14.4.1 Health Sector
Public health infrastructure is a fundamental resource. The last decade has
witnessed the resurgence of several major diseases that were once thought to
have been controlled. The resurgence of tuberculosis - which is both cost-effective
to treat and curable in virtually all cases - has been caused by persistent,
and in some cases increasing, poverty and a lack of political will to develop
and sustain effective control programmes (WHO, 1998).
The recent resurgence of malaria in areas where it had previously been eradicated
(Azerbaijan, Tajikistan) or under control (Iraq, Turkey) are the consequences
of deteriorating malaria prevention and vector control programmes due to conflict
and economic crises (WHO, 1997a). In the 1950s, vector control programmes in
Madagascar led to the eradication of the main vector in the central highland
plateau and almost total eradication of malaria (Lepers et al., 1988). Since
then there has been a progressive increase in malaria due to the collapse of
the spraying programme and population movements (Fontenille et al., 1990). In
Ethiopia, indoor spraying campaigns with DDT were shown to be effective at reducing
malaria (Fontaine et al., 1961), but over the last 20 years there has been an
increase in cases, partly due to a breakdown in the health service due to civil
war and forced movement of people. Similarly, towns in the highlands of Zambia
where malaria was once rare now experience a substantial number of cases as
a result of the cessation of vector control activities (Fisher, 1985). It is
now also recognised that effective control of infectious disease cannot occur
without active community support (WHO, 1997a). In the past, most disease control
programmes were vertically structured, lacking robust, horizontal community-based
support, but this has proven to be non-sustainable (Gubler, 1989).
The economic crises of the 1980s, in addition to poor policy decisions in the
late 1960s and 1970s, have led to cuts in both government and household expenditure
on health in many developing countries and CEIT (Evlo and Carrin, 1992). Cost-sharing
policies recently implemented in Africa have resulted in people delaying treatment
and disease progression to more life threatening forms (WHO, 1997a). In several
countries, declines in health facility use of over 30% have been recorded following
the policy of cost sharing (Waddington et al., 1989).
Decision-making whether at the policy, implementation or at the health-seeking
(individual) level depends on availability of relevant, accurate, and useful
information (Emmanuel, 1998; Sayer, 1998). The cost of data collection and analysis
is often beyond the resources of developing countries and CEIT. Thus, decision-making
is often delayed and this introduces uncertainty in the choice of policy and
interventions. In Bolivia and Zimbabwe, Nugroho et al. (1997) have observed
that malnutrition and other health problems in underprivileged communities cannot
be tackled effectively unless attention is paid to family income, housing, water
supply, sanitation, food and environmental safety. Communities with so many
needs may downgrade the importance of some diseases. Thus, the additional hazards
of climate change have to compete with existing community needs for a local
Human behaviour sometimes changes dramatically following well-targeted, culturally-sensitive
dissemination of health information, especially when a change in attitude is
first induced (as has happened with respect to exposure to passive smoke). Some
issues relating to climate change could form the subject of effective health
education programmes, for example to encourage the elimination of human-made
vector breeding sites, and promote the use of mosquito nets impregnated with
pyrethroid compounds to reduce malaria transmission, particularly among children
and pregnant women.
Monitoring and Surveillance
The most elementary form of adaptation is to launch or improve health monitoring
and surveillance systems (McMichael et al., 1996; WHO/MRC/UNEP, 1998; Stanwell-Smith,
1998). Table 14.5 summarises the mechanisms for a comprehensive monitoring scheme
for the types of potential health impact of climate change (Haines and McMichael,
Source: Haines and McMichael, 1997.
|Table 14.5 Summary of methods needed
to monitor the potential impacts of climate change and climate variability
on human health
||Urban centres in developed and developing countries
||Daily mortality and morbidity data.
|Changes in seasonal patterns of disease (e.g., asthma, allergies)
||"Sentinel" populations at different levels
||Primary health care morbidity data, hospital admissions, emergency room
||Margins of distribution (latitude and altitude). Areas with seasonal and
||Primary health care data; local field surveys, communicable disease surveillance
centres; remote sensing data. Surveillance of infectious disease must be
active and laboratory-based.
||Coastal populations, coastal zones.
||Sampling of phytoplankton for biotoxins, pathogens. Remote sensing of
algal blooms. Epidemiology of cholera, other Vibrios and shellfish poisoning.
||Mortality and morbidity data.
|Effects on health of sea level rise
||Local population surveillance
||Critical regions especially in the interior of continents
||Measures of runoff; irrigation patterns; pollutant concentrations.
||Remote sensing; measures of crop yield; food access and nutrition from
local surveys. Agricultural pest and disease surveillance
||Areas of population movement or ecological change
||Identification of "new" syndrome or disease outbreak; population-based
time series; laboratory characterisation.
In the health sector, only the basic measures of public health status (e.g.,
infant mortality) can be measured simply and uniformly around the world because
births and deaths are monitored in most countries. However, disease (morbidity)
surveillance varies widely depending on the locality, the country and the disease.
