The following
are responses and summaries of various readings related to Human Health,
Disease, and the Environment.
Under the Weather:
Toward the Development of Disease Early Warning Systems
Until now there has been very little progress made in the
development of early warning systems for infectious disease. However, just like weather forecasts, earlier
warnings are usually much less certain.
The simplest and most used warning system is the use of sentinel animals
in regions of high risks: these practices give highly predictive results but
leave officials with very little reaction time for prevent further spread of
disease. The best method to be used is
through ecological observation and climate forecasts issuing disease watches in
order to minimize its transmission.
These watches can be used to determine which areas need to be most
carefully surveyed for disease outbreaks, much like watches and warnings are
used in the informing of communities on the potential of severe weather in an
area. Early warning systems should be
used as devices which will enable national and local institutions as well as
individuals to make decisions regarding a potential threat and to improve the
coordination between them. An early
warning systems consists of watches and warnings about a particular risk,
combined with vulnerability assessments which determine which groups are most
susceptible to a disease, and risk analysis which will help determine the
potential fallout of a disease on an area or group. A good system must end with a response
strategy and public communication system to quickly inform the public about the
risks, potential outcomes, how best to be prepared. The systems need make use of the
epidemiological surveillance systems that are currently in use and follow a
standard method of practice and allow for quick analysis and dissemination of
information. Up until now most
surveillance methods have focused on the particular effect and end result of a
disease, but need to include changes in vector populations which may employ
using sentinel animals for analysis. The
systems will need to make use of new remote-sensing technologies for the
analysis of ecology. The vulnerability
assessment is a description of how sensitive a population is to a particular
disease and should be combined with surveillance systems thereby allowing the
development of control strategies. Risk
analysis provides the probability that a particular hazard will affect an area
or population. Usually the development
of scientific prediction methods greatly outpaces the development of warning
systems which use this information; from this response plans need to be
developed which consider the costs and potential pitfalls of possible response
plans for local communities. The people
and organizations disseminating the system information need to have good
credibility and trust by the persons within the community and must be sure to
properly explain and educate the public on the risks in order to prevent
overreaction and panic.
The agencies responsible for preparedness plans need to
analyze previous events and determine how the public took the warnings and what
actions were taken in order to plan for future outbreaks. Perhaps the most important aspect to
implementing early warning disease systems is the inclusion of the end user in
the creation and development of forecasts and plans. International public health organizations can
help train national and regional agencies for the use and development of
systems. Those same agencies would thereafter
be charged with the strengthening and development of their own systems and
lower level agencies.
A good early warning system must be able to regularly supply
good climate forecasts for the region, while understanding the link between
climate and particular diseases thereby offering a good level of
prediction. The system must allow for
sufficient time for response, otherwise what is the point of the system. The community or region using the system must
have the resources to support the additionally required infrastructure for its
proper implementation.
The 1999 New York City outbreak of West Nile Virus is a prime
example of how the system could best be used.
The outbreak showed the necessity of interdisciplinary approaches to the
problem and the difficulty in coordinating between different government
agencies and communication to the public.
The population of New York City found itself most vulnerable to the
disease due to very little having been done in mosquito control, persons not
practicing avoidance of the vector species, and the population lacking immunity
due to no prior exposure to the disease.
Initially the disease was misidentified due to the poor cooperation
between animal health and human health agencies, though here the effect was
minimal due to the fact that its misidentification was with a very similar disease. A better plan was later seen in neighboring
New Jersey where surveillance units were employed to detect where the virus was
from time to time, a pre-emptive mosquito control program, cooperation of lab
testing between agencies, and sufficient communication between public health
officials, professionals, and the public.
***Previous Week Online Article***
RATE OF WARMING IS
UNPRECEDENTED
Recent research by scientists at Cornell University has shown
that the recent warming trend being experience is the greatest climate change
in the previous 5000 years, since the birth of human civilization. The research focused on the recent influx of
fresh water from the melting of glaciers in the Arctic and North Atlantic
Oceans, as well as its effect on the oceanic periodic circulation, and changes
seen in particular oceanic plant and animal species. In their studies of the previous 65 million
years of climate change on Earth they have found fast cooling periods where
temperatures fell as much as ten degrees Celsius in years to decades, but now
is the first time that such a quick rise in temperature has been experienced. The recent warming, and as a result melting
of ice sheets and glaciers, has allowed for great shifts in the range of plant
and animal species. In particular one
species of algae has migrated from the Pacific Ocean to the North Atlantic due
to the warming trend – the first time this species has appeared in the North
Atlantic in the last 800 000 years. Such
changes can have great impacts for other species such as phytoplankton, which
have seen longer growing seasons, thereby affecting the animals of the food
chain all the way up to the top. The
warmer temperatures have caused a reduction in the populations of cod and
thereby an increase in shrimp and snow crab populations due to the cooler,
glacial melt waters. Perhaps the
greatest effect that the researchers hope will not be seen is the alteration or
disruption of today’s ocean circulation systems: if changed or stopped it is
likely that many of the atmospheric, glacial, and oceanic process would change
in conjunction.
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