Session 01: Environment and health community:
“The day before”
Júlia Vergara-Alert, DVM, PhD
julia.vergara@irta.cat
Lessons from SARS, Ebola, Nipah – how our
relationship with other animals got us here
Webinar -April 28, 2020

Session 01: Environment and health community: “The day before”
Lessons from SARS, Ebola and Nipah – how our relationship with other animals got us here
How are diseases transmitted between animal species,
including humans?
Animal-human diseases interconnection

Zoonotic diseases
>60% of all known human
infectious diseases
Source: FCRNfood source

https://foodsource.org.uk/sites/default/files/chapters/p
dfs/foodsource_chapter_11.pdf
Routes for diseases transmission:
• Direct contact with animal bodily fluids (saliva, faeces, blood) via:
• Touching an infected animal’s skin;
• Being bitten by an infected animal.
• Indirect contact within areas where infected animals live and
roam, including:
• Consuming contaminated food products;
• Contact with contaminated water, soil, objects or clothing.
• Disease vectors: organisms that transmit infectious disease
between animals, and between animals and humans.

Disease
emergence,
re-emergence,
persistence
Human living environments
• Increasing population density
• Increasing mobility
• Growing poverty
• Changing dietary habits
• Lack of infrastructure
Food and agricultural systems
• Expanding agricultural production
• Globalization of production
• Peri-urban livestock production
• Trade in live animals and animal
product
Natural ecosystems
• Land use
• Deforestation
• Climate change
• Biodiversity loss
• Huting, poaching, trade
• Unregulated tourism
Disease interactions at the human-livestock-ecosystem interface

Session 01: Environment and health community: “The day before”
Lessons from SARS, Ebola and Nipah – how our relationship with other animals got us here
How do animal diseases become human diseases?

The severity of infection for viruses
often increases with each step away
from the original host species
The emergence of a virus
Virus
Type represented:
Coronavirus
Animal reservoir
Bats, for Ebola and
SARS-, MERS-CoV
Intermediate hosts
Civets in the case of
SARS-CoV
Transmission to
humans, and H2H
The virus can adapt
and mutate
Dissemination
Increasing mobile
population
Species
barrier
Species
barrier
Source: Institut Pasteur

Nipah virus
transmission

Ebola virus transmission
Humans are infected by close contact with
the blood, secretions, organs or other
bodily fluids of infected animals
Ebola then spreads through H2H
transmission, with infection resulting
from direct contact throufh broken skin
or mucus or bodily fluids of infected
animals
Pigs
Antelopes
Chimpanzees
Gorillas
In Africa a particular species of fruit bat is
considered to be the posible host for Ebola
virus
Secondary
hosts
Primary host
fruit bat

Session 01: Environment and health community: “The day before”
Lessons from SARS, Ebola and Nipah – how our relationship with other animals got us here
What do we know from SARS-CoV-2?

https://www.dpz.eu/en/home/single-view/news/die-vermehrung-von-
sars-coronavirus-2-im-menschen-verhindern.html
Human coronaviruses

• SARS-CoV-2 and bat CoV RaTG13
identity: 96% (Zhou et al., 2020)
https://phys.org/news/2019-08-species-horseshoe-scientists-thought.html
SARS-CoV-2 origin

Intermediate hosts
“Based on our analyses and existing data of coronaviruses, we concluded that
the intermediate hosts of 2019-nCoV are more likely to be mammals and
birds than snakes...” (Zhang et al., 2020b)
Currently, bioinformatics and sequencing have suggested:
Pangolín (Zhang et al., 2020b) Tortugas (Liu et al., 2020) Jineta y pollos (Veljkovic et al., 2020)
?

Júlia Vergara-Alert, DVM, PhD
julia.vergara@irta.cat

• SARS-CoV-2 local
isolates
• in vitro tests to test
antivirals and
antibodies
• Set up animal models
of COVID-19:
• To study pathogenesis
• Test drugs/vaccines in
vivo
Consortium financed by GRIFOLS