OCTOBER 2000 NEWS
ACTION AGAINST INFECTION
"Without a sense of universal responsibility
and an understanding and belief
that we really are part of one big human family,
we cannot hope to overcome
the dangers to our very existence."
The Dalai Lama
BILHARZIA VACCINE IS DISCOVERED!!!
"Malaria, according to the World Health Organization, is one of the most serious and complex health problems facing humanity in the 20th century. Schistosomiasis causes illness in people for very long periods of time and kills hundreds of thousands of people each year. Dengue fever effects more than one fifth of the world's population with illness symptoms that are very debilitating, and if the more dangerous variety of this virus is not treated effectively, it also can kill. All three of these diseases are very much human diseases, in that, the proliferation and propagation are very dependent on human activities.""Finally, all of these diseases are child killers and maimers. In Africa, malaria infects about half of all children under the age of three, killing an estimated 1 million children each year (WHO 1985). Malaria not only threatens a child with death and illness, but also with stunted growth, poor levels of fitness and hinders educational achievement. Children between six and fourteen years old are more vulnerable to some diseases than younger children because they go outside more and are more exposed to air and water borne diseases. Schistosomiasis is a good example of an environmental danger to older children. At least 100 million children aged 5 to 14 years are infected with schistosomiasis (WHO. 1990; p. 31). These children tend to wash and bathe in canal or pond water infested with the parasites, because their families lack clean water. Dengue fever, likewise, has an adverse effect on the lives of many children."
Honours Research Thesis: Environmental Aspects of Tropical Diseases: A Study of the Social and Economic Impacts of Malaria, Dengue Fever and Schistosomiasis.
Schistosomiasis or Bilharziasis
Schistosomiasis is one of the major communicable diseases of public health and socio-economic importance in the developing world.
Direct mortality is "relatively low", ( "relatively low " is according to WHO "only" few hundreds of thousands each year!!) but the disease burden is high in terms of chronic pathology and disability.
The distribution is particularly related to large-scale water development. Despite control efforts in a number of countries, still an estimated 200 million people are infected, of which 120 million are symptomatic and 20 million have severe disease.
( 20 million! - as if the whole Scandinavia: Denmark, Finland, Island, Norway, Sweden where seriously afflicted and slowly dying! )
An estimated 80% of all cases, and all of the most severely affected, is now concentrated in Africa.
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One of the main challenges for WHO is therefore to revive schistosomiasis control in Africa. Given the difficulties in sustaining large-scale vertical programmes in this continent, the core of the new strategy will be a simple morbidity control package which can easily be implemented through existing health and educational services. The major challenges for sustainable schistosomiasis control in Africa are to:
- make praziquantel available at an affordable price at all levels of health care
- obtain proper case management
- integrate schistosomiasis control in school health programmes
- give simple but effective health education.
More information at WHO
Honours Research Thesis
Honours Research Thesis
Environmental Aspects of Tropical Diseases: A Study of the Social and Economic Impacts of Malaria, Dengue Fever and Schistosomiasis.
April 14, 1997
Click to the whole text
This paper is concerned with whether or not human activities affect the potency and range of tropical diseases, and the extent to which do these diseases affect the socio-economic structures and environmental activities of indigenous human populations.
For centuries malaria has been known as a tropical disease with devastating and life threatening effects on the individual human organism. Malaria and other diseases, such as schistosomiasis and cholera, are increasingly affecting whole populations within developing countries and have now reached epidemic proportions. Currently schistosomiasis affects more than 200 million people and malaria kills over one million people annually.
To what extent are anthropocentric activities increasingly becoming the prime instigators of these virulent plagues? For example, it may be that human population growth will lead to increased environmental degradation making the permanent localization and globalization of disease more prevalent thus extending and intensifying the geographic range of many diseases. Thus malaria could become a serious problem in North America as a result of both environmental and human migration The increased use of dams, and water control devices for irrigation projects and energy resources, increase the number of breeding grounds for vectors of viral, bacterial and other diseases in these environments. In addition, it may be that these diseases are using human organisms as carriers instead other animals (zoonoses), as a part of their life cycles, e.g., schistosomiasis uses the human body as part of its reproductive cycle.
