Afripox

A One Health Study of Mpox Human infection, animal reservoir, disease ecology and diagnostic tools

Our international, multidisciplinary collaboration led by the Institut Pasteur (IP) de Paris, France covers epidemiology, virology, anthropology, zoology and environmental ecology to address four principal objectives:  

  • Identify the animal reservoir and secondary hosts of mpox in areas of Central African Republic (CAR) where mpox is known to circulate in order 
  • Identify possible risk factors for zoonotic and human-to-human mpox transmission in the context of previous and future outbreaks of mpox using quantitative and qualitative methods; determine the interhuman transmissibility of mpox and the epidemic potential 
  • Understand differences in mpox viral strains circulating in animals and human populations; develop field diagnostic and next generation sequencing capacities for mpox in areas of (CAR) 
  • Determine ecological factors associated with the emergence of mpox in Central Africa and the potential geographic scope of mpox infection in this region. 
Période du projet :
-
Investigateur principal :

Arnaud FONTANET, Institut Pasteur, Paris

Membre(s) SESSTIM du projet :
Jordi LANDIER, Jean GAUDART, Pascal HANDSCHUMACHER
Membre(s) hors SESSTIM du projet :

Institut Pasteur: Arnaud FONTANET, Camille BESOMBES, Antoine GESSAIN, Tamara Giles Vernick
Institut Pasteur de Bangui: Emmanuel Nakouné 
Museum National d'Histoire Naturelle : Alexandre HASSANIN

This project involved Hein Min TUN as part of his Master 2 internship (EHESP).

Commanditaires :

ANR

Partenaires :

Institut Pasteur, Institut Pasteur de Bangui, Museum National d'Histoire Naturelle

Thèmes :
Problématique:

Prior to current global spread of specific strains characterized by interhuman transmission and sexually-transmitted disease epidemiological patterns, Mpox virus is a zoonosis, occurring mainly in forested regions of Western and Central Africa. The specific animal reservoir has not yet been identified. To date, the virus has only been isolated twice from wild animals. Further serological studies conducted in animals implicate terrestrial rodents, and squirrels, as being possible animal reservoirs of the disease. Understanding the animal reservoir and the types of exposures of human populations to the animal reservoir are critical for limiting zoonotic transmission and thus reducing further spread in the human population. This becomes all the more important in a context in which explosive demographic changes, rapid urbanization and road construction in otherwise remote locations of Central and Western Africa are bringing human populations in closer contact with suspected animal reservoirs, increasing the risk for zoonotic spillover. 

Méthode :

The eco-epidemiology workpackage of the Afripox project, led by Jordi Landier at SESSTIM, aims at leveraging epidemiological data to improve the understanding of environmental factors associated to zoonotic transmission events.
Two approaches were conducted: 

  • first, we analysed a series of well-characterized zoonotic transmission events identified from a systematic review of the scientific and grey litterature in order to identify seasonal patterns in mpox occurrence.
  • second, we focused on the Central African Republic mpox surveillance database. Relying on mpox outbreak investigation reports identifying index cases, and on open access remote sensing data, we characterized environmental features associated with the occurrence of zoonotic transmission events. Various databases (open access or available to SESSTIM through other research programs) describing environmental characteristics (land use/land cover, climate), population distribution, and recent changes (forest loss) were analysed using unsupervised classification methods to determine environmental profiles associated with outbreaks. Non-linear regression approaches (e.g. GAMMs) were used to quantify risks while adjusting for spatial and temporal autocorrelations. After describing the ecological characteristics of areas affected by monkeypox outbreaks, locations corresponding to the highest risk of monkeypox outbreaks based on their environmental profiles can be identified across CAR, which may lead to the subsequent identification of previously unsuspected outbreaks or increased targeted surveillance. 
Resultats:

In our analysis of mpox index cases extracted from a systematic review, we identified different seasonal patterns linked to latitude and climate.
Environmental analyses are ongoing.