Chapter 002. Global Issues in Medicine (Part 9)

Chronic Noncommunicable DiseasesWhile the burden of communicable diseases—especially HIV infection, tuberculosis, and malaria—still accounts for the majority of deaths in resourcepoor regions such as sub-Saharan Africa, close to 60% of all deaths worldwide in 2005 were due to chronic noncommunicable diseases (NCDs). Moreover, 80% of deaths attributable to NCDs occurred in low- and middle-income countries, where 85% of the global population lives. In 2005, 8.5 million people in the world died of an NCD before their 60th birthday—a figure exceeding the total number of deaths due to AIDS, TB, and malaria combined. By 2020, NCDs will account for 80%...
Nội dung trích xuất từ tài liệu:
Chapter 002. Global Issues in Medicine (Part 9) Chapter 002. Global Issues in Medicine (Part 9) Chronic Noncommunicable Diseases While the burden of communicable diseases—especially HIV infection,tuberculosis, and malaria—still accounts for the majority of deaths in resource-poor regions such as sub-Saharan Africa, close to 60% of all deaths worldwide in2005 were due to chronic noncommunicable diseases (NCDs). Moreover, 80% ofdeaths attributable to NCDs occurred in low- and middle-income countries, where85% of the global population lives. In 2005, 8.5 million people in the world diedof an NCD before their 60th birthday—a figure exceeding the total number ofdeaths due to AIDS, TB, and malaria combined. By 2020, NCDs will account for80% of the GBD and for 7 of every 10 deaths in developing countries. The recentrise in resources for and attention to communicable diseases is both welcome andlong overdue, but developing countries are already carrying a double burden ofcommunicable and noncommunicable diseases. Cardiovascular Disease Unlike TB, HIV infection, and malaria—diseases caused by singlepathogens that damage multiple organs—cardiovascular diseases reflect injury to asingle organ system downstream of a variety of insults. The burden of chroniccardiovascular disease in low-income countries represents one consequence ofdecades of health system neglect; furthermore, cardiovascular research andinvestment have long focused on the ischemic conditions that are increasinglycommon in high- and middle-income countries. Meanwhile, despite awareness ofits health impact during the early twentieth century, cardiovascular damage inresponse to infection and malnutrition has fallen out of view until recently. The perception of cardiovascular diseases as a problem of elderlypopulations in middle- and high-income countries has contributed to their neglectby global health institutions. Even in Eastern Europe and Central Asia, where thecollapse of the Soviet Union was followed by a catastrophic surge incardiovascular disease deaths (mortality rates from ischemic heart disease nearlydoubled between 1991 and 1994 in Russia, for example), the modest flows ofoverseas development assistance to the health sector focused on the communicablecauses that accounted for tobacco use, improve diet, and increase exercise alongside the prescription ofmultidrug regimens for persons with high levels of vascular risk. Although thisagenda could do much to prevent pandemic NCD, it will do little to help thosewith established heart disease stemming from non-atherogenic pathologies. The epidemiology of heart failure reflects inequalities in risk factorprevalence and treatment. Heart failure as a consequence of pericardial,myocardial, endocardial, or valvular injury accounts for as many as 1 in 10admissions to hospitals around the world. Countries have reported a remarkablysimilar burden of this condition at the health system level since the 1950s, but thecauses of heart failure and the age of the people affected vary with resources andecology. In populations with a high human-development index, coronary arterydisease and hypertension among the elderly account for most cases of heartfailure. Among the worlds poorest billion people, however, heart failure reflectspoverty-driven exposure of children and young adults to rheumatogenic strains ofstreptococci and cardiotropic microorganisms (e.g., HIV, Trypanosoma cruzi,enteroviruses, M. tuberculosis ), untreated high blood pressure, and nutrientdeficiencies. The mechanisms of other causes of heart failure common in thesepopulations—such as idiopathic dilated cardiomyopathy, peripartumcardiomyopathy, and endomyocardial fibrosis—remain unclear. Of the 2.3 million annual cases of pediatric rheumatic heart disease, nearlyhalf occur in sub-Saharan Africa. This disease leads to more than 33,000 cases ofendocarditis, 252,000 strokes, and 680,000 deaths per year—almost all indeveloping countries. Researchers in Ethiopia have reported annual death rates ashigh as 12.5% in rural areas. In part because the prevention of rheumatic heartdisease has not advanced since the disappearance of this disease in wealthycountries, no part of sub-Saharan Africa has yet eradicated rheumatic heart diseasedespite examples of success in Costa Rica, Cuba, and some Caribbean nations. Strategies to eliminate rheumatic heart disease may depend on active case-finding confirmed by echocardiography among high-risk groups as well as effortsto extend access to surgical interventions among children with advanced valvulardamage. Partnerships between established surgical programs and areas withlimited or nonexistent facilities may help develop capacity and provide car ...