Study of Filovirus Disease Morbi-mortality (TEMBO)

Prospective Observational Study of the Mortality of Patients With Filovirus Disease

Filoviruses, including Ebola and Marburg, cause hemorrhagic fevers associated with high mortality and still limited scientific literature, in particular for some rare species such as the Bundibugyo virus. The current epidemic of Bundibugyo virus disease in the Democratic Republic of the Congo (DRC) and Uganda, which has been declared a public health emergency of international concern by the World Health Organization (WHO), illustrates the importance of better characterizing this infection, whose genetic specificities complicate the transposition of diagnostic, therapeutic and vaccine tools developed for Ebola Zaire.

Given the incubation time of filoviruses and international mobility, cases can be diagnosed and managed outside of epidemic areas, including in exposed caregivers. However, clinical, biological and therapeutic knowledge available in this context remain very limited.

This situation justifies the implementation of an observational cohort of patients with a confirmed filovirus disease, who have arrived or were diagnosed in France.

This cohort will describe the clinical evolution of the disease, its prognosis and its pathophysiology, as well as identify new diagnostic, therapeutic or preventive leads.

Study Overview

• Status: Not yet recruiting
• Conditions: Filovirus Disease

Detailed Description

Filoviruses, including Ebola Zaire, Sudan, Bundibugyo, Tai Forest and Marburg virus, are responsible for haemorrhagic fevers with high overall mortality: a recent meta-analysis reports an average case fatality rate of 59%, with extremes of 20 to 90% depending on the epidemic. Between 1976 and 2014, about twenty epidemics of filoviruses diseases (FVD) occurred in Central Africa, without much scientific documentation. The largest ever is an outbreak of Ebola virus disease (EVD) declared in West Africa between 2014 and 2016 (in Guinea, Liberia, and Sierra Leone) and recorded 11,310 deaths for 28,616 cases. Currently, an outbreak of Bundibugyo virus disease (BVD) is active in the Democratic Republic of Congo (DRC) (Ituri and North Kivu provinces) and Uganda.

It was declared a "public health emergency of international concern" by the World Health Organization (WHO) on May 17, 2026. It currently has 399 deaths out of 1333 cases reported as of June 29, 2026, reflecting the scale of the outbreak. Bundibugyo virus (BDBV) was first identified in 2007 in Uganda. The epidemic is only the third documented emergence of BVD, following those observed in Uganda in 2007 and in the DRC in 2012. The lethality of BVD is estimated to be approximately 25%. Genetically, BDBV is different from the most common species, the Zaire Ebola virus (EBOV), in a proportion of about 40%. This genetic distance explains the difficulties in adapting diagnostic approaches (molecular biology) and therapeutic approaches (monoclonal antibodies, direct-acting antivirals, and vaccines) developed for EBOV.

By the incubation period, in the order of 2 to 21 days, and the ease of air travel in the 21st century, we can expect that cases of FVD are diagnosed and treated outside of epidemic areas (in particular the healthcare staff working in epidemic areas and contaminated in a nosocomial way). During previous filovirus epidemics, a very small number of infected people were treated outside the epidemic areas. Therefore, little is known to date about the clinical and biological characteristics and the treatment history of filovirus diseases in patients managed outside the African context.

In this context, it is necessary to set up an observational cohort study of any case of disease with proven filovirus that arrived or was diagnosed in the national territory in order to describe the disease, its clinical course, prognosis, as well as to study its pathophysiology to identify new targets for the diagnosis and curative and preventive treatment.

Knowledge on filovirus diseases acquired during the care of patients with EVD outside of epidemic areas are very fragmented and the absence of biological collections taken from the few patients with EVD in previous epidemics and hospitalized in Europe or the United States did not allow us to describe interactions between the host and the pathogenic species, this being particularly true for rare strains such as the BDBV. Given the genetic distance between species, and that this is the largest epidemic to date caused by the Bundibugyo species, BVD may have clinical, biological, and prognostic features different from other filoviruses.

