Is climate change bringing malaria to Europe?

Climate change could result in the spread of tropical diseases such as malaria, dengue, Lyme disease and yellow fever, according to a leading disease ecologist.

Speaking today to mark the World Health Organisation’s World Health Day, Durham University School of Biological and Biomedical Sciences Professor Steve Lindsay said that everyone from government and health organisations to individuals needed to be “alert” to the possibility that disease-carrying insects, known as vectors, could spread to more areas of the world.

“The world is continually changing and we are seeing vectors moving to new areas. Governments and health organisations, and individuals, need to be alert to these changes,” said Lindsay.

Lindsay, who has been researching the tools for malaria prevention such as treated bednets, said that in some areas this has already started to happen.

“The Asian Tiger mosquito, for example, is spreading across the northern shores of the Mediterranean, where it wasn’t found 20 years ago. It can transmit diseases such as Chikungunya that won’t kill, but are pretty unpleasant,” explained Lindsay.

“That is a concern for countries such as Spain and France, for example, and potentially the UK in the future, depending on environmental changes.”

mosquito

According to University of Exeter associate lecturer Dominic Henri, one type of malaria, Plasmodium vivax, which is found in Asia and is less dangerous than its African cousin Plasmodium falciparum, did previously exist in Europe.

“The symptom people ascribed to miasma, people think was actually plasmodium vivax,” explained Henri, adding that in areas such as Italy this was wiped out because “proper drainage systems and proper houses” were built that stopped its transmission.

Because of this and general increased urbanisation, Henri does not see a return of malaria in Europe due to a rise in temperatures as the wet, leafy  environments that the insects thrive in no longer exist in large quantities.

The exception to this is in areas high above sea level, where changes in temperatures have allowed mosquitoes to venture further than they previously have managed. “There’s been a big increase in the altitude that you can get malaria,” explained Henri. “That is global warming, increasing the altitude.”

However, he explained that the impact of climate change was likely to come more from rising sea levels. “You’d be more likely to get freshwater wetlands that would allow mosquitos to survive,” said Henri.

rainforest

Perhaps of greater concern, though, is that mosquitoes are increasingly building up a resistance to the most common anti-malarial treatment taken by travellers, chloroquine prophylaxis, meaning that the disease is being carried home to non-malarial countries where it can survive for the summer, infecting others who have remained at home.

Henri explained that even those who have followed their treatment regiment properly can still get the illness, and cited a study that found a 22% increase in malaria cases returning from holidays to the Indian subcontinent.

While individuals can do little to fight climate change on their own, he stressed that travellers to malaria-infection regions must make sure that they do complete the full course of their antimalarial treatment as not finishing it can aid resistance among mosquitoes.

Although he acknowledged that the tablets were expensive, they are an important consideration for any trip to an infected region. He also highlighted to benefit of treated bednets, which can easily be purchased before departure.

“Before you go you need to know if it’s in a malaria area, and before you go you need to take the prophylaxis and you need to take it correctly,” said Henri.

Spit power: How energy from saliva can predict a woman’s ovulation

Scientists have discovered that spit can be used to power small electronic devices – although the future isn’t going to involve us having to spit on our gadgets when they’re low on power.

The tiny fuel cell collects energy and can power equally small devices, the creators from Penn State University, US, say.

Potential uses include being able to predict when women are going to ovulate, days before they start.

“By producing nearly 1 microwatt in power, this saliva-powered, micro-sized MFC already generates enough power to be directly used as an energy harvester in microelectronic applications,” the researchers report in a recent issue of Nature Publishing Group’s Asia Materials.

microspitcell

They don’t produce much energy but they can produce enough to run on-chip applications.

The scientists said that one use for the technology could be in a tiny ovulation predictor – which would be based on the conductivity of a woman’s saliva. The saliva in a woman’s mouth changes five days before ovulation.

The device would measure the conductivity of the saliva in the mouth while also using it as a power source and send the reading to a nearby mobile phone.

In theory the chip could be used to collect and report data on the health of those who use it. The researchers said the fuel cell can be powered with any liquid that has enough organic material, which opens the door for wider applications of the technology.


“There is a lot of organic stuff in saliva.”


The microbial fuel cells, which are made up of saliva input ports, an anode, cathode and a chamber, create energy when bacteria break down organic material. This produces a charge that is transferred to the anode in the device.

The researchers usually look to wastewater as a source for both the organic material and the bacteria to create either electricity or hydrogen. However theses latest cells work differently.

Bruce E. Logan from the University said: “There is a lot of organic stuff in saliva.”

He continued: “We have previously avoided using air cathodes in these systems to avoid oxygen contamination with closely spaced electrodes.”

“However, these micro cells operate at micron distances between the electrodes. We don’t fully understand why, but bottom line, they worked.”