The increasing resistance by insects and other organisms to pesticide and antibiotic control has led to an unprecedented proliferation of disease carrying vectors. Since 1947, when massive post-war insecticide spraying commenced, more than 500 mosquito species have developed resistance to insecticides. Consequently, in some areas where vector-borne diseases, such as malaria, had virtually been eliminated, dramatic increases in their incidence are now occurring.
I Statement of Purpose
The purpose of this research paper is to explore some of the ways in which human socio-economic activities influence the spread of these three tropical diseases. The propagation and proliferation of malaria, schistosomiasis and dengue fever seem to be related with a variety of human activities. In consequence, therefore, the combined effects of human population stress, socio-economics and other factors are leading to a level of disease risk to the present human population. What is the impact of human activities on disease organisms and conversely how do these illnesses affect human social and economic realities of different segments of humanity?
II North versus South
The North has the money and power to use a multitude of new technologies to control diseases within its national boundaries. The South, on the other hand, is both under funded and lacks the research facilities and expertise necessary for sustained research into the causes of disease. There are differences in the philosophies of disease control or management, between the developed world (i.e. kill the disease or its carrier) and the less developed countries (reduce the symptoms or side effects of the disease). This is partially because the creating of vaccines for the Third World countries is expensive. In addition, there is a reduced chance of such vaccines being used successfully in disease management because of inadequate health service infrastructures.
III Socio-economic issues related to tropical diseases
Infectious and parasitic diseases still account for well over half the total burden of morbidity and mortality in Sub-Saharan Africa, India and much of of China. The economic effects of tropical diseases are also experienced in South and Central America. Indeed governments of Third World countries where these diseases are endemic are faced the chronic burden of difficult choices. Economic recession coupled with depressed commodity prices has led to falling levels of real income per capita in most Third World or Southern nations hence reduced amounts of spending capital is available for public health care. Furthermore, pressure to reduce macroeconomic imbalances including unsustainable levels of government debt has resulted in a tightening of the political economy resulting stabilization and adjustment policies to reduce reliance on government intervention and to encourage an independent development of the private sector (Evans and Jamison. 1994; p.1866). As a result, real government health expenditure per capita declined in the 1980s in many of the countries where these diseases are most endemic. On a microeconomic level parasitic diseases impose an economic burden on households. Scarce household resources must be used to ameliorate the consequences of infection, both in terms of direct costs, e.g., diagnosis and treatment, and indirectly as costs in the form of morbidity and mortality which further reduce the time available for productive pursuits. Combined these costs have a domino effect and can be considerable. For example, in a group of four African case studies from an area in which average daily earnings were approximately $0.20, these costs were $9.80 (or 49 times the average daily wage) per episode of malaria (Evans and Jamison. 1994.; ibid). Significant indirect costs have also been estimated for schistosomiasis. The incidence of parasitic diseases is greatest amongst the poorest people in the poorest countries.
By restricting economic potential, parasitic infections exacerbate existing inequalities between the North and the South and within the Third World communities themselves. This is why disease intervention is of paramount importance. However, it is not the size of the problem alone which should determine the priority of interventions from an economic viewpoint, but rather the extent to which the problem could be reduced given the available resources (Evans and Jamison. 1994; ibid).
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IV Epidemiology of Schistosomiasis
Schistosomiasis is one of the most critical public health problems in many countries in the Third World. It is a snail-transmitted disease that is contracted by the juvenile (cercarial) stage of the parasites penetrating the skin of an individual who comes into contact with infested waters. It is estimated that the disease infect more than 200 million people in 71 countries in Africa, the Middle East, South America, some Caribbean Islands, and the Orient (Malek. 1985; p 24). According to Maegraith (Maegraith, 1989; p 304) about two to three hundred million people suffer from schistosomiasis, either systemic or dermatological. The three main types of blood-flukes that are common parasites in humans are: Schistosoma haematobium, S. mansoni and S. japonicum.
When outside the human host, these parasites undergo a multiplicative developmental cycle in certain snails (Maegraith. 1989; p 304). Humans acquire an infection by wetting the skin with water containing the infective larvae (cercariae) shed by the snail hosts. Once outside the snail, these fork-tailed larvae must penetrate the skin of a human within 48 hours (WHO. 1990; p 57). When the larvae upon contact with human skin, they secrete lytic enzymes which they use to pierce the skin. In this way, the larvae (cercariae) actively penetrate the skin and find their way to the liver and into the portal system. It is here that general infection occurs, along with its ramifications. It is primarily in the liver and portal system that larvae develop into adult worms of both sexes (Maegraith, 1989; p 304). It is also here that they copulate and produce eggs for reproduction of their species. Eggs are produced only by mated females, who are joined with a male for life - usually five years on average (WHO. 1990; p 57).
