NINE REGIONAL EBOLA, SPECIAL PATHOGENS TREATMENT CENTERS SELECTED BY HHS

FROM:  U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES
June 12, 2015
HHS selects nine regional Ebola and other special pathogen treatment centers
New network expands US ability to respond to outbreaks of severe, highly infectious diseases

To further strengthen the nation’s infectious disease response capability, the U.S. Department of Health and Human Services has selected nine health departments and associated partner hospitals to become special regional treatment centers for patients with Ebola or other severe, highly infectious diseases.

HHS’ Office of the Assistant Secretary for Preparedness and Response (ASPR) has awarded approximately $20 million through its Hospital Preparedness Program (HPP) to enhance the regional treatment centers’ capabilities to care for patients with Ebola or other highly infectious diseases. ASPR will provide an additional $9 million to these recipients in the subsequent four years to sustain their readiness.

“This approach recognizes that being ready to treat severe, highly infectious diseases, including Ebola, is vital to our nation’s health security,” said Dr. Nicole Lurie, HHS assistant secretary for preparedness and response. “This added regional capability increases our domestic preparedness posture to protect the public’s health.”

Each awardee will receive approximately $3.25 million over the full five-year project period. This funding is part of $339.5 million in emergency funding Congress appropriated to enhance state and local public health and health care system preparedness following cases of Ebola in the United States stemming from the 2014 Ebola epidemic in West Africa.

The facilities announced today will be continuously ready and available to care for a patient with Ebola or another severe, highly infectious disease, whether the patient is medically evacuated from overseas or is diagnosed within the United States.

The nine awardees and their partner hospitals are:
Massachusetts Department of Public Health in partnership with Massachusetts General Hospital in Boston, Massachusetts
New York City Department of Health and Mental Hygiene in partnership with New York City Health and Hospitals Corporation/HHC Bellevue Hospital Center in New York City
Maryland Department of Health and Mental Hygiene in partnership with Johns Hopkins Hospital in Baltimore, Maryland
Georgia Department of Public Health in partnership with Emory University Hospital and Children’s Healthcare of Atlanta/Egleston Children’s Hospital in Atlanta, Georgia
Minnesota Department of Health in partnership with the University of Minnesota Medical Center in Minneapolis, Minnesota
Texas Department of State Health Services in partnership with the University of Texas Medical Branch at Galveston in Galveston, Texas
Nebraska Department of Health and Human Services in partnership with Nebraska Medicine - Nebraska Medical Center in Omaha, Nebraska
Colorado Department of Public Health and Environment in partnership with Denver Health Medical Center in Denver, Colorado
Washington State Department of Health in partnership with Providence Sacred Heart Medical Center and Children’s Hospital in Spokane, Washington
The regional facilities are part of a national network of 55 Ebola treatment centers, but will have enhanced capabilities to treat a patient with confirmed Ebola or other highly infectious disease. Even with the establishment of the nine regional facilities, the other 46 Ebola treatment centers and their associated health departments will remain ready and may be called upon to handle one or more simultaneous clusters of patients.
The facilities selected to serve as regional Ebola treatment centers will be required to:
Accept patients within eight hours of being notified,
Have the capacity to treat at least two Ebola patients at the same time,
Have respiratory infectious disease isolation capacity or negative pressure rooms for at least 10 patients,
Conduct quarterly trainings and exercises,
Receive an annual readiness assessment from the soon-to-be-established National Ebola Training and Education Center, composed of experts from health care facilities that have safely and successfully cared for patients with Ebola in the U.S., and funded by ASPR and the Centers for Disease Control and Prevention, to ensure clinical staff is adequately prepared and trained to safely treat patients with Ebola and other infectious diseases,
Be able to treat pediatric patients with Ebola or other infectious diseases or partner with a neighboring facility to do so, and,
Be able to safely handle Ebola-contaminated or other highly contaminated infectious waste.

Proposals from these facilities were reviewed by a panel of experts from professional associations, academia, and federal agencies and were selected based upon extensive criteria published in the funding opportunity announcement released in February.

To be eligible for consideration as an Ebola and other special pathogen treatment center, facilities also had to be assessed by a Rapid Ebola Preparedness team led by the CDC prior to Feb. 20, 2015.

The Department is working with state health officials and hospital executives in HHS Region IX, which includes Arizona, California, Hawaii, Nevada and the Pacific island territories and freely associated states, to identify a partner hospital awardee.

HHS is the principal federal department for protecting the health of all Americans and providing essential human services, especially for those who are least able to help themselves. ASPR leads HHS in preparing the nation to respond to and recover from adverse health effects of emergencies, supporting communities’ ability to withstand adversity, strengthening health and response systems, and enhancing national health security.

