Many factors aid the spread of infectious diseases
- Key determinants of health often lie outside the control of the health sector
- The critical need for collaboration
- Building partnerships with the private sector
Graphs: Not only a health problem
Initiative: Effective research
All too often, the key determinants of health – as well as the solutions – lie outside the direct control of the health sector. They are rooted in areas such as sanitation and water supply, environmental and climate change, education, agriculture, trade, tourism, transport, industrial development and housing. Yet many countries lack the capacity to measure the impact of other sectors on health. Unless these issues are addressed, it can be difficult to prevent or even control some infectious diseases.
The link between environmental quality and health, for example, is critical. Over 10% of all preventable ill-health today is due to poor environmental quality – conditions such as bad housing, overcrowding, indoor air pollution, poor sanitation and unsafe water.
Bad housing and poor environmental conditions have the greatest impact on acute respiratory infections and diarrhoeal diseases. And children are worst affected – accounting for as much as two-thirds of all preventable ill-health due to environmental conditions.
In developing countries, about 700 million people – mainly women and children in poor rural areas – inhale harmful smoke from burning wood and other fuels. They are increasingly at risk from acute respiratory infections, especially pneumonia. Over a billion people lack access to safe drinking water – increasing their vulnerability to diarrhoeal and parasitic diseases. In Africa, Asia and Latin America, at least 600 million urban dwellers live in unhealthy homes or neighbourhoods. Almost 800 million people worldwide lack access to health services.
Elsewhere, changes in land and water use can also have a major impact on the incidence and pattern of disease. Deforestation, agricultural development, dams and irrigation schemes can trigger outbreaks of parasitic or other infectious diseases through favouring the spread of malarial mosquitos or freshwater snails that spread schistosomiasis. Most at risk are the over half a billion poor people who live in ecologically fragile regions. Other diseases affected by environmental change include lymphatic filariasis, dengue fever, leishmaniasis, Chagas disease and bacterial meningitis.
Meanwhile, an increase in global warming could have a similar impact on the spread of tropical diseases. A temperature rise of only 1-2oC over the next 50 years could extend the range of malarial mosquitos further north – increasing the proportion of the world's population at risk of malaria and other mosquito-borne diseases such as dengue and lymphatic filariasis.
Poverty and malnutrition are other key factors that affect health. Malnutrition is particularly lethal in combination with infectious diseases such as pneumonia, malaria, measles and diarrhoeal diseases – the major killer diseases affecting children. It is an underlying factor in over half of all child deaths. In 1997, an estimated 160 million children were moderately or severely malnourished. More than one in four of the world's population were estimated to be living in poverty – over a billion of them with incomes of less than $1 a day. Even in industrialized countries, 100 million people live below the poverty line.
The critical need for collaboration between health and other sectors has been highlighted most recently by efforts to prevent HIV/AIDS. A few governments have attempted to reduce individual vulnerability to HIV/AIDS through a cross-sectoral approach. The aim is to influence infrastructure development plans, laws, education, labour policies and the exercise of human rights, for example, in an effort to create an environment that makes it easier for people to avoid HIV/AIDS. This can involve providing incentives to enable girls to finish secondary education, boosting job and educational opportunities for women to break the cycle of economic and sexual dependency, and ending the criminalization of marginalized groups such as sex workers and injecting drug users. It can also involve carrying out impact assessments for development projects to foresee ways in which schemes could fuel the epidemic – through accelerating the pace of urbanization, for example, or splitting up families through creating the need for a migrant labour force.
In Thailand, where prostitution remains illegal, the government's pragmatic approach to slowing down the epidemic has brought a significant decline in infections – especially among the young. The multisectoral approach included work with brothel owners to urge 100% condom use in brothels, the launch of mass media campaigns to encourage respect for women and discourage men from visiting sex workers, improved educational and vocational opportunities for women to keep them out of the sex industry and improved access to care, as well as economic and social support for people living with HIV/AIDS.
In addition to the need for increased collaboration between the different public sectors which impact on health, there is a need to build partnerships with the private sector. The recent launch of the New Medicines for Malaria Venture – a joint initiative by the public and private sectors to develop new antimalarial drugs – is an example of efforts to harness greater public and private sector collaboration in developing new products for use in developing countries. Another example is the donation of drugs by industry free-of-charge to help eliminate infectious diseases with a high disease burden in developing countries. These include donations of drugs by pharmaceutical manufacturers SmithKline Beecham and Merck for the treatment of lymphatic filariasis and river blindness, and Pfizer for trachoma. In addition vaccine manufacturers have occasionally donated vaccines during outbreaks of disease, such as meningitis, for polio eradication, and for vaccine trials in developing countries.
WHO's efforts to eradicate or eliminate diseases are a collaborative effort by global partnerships. WHO has forged strategic alliances with governments, ministries of health in developing countries, international development banks, foundations, the private sector, civil society, non-governmental and international organizations and other UN agencies.
Global efforts to eradicate polio, for example, have demonstrated what can be achieved through private sector collaboration. Rotary International, a private sector service organization, has raised $500 million to fund vast quantities of vaccine for mass immunization campaigns and to help equip a refrigerated cold chain for vaccine transport. Rotary has used its global network of over 28 000 clubs in 155 countries to enlist volunteers to carry out social mobilization campaigns, provide organizational skills for immunization campaigns, and administer polio vaccine drops to children.
