| Background Element |
| Malaria Genetics and Epidemiology |
Malaria
Malaria Today
Today, over 100 years after the work of the pioneering malariologists who uncovered the causes of the disease, malaria is
responsible for 300-500 million cases worldwide every year, of which 0.5 – 2.5 million are fatal (White et al., 1999). The
majority of these deaths are of children under five years old, and it is estimated that a child dies of malaria every 30 seconds
(WHO, 2004). Most of these deaths occur in sub-Saharan Africa where the most virulent species of human malaria,
Plasmodium falciparum, is endemic. The disease is also widespread in South Asia, Central and South America, and the
Western Pacific. The mortality from malaria is less in these areas than in Africa, but morbidity is high leading to considerable
social and economic costs (Trigg and Kondrachine, 1998). These enormous socio-economic costs are made even more
significant by the fact that the areas affected are amongst the poorest in the world. In 1995 alone, the direct and indirect cost
attributed to the malaria problem world-wide was estimated at US$1800 million (The Wellcome Trust, 1998), despite
concerted efforts by organisations such as the World Health Organisation (WHO) to control the disease. In fact, the situation
is getting worse (WHO, 1998)
It is easy to observe the correlation between the disease and poverty. In 1995 the gross domestic product (GDP) of
malarious countries was more than 5 times less than that of non-malarious areas (Gallup and Sachs, 2001). This correlation
between malaria and poverty can be interpreted in a number of ways. It is possible that the link between poverty and malaria
is purely co-incidental, with tropical countries being impoverished for reasons of geography, climate, political history and
other tropical diseases, independent of malaria. Gallup and Sachs (2001) analysed the income per capita of malarious
countries and included these other factors in their analysis. They concluded that the “association of malaria with poverty
seems to be more than just a mask for other plausible causes of low income”.
Is, then, malaria a cause or an effect of poverty? It is true that the richer countries of the world have been able to eradicate
malaria in the last 50 years. In 1946, for example, large areas of the USA, Southern Europe and northern Australia were
afflicted with the disease, but managed to eradicate it by the mid 1960s (Sachs and Malaney, 2002). Certainly this was due, in
part, to the economic power of the nations involved, which were able to organise efficient and effective strategies of
mosquito control. The control attempts were probably aided by the affluence of the people living in these countries,
particularly in relation to good quality housing and reliable access to medical services – both features of Western affluence
that are sadly lacking in poorer nations.
It is easy, then, to postulate that rich countries can afford to be malaria-free, while poorer nations are burdened with the
disease due to the poor infrastructure associated with poverty. This explanation is overly simplistic, however, for though
there is undoubtedly some truth in it, it ignores the very real biological differences in malaria parasite transmission between
the rich and poor countries. It is often overlooked that it is far easier to eliminate malaria in regions where transmission is
low, (an effect of human population density, mosquito population density and, crucially, climate), than where transmission is
high and endemic. Countries that have successfully eradicated malaria are predominantly found in temperate climate zones,
which are associated with less efficient vectors, lower night-time temperatures and marked seasonality in parasite
transmission (Gallup et al., 2001). Control of malaria in tropical zones, then, is far more difficult. This argument against a
purely economic cause of malaria is supported by rich countries in tropical locations that have not been able to eradicate the
disease. Oman and Saudi Arabia, for example, whilst both enjoying high GDPs due to oil revenues, still suffer from the
presence of malaria.
The incidence of malaria, then, cannot be directly attributed to the poverty of the country in which it is found. What is
absolutely attributable to poverty, though, is death from the disease. The startling statistic mentioned above, that “a child dies
of malaria every 30 seconds” is often quoted in the introduction to scientific papers concerned with malariology, so much so
that its impact is somewhat reduced on those working in the field. The fact is that this is a sickening statement to make in the
21st Century. Malaria is completely curable today thanks to highly effective anti-malarial drugs. Yes, there are huge problems
of drug resistance in large areas of the world, but combination therapy with artemisinin has yet to be affected by this
problem. The simple fact is that any child that contracts malaria need not die if treated with effective drugs such as
Coartem® (artemisinin-derivative in combination with lumefantrine), and yet 2000 children are dying every day, because,
fundamentally, their parents simply cannot get access to a medicine that costs US$2 for an effective dose.