HHS REPORTS ON QUICK AND EASY TEST FOR EBOLA VIRUS

FROM:  U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES
HHS pursues fast, easy test to detect Ebola virus infections
Promising point-of-care test could improve diagnosis and speed response

To assist doctors in diagnosing Ebola virus disease quickly, the U.S. Department of Health and Human Services’ Office of the Assistant Secretary for Preparedness and Response (ASPR) will pursue development of an Ebola virus diagnostic test for use in a doctor’s office, hospital, clinic, or field setting that will provide results within 20 minutes.

“Fast and inexpensive point-of-care diagnostics will improve our ability to control Ebola virus disease outbreaks,” said Robin Robinson, Ph.D., director of ASPR’s Biomedical Advanced Research and Development Authority (BARDA), which will oversee this development program for HHS. “Faster diagnosis of Ebola virus infections allows for more immediate treatment and an earlier response to protect public health worldwide.”

Diagnosing Ebola virus infections quickly in resource-poor areas would enable health care providers to isolate and provide necessary treatment and supportive care to patients suffering from Ebola. Quickly isolating patients helps limit the spread of the disease. Emerging evidence has shown that early initiation of supportive care improves outcomes for patients suffering from Ebola virus disease.

The development of this simple, low-cost, lateral-flow test, called the OraQuick rapid Ebola antigen test, will take place under a $1.8 million contract with OraSure Technologies Inc., headquartered in Bethlehem, Pennsylvania. Lateral flow tests detect the presence of a virus with a drop of the patient’s blood or saliva on a test strip, similar to the tests used in doctors’ offices to diagnose strep throat.

The agreement supports clinical and non-clinical work necessary to apply for approval of the test by the U.S. Food and Drug Administration. The contract could be extended for up to a total of 39 months and $10.4 million.

In addition, OraSure will evaluate whether the test can be used in the post-mortem analysis of oral fluids. During the current epidemic, people died before Ebola virus infections could be confirmed, yet the bodies of people infected with Ebola virus would have remained highly infectious. A simple, rapid test that could determine disease status quickly from the body’s oral fluids would facilitate infection control efforts and support the appropriate handling of remains infected with the Ebola virus.

The OraQuick rapid Ebola antigen test is the first point-of-care Ebola virus testing device to receive BARDA support. To help the United States prepare for and control Ebola virus disease outbreaks, BARDA also is supporting development of vaccines to prevent Ebola virus infections and therapeutic drugs to treat the disease.

BARDA is seeking additional proposals for advanced development of new drugs and products to diagnose and treat Ebola and related illnesses.

The new test is part of BARDA’s comprehensive integrated portfolio approach to the advanced research and development, innovation, acquisition, and manufacturing of vaccines, drugs, therapeutics, diagnostic tools, and non-pharmaceutical products for public health emergency threats. These threats include chemical, biological, radiological, and nuclear (CBRN) agents, pandemic influenza, and emerging infectious diseases.

ASPR leads HHS in preparing the nation to respond to and recover from adverse health effects of emergencies, supporting communities’ ability to withstand adversity, strengthening health and response systems, and enhancing national health security. HHS is the principal federal agency for protecting the health of all Americans and providing essential human services, especially for those who are least able to help themselves.

SCIENTISTS FIND CONSEQUENCES FOR DISEASE REMEDIES

FROM:  THE NATIONAL SCIENCE FOUNDATION 
Treatment for parasitic worms helps animals survive infectious diseases--and spread them

Scientists discover unanticipated consequences of some disease remedies
Parasitic worms, which infect millions of people and other animals around the world, influence how the immune system responds to diseases like HIV and tuberculosis.

In a new study of African buffalo, University of Georgia (UGA) ecologist Vanessa Ezenwa has found that de-worming drastically improves an animal's chances of surviving bovine tuberculosis--but with the consequence of increasing the spread of TB in the population.

"Health interventions can sometimes have unexpected and unwelcome outcomes," said Sam Scheiner, National Science Foundation (NSF) director for the Ecology and Evolution of Infectious Diseases (EEID) program, which funded the research. NSF, the National Institutes of Health and the U.S. Department of Agriculture support the EEID program.

"By examining such outcomes, we can design better intervention strategies for infectious diseases."

The findings, published this week in the journal Science, have implications for human health.

"If you think about humans in this context, this is what we'd like to do--to figure out how to help people who get infected by something live longer and be less sick," Ezenwa said. "But here we found that doing exactly that can have unanticipated consequences."

Testing buffalo for parasitic worms

Ezenwa and co-author Anna Jolles of Oregon State University conducted the research in South Africa's Kruger National Park.

