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Investigating the zoonotic origin of the West African Ebola epidemic
Almudena Mar? Sa?z, Sabrina Weiss, Kathrin Nowak, Vincent Lapeyre, Fee Zimmermann, Ariane D?x, Hjalmar S K?hl, Moussa Kaba, Sebastien Regnaut, Kevin Merkel, Andreas Sachse, Ulla Thiesen, Lili Vill?nyi, Christophe Boesch, Piotr W Dabrowski, Aleksandar Radonić, Andreas Nitsche, Siv Aina J Leendertz, Stefan Petterson, Stephan Becker, Verena Kr?hling, Emmanuel Couacy‐Hymann, Chantal Akoua‐Koffi, Natalie Weber, Lars Schaade, Jakob Fahr, Matthias Borchert, Jan F Gogarten, S?bastien Calvignac‐Spencer, Fabian H Leendertz
Author Affiliations
DOI 10.15252/emmm.201404792 |Published online 30.12.2014
EMBO Molecular Medicine(2014)emmm.201404792
Abstract
The severe Ebola virus disease epidemic occurring in West Africa stems from a single zoonotic transmission event to a 2‐year‐old boy in Meliandou, Guinea. We investigated the zoonotic origins of the epidemic using wildlife surveys, interviews, and molecular analyses of bat and environmental samples. We found no evidence for a concurrent outbreak in larger wildlife. Exposure to fruit bats is common in the region, but the index case may have been infected by playing in a hollow tree housing a colony of insectivorous free‐tailed bats (Mops condylurus). Bats in this family have previously been discussed as potential sources for Ebola virus outbreaks, and experimental data have shown that this species can survive experimental infection. These analyses expand the range of possible Ebola virus sources to include insectivorous bats and reiterate the importance of broader sampling efforts for understanding Ebola virus ecology.
Synopsis
The severe Ebola virus disease epidemic occurring in West Africa likely stems from a single zoonotic transmission event involving a 2‐year‐old boy in Meliandou, Guinea, who might have been infected by hunting or playing with insectivorous free‐tailed bats living in a nearby hollow tree.
Monitoring data show that larger wildlife did not experience a recent decline and is therefore unlikely to have served as the source for the Ebola virus disease epidemic in West Africa.
Fruit bat hunting and butchering are common activities in southern Guinea, therefore facilitating direct human contact.
Children are also exposed to insectivorous bats through hunting in and around villages.
No large colony of fruit bats exists in or nearby the index village (Meliandou).
The 2‐year‐old index case may have been infected by playing in a hollow tree housing a colony of insectivorous free‐tailed bats (Mops condylurus).
...
Consumption of fruit bats in the household is an unlikely source of infection for the index case; no hunters were members of this household and a food item‐borne transmission would likely have affected adults before or concurrently with the index case. Under the assumption that the 2‐year‐old boy was indeed the index case, a source of infection unrelated to food items consumed in the home might be more plausible. The close proximity of a hollow tree housing a large colony of free‐tailed bats (i.e., insectivorous bats), of a species for which serological evidence also suggests EBOV exposure (Pourrut et al, 2009), provided opportunity for infection. Children regularly caught and played with bats in this tree. Free‐tailed bats were suggested as a source for the first Sudan Ebola virus outbreaks (World Health Organization/International Study Team, 1978). Risk of infection via exposure to high‐density bat colonies is well documented for the Marburg virus (MARV), a virus also in the Filoviridae family (Amman et al, 2012).
Our findings support the idea that bats were the source of the current EVD epidemic in West Africa and enlarge the list of plausible reservoirs to include insectivorous bats. Future sampling campaigns, in‐depth serological studies, and modeling efforts should take into account the possibility that fruit bats may not always be the ultimate source of EVD outbreaks.
...
Full text:
http://embomolmed.embopress.org/content/early/2014/12/29/emmm.201404792
Almudena Mar? Sa?z, Sabrina Weiss, Kathrin Nowak, Vincent Lapeyre, Fee Zimmermann, Ariane D?x, Hjalmar S K?hl, Moussa Kaba, Sebastien Regnaut, Kevin Merkel, Andreas Sachse, Ulla Thiesen, Lili Vill?nyi, Christophe Boesch, Piotr W Dabrowski, Aleksandar Radonić, Andreas Nitsche, Siv Aina J Leendertz, Stefan Petterson, Stephan Becker, Verena Kr?hling, Emmanuel Couacy‐Hymann, Chantal Akoua‐Koffi, Natalie Weber, Lars Schaade, Jakob Fahr, Matthias Borchert, Jan F Gogarten, S?bastien Calvignac‐Spencer, Fabian H Leendertz
Author Affiliations
DOI 10.15252/emmm.201404792 |Published online 30.12.2014
EMBO Molecular Medicine(2014)emmm.201404792
Abstract
The severe Ebola virus disease epidemic occurring in West Africa stems from a single zoonotic transmission event to a 2‐year‐old boy in Meliandou, Guinea. We investigated the zoonotic origins of the epidemic using wildlife surveys, interviews, and molecular analyses of bat and environmental samples. We found no evidence for a concurrent outbreak in larger wildlife. Exposure to fruit bats is common in the region, but the index case may have been infected by playing in a hollow tree housing a colony of insectivorous free‐tailed bats (Mops condylurus). Bats in this family have previously been discussed as potential sources for Ebola virus outbreaks, and experimental data have shown that this species can survive experimental infection. These analyses expand the range of possible Ebola virus sources to include insectivorous bats and reiterate the importance of broader sampling efforts for understanding Ebola virus ecology.
Synopsis
The severe Ebola virus disease epidemic occurring in West Africa likely stems from a single zoonotic transmission event involving a 2‐year‐old boy in Meliandou, Guinea, who might have been infected by hunting or playing with insectivorous free‐tailed bats living in a nearby hollow tree.
Monitoring data show that larger wildlife did not experience a recent decline and is therefore unlikely to have served as the source for the Ebola virus disease epidemic in West Africa.
Fruit bat hunting and butchering are common activities in southern Guinea, therefore facilitating direct human contact.
Children are also exposed to insectivorous bats through hunting in and around villages.
No large colony of fruit bats exists in or nearby the index village (Meliandou).
The 2‐year‐old index case may have been infected by playing in a hollow tree housing a colony of insectivorous free‐tailed bats (Mops condylurus).
...
Consumption of fruit bats in the household is an unlikely source of infection for the index case; no hunters were members of this household and a food item‐borne transmission would likely have affected adults before or concurrently with the index case. Under the assumption that the 2‐year‐old boy was indeed the index case, a source of infection unrelated to food items consumed in the home might be more plausible. The close proximity of a hollow tree housing a large colony of free‐tailed bats (i.e., insectivorous bats), of a species for which serological evidence also suggests EBOV exposure (Pourrut et al, 2009), provided opportunity for infection. Children regularly caught and played with bats in this tree. Free‐tailed bats were suggested as a source for the first Sudan Ebola virus outbreaks (World Health Organization/International Study Team, 1978). Risk of infection via exposure to high‐density bat colonies is well documented for the Marburg virus (MARV), a virus also in the Filoviridae family (Amman et al, 2012).
Our findings support the idea that bats were the source of the current EVD epidemic in West Africa and enlarge the list of plausible reservoirs to include insectivorous bats. Future sampling campaigns, in‐depth serological studies, and modeling efforts should take into account the possibility that fruit bats may not always be the ultimate source of EVD outbreaks.
...
Full text:
http://embomolmed.embopress.org/content/early/2014/12/29/emmm.201404792