Cardiovascular Diseases. The spectrum of cardiovascular diseases due to endemic causes in Africa represents another "neglected" set of conditions, according to Dr. Ana Mocumbi, a cardiologist and researcher at the Maputo Heart Institute in Mozambique.
Although Africa is seeing a rise in lifestyle-associated atherosclerosis and other conditions common in the developed world, there are also large numbers of people suffering from chronic heart conditions with infectious origins, including rheumatic heart disease arising from streptococcal infection, endomyocardial fibrosis, and tuberculous pericarditis.
Together, these conditions "can be considered neglected diseases because, despite considerable numbers of people, they have not been the subject of systematic research or structured control programs and did not benefit from translation of knowledge obtained in other areas of human knowledge," Dr. Mocumbi said.
Dr. Mocumbi was an investigator for a survey using clinical and echocardiographic screening in 2,370 children aged 6-17 years who were randomly selected from six primary schools in Mozambique. The prevalence of rheumatic heart disease was about 30 per 1,000, a rate far higher than had been previously found in studies that only used echocardiography for cases suspected from clinical screening (New Engl. J. Med. 2007;357:470-6).
Another echocardiographic screening study for which Dr. Mocumbi was the lead investigator assessed a random sample of 1,063 individuals of all ages selected by clustering in a rural area of Mozambique with about 76,000 inhabitants, and found an endomyocardial fibrosis prevalence of 20%. The highest prevalence, 28%, was among children and adolescents aged 10-19 years (New Engl. J. Med. 2008;359:43-9).
That was the only epidemiologic study ever done on endomyocardial fibrosis, a restrictive cardiomyopathy that primarily affects children from sub-Saharan Africa. Its exact etiology and pathogenesis are unknown, although autoimmunity and infectious triggers are believed to play a role. Endomyocardial fibrosis "places a high burden on a community, where children and young adults are disabled," Dr. Mocumbi commented.
Chronic Respiratory Disease. Chronic respiratory disease is another NCD area for which the picture is different among the bottom billion. While smoking is by far the most common cause of chronic obstructive pulmonary disease (COPD) in developed countries, emerging evidence suggests that other environmental factors may play a greater role in poor countries, where an estimated 25%-45% of COPD patients have never smoked, said Dr. Sundeep Salvi, director of the Chest Research Foundation, Pune, India.
About 3 billion people, half the world’s population, are exposed to smoke from biomass fuel, compared with 1.01 billion people who smoke tobacco, suggesting that exposure to biomass smoke might be the biggest risk factor for COPD globally, Dr. Salvi said (Lancet 2009;374:733-43).
A recently published meta-analysis of 25 studies identified significant associations between exposure to solid biomass fuels such as wood, dung, and charcoal and acute respiratory infection in children (pooled odds ratio 3.53), chronic bronchitis in women (OR 2.52), and chronic pulmonary disease in women (OR 2.40). No associations were seen with asthma (Thorax 2011;66:232-9).
Other NCDs include sickle cell anemia, diabetes (including that associated with malnutrition rather than obesity), mental illness, diseases requiring surgery, cervical cancer, epilepsy, and anemia, which is often a result of infectious diseases such as malaria and bacteremia in the developing world rather than iron deficiency.
A ‘Diagonal’ Approach. Experts at the meeting agreed that integrated approaches are necessary to address endemic NCDs, most of which are relatively uncommon individually, but together account for a large burden of disease among the bottom billion.
Dr. Julio Frenk
Dr. Julio Frenk, dean of Harvard’s School of Public Health, advocated in favor of taking a so-called "diagonal approach" as an alternative to the narrow, disease-specific "vertical approach" to care as has been used to address HIV/AIDS, malaria, and tuberculosis. A diagonal approach is also preferred, he said, to taking a broad, and often ineffectual, "horizontal" approach that generally aims at strengthening health systems.
"Global health in the 21st century should integrate vertical and horizontal programs, because we now know that, through what [Dr.] Jaime Sepulveda has called the ‘diagonal approach,’ we can use explicit intervention priorities to strengthen the overall structure and function of health systems," Dr. Frenk said.
Such an approach is now being used by Partners In Health in Rwanda, an effort that began in 2005 with the Rwandan government’s request for support for rural health services. Also financed in part by the Clinton Foundation, the project provides building and renovations, supplementation of operational budgets, and staff training to three rural districts serving more than 750,000 in 2010.
The approach to chronic care in these regions follows a model similar to the way health systems were progressively decentralized to address HIV/AIDS in the 1990s: from tertiary referral centers to district hospitals, to local health centers, to community health workers. Under the model, primary care – typically delivered by nonphysician health care providers or trained laypeople – takes place at the community level, while increasingly specialized care takes place up the hierarchy of facilities, Dr. Bukhman explained.