Overview
Situation at Glance
Currently, no suspected, probable, or confirmed cases of Ebola virus disease (EVD) associated with this outbreak have been reported in the United States or outside of Uganda. However, as a precaution, and given other outbreaks of viral hemorrhagic fevers in East Africa, CDC is sharing best practices with public health departments, clinical laboratories, and health care workers in the United States to increase awareness of this outbreak.
On January 30, 2025, the Ugandan Ministry of Health declared an outbreak of EVD caused by Sudan Ebola virus disease (SEVD) after it was confirmed by three national reference laboratories. The case developed symptoms between January 20 and 21 and died on January 29 at the National Referral Hospital in Kampala.
SEVD is a member of the same family as Ebola virus disease (EVD) and is a serious illness with a high case fatality rate of 41% to 70% in previous outbreaks. Because there are no licensed vaccines or treatments available to prevent or treat Ebola virus disease Sudan, the risk of significant public health impact remains high. Providing early supportive care and treatment may increase the chances of survival from severe disease.
Description of the Situation:
On 30 January 2025, the Ugandan Ministry of Health declared an outbreak of Ebola virus disease (EVD) caused by Sudan Ebola virus disease (SEEV) after confirmation by three national reference laboratories. The case was confirmed in an adult male nurse who initially presented with fever-like symptoms and sought treatment from a traditional healer and then at several health facilities. The patient developed high fever, chest pain, and difficulty breathing, with symptoms beginning between 20 and 21 January, and later progressed to unexplained bleeding from multiple sites. The patient developed multiple organ failure and died at the National Referral Hospital on 29 January. Sudan Ebola virus disease (SEVD) was confirmed through postmortem samples. To date, 45 people have been identified as contacts of the patient, including 34 healthcare workers and 11 family members. There have been 8 previous outbreaks of Sudan Ebola virus disease (SEVD), 5 in Uganda and 3 in Sudan. The last outbreak of Sudan Ebola virus disease was in Uganda in 2022. Case fatality rates in previous outbreaks ranged from 41% to 100%. There are no licensed treatments or vaccines for the disease, but early supportive treatment can significantly reduce mortality.
Ebola virus disease (EVD):
Ebola virus disease (EVD) is a deadly disease that occurs sporadically in Africa, infecting humans and animals, including monkeys, gorillas, and chimpanzees. The disease is caused by six types of
Ebolaviruses:
- Zaire ebolavirus (ZEBOV).
- Sudan virus (SVD).
- Taï Forest virus.
- Bundibugyo virus.
- Reston virus.
- Bombali virus.
Of these, only four cause disease in humans:
- Zaire ebolavirus (ZEBOV).
- Sudan virus (SVD).
- Taï Forest virus.
- Bundibugyo virus.
While Reston virus infects only animals, it does not cause disease in humans.
History of the disease in Africa:
Ebola virus was first detected in 1976 near the Ebola River in the Democratic Republic of Congo, and has since recurred periodically, causing numerous outbreaks in several African countries.
The Democratic Republic of the Congo has faced more than 10 outbreaks of Ebola virus disease (ZEBOV) over the past decades, the most severe of which occurred between 2018 and 2020, when 3,481 cases were reported, with a case fatality rate of 66%. The most recent outbreak was recorded on 22 April 2022, when one case was confirmed in a Congolese citizen.
Ebola virus Sudan was first reported in South Sudan in June 1976, and has since continued to recur periodically, with seven outbreaks recorded to date, including four cases in Uganda and three in Sudan. The case fatality rates have ranged from 41% to 100% in previous outbreaks.
Uganda has experienced several outbreaks of the virus, with four outbreaks reported in 2000, 2011, and 2012 (two cases), in addition to the Bundibugyo outbreak in 2007, and the Sudan Ebola outbreak in 2019.
Transmission:
Ways of transmitting Ebola virus include:
- Direct contact with infected animals, such as fruit bats, monkeys, chimpanzees, antelopes, and porcupines.
- Direct exposure to the blood or body fluids of a person infected with or deceased from Ebola virus, including urine, saliva, sweat, feces, vomit, breast milk, amniotic fluid, and semen.
