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 decision-maker.

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, 1997).

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.

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.

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