Organised by the ESCMID Emerging Infections Subcommittee and Amsterdam University Medical Center

Epi Alert

About Epi Alert

Summary: 04 August 2026

The Ebola virus disease outbreak in the Democratic Republic of the Congo has reached 3,553 confirmed cases and 1,558 deaths across 49 health zones in five provinces, the fastest-growing outbreak in recorded history, with Ituri accounting for 87.9% of cases. West Nile virus transmission has been identified in 49 areas across seven European countries, with Greece reporting 42 cases and four deaths, while the United States reports 113 cases from 23 states, 61 of them in Arizona. Chile has declared its first national Hantavirus Health Alert after 41 cases and 14 deaths from Andes virus. São Paulo state reports a 94.7% case-fatality rate for Brazilian spotted fever, with 18 deaths among 19 confirmed cases. Cholera in Cameroon's Far North region has caused 754 cases and 25 deaths, severely affecting the Minawao refugee camp. Meanwhile, Cambodia reports a 58% surge in dengue cases, and Taiwan has recorded ten Japanese encephalitis cases, including one death.

Highlights

Ebola virus disease — Global
The CDC reports 3,553 confirmed cases and 1,558 deaths across 49 health zones in five provinces. In the past 24 hours, 69 new confirmed cases and 34 deaths were recorded. The event is the fastest-growing Ebola outbreak in recorded history, reaching 1,000 deaths in just over two months. Ituri remains the epicenter, accounting for 87.9% of cumulative cases.

West Nile virus disease — Global
As at 29 July, 49 areas with WNV transmission have been identified across seven European countries: Italy (30), Greece (8), Romania (4), North Macedonia (2), Spain (2), France (2) and Germany (1). Greece reports an early and intense season with 42 cases, 37 of them neuroinvasive, and four deaths, concentrated in Attica. In the United States, 113 cases have been reported from 23 states through 28 July, with Arizona accounting for 61, a 62.5% increase over the same period of 2025.

Hantavirus disease — Central & South America
Chile has declared its first-ever national Hantavirus Health Alert following a doubling of the case fatality rate in 2026. 41 cases and 14 deaths from Andes virus have been reported. Recent infections include two occupational cases among aquaculture divers in the Aysén Region, a fatal pediatric case in the Valparaíso Region, and cases linked to outdoor activities in the Los Lagos Region.

Rocky Mountain spotted fever — Central & South America
The São Paulo State Health Secretariat has recorded 19 confirmed cases and 18 deaths from Brazilian spotted fever this year, representing a 94.7% case-fatality rate. In 2025, the state confirmed 61 cases and 44 deaths. The acute febrile disease is caused by Rickettsia rickettsii.

Cholera — Africa
The Far North region of Cameroon has reported 754 cases and 25 deaths, including at least 24 cases in the Minawao refugee camp, which is operating at 325 percent of capacity and where multiple chains of transmission are suspected. Between 22 June and 27 July 2026, 8 247 new cases and 326 new deaths were reported worldwide, with the Democratic Republic of the Congo (3 841), Sudan (1 502), Somalia (962) accounting for most cases, and Sudan (153), DRC (105), Central African Republic (36) for most deaths. Cumulative figures since 1 January 2026 stand at 132 313 cases and 1 556 deaths globally.

Ebola virus disease
Democratic Republic of the Congo (Ituri)
Africa
Ebola virus disease
Democratic Republic of the Congo (Ituri)
Africa

Outbreak is now the second-largest Ebola outbreak on record (3553 cases and 1558 deaths)

Source: CDC - 03 Aug 2026
Dengue
Cambodia
Asia
Dengue
Cambodia
Asia

Cases surge 58% percent above 2025 levels amid flooding

Source: BEACON - 28 Jul 2026
Diphtheria
Somalia
Africa
Diphtheria
Somalia
Africa

156 new suspected cases and 6 deaths (2,661 cumulative cases).

