to Rwanda. A C.D.C. order issued on Monday allows the United States to bar foreigners from entering the country if they have been those countries in the previous 21 days.
President Félix Tshisekedi of Congo urged citizens to remain calm and to follow containment measures to curb the spread of the disease. But several countries in the region, including neighboring Rwanda, have started screening travelers or tightening border controls.
The Africa Centers for Disease Control and Prevention said in a statement on Tuesday that it had acted “rapidly, transparently and responsibly” to call the world’s attention to the outbreak, and criticized the “use of broad travel restrictions as a primary public health tool.”
“Global health security cannot succeed if countries are penalized for transparency during outbreaks,” Dr. Jean Kaseya, the head of the organization, said on social media.
One of those infected in the outbreak is Dr. Peter Stafford, an American medical missionary who was exposed to the virus while working at a hospital in Ituri province and who is expected to be treated in Germany.
A spokeswoman for German federal health authorities said on Tuesday that Germany was preparing to receive and treat “a U.S. citizen who contracted Ebola in the Congo” after the United States requested assistance, but she did not provide more details.
Two other physicians working in the Democratic Republic of Congo with the same organization as Dr. Stafford — his wife, Dr. Rebekah Stafford, and Dr. Patrick LaRochelle — may have been exposed to the virus. All three doctors have been quarantining.
Peter LaRochelle, Dr. LaRochelle’s father, said in a phone interview on Tuesday that he had spoken with his son that morning and that he, along with Dr. Stafford’s wife and four children, were asymptomatic.
Still, the father said: “We are losing sleep.”
Nick Cumming-Bruce contributed reporting from Geneva; Brian Otieno from Nairobi, Kenya; Pooja Salhotra from New York; and Christopher F. Schuetze from Berlin.