The gravid female worms, wrapped within the males, make their way to the terminal radicles of the portal venous system, dilating these small vessels as they ascend through them against the direction of the blood flow (Maegraith, 1989; p 304). They then deposit their eggs one by one, retreating a little down the vessel after each egg is laid. Only about half the eggs leave the human body; the rest remain embedded in the body where they cause damage to important organs (WHO. 1990; p 58). Those eggs that do leave the human body, are extruded from the aforementioned vessels through the tissues into the bladder or the intestine, according to the location of the worms, and are voided to the exterior in the urine or faeces (Maegraith. 1989; p 304). These eggs must enter fresh water or they perish; and such eggs deposited into tropical freshwater, hatch and become a free-swimming ciliated larva (miracidium) (WHO. 1990; p 22).
The life cycle of the schistosoma then continues in a similar fashion in another snail host. The ciliated miracidium swim for several hours until they penetrate a suitable snail. In fact, these larvae must find a suitable snail host within a few hours in order to survive. They then actively penetrate into the snail's body and migrate to its liver gland. Here the miracidia undergo further development and multiply, giving rise in due course to large numbers of infective larvae (cercariae) (Maegraith. 1989; p 304). Again, the larvae (cercariae) are emitted into the water. If they are to survive they must find their alternate host within two days.
D. Social Aspects of these Diseases and their Control
Parts of the world are finding that available disease control measures are either too expensive, not efficacious, or only sporadically efficacious under certain conditions. Obtaining high rates of acceptance and use of such interventions, especially for those that are marginally efficacious, is crucial to successful disease control. Yet, human behaviour and social organization are vital determinants for the success of control programs (Oaks-SC et al. 1991; p 258). In particular, it is the behaviour of individuals and groups, which determine whether efforts to combat malaria, dengue fever, and schistosomiasis will be successful.
In general, urban areas have higher population densities, which allow for increased rates of disease transmission, large number of larval development sites and limited methods for disposal of wastewater and refuse. But malaria and dengue fever, because they are transmitted by insect vectors, have been mistakenly thought to be illnesses of rural areas. In fact, an Indian government evaluation study of its National Malaria Eradication Program (to control the Anopheles stephensi malarious mosquito species) concluded that the absence of control strategies for urban malaria was the program's most important failure (Oaks-SC et al.. 1991; p 263). Similarly, the vector for dengue fever, A. egypti, has adapted its lifestyle to migrating populations and now thrives in urban areas of dense human populations (Monath. 1995; p 50). Also since irrigation projects tend to attract human settlement, schistosomiasis has become problematic in these areas of high population density especially in tropical countries. Nevertheless, the main malarial vectors in Africa, Latin America, and most of Asia, remain confined to rural and semi-rural areas. Apparently, the Anopheles larvae need relatively clean water in order to survive since with increased fecal matter in areas of standing water, they are eliminated. How long this natural method of larval control will be effective is not known since the dengous A. egypti egypti can breed in rainwater in a pop can!
All these diseases affect a large percentage of the world's human population and cause many human deaths. These two factors alone are psychologically and socially stressful. The diversion of health resources to treat and control these diseases, places heavy social and environmental hardships on communities where they are endemic.
One of the defining characteristics of any society is the way in which it addresses the health of its members. Health is not only an economic perspective; health is also a basic human need (ICC on Africa.1993.; p. 8). Although the aggregate health effects of such problems, from dengue or malaria, are typically less than those of other diseases associated with poor sanitation, e.g., cholera, or other problems affecting poor households, the more articulate and politically influential members of the public often perceive them as the more important health threat. The result is that resources are often devoted disproportionately to addressing these problems relative to their public health impact.
Even in Third World cities that have excellent water systems, relatively clean air, and most other features typically associated with environmental health, there are still serious health hazards that fall heavily on the poor. As described below, many of these hazards involve social rather than physical threats to health: stress, fear, depression, chemical dependency, and violence. Other environmental conditions conducive to ill health within poverty groups, such as overcrowding, clearly have a physical aspect.
