The Delta Amazonia project: better understanding hepatitis delta in Amazonia

Hepatitis delta in the Amazon Basin and neighbouring areas from the 20th to the 21st century: landscapes and memories of epidemics and the current epidemiological situation

Last updated on 12 February 2026

In brief

This multidisciplinary, international project aims to deepen understanding of hepatitis delta in the Amazon region.
Promoted by ANRS MIE, it is funded under the 2024-2 call for proposals.

The context

The hepatitis delta virus (HDV) is a virus whose replication requires underlying infection with the hepatitis B virus. It affects between 15 and 25 million people worldwide. HDV aggravates the progression of chronic hepatitis B.

Despite its identification in 1970, this virus remains an epidemiological enigma. Its geographical distribution does not overlap with that of hepatitis B and is predominantly found in equatorial regions of Africa, South America and the Pacific, which remains unexplained. In addition, epidemics of fulminant hepatitis linked to the HDV3 viral subtype have been observed in the Amazon since the 1930s, decimating Amerindian communities.

In brief

Investigator France
Camille Besombes

Investigator South Americas
Joao Pinho

Sites/teams France
Médialab Sciences Po (Camille Besombes, Guillaume Lachenal)
Inserm U1052, Lyon (Isabelle Chemin)
ANRS MIE (Simon Amador Paz, Mathilde Certoux)

Sites/teams Brazil
Instituto de Medicina Tropical Sao Paulo (Joao Pinho)
Institut Evandro Chagaz (Andreisa Pinheiro Malheiros)
Ecole de Médecine, Université Fédérale de Bahia (Raymundo Parana)
Fiocruz Rondonia (Deusiène Vieira)

Sites/teams Peru
Tropical and Infectious Diseases INS National Institut of Health Péru (Cezar Cabezas)

Sites/teams Venezuela
Instituto Venezolano de Investigaciones Científicas (Flor Pujol)

Status
Start date: January 2026

Pathology
Hepatitis delta

Sponsorship
ANRS MIE

What is the objective of Delta Amazonia?

This multidisciplinary and international project that combines virological, phylogenic and phylogeographic, epidemiological and ethno-historical approaches aims to deepen our understanding of hepatitis delta in the Amazon region.

Past epidemics and their contexts of emergence, from the first cases in the 1930s to the present day, will be addressed by exploring various hypotheses, including a ‘One Health’ approach.

These hypotheses will be explored on the basis of:

a reconstruction of the history of fulminant forms of epidemic hepatitis that occurred in the Amazon between 1930 and 1990
a study of the temporal and spatial contexts of the emergence of these specific viral strains within Amazonian equatorial forest and plantation ecosystems in the colonial and post-colonial context

The Delta Amazonia project uses a geographical approach to characterise the landscapes and territories of hepatitis delta epidemics, combined with ethnohistorical approaches to epidemics and phylogeny/phylogeography of ancient and recent viral strains.