There can be no doubt that increases in the economic development of malarious countries will decrease the terrible death
rates presently associated with the disease. A case study conducted by Medecins Sans Frontieres involving 5 African
countries suffering huge malaria burdens (Burundi, Kenya, Rwanda, Tanzania and Uganda) estimated that for the 25.3 million
cases of malaria between all 5 countries to be treated with artemisinin combination therapy would cost an extra US$19.1
million per year (Kindermans et al., 2002). Extrapolating this estimate to include the whole of Africa (in which there
approximately 200-450 million cases of the disease annually), the figure rises to approximately US$300 million extra a year.
To put this figure into context, the combined yearly military expenditure of the 5 African countries listed above comes to
US$414.4 million (SIPRI, 2004).
If the prevalence of malaria is a not direct result of poverty, then the problem is certainly exacerbated by it, but what of the
effects of the disease on the prevalence of poverty? There can be little doubt that countries in which malaria is endemic bear
a great economic burden which can be directly attributed to the disease. Gallup and Sachs (2001) showed that countries that
suffered severe malaria in 1965 had “dramatically lower economic growth in the next 25 years” than malaria-free countries
(even after controlling for other factors such as geographic location, initial poverty, political economic policies, etc.). This
reduction in the economic viability of malarious countries can be attributed to a number of factors. There is the direct
personal economic cost borne by the people living in malarious areas who are forced to pay for preventative and curative
measures against the disease. There is also the proportion of government spending on programmes designed to control the
disease. Then there is the loss of revenue from foreign tourism and investment, which suffers due to reluctance on the part
of would-be tourists and investors to travel to countries with a serious malaria problem. When malaria was eradicated from
Portugal, Spain, and Greece in the mid 1950s, for example, there was huge economic development in these countries, which
can be directly attributed to large increases in tourism and foreign investment (Sachs et al., 2002) .
Less quantifiable, but certainly as important, is the reduction in economic growth associated with having a large proportion of
the population unable to work due to sickness. High morbidity reduces the effective productivity of the population directly, in
terms of the numbers of people unable to work, and indirectly, with the loss of earnings of the many people who have to look
after affected family members (Nur, 1993). The fact that malaria is mostly prevalent among children has huge implications
for education in the poorest regions of the world, sick children being unable to attend school. A study by Brooker et al.
(2000), attributed 13-50% of medically related school absences in Kenya to malaria (Brooker et al., 2000). Malaria has been
shown to have an adverse effect on the school performance of infected children in Sri Lanka (Fernando et al., 2003). There
is also evidence to suggest that people who suffer from the disease in infancy experience impairment of cognitive
development and learning capabilities (Holding and Snow, 2001). Related to this is the fact that mothers are particularly prone
to malaria as the association between pregnancy and lowered immune status leads to an increased risk of the development of
the disease. Malaria during pregnancy is directly associated with low birth-weights, which is also a risk factor for diminished
cognitive development (Mccormick et al., 1992).
Another malaria-related factor that affects economic development is that the disease limits the movement of people within
malarious areas. When people move away from a malarious area for prolonged periods, there is an associated loss of
immunity against the disease. This prevents those people who have gone to non-malarious areas to work or study returning to
the areas they left, and so contributes to the lack of skills and education in endemic areas. Similarly, as immunity to malaria is
known to be strain-specific, there is a risk involved in workers migrating from one endemic area to another, thus preventing
the movement of labour to regions where it is most productive (Sachs et al., 2002).
All these factors combine to present the depressing picture of a disease strongly associated with poverty, both as a cause and
as an effect. There can be little doubt that improving the economic development of the poorest countries will greatly aid the
fight against malaria, while, paradoxically, effectively reducing the disease burden will increase the economic development of
the countries affected.
References
White,N.J., Nosten,F., Looareesuwan,S., Watkins,W.M., Marsh,K., Snow,R.W., Kokwaro,G., Ouma,J., Hien,T.T., Molyneux,M.E., Taylor,T.E.,
Newbold,C.I., Ruebush,T.K., Danis,M., Greenwood,B.M., Anderson,R.M., and Olliaro,P. (1999). Averting a malaria disaster. Lancet, 353, 1965-
1967.
WHO. What is Malaria? http://www.rbm.who.int/cmc_upload/0/000/015/372/RBMInfosheet_1.htm . 2004.
