Chapter 002. Global Issues in Medicine (Part 7)

MalariaWe turn now to the worlds third largest infectious killer, which has taken its greatest toll among children, especially African children, living in poverty.The Cost of Malaria Malarias human toll is enormous. An estimated 250 million people suffer from malarial disease each year, and the disease annually kills between 1 million and 2.5 million people, mostly pregnant women and children under the age of 5. The poor disproportionately suffer the consequences of malaria: 58% of malaria deaths occur in the poorest 20% of the worlds population, and 90% are registered in sub-Saharan Africa. The differential magnitude of this mortality...
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Chapter 002. Global Issues in Medicine (Part 7) Chapter 002. Global Issues in Medicine (Part 7) Malaria We turn now to the worlds third largest infectious killer, which has takenits greatest toll among children, especially African children, living in poverty. The Cost of Malaria Malarias human toll is enormous. An estimated 250 million people sufferfrom malarial disease each year, and the disease annually kills between 1 millionand 2.5 million people, mostly pregnant women and children under the age of 5.The poor disproportionately suffer the consequences of malaria: 58% of malariadeaths occur in the poorest 20% of the worlds population, and 90% are registeredin sub-Saharan Africa. The differential magnitude of this mortality burden isgreater than that associated with any other disease. Likewise, the morbiditydifferential is greater for malaria than for diseases caused by other pathogens, asdocumented in a study from Zambia that revealed a 40% greater prevalence ofparasitemia among children under 5 in the poorest quintile than in the richest. Despite suffering the greatest consequences of malaria, the poor areprecisely those least able to access effective prevention and treatment tools.Economists describe the complex interactions between malaria and poverty froman opposite but complementary perspective: they delineate ways in which malariaarrests economic development both for individuals and for whole nations.Microeconomic analyses focusing on direct and indirect costs estimate thatmalaria may consume up to 10% of a households annual income. A Ghanaianstudy that categorized the population by income group highlighted the regressivenature of this cost: the burden of malaria represents only 1% of a wealthy familysincome but 34% of a poor households income. At the national level, macroeconomic analyses estimate that malaria mayreduce the per capita gross national product of a disease-endemic country by 50%relative to that of a nonmalarial country. The causes of this drag include highfertility rates, impaired cognitive development of children, decreased schooling,decreased saving, decreased foreign investment, and restriction of workermobility. Given this enormous cost, it is little wonder that an important review bythe economists Sachs and Malaney concludes that where malaria prospers most,human societies have prospered least. Rolling Back Malaria In part because of differences in vector distribution and climate, resource-rich countries offer few blueprints for malaria control and treatment that areapplicable in tropical (and resource-poor) settings. In 2001, African heads of state endorsed the WHO Roll Back Malaria(RBM) campaign, which prescribes strategies appropriate for sub-Saharan Africancountries. RBM recommends a three-pronged strategy to reduce malaria-relatedmorbidity and mortality: the use of insecticide-treated bed nets (ITNs),combination antimalarial therapy, and indoor residual spraying. ITNs are an efficacious and cost-effective public health intervention. Ameta-analysis of controlled trials indicates that malaria incidence is reduced by50% among persons who sleep under ITNs compared with that among those whodo not use nets at all. Even untreated nets reduce malaria incidence by one-quarter. On anindividual level, the utility of ITNs extends beyond protection from malaria.Several studies suggest that all-cause mortality is reduced among children under 5to a greater degree than can be attributed to the reduction in malarial disease alone. Morbidity (specifically that due to anemia) predisposing children todiarrheal and respiratory illnesses and pregnant women to the delivery of low-birth-weight infants is also reduced in populations using ITNs. In some areas, ITNs offer a supplemental benefit by preventingtransmission of lymphatic filariasis, cutaneous leishmaniasis, Chagas disease, andtick-borne relapsing fever. At the community level, investigators suggest that the use of an ITN in justone household may reduce the number of mosquito bites in households up toseveral hundred meters away. The cost of ITNs per DALY saved is estimated at $10–$38 (U.S.), whichqualifies ITNs as a very efficient use of resources and [a] good candidate forpublic subsidy.1 Some RBM programs have had limited success, but overall the burden ofmalarial disease has continued to grow. In fact, annual malaria-attributablemortality increased between 1999 and 2003. While the RBM campaigns own report from that year is quick to note thatmorbidity and mortality data-collection methods in sub-Saharan Africa areinadequate and indicators may thus lag behind actual outcomes of ongoing ...