[afro-nets] New diseases arise as environments destroyed, says UN

[Leela McCullough <leela@healthnet.org>]

New diseases arise as environments destroyed, says UN
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New diseases arise as environments destroyed, says UN
By Michael McCarthy, Environment Editor
The Independent

22 February 2005

Changes to the environment that are sweeping the planet are
bringing about a rise in infectious diseases, the United Nations
Environment Programme (UNEP) has warned.

Loss of forests; the building of roads and dams; urban growth;
the clearing of natural habitats for agriculture; mining; and
pollution of coastal waters are promoting conditions under which
new and old pathogens can thrive, according to research pub-
lished today in UNEP's Global Environment Outlook Year Book for
2004/2005.

Ailments previously unknown in human beings are appearing, such
as the Nipah virus, which until recently was found normally in
Asian fruit bats, according to the report.

Nipah's emergence in the late 1990s as an often fatal disease in
humans has been linked to a combination of forest fires in Suma-
tra and the clearance of natural forests in Malaysia for palm
plantations. In searching for fruit, bats were forced into
closer contact with domestic pigs, giving the virus its chance
to spread to humans.

Climate change in particular may aggravate the threats of infec-
tious diseases in three ways, the report suggests. First, by in-
creasing the temperatures under which many diseases and their
carriers flourish.

Second, by further stressing and altering habitats. For example,
the geographic range and seasonality of two of the world's most
serious mosquito-borne infections, malaria and dengue fever, are
very sensitive to changes in climate. Also, Neisseria meningiti-
des, a common cause of meningitis, can be spread many miles in
the dusty conditions that occur following prolonged drought in
the Sahel.

Third, climate change may increase the number of environmental
refugees who are forced to migrate to other communities, or even
countries. This in turn will also favour the spread of diseases
from one location to another. Overall, it seems that intact
habitats and landscapes tend to keep infectious agents in check.

The issue of environmental degradation and a rise of many new
and old infectious diseases is a complex, sometimes subtle one
that is causing increasing concern among scientists and disease
specialists.

Many scientists are now convinced that ecological disruption,
dramatic environmental change, and poor handling of human and
animal wastes are playing an important part in the spread of
diseases such as malaria, bilharzia, Japanese encephalitis, and
dengue haemorrhagic fever.

The report is based on research by some of the leading special-
ists. They include Tony McMichael of the Australian National
University, Bernard Goldstein of the University of Pittsburgh
and Jonathan Patz of the University of Wisconsin.

--
Leela McCullough, Ed.D.
Director of Information Services
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