Ref Type: Electronic Citation
Trigg,P.I. and Kondrachine,A.V. (1998). The current Global Malaria Situation. In Sherman,I.W. (Ed.), Malaria: Parasite biology, Pathenogenesis and
Protection., . ASM Press, Washngton D.C, pp. 11-22.
The Wellcome Trust. Malaria CDROM. 1998. The Trustee of the Wellcome Trust.
Ref Type: Audiovisual Material
WHO. World Health Organisation Factsheet 94. 1998.
Ref Type: Pamphlet
Gallup, J. L. and Sachs, J. D. The economic burden of malaria. American Journal of Tropical Medicine and Hygiene 64[1-2], 85-96. 2001.
Sachs,J. and Malaney,P. (2002). The economic and social burden of malaria. Nature, 415, 680-685.
Kindermans, J.-M., Pecoul, B., Perez-Casas, C., Den Boer, M., Berman, D., and Cox, I. Changing national malaria treatment protocols in Africa:
What is the cost and who will pay? http://www.accessmed-msf.org/ . 2002.
SIPRI. Information from the Stockholm International Peace Research Institute. http://www.sipri.org/ . 2004.
Nur,E. (1993). The impact of malaria on labour use and efficiency in the Sudan. Soc Sci Med., 37, 1115-1119.
Brooker,S., Guyatt,H., Omumbo,J., Shretta,R., Drake,L., and Ouma,J. (2000). Situation analysis of malaria in school-aged children in Kenya - What
can be done? Parasitology Today, 16, 183-186.
Fernando,S.D., Gunawardena,D.M., Bandara,M.R.S.S., De Silva,D., Carter,R., Mendis,K.N., and Wickremasinghe,A.R. (2003). The impact of
repeated malaria attacks on the school performance of children. American Journal of Tropical Medicine and Hygiene, 69, 582-588.
Holding,P.A. and Snow,R.W. (2001). Impact of Plasmodium falciparum malaria on performance and learning: Review of the evidence. American
Journal of Tropical Medicine and Hygiene, 64, 68-75.
Mccormick,M.C., Brooksgunn,J., Workmandaniels,K., Turner,J., and Peckham,G.J. (1992). The Health and Developmental Status of Very-Low-
Birth-Weight Children at School Age. Jama-Journal of the American Medical Association, 267, 2204-2208.
Today, over 100 years after the work of the pioneering malariologists who uncovered the causes of the disease, malaria is
responsible for 300-500 million cases worldwide every year, of which 0.5 – 2.5 million are fatal (White et al., 1999). The
majority of these deaths are of children under five years old, and it is estimated that a child dies of malaria every 30 seconds
(WHO, 2004). Most of these deaths occur in sub-Saharan Africa where the most virulent species of human malaria,
Plasmodium falciparum, is endemic. The disease is also widespread in South Asia, Central and South America, and the
Western Pacific. The mortality from malaria is less in these areas than in Africa, but morbidity is high leading to considerable
social and economic costs (Trigg and Kondrachine, 1998). These enormous socio-economic costs are made even more
significant by the fact that the areas affected are amongst the poorest in the world. In 1995 alone, the direct and indirect cost
attributed to the malaria problem world-wide was estimated at US$1800 million (The Wellcome Trust, 1998), despite
concerted efforts by organisations such as the World Health Organisation (WHO) to control the disease. In fact, the situation
is getting worse (WHO, 1998)
It is easy to observe the correlation between the disease and poverty. In 1995 the gross domestic product (GDP) of
malarious countries was more than 5 times less than that of non-malarious areas (Gallup and Sachs, 2001). This correlation
between malaria and poverty can be interpreted in a number of ways. It is possible that the link between poverty and malaria
is purely co-incidental, with tropical countries being impoverished for reasons of geography, climate, political history and
other tropical diseases, independent of malaria. Gallup and Sachs (2001) analysed the income per capita of malarious
countries and included these other factors in their analysis. They concluded that the “association of malaria with poverty
seems to be more than just a mask for other plausible causes of low income”.
Is, then, malaria a cause or an effect of poverty? It is true that the richer countries of the world have been able to eradicate
malaria in the last 50 years. In 1946, for example, large areas of the USA, Southern Europe and northern Australia were
afflicted with the disease, but managed to eradicate it by the mid 1960s (Sachs and Malaney, 2002). Certainly this was due, in
part, to the economic power of the nations involved, which were able to organise efficient and effective strategies of
mosquito control. The control attempts were probably aided by the affluence of the people living in these countries,
particularly in relation to good quality housing and reliable access to medical services – both features of Western affluence
that are sadly lacking in poorer nations.