• Study Type: Observational
• Enrollment (Estimated): 10

Contacts and Locations

• Study Contact: Name: Marie JASPARD, MD; Phone Number: 06 58 80 90 12; Email: marie.jaspard@aphp.fr
• Study Contact Backup: Name: Mathieu REVEST, MD; Phone Number: +33 2 99 28 95 64; Email: Matthieu.REVEST@chu-rennes.fr

Study Locations

• France
  • Paris, France, 75012
    • Hopital Saint Antoine
    • Contact: Marie JASPARD, MD; Phone Number: 06 58 80 90 12; Email: marie.jaspard@aphp.fr
    • Contact: Mathieu REVEST, MD; Phone Number: +33299289564; Email: Matthieu.REVEST@chu-rennes.fr
    • Principal Investigator: Marie JASPARD, MD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Any individual, including adults, children, minors under 18, and pregnant women, with a filovirus infection:

• Either repatriated to the national territory with a virologically confirmed diagnosis
• Or virologically diagnosed within the national territory

Description

Inclusion criteria :

• Confirmed filovirus disease
• Hospitalized in a Referenced Healthcare Facility in France

Non inclusion criteria :

• Refusal by the patient or their legal representative to sign the consent form for the study
• Patient deprived of their liberty or subject to a legal protection measure

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort
Patients with a confirmed filovirus disease; Any individual, adult or minor, including pregnant women, suffering from a filovirus disease and responding to one of the following situations: person repatriated to the national territory with a confirmed virological diagnosis; person who has received a virologically confirmed diagnosis in France

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Vital status on day 28.	The objective is to describe mortality at day 28 in patients with confirmed filovirus diseases. Day 1 is the day of the first documented positive PCR, regardless of the location of the PCR.	28 days

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Symptoms collected daily until discharge from hospitalization	The aim is to describe the natural history of the disease	12 months
All-cause mortality at day 90	The objective is to describe mortality on day 90	90 days
Failure of at least one organ requiring intensive care between D1 and D90 or death	The objective is to identify the factors associated with a severe form of the disease (failure of at least one organ requiring management in intensive care) and death.	90 days
Dosage of supportive care received up to day 28 or hospital discharge	The objective is to describe the supportive care received by patients as part of the care	28 days
Duration of supportive care administered through Day 28 or hospital discharge	The objective is to describe the supportive care received by patients as part of the care	28 days
Drug administered through Day 28 or hospital discharge	The objective is to describe the supportive care received by patients as part of the care	28 days
Vital status on day 28 by subgroups: patients who have received or have not received antiviral and/or immunomodulatory tests	The objective is to describe the response in terms of mortality according to the specific treatments received (antiviral and/or immunomodulator).	28 days
Quantitative viral load at each assessment time point : blood, urine, saliva, vaginal fluid, semen	The objective is to study the viral kinetics in blood and other biological samples	12 months
Assessment of innate and adaptive immune responses at each available time point, including M6 and M12.	The objective is to characterize host responses to understand its pathogenesis, including innate immune responses and acquired, circulating levels of immune signaling molecules in peripheral blood to identify new diagnostic and prognostic biomarkers as well as potential therapeutic avenues.	12 months
Assessment of circulating levels of immune signaling molecules in peripheral blood, at each available time point, particularly at M6 and M12.	The objective is to characterize host responses to understand its pathogenesis, including innate immune responses and acquired, circulating levels of immune signaling molecules in peripheral blood to identify new diagnostic and prognostic biomarkers as well as potential therapeutic avenues.	12 months

Collaborators and Investigators

• Sponsor: Assistance Publique - Hôpitaux de Paris

Study record dates

Study Major Dates

• Study Start (Estimated): September 1, 2026
• Primary Completion (Estimated): September 1, 2031
• Study Completion (Estimated): September 1, 2032

Study Registration Dates

• First Submitted: August 28, 2026
• First Submitted That Met QC Criteria: September 9, 2026
• First Posted (Actual): September 16, 2026

Study Record Updates

• Last Update Posted (Actual): September 16, 2026
• Last Update Submitted That Met QC Criteria: September 9, 2026
• Last Verified: August 1, 2026

More Information

Terms related to this study

• Keywords: filovirus; Bundibugyo virus
• Other Study ID Numbers: APHP260973; 2026-A01690-51 (Other Identifier: ANSM)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No