redOrbit Staff & Wire Reports – Your Universe Online
Researchers from Duke University say that changes in temperature and precipitation in Madagascar could cause disease-carrying lemur parasites to grow and reproduce more quickly, spreading to new areas and presenting a potential danger to the island nation´s human population.
Graduate student and lead author Meredith Barrett and her colleagues analyzed several species of parasites that are commonly known to infect the primates, the university explained in a statement. They then combined that information with weather-related information and other environmental information for Madagascar to create probability maps for the distribution of those parasites throughout the landscape today. Finally, they used climate projections from the year 2080 to predict what changes would occur between now and then.
“The team focused on six species of mites, ticks and intestinal worms commonly known to infect lemurs,” said the statement. “The parasites are identified in lemur fur and feces. Some species — such as pinworms, whipworms and tapeworms — cause diarrhea, dehydration and weight loss in human hosts. Others, particularly mites and ticks, can transmit diseases such as plague, typhus or scabies.”
“When the researchers compared their present-day maps with parasite distributions predicted for the future, they found that lemur parasites could expand their range by as much as 60 percent. Whipworms, for example, which are now largely confined to Madagascar’s northeast and western coasts, may become widely distributed on the country’s southeastern coast as well,” they added.
The study, which appears in this month´s edition of the journal Biological Conservation, is based on predictions that the average annual temperatures in Madagascar will increase by an estimated 1.1 degrees Celsius to 2.6 degrees Celsius by the year 2080. Similarly, the researchers are predicting changes to the country´s rainfall, drought and cyclone patterns.
“We can use these models to figure out where the risk of lemur-human disease transmission might be highest, and use that to better protect the future of lemur and human health,” Barrett explained.
Senior author Anne Yoder, the head of the Duke Lemur Center, added that the research was of great importance now, as the International Union for the Conservation of Nature (IUCN) has declared the lemur to be the most endangered mammal species on Earth, according to the university.
“Warmer weather means that parasites could grow and reproduce more quickly, or spread to higher latitudes and elevations where once they were unable to survive,” said the statement. “As lemur parasites become more prevalent, the diseases they carry could show up in new places. The spread could be harmful to lemur populations that have never encountered these pests before, and lack resistance to the diseases they carry.”
“Shifting parasite distributions could have ripple effects on people too. As human population growth in Madagascar drives people and their livestock into previously uninhabited areas, wildlife-human disease transmission becomes increasingly likely,” the university added. “The authors hope their results will help researchers predict where disease hotspots are likely to occur, and prepare for them before they hit.”
Meredith Barrett is currently a postdoctoral scholar at the Robert Wood Johnson Foundation Health & Society Scholars Program at the University of California at San Francisco and Berkeley. Jason Brown of Duke University and Randall Junge of the Columbus Zoo & Aquarium were co-authors of this study.