Source: H-Radar - 27 Jul 2026
Japanese encephalitis
Taiwan, Chinese Taipei
Asia
Japanese encephalitis
Taiwan, Chinese Taipei
Asia

10 cases this year, including the first death

Source: H-Radar - 28 Jul 2026
Measles
Guatemala
Central & South America
Measles
Guatemala
Central & South America

30,040 confirmed cases and 29 deaths

Source: Outbreak News Today - 27 Jul 2026
Poliomyelitis
Ethiopia
Africa
Poliomyelitis
Ethiopia
Africa

Two new cVDPV1 cases (9 national total)

Source: H-Radar - 27 Jul 2026
Rabies
Pakistan
Asia
Rabies
Pakistan
Asia

19 deaths this year across Sindh

Source: H-Radar - 29 Jul 2026
Cyclosporiasis
United Kingdom, Mexico, United States
Europe
Cyclosporiasis
United Kingdom, Mexico, United States
Europe

67 cases in returning travellers, primarily from Mexico.

Source: Outbreak News Today - 30 Jul 2026
Dengue
United States
North America
Dengue
United States
North America

First confirmed locally-acquired case of 2026

Source: Outbreak News Today - 29 Jul 2026
Leprosy
United States
North America
Leprosy
United States
North America

17 confirmed autochthonous cases year-to-date, linked to armadillo exposure.

Source: BEACON - 27 Jul 2026
West Nile virus disease
United States
North America
West Nile virus disease
United States
North America

52 cases and five deaths (62% increase)

Source: CDC - 02 Aug 2026
Hantavirus disease
Chile
Central & South America
Hantavirus disease
Chile
Central & South America

First-ever national health alert declared amid doubling CFR and 41 reported cases.

Source: BEACON - 29 Jul 2026
Rocky Mountain spotted fever
Brazil
Central & South America
Rocky Mountain spotted fever
Brazil
Central & South America

19 confirmed cases and 18 deaths reported this year in São Paulo

Source: Outbreak News Today - 28 Jul 2026
Dengue
Sri Lanka
Asia
Dengue
Sri Lanka
Asia

DENV-2 epidemic surpasses 84.000 cases, with July recording 29.350 cases.

Source: BEACON - 31 Jul 2026
Cholera
Cameroon
Africa
Cholera
Cameroon
Africa

754 cases and 25 deaths, including Minawao refugee camp.

Source: H-Radar - 29 Jul 2026
Mpox
Nigeria
Africa
Mpox
Nigeria
Africa

513 cases this year

Source: H-Radar - 27 Jul 2026

About

The ESCMID-AUMC Epi Alert, a strategic collaboration between the ESCMID Emerging Infections Subcommittee and the Center of Tropical Medicine and Travel Medicine of Amsterdam University Medical Center (AUMC) that integrates expertise and resources to advance emerging infectious diseases surveillance and intelligence sharing. This collaboration integrates ESCMID's extensive international network and emerging infections expertise with AUMC's proven surveillance capabilities, led by Dr. Abraham Goorhuis and the AUMC team and other collaborators form European Institutions. 

The Epi Alert aims to be a weekly publication. The briefings are curated by infectious disease specialists prioritising data from trusted sources (such as Beacon, H-Radar, Outbreaknews, WHO, ECDC, CDC) based on potential impact, geographic region and urgency/relevancy to clinical practice. It aims to provide concise summaries for busy healthcare professionals with direct links for further investigation and transparency. 

This integrated collaboration represents a significant milestone in ESCMID's commitment to emerging infections preparedness, strengthening our collective capacity to detect, analyse, and respond to infectious disease threats through international cooperation.

Disclaimer: The information in this epi-alert is a weekly summary of the information that is available on the internet, mainly the websites of Beacon, H-Radar, Outbreaknews, WHO, ECDC, CDC, and others. For this summary, we consider issues that are most relevant to the ESCMID members involved in clinical patient care. Therefore, this report is not comprehensive, but we strive to include all major global issues in this report on a weekly basis.