Epi Alert

Summary: 23 June 2026

An expanding outbreak of Ebola disease caused by Bundibugyo virus in the Democratic Republic of the Congo has reached 896 confirmed cases and 232 deaths, with 19 linked cases in Uganda. In the Americas, Colombia is managing a sylvatic yellow fever outbreak with 200 confirmed cases and 89 deaths, while Haiti reports 159 confirmed and 1,616 suspected diphtheria cases amid declining vaccination coverage. The United States reported on a seasonal influenza A outbreak at a Texas military base. In Asia, Pakistan has documented over 20,000 measles cases and 96 child deaths, other measles outbreaks have been reported in Syria, Peru and Guatemala. Elsewhere, Yemen has reported 4,819 dengue cases and 18 deaths, and Canada continues to track a sustained hepatitis A outbreak that has caused 784 cases and four deaths since 2024.

Highlights

Ebola virus disease — Africa
The outbreak of Ebola disease caused by Bundibugyo virus continues to expand in the Democratic Republic of the Congo (DRC), with 896 confirmed cases and 232 deaths reported across 33 health zones in Ituri, North Kivu, and South Kivu provinces as of 17 June 2026. Uganda has reported 19 confirmed cases, two deaths, and one probable fatal case, with all infections linked epidemiologically to transmission originating in the DRC and no new cases detected since 5 June. The outbreak remains concentrated in Ituri Province, which accounts for over 90% of confirmed cases, while more than 6,300 contacts are under follow-up in the DRC. Response efforts are complicated by insecurity, population displacement, and limited access to healthcare in conflict-affected areas, increasing the risk of undetected transmission. WHO assesses the risk as very high in the DRC, high in Uganda and neighbouring border countries, and low globally.

Diphtheria — Caribbean
As of mid-June 2026, the number of diphtheria cases in Haiti has increased to 159 confirmed and 1,616 suspected infections, alongside five reported deaths. This epidemiological update notes that the rise in cases is occurring amid a broader regional decline in diphtheria, tetanus, and pertussis (DTP) vaccination coverage.

Influenza — North America
A large influenza outbreak has been reported among recruits at Lackland Air Force Base (Joint Base San Antonio), Texas, with 222 cases, at least two hospitalizations, and one death under investigation as of 18 June 2026. The outbreak has occurred within a Basic Military Training unit where recruits live in congregate settings, facilitating rapid respiratory virus transmission. Notably, the outbreak followed a policy change that made annual influenza vaccination optional, resulting in vaccination coverage falling from nearly 100% to approximately 40% among trainees. The fatal case involved an unvaccinated 25-year-old recruit whose illness progressed to pneumonia, prompting a comprehensive medical review. In response, the Pentagon has authorized military branches to reinstate mandatory influenza vaccination requirements, while local control measures include case isolation, contact monitoring, and antiviral treatment with oseltamivir.

Measles — Global
Measles outbreaks continue to expand across multiple regions, highlighting persistent immunity gaps and challenges in vaccination coverage. In Guatemala, more than 23,000 cases and 22 deaths have been reported since January 2026, prompting a nationwide red alert and mass vaccination campaign following an outbreak linked to an international religious gathering. Pakistan has recorded over 20,000 cases and 96 deaths, with the highest mortality burden reported in Sindh province. In Peru, an outbreak that began in Puno has spread to additional regions, leading to a public health emergency declaration, while Syria has reported measles transmission among displaced populations in Daraa Governorate.

Yellow fever — Central & South America
Through mid-June 2026, Colombia has recorded 200 confirmed cases and 89 deaths in an ongoing yellow fever outbreak spanning 10 departments. The Tolima department accounts for the highest morbidity and mortality burden. Transmission is primarily driven by unvaccinated travelers entering sylvatic zones, a situation compounded by vaccine hesitancy and sub-optimal immunization coverage.