Current climate impact assessment
methodologies for public health rely
on indicators like rainfall
distribution, temperature, humidity,
vector population and disease cycle.
These provide little time before the
outbreak of epidemics to undertake
public health intervention measure.
The ENSO forecast on climate
anomalies now available enables
public health agencies to undertake
potential impact assessments with
sufficient lead-time. In this
session, participants learned about
the methodology adopted by the
Philippines public health agency in
exploring the possibilities of
utilizing long-range climate
forecasts in dealing with potential
epidemics.
Presentation Highlights
Eric
Tayag reported on the ECE research
study that assessed the impact of
climate variables such as
temperature and relative humidity,
and focused on dengue, cholera,
typhoid, measles and malaria in
Metro Manila. The correlation
analysis of the time-series data
from 1992-98 revealed a relationship
between weather variables and
dengue, malaria and cholera in the
study area. Though there was a
correlation between ECEs and disease
outbreaks, there may be other
responsible factors. Efforts may
have to be made to study all factors
before utilizing climate forecast
information to undertake disease
prevention measures. A need was
noted to design forecast models and
to focus on local responses for
hazard mitigation and management, as
well as extending data collection
and analysis to all regions, over a
longer time period and considering
other diseases.
Discussion Points
There
are strong links between the water
and public health sectors. One of
the biggest impacts on public health
has been water-borne illnesses
experienced from extreme
climate-related events. At one end
of the hydrological continuum,
droughts can result in decreased
water availability, contamination of
water resources and saltwater
intrusion into freshwater sources.
At the opposite extreme, floods may
have an impact on public health by
overflowing sewage systems and
cesspools and by contaminating water
with minerals and non-point
pollution sources.
More
frequent natural hazards such as
floods and droughts often create
favorable conditions for the
transmission of various diseases.
Hence, continuous monitoring of the
environment, and pathogen and host
relationships, needs to be carried
out. This monitoring mechanism could
be useful for associating ECEs in
the disease cycle.
Further research needs to be
conducted on identifying the links
between disease vectors and climate.
Some of the changes may be in
community behavior. For example, to
deal with droughts, people are
taught to store water; however,
these stagnant water sources may be
breeding grounds for mosquitoes that
are the source of dengue and
malaria. Reports have been issued
that mosquitoes will be "fiercer" in
the future from climate-dependent
factors. This shows the importance
of understanding the links between
mosquito-borne diseases and climate
effects.
The
following water use management and
practices driven by emergency
situations during droughts and
floods could contribute to the
outbreak of epidemics:
-
The disruption of environmental
health services and
infrastructure (like water
supply and public sanitation) by
climatic variations can
contribute to a significant rise
in water- and food-borne
disease.
-
The use of booster pumps adds to
the contamination of water
supply.
-
The communityØs eagerness to
store water during emergency
situations could provide a
breeding ground for vectors
carrying pathogens.
There
is a need to look at these
behavioral practices to develop an
awareness campaign for water
management practices in the context
of ECEs.
Other
factors have been observed that may
be linked to climate effects, but
there has not been enough study and
analysis of them. One example is the
disease leptospirosis, which is
found in streams, and may occur as a
streamflow factor. In Vietnam, there
has been an observed increase in
pests during the hydrological
extremes. During floods, there are
increased numbers of mosquitoes, and
during droughts, an increased number
of mice; hence, diseases associated
with these pests increase.
Recommendations
The
discussions revealed that there are
a number of unknown factors and
research that needs to be conducted
to relate climate extremes to
diseases and public health risks.
The participants focused on two
recommendations to address the
identified issues:
-
Develop a multi-disciplinary and
multi-dimensional approach to
assess the impacts of ENSO and
extreme climate events on local
responses to climate-related
health impacts in close
cooperation among
epidemiologists, entomologists,
microbiologists, climatologists
and other specialists. The
impact that any given ENSO event
will have on human health will
depend not only on the
prevailing climatic regime, and
the specific vector and pathogen
ecology, but also on human
factors, including but not
limited to population
distribution and concentration,
immune status of the population,
population mobility and a whole
host of infrastructural,
socio-economic and environmental
factors.
-
Develop and use tools that
improve the ability of the
health sector to respond to
climate-related health hazards.
Coupling epidemiological models
with climate models will help to
utilize climate forecast
information for undertaking
prevention measures against
disease outbreaks in the context
of ECEs.