Most of the least developed countries have poorly developed surveillance systems.
Many developing country governments lack the resources and expertise for collecting
appropriate data for effective monitoring of the impacts of climate change.
Data sharing and capacity strengthening for local data collection and development
of integrated early warning systems are very important. A strong public health
infrastructure - international, national and local - along with active local
community involvement is necessary to achieve effective response to information
provided by the surveillance of infectious diseases.
Reliable, continuous monitoring of cause-specific mortality in vulnerable populations
would be invaluable. Effective infectious disease surveillance requires good
laboratory support. In addition, low-cost data from primary care facilities
could be collected in sentinel populations in vulnerable zones. The use of animal
sentinel populations (including the investigation of outbreaks of diseases in
animals) can be used to detect early changes in patterns of human disease as
part of a comprehensive surveillance programme. For example, sentinel caged
chicken flocks are used to monitor encephalitis virus in the US (Tsai and Mitchell,
1989). Animal reservoirs are also used to monitor leishmaniasis (Semiao Santos
et al., 1996; Mancianti et al., 1994). Effective surveillance demands global
cooperation and exchange of information, as well as the modernising of monitoring
and surveillance systems. Such initiatives should build on current successes
like ProMED - a network for the exchange of information on outbreaks of new
and resurgent infectious diseases (Morse, 1995).
Mosquito vectors of malaria are expected to increase their altitudinal range
as the world warms, and the incidence of malaria may increase in certain highland
areas in the tropics and subtropics. There is some indication that increases
may already be occurring (Loevinsohn, 1994; Epstein et al., 1998) although this
remains contentious (Reiter, 1998). To track these possible changes, new surveillance
measures must be initiated to monitor vector populations and disease incidence
in many highland areas that are not well served by clinical health services
(Le Sueur et al., 1997). There is also a need for additional data that would
enable researchers to distinguish the effect of climate change from other environmental
factors which affect malaria distribution, e.g., deforestation.
Control of Vector-borne and Water-borne Diseases
In addition to the vector control and surveillance strategies discussed above,
populations can be protected from vector-borne diseases by immunisation campaigns
when a suitable vaccine exists. The coverage of existing vaccination programmes
aimed at elimination of diseases such as yellow fever should be expanded. Unfortunately,
no vaccines yet exist for some of the diseases most sensitive to climate change,
e.g., malaria, dengue, schistosomiasis, nor for many newly emerging infections.
While there is no vaccine for dengue currently approved for general use, there
are vaccines at an early stage of development. Other strategies are important
to combat diseases like malaria. For example, periodic checks may be carried
out on parasite sensitivity to the commonly used antimalarial drugs. The use
of insecticide-impregnated bed nets has been successful in reducing malaria
transmission in endemic areas. However, there have been economic barriers and
difficulties in obtaining the appropriate bed nets because of distribution problems.
The control of some epidemic diseases, such as malaria, could benefit from
the application of new technology (e.g., geographical information systems (GIS)
and remote sensing technologies) to forecast outbreaks using meteorological
data (e.g., Snow et al., 1996; Le Sueur et al., 1997; GCTE, 1998). For example,
a prediction system for malaria outbreaks in the western Kenyan highlands is
being developed (Githeko, 1998). Initial investment in such predictive modelling
is relatively high. Once established, however, these systems become cost-effective.
Table 14.6. highlights malaria to indicate some types of adaptive strategies,
and the level at which they operate. For example, specific products for vector
control, malaria vaccines, and drugs are developed, around the world, under
the guidelines of WHO. However, the local use of the products depends upon national
policies and demand by users.
|Table 14.6 Types of adaptive strategies,
illustrated with malaria as an example
||Access to anti malarial drugs
|Regional or Federal
|National or State
|Local or community
Populations that are vulnerable to water-borne diseases should have access
to technology for safe drinking water. Cryptosporidium oocysts are resistant
to chlorine and other disinfectants (Venczel et al., 1997) and have a very low
sedimentation rate (Medema et al., 1998). Consequently boiling may be the most
appropriate method of disinfecting water where risks of infection exist (Willcocks
et al., 1998). The use of submicron point-of-use filters may reduce the risk
of waterborne cryptosporidiosis (Addiss et al., 1996). In addition, a number
of simple and cheap techniques have been found to be effective in reducing the
risk of infection with cholera from contaminated water. A simple filtration
procedure involving the use of domestic sari material can reduce the number
of Vibrios attached to plankton in raw water (Huo et al., 1996). In Bolivia,
the use of 5% calcium hypochlorite to disinfect water, and the subsequent storage
of the treated water in a narrow-mouthed jar produced drinking water from non-potable
sources that met the WHO standards for microbiologic quality (Quick et al.,
1996). These examples of low cost technologies should become widely available
to populations that are likely to be affected by contaminated water supplies,
for example, following flooding.