- Contact with tools and materials contaminated with body fluids of infected or deceased people with the virus, such as clothing, bedding, needles, and medical equipment.
- Transmission of the virus through the semen of people who have recovered from Ebola, as the virus can remain in some body fluids, including semen, even after the person has recovered and severe symptoms have disappeared.
It is worth noting that an infected person cannot transmit the infection to others until symptoms appear.
Symptoms and diagnosis:
- The incubation period for Ebola virus ranges from 2 to 21 days. Initial symptoms include fever, fatigue, muscle aches, headache, and sore throat, followed later by vomiting, diarrhea, rash, and impaired kidney and liver function. In severe cases, patients may experience internal and external bleeding, such as bleeding from the gums or blood in the stool.
- Infected people are not contagious until they develop symptoms, and they can still transmit the virus if the virus is present in their blood. Because the initial symptoms are similar to other common diseases, such as malaria and typhoid fever, diagnosis requires specialized tests.
- The polymerase chain reaction (PCR) is the most common diagnostic method, as it can detect low levels of the virus, and an antibody test can determine whether a person has been previously exposed to Ebola.
Prevention:
- To reduce the transmission of Ebola, measures must be taken to reduce the risk of transmission from wildlife to humans, as well as from humans to humans, particularly through direct or close contact with infected people, particularly through bodily fluids. Additional precautions should also be taken to reduce the risk of potential transmission of the virus through some bodily fluids of survivors.
- WHO recommends that survivors receive medical care and psychological support, as well as biological testing (including two consecutive negative tests), as part of the Ebola survivor care program.
Vaccines and treatments:
- Currently, a candidate vaccine and two candidate treatments—one monoclonal antibody-based, the other antiviral—are available and will be provided through a clinical trial protocol.
- It is important to note that the two licensed Ebola vaccines do not provide cross-protection against Sudan Ebola virus and therefore cannot be used in this outbreak.
Risk assessment:
- On February 5, 2025, the Centers for Disease Control and Prevention (CDC) issued a Level 2 Traveler Health Notice, urging enhanced precautions for persons traveling to Uganda.
- To date, CDC has not issued any interim recommendations for health departments regarding risk assessment and management for travelers after arrival, including U.S. health care workers, who are traveling from Uganda.
Recommendations for travelers:
- Monitor for possible symptoms of Ebola disease caused by Sudan Ebola virus disease while in the outbreak area and for 21 days after leaving.
- Isolate yourself immediately and contact your local health authority or physician if you develop any symptoms.
Possible symptoms:
- Early “dry” symptoms: fever, aches, fatigue.
- Late “wet” symptoms: diarrhea, vomiting, unexplained bleeding.
Effective control of the Sudan Ebola virus disease outbreak depends on implementing a set of core interventions, including:
- Clinical case management to ensure appropriate care for those affected.
- Case and contact tracing to prevent further spread of the virus.
- Strengthening laboratory services to ensure rapid and accurate diagnosis.
- Implementing infection prevention and control measures in health facilities and communities to reduce transmission of the virus.
- Increase community engagement in control and awareness efforts, to ensure compliance with health guidelines and reduce the risk of outbreaks.
WHO Recommendations:
As there are no direct flights from Uganda to the United States, travelers coming from or transiting through affected areas in Uganda can enter the United States via connecting flights from other countries.
CDC Actions:
- Continuous communication with public health departments, clinical laboratories, and health care workers in the United States.
- Educate travelers to increase awareness of the current outbreak and take necessary precautions.
- Recommendations for health care providers:
- Remain alert and evaluate any patients suspected of having Ebola disease caused by Ebola Sudan virus.
- Take a detailed travel history of suspected patients, especially those coming from affected areas in Uganda.
Early consideration of possible Ebola Sudan virus infection as part of the differential diagnosis, which contributes to:
- Providing appropriate and rapid care to the patient.
- Making the necessary diagnoses in a timely manner.
- Reducing the spread of infection within health facilities and the community.
References:
World Health Organization - US Centers for Disease Control and Prevention CDC.