World Malaria Day (25th April) was extensively featured on TropIKA.net (1, 2, 3). The Lancet also chose to publish several articles on the subject in its 25th April edition:

-Speaking in an interview researcher Bob Snow expresses his frustration with the slowness to put into practice research that has been shown to work. He says it is not yet appropriate to talk in terms of eradication: “Across sub-Saharan Africa, we are massively way behind the goals we set as important milestones 10 years ago in the Abuja Declaration. And it seems crazy to me that if we haven’t done the job we set out to do, we would then change the bar to one of elimination”.
-Richard Feachem and Allison Phillips of UCSF Global Health Sciences say there are many reasons to be optimistic that a malaria-free world will be achievable by the mid-21st century
-Vasee Moorthya, Peter Smith and Marie-Paule Kieny discuss the findings of two trials (published last year) on the use of the RTS,S malaria vaccine.
-An editorial says that the Affordable Medicines Facility for Malaria may have been launched prematurerly: “Although this ambitious scheme is a welcome addition to the fight against malaria, the AMFm could also create additional problems by unintentionally increasing the risk of resistance to artemisinin by failing to endorse fixed-dose combinations of ACTs.”

“The Economics of Climate Change in Southeast Asia: A Regional Review” is a major new report from the Asian Development Bank. It is based on the results of a 15-month study, funded by the UK, which examined climate change issues in Southeast Asia, with a particular focus on Indonesia, Philippines, Singapore, Thailand, and Vietnam. The report says that:

“The study observed that climate change is already affecting Southeast Asia, with rising temperature, decreasing rainfall, rising sea levels, increasing frequency and intensity of extreme weather events leading to massive flooding, landslides and drought causing extensive damage to property, assets, and human life. Climate change is also exacerbating the problem of water stress, affecting agriculture production, causing
orest fires, degrading forests, damaging coastal marine resources, and increasing outbreaks of infectious diseases.”

Health

In the report’s section on human health, the startling rise in the incidence of dengue in the region, with many previously unaffected areas now reporting cases, is regarded as being of particular concern. Further increases in temperature could lead to a worsening of the position for other vector-borne infections such as malaria.

Diarrhoeal disease, including cholera, is also considered likely to increase. The report concludes that: “An increase in morbidity and mortality is predicted to occur in most Southeast Asian countries due to water-borne diseases, primarily associated with floods and droughts.” Other likely impacts on human health range from malnutrition to thermal stress.

Despite these concerns and the potential economic impact resulting from the damage to health, agriculture and natural resources, the Asian Development Bank considers there is a positive side. Bank Vice-President Ursula Schaefer-Preuss says:

“The global economic crisis provides an opportunity for the world, and Southeast Asia, to start the transition toward a climate-resilient and low-carbon economy.”

How are climate change and infectious disease incidence related and is global warming leading to increased rates of certain infections? The question is often asked but reliable data on the issue are in short supply. A new study [1] based on research, carried out in Lusaka (Zambia) between 2003 and 2006, analyses data from three cholera epidemics which occurred in a consecutive fashion. The results appear to show that climatic variables (rainfall and environmental temperature) are associated with the number of cholera cases.

There is a known to be a seasonal element to cholera in Zambia, which is associated with the rainy season. In the study - led by researchers from the Madrid Carlos III Institute of Health, Madrid - environmental temperatures were recorded six weeks before the beginning of the rains. The authors claim to have showed that a 1º C increase in temperature six weeks before the beginning of an outbreak is associated with a 5.2% increase in cholera cases. Looking at rainfall, they found that, if a 50 millimetre rise in precipitation three weeks later is added to this increase it is associated with a 2.5% increase in risk.

The authors say that with further research it could be possible to predict the likely severity of outbreaks, which would be of assistance in epidemic preparedness. (A summary of the study is available on Science Daily.)

Reference
1. Miguel Ángel Luque Fernández, Ariane Bauernfein, Julio Díaz Jiménez, Cristina Linares Gil, Nathalie El Omeiria, Dionisio Herrera Guibert (2009). Influence of temperature and rainfall on the evolution of cholera epidemics in Lusaka, Zambia, 2003-2006: analysis of a time series. Transactions of the Royal Society of Tropical Medicine and Hygiene; 103(2).