It is easy, then, to postulate that rich countries can afford to be malaria-free, while poorer nations are burdened with the
disease due to the poor infrastructure associated with poverty. This explanation is overly simplistic, however, for though
there is undoubtedly some truth in it, it ignores the very real biological differences in malaria parasite transmission between
the rich and poor countries. It is often overlooked that it is far easier to eliminate malaria in regions where transmission is
low, (an effect of human population density, mosquito population density and, crucially, climate), than where transmission is
high and endemic. Countries that have successfully eradicated malaria are predominantly found in temperate climate zones,
which are associated with less efficient vectors, lower night-time temperatures and marked seasonality in parasite
transmission (Gallup et al., 2001). Control of malaria in tropical zones, then, is far more difficult. This argument against a
purely economic cause of malaria is supported by rich countries in tropical locations that have not been able to eradicate the
disease. Oman and Saudi Arabia, for example, whilst both enjoying high GDPs due to oil revenues, still suffer from the
presence of malaria.
The incidence of malaria, then, cannot be directly attributed to the poverty of the country in which it is found. What is
absolutely attributable to poverty, though, is death from the disease. The startling statistic mentioned above, that “a child dies
of malaria every 30 seconds” is often quoted in the introduction to scientific papers concerned with malariology, so much so
that its impact is somewhat reduced on those working in the field. The fact is that this is a sickening statement to make in the
21st Century. Malaria is completely curable today thanks to highly effective anti-malarial drugs. Yes, there are huge problems
of drug resistance in large areas of the world, but combination therapy with artemisinin has yet to be affected by this
problem. The simple fact is that any child that contracts malaria need not die if treated with effective drugs such as
Coartem® (artemisinin-derivative in combination with lumefantrine), and yet 2000 children are dying every day, because,
fundamentally, their parents simply cannot get access to a medicine that costs US$2 for an effective dose.
There can be no doubt that increases in the economic development of malarious countries will decrease the terrible death
rates presently associated with the disease. A case study conducted by Medecins Sans Frontieres involving 5 African
countries suffering huge malaria burdens (Burundi, Kenya, Rwanda, Tanzania and Uganda) estimated that for the 25.3 million
cases of malaria between all 5 countries to be treated with artemisinin combination therapy would cost an extra US$19.1
million per year (Kindermans et al., 2002). Extrapolating this estimate to include the whole of Africa (in which there
approximately 200-450 million cases of the disease annually), the figure rises to approximately US$300 million extra a year.
To put this figure into context, the combined yearly military expenditure of the 5 African countries listed above comes to
US$414.4 million (SIPRI, 2004).
If the prevalence of malaria is a not direct result of poverty, then the problem is certainly exacerbated by it, but what of the
effects of the disease on the prevalence of poverty? There can be little doubt that countries in which malaria is endemic bear
a great economic burden which can be directly attributed to the disease. Gallup and Sachs (2001) showed that countries that
suffered severe malaria in 1965 had “dramatically lower economic growth in the next 25 years” than malaria-free countries
(even after controlling for other factors such as geographic location, initial poverty, political economic policies, etc.). This
reduction in the economic viability of malarious countries can be attributed to a number of factors. There is the direct
personal economic cost borne by the people living in malarious areas who are forced to pay for preventative and curative
measures against the disease. There is also the proportion of government spending on programmes designed to control the
disease. Then there is the loss of revenue from foreign tourism and investment, which suffers due to reluctance on the part
of would-be tourists and investors to travel to countries with a serious malaria problem. When malaria was eradicated from
Portugal, Spain, and Greece in the mid 1950s, for example, there was huge economic development in these countries, which
can be directly attributed to large increases in tourism and foreign investment (Sachs et al., 2002) .
Less quantifiable, but certainly as important, is the reduction in economic growth associated with having a large proportion of
the population unable to work due to sickness. High morbidity reduces the effective productivity of the population directly, in
terms of the numbers of people unable to work, and indirectly, with the loss of earnings of the many people who have to look
after affected family members (Nur, 1993). The fact that malaria is mostly prevalent among children has huge implications
for education in the poorest regions of the world, sick children being unable to attend school. A study by Brooker et al.
