Climate change provokes heated debate. Opinion polls repeatedly show that many people doubt that the world’s climate is changing and, of those who accept reality, many do not believe that the changes are man-made. The lack of public support for efforts to address climate change seems likely to hinder the progress of these efforts. As discussed in a TropIKA.net editorial, governments have focused on the impact of climate change on economies and not on the threat it poses to the health and wellbeing of individuals. Perhaps this is one reason why the public at large has yet to grasp the seriousness of the situation.

There are of course many ways in which climate change threatens human health, including injury from extreme climatic events such as flooding, and food shortages caused by droughts. Many infectious diseases are also likely to become more widespread. Poor communities face the greatest threats and are least well placed to respond. Health inequalities are in consequence likely to widen.

The 15th UN Climate Change Conference (COP15) is now under way in Copenhagen, 7-18th December. So far, since the conference began, very little time appears to have been devoted to the infectious diseases of poverty, although some delegates have made reference to their concerns regarding the likely increase in certain infections including malaria, dengue, pneumonia and diarrhoeal disease.

The health community itself has come late to the climate change debate, seemingly content until now to leave it to climatologists and politicians but, in the run-up to the conference, the Lancet has performed a considerable service in highlighting the health dimension in a series of articles that deserves detailed scrutiny.

In the first week of COP15, other medical journals are also publishing editorials on the subject but, thus far, we have not seen the publication of new data timed to coincide with the beginning of the conference. Data, however, are needed to inform the debate and to determine the action that the world must now take to address climate change.

There is indeed so much that we do not yet know. As Tony McMichael of Australia’s National Centre for Epidemiology & Population Health points out in a TropIKA.net interview, how people will respond to climate change is more difficult to predict than climate change itself. Professor McMichael’s view is that far the biggest infectious disease risk from climate change is diarrhoeal disease. Others, however, have been more inclined to highlight the threats posed by vector-borne diseases particularly malaria, dengue and Chikungunya.

These are not the only diseases that could become more common in a warmer world. Schistosomiasis seems to be expanding its range in many countries. In a TropIKA.net interview Dr Justin Remais of Emory University, USA discusses his use of a mathematical model to quantify environmental impacts on transmission intensity.

But will there, for example, be any effect on tuberculosis as a result of climate change? We don’t know. We should not jump to too many conclusions or try to blame everything on climate change. It has been commonplace, for example, to blame the serious outbreaks of dengue now occurring in many countries on global warming, but this ignores the role of increasing urbanisation and the growth of populations in poor urban environments where vector control activities are inadequate.

We need to be better informed and research will be crucial in determining the effectiveness of efforts to adapt to a changing climate. As Andrew Githeko points out in a guest blog on TropIKA.net, the organisms responsible for the transmission of infectious disease have demonstrated their ability to adapt. We must now do the same.

See the TropIKA.net Copenhagen blog for other climate change developments that relate to the infectious diseases of poverty.

Paul Chinnock
Editor, TropIKA.net

In the English-speaking parts of the northern hemisphere, the time of the year around August when many of the working population are on holiday is known to the media as “the silly season”. There is a lack of hard news to report and much of what gets published is of a trivial nature.

Infectious diseases do not, however, take a holiday. The world’s poorest countries continue to suffer from the ravages of many infections. As we have reported on TropIKA.net, in Zimbabwe one of the worst cholera epidemics of recent years appears to be over but several other African countries, including Ethiopia and Kenya, are still coping with epidemic cholera. Zimbabwe itself may face a return of the disease in the forthcoming rainy season.

Dengue fever continues to wreak havoc in many parts of the tropics; a report from an expert group in the Philippines concludes that many cases are treated inappropriately. The impact that swine flu will have in developing countries is not yet clear.

TropIKA.net News has reported over the last few weeks on a number of initiatives to tackle the infectious diseases of poverty. Diagnosis is generally a neglected area, receiving less attention than prevention and treatment. However, the Stop TB Partnership’s New Diagnostics Working Group has launched new web resource called Evidence-based Tuberculosis Diagnosis. Also several African nations are drawing up plans to revamp their laboratories to qualify for World Health Organization laboratory accreditation under a new scheme designed specifically for developing countries.

