Poor health, poor agriculture

Growing our food is often bad for our health, just as poor health hampers us in growing our food. And defeating diseases such as malaria can clash with agricultural practice. In the tail of a challenge, the sting of a dilemma. We can feel it each time a fever aches its way through our bodies. We can feel what we know: diseases such as malaria have a direct and negative impact on many aspects of our lives - including agricultural production. According to the World Health Organisation, the single disease of malaria reduces the gross national product of countries in sub-Saharan Africa by more than 1%, rising to as much as 2-6% in Kenya or 1-5% in Nigeria. Premature death and spells of illness from infectious diseases cut down tomorrow s and today s labour force. It is no wonder, then, that the re-emergence of certain infectious diseases brings not only a shudder to the body of the victim, but also to the body politic, and the body economic, of a nation. There are signs of frightening levels of expansion of diseases that seemed to be getting under control. The question now is: how much further will they dig into an agricultural sector that is already prey to under-nourishment in terms of income and input and to the ill-health of its people? The breeding grounds for disease are changing. In Ghana, for example, the massive lakes created by dams in the Volta basin have had the effect of increasing the incidence of bilharzias: among school-age children, it rose from 5% in the pre-dam era to more than 90% afterwards. This was the result of increasing still or slow waters, which encourage the growth of aquatic weeds, home to the snail hosts of bilharzias. The reduction in fast moving waters, however, cut down the population of blackfly, which transmit blindness. Some diseases are also spreading into new areas across the world, as witnessed by the emergence in North America of West Nile Fever, a mosquito-borne disease that provokes encephalitis, an inflammation of the brain. Of the six major human communicable diseases, each killing more than a million people a year, one is transmitted by direct bodily contact, HIV/AIDS; it is the leading killer disease, its effect on agriculture and rural life too sadly evident in our daily lives (see Spore 82). Onchocerciasis (river blindness) is a major example of diseases transmitted by nematodes carried by such external agents as blackfly. Diarrheal diseases and acute respiratory diseases, such as influenza, pneumonia or whooping cough, thrive in damp and unclean environments, and seize on the ill-nourished young and old. The same conditions encourage the spread of tuberculosis, now gaining ground in many countries as the number one killer of adults, including many HIV sufferers. Of special relevance to agriculture is malaria, and its vector, or carrier, the mosquito, guilty of two million deaths in Africa alone each year. Weakness and strength The overall effect of these and other communicable diseases, such as djengue fever, or the yellow fever recently established in eastern Africa, is not only the tragedy of lives lost early, but also the debilitating effect on a nation s health and welfare of a debilitated youth, and a debilitated labour force. Since communicable diseases are rife in developing countries (developed ones are more prone to death from lifestyle illnesses, such as cancer and cardiovascular disease), it is agriculture which suffers the most. In the field, or the workshop, the energy and concentration of a person is sapped by illness. Accidents are more frequent. A weakened body is further worn down by the strain of ill-designed equipment and the misuse of chemicals in pesticides and processing. Some diseases, such as malaria, are often most prevalent at harvest time, and play havoc with the work force. The idyllic picture that some urbanites have of rural life is not the same one we see through the mist of pain and sweat, and our exposure to physical, chemical and above all biological hazards. In the field, the harvest store and the fish pond, we stand unprotected from the many dangers, literally bugs and bacteria, that form what the experts call 'microbiological production systems' breeding grounds in short. Opportunities and threats Many agricultural practices have the effect of encouraging breeding grounds for disease vectors causing a real clash between the interests of food producers and health. The large-scale dams built for water and energy supply and the small dams and fish ponds currently favoured for irrigation and protein production are both homes to insect larvae and other vectors of diseases. Similarly, the avoidance of pesticides in sound agricultural practice has encouraged more insect populations, as has the less politically correct practice of deforestation. Even health-and-hygiene and commercial advances in packaging have their knock-on effects on health. Cleaner food, yes, but the packaging, when discarded, adds to the breeding opportunities for insects. The clash of interests is most vivid in the case of DDT (dichloro diphenyl trichloroethane) chemicals. Their use in breaking the breeding cycle of malarial mosquitoes is unquestioned, just as their toxic nature for both animals and humans. The United States, for example, banned their use in 1972, and yet did not insist on a total global ban while negotiating, in 2001, the treaty to withdraw all persistent organic polluants such as DDT. At the same time, negotiations were underway in the World Health Organisation for a new Roll Back Malaria campaign which relies in part on continuing to allow the use of DDTs in developing countries to eradicate malaria. Here the world community is caught on the horns of dilemma, and forced to constantly choose for the other, lesser evil. Of such irresolvable clashes are made the endless agonies of the rural poor, for they will suffer one way or the other, as they always do (they already spend 40% of scarce disposable income on malaria cures ), and, less pitifully, the headaches of policy-makers. It seems that the only real policy in achieving co-existence between the two sectors is to apply the art of compromise, not always the most obvious skill of novice policy-makers. At the end of the day There is much that can be, is being, done instead of spraying harmful chemicals. One is to develop harmless substances, such as the relatively benign but expensive biological bug-killer Bacillus thuringiensis israelensis (Bti). Another option is the genetic engineering of mosquito variants which are either sterile, thus breaking the breeding cycle, or immune to malaria. Also requiring more research is the use of predatory fish, such as the Gambusia, which eat the larvae of mosquito and blackfly. Yet another option is to reduce the volume of still waters in ponds and irrigation systems, through using ditches to encourage water flow. Many such options are on the research agenda of the System-wide Initiative on Malaria and Agriculture launched recently by international agricultural research centres. The only immediate solution, or method of prevention, is physical protection until a viable vaccine can emerge. As in the case of HIV/AIDS transmission, in the absence of behaviour change, abstention or total separation of the players, a physical barrier has to be put in place. Screens and nets over water tanks, ponds and human dwellings are the order of the day, however much of a challenge they may be to a household s purse, a farmer s budget or an architect s skills. The most promising single factor is increasing use of impregnated bed nets which repel aggressive mosquitoes. Following the African summit on malaria in Abuja, Nigeria, in April 2001, concrete measures have been taken. Uganda, for example, has removed all duties and taxes on such bed nets to make them more affordable for rural homes. The trouble is, you cannot farm in a bed net. [caption to illustration] Healthy crops, so-called, do not always make healthy people For more information: Roll Back Malaria WHO, 20 Avenue Appia, CH 1211 - Geneva 27 Switzerland Fax: +41 22 791 4824 Email: rbm@who.int Website: www.rbm.who.int System-wide Initiative on Malaria and Agriculture Website: www.iwmi.org/sima [summary points] The impact of infectious diseases on rural life is growing, and will be worsened by expected changes in climate. principal vectors of diseases such as malaria are insects which breed in still water much scientific research is needed on changes in agricultural practice to reduce breeding grounds exposure to risks cannot be avoided in agriculture more attention is needed on protective clothing and home architecture, and affordable preventive medicine the economic impact of infectious diseases on agricultural productivity need further researchGrowing our food is often bad for our health, just as poor health hampers us in growing our food. And defeating diseases such as malaria can clash with agricultural practice. In the tail of a challenge, the sting of a dilemma.We can feel it each..