(2000), attributed 13-50% of medically related school absences in Kenya to malaria (Brooker et al., 2000). Malaria has been
shown to have an adverse effect on the school performance of infected children in Sri Lanka (Fernando et al., 2003). There
is also evidence to suggest that people who suffer from the disease in infancy experience impairment of cognitive
development and learning capabilities (Holding and Snow, 2001). Related to this is the fact that mothers are particularly prone
to malaria as the association between pregnancy and lowered immune status leads to an increased risk of the development of
the disease. Malaria during pregnancy is directly associated with low birth-weights, which is also a risk factor for diminished
cognitive development (Mccormick et al., 1992).
Another malaria-related factor that affects economic development is that the disease limits the movement of people within
malarious areas. When people move away from a malarious area for prolonged periods, there is an associated loss of
immunity against the disease. This prevents those people who have gone to non-malarious areas to work or study returning to
the areas they left, and so contributes to the lack of skills and education in endemic areas. Similarly, as immunity to malaria is
known to be strain-specific, there is a risk involved in workers migrating from one endemic area to another, thus preventing
the movement of labour to regions where it is most productive (Sachs et al., 2002).
All these factors combine to present the depressing picture of a disease strongly associated with poverty, both as a cause and
as an effect. There can be little doubt that improving the economic development of the poorest countries will greatly aid the
fight against malaria, while, paradoxically, effectively reducing the disease burden will increase the economic development of
the countries affected.
References
White,N.J., Nosten,F., Looareesuwan,S., Watkins,W.M., Marsh,K., Snow,R.W., Kokwaro,G., Ouma,J., Hien,T.T., Molyneux,M.E., Taylor,T.E.,
Newbold,C.I., Ruebush,T.K., Danis,M., Greenwood,B.M., Anderson,R.M., and Olliaro,P. (1999). Averting a malaria disaster. Lancet, 353, 1965-
1967.
WHO. What is Malaria? http://www.rbm.who.int/cmc_upload/0/000/015/372/RBMInfosheet_1.htm . 2004.
Ref Type: Electronic Citation
Trigg,P.I. and Kondrachine,A.V. (1998). The current Global Malaria Situation. In Sherman,I.W. (Ed.), Malaria: Parasite biology, Pathenogenesis and
Protection., . ASM Press, Washngton D.C, pp. 11-22.
The Wellcome Trust. Malaria CDROM. 1998. The Trustee of the Wellcome Trust.
Ref Type: Audiovisual Material
WHO. World Health Organisation Factsheet 94. 1998.
Ref Type: Pamphlet
Gallup, J. L. and Sachs, J. D. The economic burden of malaria. American Journal of Tropical Medicine and Hygiene 64[1-2], 85-96. 2001.
Sachs,J. and Malaney,P. (2002). The economic and social burden of malaria. Nature, 415, 680-685.
Kindermans, J.-M., Pecoul, B., Perez-Casas, C., Den Boer, M., Berman, D., and Cox, I. Changing national malaria treatment protocols in Africa:
What is the cost and who will pay? http://www.accessmed-msf.org/ . 2002.
SIPRI. Information from the Stockholm International Peace Research Institute. http://www.sipri.org/ . 2004.
Nur,E. (1993). The impact of malaria on labour use and efficiency in the Sudan. Soc Sci Med., 37, 1115-1119.
Brooker,S., Guyatt,H., Omumbo,J., Shretta,R., Drake,L., and Ouma,J. (2000). Situation analysis of malaria in school-aged children in Kenya - What
can be done? Parasitology Today, 16, 183-186.
Fernando,S.D., Gunawardena,D.M., Bandara,M.R.S.S., De Silva,D., Carter,R., Mendis,K.N., and Wickremasinghe,A.R. (2003). The impact of
repeated malaria attacks on the school performance of children. American Journal of Tropical Medicine and Hygiene, 69, 582-588.
Holding,P.A. and Snow,R.W. (2001). Impact of Plasmodium falciparum malaria on performance and learning: Review of the evidence. American
Journal of Tropical Medicine and Hygiene, 64, 68-75.
Mccormick,M.C., Brooksgunn,J., Workmandaniels,K., Turner,J., and Peckham,G.J. (1992). The Health and Developmental Status of Very-Low-
Birth-Weight Children at School Age. Jama-Journal of the American Medical Association, 267, 2204-2208.