Diseases, such as malaria, dengue fever and schistosomiasis, also have such physical aspects. In the developed world, these waste disposal problems related to overcrowding (or their equivalent) were solved, or were at least displaced, by providing indoor piped water and flush toilets (and sewage treatment) to virtually all urban residents. The same is true for the wealthy in developing countries. For the poor majority, however, comprehensive technological solutions like these are unrealistic because they were deemed economically unrealizable. Neither low-income residents nor their financially strapped governments can afford anything like complete coverage with indoor plumbing (WRI. 1997; Chapter 2, p. 1).
A century and a half ago, average urban mortality rates in European cities were often far higher than those in the surrounding rural areas. Bad sanitation, which then referred to a range of poorly understood environmental health hazards rather than just disposal of excreta, was increasingly seen as being responsible for this urban disadvantage. Prominent scientists studied sanitary conditions and health, and reformers in urban centers around the world discussed both the technical and the moral aspects of urban sanitary reform (WRI. 1997; ibid). .
In many ways, the so-called sanitary revolution that resulted from these reforms was the environmental movement of the 19th Century. Similar to environmental discussions today, one of the most heated debates was about the appropriate role for government and whether attempts to impose sanitary improvements constituted an infringement on what would now be called the private sector. Eventually, the reformers won. One reason for their success is that, although the health problems were far worse in poor areas, the wealthy were also at risk (WRI. 1997; ibid). Politicians even worried that the military strength of their nations was being undermined by the threat of urban health problems . The politically powerful gradually accepted the fact that the threat from these unhealthy urban conditions was indeed public and required a public response.
II Factors That Contribute to Emergence of New Threats from Tropical Diseases
What are the factors that lead to the emergence of new threats from infectious disease? Infectious disease experts generally identify six factors: environmental change and disturbances to the balance of natural habitats, human demographics and behavior, international travel and commerce, complications of modern medicine, microbial adaptation and change, and the breakdown of public health measures (WRI. 1997; ibid).
Some emerging diseases are associated with environmental changes that occur with economic or agricultural development or changes in land use patterns. Certainly, the development and growth of cities often fuelled by an influx of migrants can foster the establishment of a new infection in a population. Once established in a crowded urban area, a disease can easily take root and can be extremely difficult to eradicate (WRI. 1997; ibid). Other human activities that disturb natural ecosystems, including road-building, logging, and irrigation projects, can also bring humans into new areas while displacing microbes that must then seek out new hosts. Changes in local climate, such as drier, wetter, or warmer periods, can extend the range of mosquitos and other disease vectors.
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It took time for SUCAM to learn that the frontier malaria was a completely new type of malaria (Kingman. 1989; ibid). Although the disease concentrates in areas of settlements and gold mines, the epidemic dies down after three or four years, when the water around the settlement becomes too polluted for the mosquitoes to lay their eggs in it. However, when water becomes this polluted there is increased likelihood that schistosomiasis and sanitation related illnesses will take over as the primary health concerns.
Finally, all of these diseases are child killers and maimers. In Africa, malaria infects about half of all children under the age of three, killing an estimated 1 million children each year (WHO 1985). Malaria not only threatens a child with death and illness, but also with stunted growth, poor levels of fitness and hinders educational achievement. Children between six and fourteen years old are more vulnerable to some diseases than younger children because they go outside more and are more exposed to air and water borne diseases. Schistosomiasis is a good example of an environmental danger to older children. At least 100 million children aged 5 to 14 years are infected with schistosomiasis (WHO. 1990; p. 31). These children tend to wash and bathe in canal or pond water infested with the parasites, because their families lack clean water. Dengue fever, likewise, has an adverse effect on the lives of many children.
E. Economics of Tropical Diseases/- - -/
Malaria, according to the World Health Organization, is one of the most serious and complex health problems facing humanity in the 20th century. Schistosomiasis causes illness in people for very long periods of time and kills hundreds of thousands of people each year. Dengue fever effects more than one fifth of the world's population with illness symptoms that are very debilitating, and if the more dangerous variety of this virus is not treated effectively, it also can kill. All three of these diseases are very much human diseases, in that, the proliferation and propagation are very dependent on human activities.
