Summary
By
reviewing the most significant zoonotic disease outbreaks that have
occurred mostly during the past ten years, the author provides a
clear idea of how varied these diseases can be in regard to their
aetiological agent, size and direct impact on public health. Most
examples involve emerging zoonotic diseases caused by viruses and
prions and transmitted to humans by a bite, close contact with affected
live animals or carcasses, or through the consumption of their tissues.
These outbreaks vary from very small and localised clusters of individual
cases to millions of deaths, as reported during the past influenza
pandemics. The author also shows that even for the larger outbreaks,
the direct impact on public health measured by the morbidity and
mortality of zoonoses is largely inferior to that of major communicable
diseases that affect only humans, particularly human tuberculosis,
malaria, HIV/AIDS. However, it is very difficult to predict the
outcome on public health of these emerging zoonotic diseases since
transmission patterns are not always sufficiently understood to
assess this impact accurately. In addition, new modes of agent transmission
may compound the initial impact on public health. Finally, the author
indicates additional reasons that explain why these diseases are
important by placing special emphasis on the financial losses recorded
in both human and animal health and also the societal non-monetary
losses these diseases can incur. Lessons learnt following major
crises generated by the emergence of zoonotic diseases, such as
bovine spongiform encephalopathy, severe acute respiratory syndrome
and avian influenza, are provided.
Keywords
Animal
diseases, Avian influenza, Bovine spongiform encephalopathy, Public
health, Severe acute respiratory syndrome, Zoonoses. |