(English captions by Trisha Paul, University of Michigan.)
Introduction to Epi-zoonotic Diseases.
In this session, we shall look at key terminologies and definitions related to zoonotic diseases
of epidemic potential.
We shall look at the zoonotic diseases of epidemic potential in Eastern Africa, the
significance of epi-zoonotics as emerging diseases, the factors promoting emergence
of epi-zoonotic diseases, the consequences of epi-zoonotic diseases, and general response
interventions, and then, issues related to animal welfare.
A zoonosis is a disease or infection which is naturally transmitted between animals and
humans.
It may occur from an animal to human, or from human to an animal.
A simpler definition is a disease that normally infects animals, but can also infect humans.
An epizootic disease is an outbreak (epidemic) of disease in an animal population.
An enzootic is a disease that is endemic in animals.
Exotic diseases are those which are imported into a country in which they do not otherwise
occur.
An example is avian influenza.
Emerging and re-emerging zoonoses are diseases caused either by totally new or partially
new agents, or by micro-organisms previously known, but now occurring in places or in species
where the disease was previously unknown.
Examples of this include influenza, ebola, and SARS.
The priority of zoonotic diseases of epidemic potential in Eastern Africa include rift valley
fever, influenza A viruses, anthrax, rabies, ebola and other viral hemorrhaegic fevers,
plague, and trypanosomiasis.
What is the significance of epi-zoonotics as emerging diseases, especially in Eastern
Africa?
Globally, there have been over 20 new diseases in the last 30 years.
Over 2/3 of new disease causing agents arise from wild-life.
Examples include SARS, nipah, H5N1, H1N1.
Domestic animals account for 20% of new zoonoses.
The East and Central Africa Region is a 'hot spot' for new diseases.
Factors promoting the emergence of epidemic-prone epi-zoonotic diseases include socio-economic
factors like intensive farming without bio-security measures, water-supply projects, urbanization,
human population movement, animal movement, famine, free-range farming systems.
Environmental factors include climate change (e.g. global warming) and presence of vectors
and/or reservoirs.
Human-related factors include co-infection with other diseases agents (like HIV and tuberculosis or TB),
lack of knowledge on bio-security measures, inadequate personal hygiene like sneezing
without covering mouth or not washing hands.
Cultural and behavioural risk factors include lack of knowledge, food habits, changes in
life-style, human-livestock-wildlife interaction.
These are some of the characteristics of the human-animal interface that increases the
likelihood of transferring diseases that were previously not known in humans from animals.
Intense handling of animal products with low bio-security causing diseases like brucellosis,
anthrax, avian influenza.
Pastoralism and free-range systems, hunting, gathering, eating game meat and carcasses
predisposing to ebola and anthrax.
Contact with bats predisposing to ebola and marburg.
Ill cooked products causing salmonellosis and brucellosis.
Hygiene and rats predisposing to leptospirosis and hepatitis E.
Free-range poultry and migratory birds predisposing to avion influenza.
Conservation areas like Ngorongoro and Samburu. Ill-handling of domestic canines predisposing
to rabies.
Socio-cultural factors including sharing accommodation with animals, and cross-border risk as well
as gender related risk
What are the consequences of epidemic-prone epi-zoonotic diseases?
They include:
Socio-economic impacts like reduction in the level of outputs from animal production, reduction
in perceived or actual output quality, waste of inputs to animal production, resource costs
of disease prevention and control, negative animal welfare effects, and international
trade restrictions.
Human health costs including effects or costs of treatment, effects on the environment,
effects on tourism, effects on rural livelihoods, political and social disruption, and increased
poverty.
All the public health consequences of epi-zoonoses include increased deaths, increased illness,
social disruption and panic, collapse of regular heath care systems, health workers are at
high-risk of contracting the diseases, and health workers may run away from health units.
Response interventions include farmers should report incidents to animal and human health
workers, provisional quarantine of affected areas if necessary, confirming the occurrence
of an outbreak and notifying authorities
Activating the Rapid Response Team including vets, health workers, leaders, and police,
etc), identifying source of infection and identifying the severity of the infection
and extent of spread, setting up immediate control measures
Disposing of dead animals in safe ways, either by burning them or burying them, quarantining
the sick and suspected and observing general conditions, stopping movement of animals,
and vaccination where necessary.
In outbreak situations of epi-zoonotic diseases, animal welfare situations should be taken into consideration.
If they are to be destroyed or killed, animals should be treated in a humane manner.
Reduce undue pain.
Confine them in a considerate manner.
Thanks for listening.