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F. ConclusionThese diseases have also been shown to have deleterious effects on the economic life of human populations so affected. Not only is there the toll of human physical and spiritual suffering, there is increased poverty and environmental degradation in areas where these diseases are endemic. The increased stresses caused by these diseases, have resulted in further stretching the health resources of these populations to the very limit. This has been especially disturbing, in that these populations have faced simultaneously an increase in parasitic epidemics while enduring a decrease in their standard of living, primarily being caused be the global economic effects of restructuring.
The global and national pictures for such people, and the global population as a whole is very bleak, unless the countries and people of the developed countries invest more money, social/political and medical resources into combatting the fundamental causes of the spread of these diseases and the suffering that they are causing. These diseases are not apolitical, i.e., it is the poverty and ignorance of the people in developing countries that are the primary cause effecting the spread of these diseases, and yet these illnesses will affect all of us. They will affect all of us because they lead to greater environmental degradation than is necessary, and hence decrease, for example the biodiversity of our world. They also they create many breeding situations for opportunistic illnesses, which may then be able to escape to areas of the world where they are not yet present. One might suspect some viruses such as HIV and AIDS as having functioned in this manner, although there is no proof. However, it is known that some illnesses depend on a weakened condition of the host in order to establish itself, e.g. pneumonia.
The solution to these problems is not easy since it requires a fundamental shift in the philosophy towards health care in a global sense. Do we just provide health care to those who can afford it? Or do we engage in a world communal type attitude towards providing more than the bare essential health care system? Finally, the solution requires in-depth interactive participation of all parties concerned, including the indigenous population, and each development project must have a Disease Impact Assessment prepared before any action takes place on the project.
Good health is not just the absence of disease yet it must meet this minimal condition. Health is the product of a complex set of actors. Real income, nutrition, environment, education, clean water and sanitation are among the factors that contribute to individual and communal health. One of the impediments to health is poverty. Many governments of the Third World spend more money on the military or servicing their multilateral debt than they do on health services, e.g. the total amount spent for health services for the whole of Africa, during 1985-87 (ICC; p.9), was only 3.9% of government spending whereas that used to pay interest on debt was 15.8%. Actual spending on health in these countries ranged from $5 to $25 per person per year (ICC; p.38). This is clearly an insufficient amount of resources being allocated for such purpose.
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BILHARZIA VACCINE DISCOVERED BY:
Miriam Tendler och Andrew Simpson.
Miriam Tendler, Ph.D.
Instituto Oswaldo Cruz,
Rio de Janeiro.
Phone at the laboratory:
+55-21-495 68 31, or 493 82 10, or 598 43 61
* * * * *
Andrew J. G. Simpson, Ph.D.
Ludwig Institute for Cancer Research
Rua Professor Antonio Prudente, 109 - 4.andar
01509-010 Sao Paulo, SP, Brazil
* * * * *
We don't need to wait any longer for the discovery of a vaccine against Bilharzia, we just need a producer. But since this is a "3rd World" tragedy - a poverty question- no producer is to find - anywhere!
Please, do what ever you can to raise awareness of the possibility to cure millions of suffering children.
Send an Email appeal.
YOU CAN ALSO SEND YOUR APPEALS TO WHO and UN:
Dr Gro Harlem Brundtland
The World Health Organization
Headquarters Office in Geneva (HQ)
Avenue Appia 20
1211 Geneva 27
Telephone: (+00 41 22) 791 21 11
Facsimile (fax): (+00 41 22) 791 3111
Telex: 415 416
Telegraph: UNISANTE GENEVA
The Consultative Committee on Administrative Questions (Financial and Budgetary Questions) at UN
Chair Mr. Abraham Espino (IAEA).
Mr Peter Leslie
United Nations Office at Geneva
Palais des Nations
1211 Geneva 10
Tel: +41 22 917 2742
Fax: +41 22 917 0123
Email : email@example.com
The World Health Organization Office at the European Union (WEU)
14 rue Montoyer
General enquiries / administrative assistant (32-2) 506 4660
Facsimile (fax): (32-2) 506 4666
Dr Wilfried Kreisel, Executive Director
Dr Marie-Hélène Mathey-Boo, Special Adviser on Africa
Dr Anne Pinteaux, External Relations
THANK YOU FOR YOUR CONTRIBUTION !