Extreme weather events can unleash a 'perfect storm' of infectious diseases, research study says

June 25, 2008

Climatic conditions can alter normal host-pathogen relationships
An international research team, including University of Minnesota researcher Craig Packer, has found the first clear example of how climate extremes, such as the increased frequency of droughts and floods expected with global warming, can create conditions in which diseases that are tolerated individually may converge and cause mass die-offs of livestock or wildlife.

The study, published June 25 by PloS (Public Library of Science) ONE, an online peer-reviewed research journal, suggests that extreme climatic conditions are capable of altering normal host-pathogen relationships and causing a "perfect storm" of multiple infectious outbreaks that could trigger epidemics with catastrophic mortality.

Led by scientists at the University of California, Davis, the University of Illinois and the University of Minnesota, the research team examined outbreaks of canine distemper virus (CDV) in 1994 and 2001 that resulted in unusually high mortality of lions in Tanzania's Serengeti National Park and Ngorongoro Crater. CDV periodically strikes these ecosystems, and most epidemics have caused little or no harm to the lions.

But the fatal virus outbreaks of 1994 and 2001 were both preceded by extreme drought conditions that led to debilitated populations of Cape buffalo, a major prey species of lions. The buffalo suffered heavy tick infestations and became even more common in the lions' diet, resulting in unusually high levels of tick-borne blood parasites in the lions. (These parasites are normally present in lions at harmlessly low levels.)

The canine distemper virus suppressed the lions' immunity, which allowed the elevated levels of blood parasites to reach fatally high levels, leading to mass die-offs of lions. In 1994 the number of lions in the Serengeti study area dropped by over 35 percent after the double infection. Similar losses occurred in the Crater die-off in 2001.

The lion populations recovered within 3-4 years after each event, but most climate change models predict increasing frequency of droughts in East Africa.

"The study illustrates how ecological factors can produce unprecedented mortality events and suggests that co-infections may lie at the heart of many of the most serious die-offs in nature," said Packer, Distinguished McKnight University Professor of Ecology, Evolution and Behavior at the University of Minnesota.

Source: University of Minnesota

Explore further: How severe, ongoing stress can affect a child's brain

Related Stories

How severe, ongoing stress can affect a child's brain

July 12, 2017
A quiet, unsmiling little girl with big brown eyes crawls inside a carpeted cubicle, hugs a stuffed teddy bear tight, and turns her head away from the noisy classroom.

4 in 10 job-based health plans in U.S. are now 'high-deductible'

June 6, 2017
(HealthDay)—High-deductible health plans are gaining ground among U.S. adults with employer-sponsored health insurance coverage. But too often, enrollees say high out-of-pocket costs are causing them to skip or delay needed ...

Three new feline viruses raise questions about transmission and disease

January 28, 2014
(Medical Xpress)—Pathogen researchers at Colorado State University have discovered a family of cancer-causing viruses in several U.S. populations of bobcats, mountain lions and domestic cats, raising questions about whether ...

What science doesn't know about menopause

December 15, 2015
My physio, a young woman called Lucy, was simply making conversation. She wanted to distract me from the serious discomfort she was about to inflict by massaging the nerves around my painful posterior tibial tendon, an ankle ...

Prevention of macular degeneration possible, research shows

November 10, 2015
A University of Arizona-led study on age-related macular degeneration - the eye disease that gradually destroys the ability to read, drive, write and see close-up in 30 percent of older Americans - likely will lead to a way ...

What's really going on in PTSD brains? Experts suggest new theory

October 7, 2016
For decades, neuroscientists and physicians have tried to get to the bottom of the age-old mystery of post-traumatic stress disorder, to explain why only some people are vulnerable and why they experience so many symptoms ...

Recommended for you

Exploring the potential of human echolocation

June 25, 2017
People who are visually impaired will often use a cane to feel out their surroundings. With training and practice, people can learn to use the pitch, loudness and timbre of echoes from the cane or other sounds to navigate ...

Team eradicates hepatitis C in 10 patients following lifesaving transplants from infected donors

April 30, 2017
Ten patients at Penn Medicine have been cured of the Hepatitis C virus (HCV) following lifesaving kidney transplants from deceased donors who were infected with the disease. The findings point to new strategies for increasing ...

'bench to bedside to bench': Scientists call for closer basic-clinical collaborations

March 24, 2017
In the era of genome sequencing, it's time to update the old "bench-to-bedside" shorthand for how basic research discoveries inform clinical practice, researchers from The Jackson Laboratory (JAX), National Human Genome Research ...

The ethics of tracking athletes' biometric data

January 18, 2017
(Medical Xpress)—Whether it is a FitBit or a heart rate monitor, biometric technologies have become household devices. Professional sports leagues use some of the most technologically advanced biodata tracking systems to ...

Financial ties between researchers and drug industry linked to positive trial results

January 18, 2017
Financial ties between researchers and companies that make the drugs they are studying are independently associated with positive trial results, suggesting bias in the evidence base, concludes a study published by The BMJ ...

Best of Last Year – The top Medical Xpress articles of 2016

December 23, 2016
(Medical Xpress)—It was a big year for research involving overall health issues, starting with a team led by researchers at the UNC School of Medicine and the National Institutes of Health who unearthed more evidence that ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.