SciDev.Net

This series of commentaries and research articles — published by The Lancet, the Peking University Health Sciences Centre and the China Medical Board — addresses China's major health challenges, strategies and future. It has been produced by a group of 63 scientists from 10 countries with Chinese scientists making up two-thirds of the authors.

The research papers give scientific evidence on key health issues including the emergence and control of both infectious and chronic non-infectious diseases in China as well as the performance of China's healthcare system.

Authors of the series' commentaries further discuss a range of topical issues affecting China's health system, including the state of biomedical science and technology (see 'Progress in Chinese biomedicine a massive challenge'), medical research ethics, the lessons learnt from China's schistosomiasis control programme and the challenges the country faces in controlling HIV/AIDS.

This series of five articles outlines new challenges and unsolved problems since the journal's last series in 2005. The first article ([189kB]) predicts the disease burden and economic losses that developing countries would face from chronic diseases such as cardiovascular disease, cancer, chronic respiratory disease, and diabetes. In the 23 countries that the authors incorporated into a model, chronic disease was responsible for 50% of the disease burden in 2005. If no action is taken, they say, about US$84 billion of economic production will be lost from heart disease, stroke, and diabetes alone in these 23 countries between 2006 and 2015. The second article ([105kB]) looks at how to scale-up strategies to fight chronic diseases in developing countries. The authors review evidence to identify which methods are cost-effective and financially feasible, and therefore ready to be scaled-up.

Tobacco control, salt reduction (both of which are detailed in the series' third paper ([177kB])), and a multidrug strategy to treat individuals with high-risk cardiovascular disease (see an in-depth look in paper four ([220kB])) are prime candidates for scaling-up. What effect improving health systems has on the level of chronic diseases should be properly evaluated, say the authors. For some health interventions, such as preventing or controlling diabetes, there is little cost-effectiveness data for low or middle-income countries, but their scientific effectiveness is so compelling that countries should consider how best to incorporate them. The final paper ([92kB]) is a call to action to incorporate existing interventions into healthcare programmes, which in 2005 was costed at US$5.8 billion.

1990 saw the first major effort to estimate the main causes of illness and the biggest killer diseases in different countries. The data are important for public-health officials to allocate their resources wisely but also for feeding into estimates to plan for the future. Importantly, these need to be regularly updated to ensure that health programmes are still going in the right direction. This paper updates the 1990 study and offer predictions up to 2030.

The most forceful change in disease trends is in developing countries, with the proportion of people affected by non-communicable diseases set to increase. Proportionally, the number of people with infectious diseases is set to fall, though not when it comes to HIV/AIDS.

Because the authors also rely on predicting socio-economic development trends, they created best-case and worst-case scenarios for economic growth. In the pessimistic scenario, by 2030, the three leading causes of illness will be HIV/AIDS, depression, and ischaemic heart disease; in the optimistic scenario, road-traffic accidents will replace heart disease as the third leading cause.

The WHO has provided its own estimates of how non-communicable diseases are set to rise in developing countries. These authors pool data from national registries and international databases to compare data on the differing burden from individual diseases. They outline the risk factors associated with the diseases.

The main three killers are cardiovascular disease, diabetes, and cancer. The paper ranks different types of cancer by how many people in developing countries they kill (lung and breast cancer are the deadliest) and also ranks diabetes prevalence by country (India, followed by China, has the highest prevalence).

To tackle these diseases, say the authors, people need to look closely at the risk factors in their life – eating healthily and exercising can do much to reduce the chances of getting one of these diseases.

Cardiovascular diseases are set to rise dramatically in developing countries, partly because of an increase in risk factors for the diseases, which include diet, physical activity, smoking. The authors looked at cardiovascular disease risks such as being overweight or obese, systolic blood pressure, and total cholesterol, and related them to national income, food purchase constraints, and urbanisation. Body mass index (BMI) and cholesterol increased as national income increased, then flattened, and eventually declined. BMI also rose with increasing urbanisation.

The authors suggest that cardiovascular disease risks will increasingly be concentrated in low-income and middle-income countries. Thus, preventing obesity should be considered a priority in these countries, along with measures to control blood pressure, cholesterol, and tobacco use.

This document presents the proceedings of a conference at the Royal Netherlands Academy of Arts and Sciences in December 2001. The conference papers deal with themes relating to the role of scientific research in the development of Northern countries and the need for North–South research cooperation. They document the experiences of research cooperation involving, among others, India, South Africa and a number of East African countries. Several papers deal with innovation and scientific cooperation, with case studies.

Bt cotton, developed to resist bollworm attack, can have significant economic and environmental benefits, according to a three-year study of hundreds of Chinese smallholder farmers. The study, carried out by collaborators from China and the USA, also revealed that growing Bt cotton can have a positive impact on human health. The main benefits to farmers from using Bt varieties were increased crop yield and reductions in the amount of pesticide used. As well as lower input costs, growers reported fewer pesticide-related illnesses associated with growing Bt cotton, as compared with the non-Bt varieties.

While the authors describe greater chemical use in some areas of China growing Bt cotton, they found no evidence of an associated increase in pesticide resistance within the bollworm population. They believe that the transient increase in pesticide use was due either to changes in pest pressure, or the fact that some farmers were sowing seed saved from the previous year. This could have reduced the effectiveness of the resistant crop variety. Economic theory has correctly predicted that increased supply would result in lower market prices for cotton growers. The authors conclude, however, that current prices still offer considerable economic gains for farmers growing the Bt varieties.