SciDev.Net

This report from the WHO assesses the potential for creating early warning systems for vector-borne disease. It reviews the current state of research for several diseases such as dengue fever, leishmaniasis, malaria and West Nile virus.

The report includes an algorithmic framework for developing early warning systems, outlining data requirements and the different components of the system. It also contains two useful tables: one on the sensitivity of different infectious diseases to climate; and one summarising the existing research, identifying in which region the disease is most common, data availability and proposed actions.

A key problem in developing early warning systems, as highlighted by this report, is that non-climatic risk factors such as population immunity and food security strongly affect the potential for a disease outbreak. Equally challenging is the poor disease surveillance in many developing countries — the authors call on these countries to strengthen these systems, to help in the fight against climate change.

The report concludes that it will be important for researchers not to design these systems in isolation — health policymakers should be included at all stages of the design.

This extensive report from the Institute of Medicine of the US National Academies takes on the considerable challenge of understanding how, and to what extent, climate change will affect infectious diseases.

The report provides detailed summaries of current knowledge on diseases such as cholera and rift valley fever. Several pages are devoted to reviewing the latest climate science to contextualise the effect on infectious disease; it also includes several maps on climate anomalies to show how they are linked to disease.

One section highlights methods to assess climate change impacts on infectious diseases. These include analyses of historical records; monitoring programs, especially those that track disease in wild animals; and comparisons of satellite-derived environmental measurements with epidemiological data.

The report concludes with an analysis of the challenges facing policymakers. In many cases, it says, the best public health measures against climate change are those that strengthen health systems in general, such as better training for professionals and better disease surveillance. Policymakers will need to move away from the traditional thinking of individual policies for individual diseases, towards a joined-up approach aimed at tackling "systemic, long-term" stresses that cause a range of effects.

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.

Vaccination for infectious diseases is a vital method of prophylaxis, and has transformed modern medicine. By contrast, research into vaccines against chronic diseases has been less successful, in part because of the increased complexity involved.

In this opinion piece, the authors outline the prospects for the development of chronic disease vaccines. These might not need to rely on the traditional method of inducing the body to produce antibodies, but rather on introducing monoclonal antibodies against specific proteins — this has so far worked well against Crohn's disease and rheumatoid arthritis.

The authors outline key hurdles in developing a successful therapeutic vaccine. Safety and efficacy are two obvious ones, but there is a third that is unique to vaccines for chronic diseases. Because these vaccines would block bodily chemicals — such as cytokines or hormones — it would not be acceptable for a vaccine to induce a life-long block (unlike a malaria vaccine, for example, where a lifelong block would be ideal).

These might be particularly useful in developing countries, say the authors. Because prophylaxis with vaccines is already a familiar concept, there should be no problem with patients' compliance, and judicious partnerships between public and private organisations could mean the vaccines are produced cheaply.

Schizophrenia is relatively rare — affecting 1% of the world's population — but is arguably one of the most severe mental illnesses. Diagnosing and treating it can be hard enough in developed countries; the challenges are magnified in developing nations with inadequate health systems; few trained staff; and pervasive social stigma. So how best to treat it? In this debate, three psychiatrists offer their different viewpoints.

Vikram Patel, at the London School of Hygiene and Tropical Medicine, says the shortage of mental health specialists means that the most effective way of spreading the expertise around might be for non-specialist health workers or community representatives to be trained to bear the brunt of providing first-line mental health services. Saeed Farooq, at Pakistan's Lady Reading Hospital, argues that the principles of the WHO's DOTS TB programme, in which patients are given an uninterrupted supply of medication taken under close supervision, could be used to treat schizophrenia. The rationale is that missing medication for schizophrenia, which can be common given the cognitive impairment associated with the illness, has serious consequences and can lead to much higher risks of relapse. R. Thara, director of the Schizophrenia Research Foundation, Chennai, India, advocates tackling stigma by offering proper treatment. In India at least, he says, the mystification of mental illness is intensified by a lack of awareness about schizophrenia and also by "magico-religious" beliefs. Effective treatment that shows the symptoms to be an illness rather than a religious curse is the best antidote to stigma, he says.

In 2005, the World Health Assembly called on WHO member states to tackle their growing rates of cancer by developing rigorous cancer control programmes. To help guide the process, the WHO developed a series of six modules that provide practical advice for programme managers and policy-makers on how to advocate, plan and implement effective cancer control programmes, particularly in developing countries.

Individual modules focus on planning; prevention; early detection; diagnosis and treatment; palliative care; and policy and advocacy. As of May 2008, all but the one on policy and advocacy have been published.

Worldwide, cancer kills more people than HIV/AIDS, malaria and TB put together. In developing countries where chronic diseases are now growing alongside infectious diseases, new strategies need to be developed.

This article outlines how to develop an effective cancer strategy in African countries on the basis of discussions at the recent African Cancer Reform convention. A cancer control plan clearly needs to take into account African countries' financial constraints and the authors outline six key essentials that would offer most health gain for money invested. These are: setting up cancer intelligence units to collect data on cancer incidence; controlling tobacco use; early diagnosis and prevention; offering treatment wherever possible; palliative care when treatment is no longer useful; and training and educating future generations of African oncologists.

Developed countries can offer crucial expertise and experience and collaborate on cancer information networks. Educating local communities about a disease that is relatively new but growing quickly will also be essential to stop it spiralling when many cancers are preventable or treatable when detected early enough.

This joint publication between the World Health Organization and the Global Forum for Health Research reveals mental health research capacity in 114 low-income and middle-income countries in Africa, Asia, and Latin America and the Caribbean. The extensive review identified over 10,000 articles, 4,633 mental health researchers and 3,829 other stakeholders. The authors argue that this is "the first systematic attempt to confirm the pressing needs of improving research capacity in mental health".

The publication provides useful details in table and charts, analysed by group of stakeholders and by region, on topics such as: researchers' profiles; priority-setting process; amount and type of research production; services and technical support available to them; courses and trainings offered; funding patterns; and dissemination of research findings. The appendix provides two extensive lists — by country — of policy and practice that resulted from research evidence, as well as research evidence that was never translated into policy and practice.

Nine recommendations indicate how the management of mental health research can be strengthened so that it meets the national needs of the countries as well as contributes to the global fund of knowledge. The authors say their report thus enables evidence-based decision-making in funding and priority setting in the area of mental health research in low-income and middle-income countries.

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.

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 extensive report was one of the first to document the scale of the problem of chronic diseases in developing countries, and crucially, to offer guidance on feasible and practical methods of tackling them.

The document starts by laying out in detail the profiles of chronic diseases in different countries, projections for the future, and how chronic diseases are linked with poverty. It also examines in depth the economic costs of such diseases and the macroeconomic consequences of not tackling them quickly enough. The authors outline interventions — whether community, workplace, or school — that have robust evidence supporting them.

The report ends with a call for a unifying framework of global health experts and stakeholders, in which the government has a key role. It also specifies what policymakers need to do to ensure that measures to tackle chronic diseases are put into action.