World Bulletin / News Desk
Parasites look set to become more virulent because of climate change, according to a study showing that frogs suffer more infections from a fungus when exposed to unexpected swings in temperatures.
Parasites, which include tapeworms, the tiny organisms that cause malaria and funguses, may be more nimble at adapting to climatic shifts than the animals they live on since they are smaller and grow more quickly, scientists said.
"Increases in climate variability are likely to make it easier for parasites to infect their hosts," Thomas Raffel of Oakland University in the United States told Reuters, based on findings about frogs and a sometimes deadly skin fungus.
"We think this could exacerbate the effects of some disease," he said of the report he led withcolleagues at the University of South Florida. It will be published in Monday's edition of the journal Nature Climate Change.
A U.N. panel of experts says that global warming is expected to add to human suffering from more heatwaves, floods, storms, fires and droughts, and have effects such as spreading the ranges of some diseases.
And climate change, blamed on greenhouse gases released by burning fossil fuels, is also likely to mean more swings in temperatures.
"Few...studies have considered the effects of climate variability or predictability on disease, despite it being likely that hosts and parasites will have differential responses to climatic shifts," they wrote.
The scientists exposed Cuban treefrogs in 80 laboratory incubators to varying temperatures and infections of a fungus, Batrachochytrium dendrobatidis, that is often deadly for the amphibians.
In one experiment, frogs kept at a temperature of 25 degrees Celsius (77F) for four weeks suffered far more infections when they were shifted to incubators at 15C (59F) and exposed to the fungus than frogs already used to living at 15C.
"If you shift the temperature a frog is more susceptible to infection than a frog that is already adapted to that temperature," Raffel said.
In another test, frogs that were exposed to predictable daily temperature variations between 15 and 25 Celsius, typical of shifts from night to day, were much better at resisting the fungus.
Based on factors including their size, life expectancy and factors such as their metabolisms, the scientists said frogs probabably took 10 times as long as fungus to get used to unexpected temperature changes, a process known as acclimation.
Raffel said that more tests were needed of other parasites and hosts to confirm the findings. "Thisstudy was only done on an single tropical frog species," he said.
He said he was unaware of studies about how other parasites such as malaria, for instance, might be affected by temperature swings that affect both its mosquito and human hosts. "It's an open question," he said.
Still, he said that there was speculation that cold-blooded creatures such as frogs, insects, reptiles or fish might be more susceptible to parasites as temperature shifted than warm-blooded birds and mammals.
A man left brain-dead after an experimental drug trial in France has died, local media report.
Facebook founder to donate majority of fortune over lifetime to newly formed charity
Facebook will appeal a date privacy ruling in Belgium that forces the social media giant to stop collecting digital information about people who are non-members
Japanese, Chinese, Irish scientists win 2015 Nobel prize in medicine for malaria and parasite research
Discovery could have major implications for pursuit of life on the red planet
Lawsuit sheds light on no poaching policy at Silicon Valley’s biggest companies
Searches for oncoming storms will display information such as maps, forecasts, reminders and preparedness instructions
New service unveiled as survey finds Americans having hard time navigating smartphone etiquette
Turkcell, Vodafone and Avea bid total of over €1.14 billion for the right to use frequencies on the new network
Petition 'will present at least two substantial questions concerning design-patent liability and damages'
The Istanbul Electric Tram and Tunnel Company plans to launch one solar-powered bus on Thursday and several more in the coming days
Roughly 70 million tonnes of fibres are traded globally per year, but nearly two thirds are made from non-renewable products like petroleum and natural gas.
Researchers havfe said that the flaw leaves data stored by apps vulnerable with almost every category of app considered vulnerable
SpaceX revealed Monday that it is building a test track for the Hyperloop, a concept for ultra-fast ground transport the company’s CEO, Elon Musk, unveiled.
Biologists have created chicken embryos with dinosaur-like faces by tinkering with the molecules that build the birds' beaks.
Product available for pre-order in nine countries but devices won’t ship for weeks.