There has been formal publication of data confirming the emergence of resistance to artemisinin - the drug that is the now the recommended treatment for malaria. A major international effort is already under way to combat this new public health crisis. The use of insecticide-treated bednets is another cornerstone of malaria control programmes and massive net distribution programmes now exist in many countries, but a recent study shows that many of the nets distributed are not used by the families who receive them.

More encouraging news includes advances in the understanding of how the parasite responsible for leishmaniasis manages to evade the human immune system so successfully. Leishmaniasis receives woefully inadequate attention and progress of this kind is to be welcomed. We also report that a new Chinese drug could be used to kill parasitic intestinal worms in regions where parasites are developing resistance to the widely used deworming drug albendazole. And efforts to develop a new tuberculosis vaccine will be stepped up thanks to new funding.

TropIKA.net’s Funding section includes details of opportunities that have come to our attention. Silly season or not, several new grants have become available in the last few weeks.

Our remit at TropIKA.net is the infectious diseases of poverty and we cover a wide range of medical conditions and associated issues. However, during the last few days, one disease – malaria – has been the dominant theme of our new content. We marked World Malaria Day 2009 with an interview with Professor Kilama of the African Malaria Network Trust and a News story summing up what happened in the build-up to the Day and the response to it. Many glitzy, glamorous events were held to mark the Day but my editorial focussed on the front line of care, where “Every day is Malaria Day”. There were also numerous new items on malaria within the TropIKA.net blog.

But, since the announcement by WHO on 24th April of a major outbreak of influenza caused by the A/H1N1 virus, the world’s most talked about infectious disease has been swine flu. The TropIKA.net update on swine flu highlights the fact that the epidemic started in a poor community and that, while rich and poor are now at risk, people in the developing world are less likely to receive appropriate diagnosis and treatment.

World Malaria Day and swine flu notwithstanding, we have also reported some important new developments in the fight against trachoma , tuberculosis and dengue fever.

Other recent topics have included human rights , patent pools for drugs for neglected infections and the encouraging rise in the number of publications where the first-named author is from sub-Saharan Africa.

TropIKA.net is an interactive project. Our articles and blogs include the facility to leave comments. Please feel free to share your views or add information that we may have missed.

Paul Chinnock
Editor-in-Chief, TropIKA.net

What impact will the global economic decline have on the lives of the poor? Will it reduce the already inadequate funding for research and control programmes devoted to the infectious diseases of poverty?

Kofi Annan fears that it may indeed be the poor who suffer most and he calls for a “coordinated global stimulus” which will benefit the least developed countries. But there is simply less money around just now. No one can avoid the effects of the financial crisis – sadly not even the Gates Foundation, which plays such a crucial role in global efforts to eliminate infectious disease.

Infectious diseases add of course to the economic burdens faced by developing nations. Nevertheless, it is hard to quantify their impact. TropIKA.net has recently published a summary of preliminary calculations made by the Indian Institute of Management, Ahmedabad seeking to calculate the economic cost of dengue fever. This comes at a time when there are indications that, in Asia, dengue may be more common than shown in official figures.

The prevalence and incidence of many other diseases may also be under-estimated. A recent survey suggests that India’s progress towards the elimination of leprosy may be less impressive than has been claimed. It is good to know therefore that a useful dialogue on issues related to leprosy still continues. Playing a part in this is the Leprosy Mailing List, one of the mailing lists featured in our Networking section.

It is not disputed that rates of tuberculosis are high in China but the consequences may be even more serious than recognised. A new study provides evidence that the infection increases the risk of lung cancer.

My selection of new content on TropIKA.net does seem to have focused on the bad news this time around, so let me finish with a positive research finding – chloroquine, once the mainstay of malaria treatment, has been found to be active against two emerging threats to health, the Nipah and Hendra viruses. This is a drug which should not be consigned to history. At a time like this we need some old friends around us!

Paul Chinnock
Editor-in-Chief, TropIKA.net