By Stan Deresinski, MD, FACP, FIDSA
Clinical Professor of Medicine, Stanford University
SYNOPSIS: A new outbreak of a more lethal Ebola virus is occurring in Uganda with concern about its exportation.
SOURCES: World Health Organization. Ebola disease caused by Sudan virus - Uganda. Sept. 26, 2022. https://www.who.int/emergencies/disease-outbreak-news/item/2022-DON410
Centers for Disease Control and Prevention. Health Advisory Alert. Outbreak of Ebola virus disease (Sudan ebolavirus) in Central Uganda. Oct. 6, 2022. https://emergency.cdc.gov/han/2022/han00477.asp
A 24-year-old man in Uganda became ill on Sept. 11, 2022. His symptoms progressively worsened, and he was admitted to a regional referral hospital on Sept. 15 with a hemorrhagic fever syndrome. He was placed in isolation, and a diagnosis of Ebola was confirmed on the day of his death four days later.
An outbreak of Ebola was officially declared on Sept. 20, 2022, and control measures were implemented. By Oct. 2, a total of 43 cases with nine deaths had been confirmed together with more suspected cases and a death toll that has reached 30. Among those dying have been healthcare providers. The infections are caused by the Sudan version of the virus (Sudan ebolavirus), which has not been responsible for an outbreak for the last decade.
On Oct. 6, the U.S. Centers for Disease Control and Prevention (CDC) issued a Health Advisory Alert as well as a travel alert for the affected districts in Uganda. On the same day, they implemented screening at receiving airports, requiring that travelers from Uganda enter the country at one of five airports. These are Chicago O’Hare, New York–JFK, Atlanta, Newark, and Washington Dulles.
COMMENTARY
Among the six known species of Ebola virus, four may infect humans, but only two have been responsible for most human disease: Zaire ebolavirus and Sudan ebolavirus. Mortality rates as high as 50% have occurred during previous outbreaks of infection caused by the Sudan virus, a rate generally higher than occurs with the Zaire virus.
The response to the 2013-2016 outbreak caused by the Zaire virus led to the development of effective vaccines and therapies, and ring vaccination strategies were important in controlling the outbreak. Unfortunately, the resultant prophylactic vaccines and therapeutic monoclonal antibodies are not effective against the Sudan virus that is causing infections in Uganda, where the last such outbreak in 2000 resulted in 425 infections and 224 deaths. However, three vaccines directed against Sudan ebolavirus have undergone successful early phase human safety testing (and three others are in the pipeline), and human studies are being initiated in Uganda.1
Ebola (Zaire) was introduced into the United States in 2014-2016 and, in total, 11 patients received care for this disease. The first of these was a man who traveled from West Africa to Dallas, TX. He died on Oct. 8, 2014. Two healthcare providers who had cared for him developed Ebola, but both recovered. This experience illustrates the need for clinicians to be alert to this diagnosis in patients with appropriate epidemiologic history and clinical manifestations — as well as the need for rapid implementation of isolation procedures.
The Ebola story also illustrates the need to deal decisively with infectious disease everywhere to prevent future outbreaks.
Editor’s note: An excellent updated presentation is available at: CDC. Center for Preparedness and response. Update on 2022 Ebola Ourbreak in Uganda. Clinician Outreach and Communication Action (COCA). Oct. 12, 2022. https://emergency.cdc.gov/coca/calls/2022/callinfo_101222.asp
REFERENCE
- Kozlov M. Ebola outbreak in Uganda: How worried are researchers? Nature. Oct. 7, 2022. https://www.nature.com/article...
