Noncommunicable Disease Looks Different in "Bottom Billion"

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.

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, 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.

District hospital leaders work closely with the staff of health centers, providing training, mentoring, and education, with the idea of reducing the need to transfer patients to referral centers. Each Partners In Health–supported district hospital in Rwanda has an advanced chronic care clinic for noninfectious diseases. Countries such as Rwanda that already have such integrated programs to address HIV/AIDS can more easily and less expensively integrate NCDs into their health systems, Dr. Bukhman noted.

Dr. Farmer, chair of the department of global health and social medicine at Harvard, stressed the need for "health systems strengthening" and for partnerships between governments, academia, nongovernmental organizations, private industry, and other stakeholders in order to tackle the complexity and heterogeneity of the endemic NCDs.