In 2008, with the assistance of the park's Veterinary Wildlife Services Department, they captured 216 African buffalo and tested them for parasitic worms, known as helminths, and for bovine TB.

Half the buffalo received treatment for helminths; the rest were left untreated as a control group.

For the next four years, the scientists recaptured and retested each buffalo approximately once every six months.

They found that animals treated for worms were nine times more likely to survive TB infections than untreated animals; with the worms gone, their immune systems were able to mount a stronger defense against TB.

According to Ezenwa, this finding confirmed predictions about the effects of worms on the immune system based on an earlier study of TB and helminth infections in African buffalo.

"We'd done a one-off, short-term experiment to see if we could replicate, in this wild animal, the immunological results seen in laboratory experiments treating helminths in mice," she said. "That led to this larger experiment in a much bigger population over a longer time."

Treatment not always a plus

Ezenwa said that the previous work also suggested that treatment would reduce the rate at which individuals acquire TB infection and therefore the TB transmission rate.

"We expected it would be a net positive for the individual and for the population," she said. "But in fact when you carry out an experiment at this larger scale, in a real population, you see it's not all positive outcomes."

The improved survival rate allows infected buffalo to continue to spread TB within the herd, Ezenwa said.

Since they still get infected at the same rate there is an unexpected negative result for the population as a whole.

"Because coinfection is such a complicated area, laboratory studies are really essential in telling us about the detailed mechanisms of how immunological interactions work," she said.

"But we will never understand the real implications if all the work concentrates in the lab."

Need to look at similar animals to humans

Ezenwa said that in order to address human infectious disease problems, researchers need to also look at coinfection in populations that bear more similarity to humans.

"African buffalo are long-lived, they're in the wild in social groups, they're genetically variable--that's a little bit closer to people than laboratory mice, which have the same genetic background and live under artificial conditions," she said.

And understanding bovine TB-helminth coinfection in African buffalo is particularly relevant for human health because helminths are known to influence human immune responses to TB.

"The number of human cases of bovine TB worldwide is unknown, but where it's studied, it appears to be a substantial fraction of the total," said Frederick Quinn, head of the UGA Department of Infectious Diseases in the College of Veterinary Medicine.

"It's also unknown if bovine TB bacteria transmit more efficiently than other TB bacteria, what traits this pathogen possesses that allow infection of so many different species of mammals, and what happens when the host is co-infected with parasites or HIV.

"This work is a tremendous start in answering some of the fundamental questions about this disease and how best to control it in humans and other animals."

-NSF-


Media Contacts
Cheryl Dybas, NSF

SCIENTIST STUDYING ECONOMIC IMPACT OF INFECTIOUS DISEASES

FROM:  NATIONAL SCIENCE FOUNDATION
Ebola, Dengue fever, Lyme disease: The growing economic cost of infectious diseases

Five new such diseases expected each year; strategies to reduce climate change adaptable to infectious diseases.

Emerging pandemic disease outbreaks such as Ebola increasingly threaten global public health and world economies, scientists say. We can expect five new such diseases each year, into the future.

And expect them to spread. The tropical disease dengue fever, for example, has made its way to Florida and Texas, seemingly to stay.

But the global response to infectious diseases is often too late to prevent major effects on health and economic growth, researchers believe.

According to the World Health Organization (WHO), the number of people infected with Ebola has surpassed 17,000, with more than 6,000 deaths. The World Bank now estimates that the two-year financial cost of Ebola may reach $32.6 billion and force some already suffering West African economies into a deep recession.

Growing economic cost of global disease outbreaks

Scientists at EcoHealth Alliance in New York and other organizations studied the economic cost of such global disease outbreaks.

Economists, disease ecologists and others collaborated on an in-depth economic analysis of strategies to address pandemic threats in a proactive way--rather than a reactive response to a crisis. The results are published in this week's issue of the journal Proceedings of the National Academy of Sciences (PNAS).

"Our research shows that new approaches to reducing emerging pandemic threats at the source would be more cost-effective than trying to mobilize a global response after a disease has emerged," says Peter Daszak, senior author of the paper and president of EcoHealth Alliance.

The researchers used economic modeling to analyze two strategies for a pandemic response: Current business-as-usual approaches that rely on global surveillance to identify new diseases in people, and new "mitigation" strategies to reduce the underlying drivers of emerging diseases and lower the risk of their emergence.

"Our economic modeling demonstrates that the new approach to dealing with disease emergence is the right strategy in the long-term," says Jamie Pike, an economist at EcoHealth Alliance and first author of the paper.

The results indicate that the strategy for pandemics needs to be coordinated on a global scale to be effective in reducing risk. And that mitigation strategies will be far more cost-effective in the long-term.

The results follow those reported in a September, 2014, paper in the journal EcoHealth, in which Daszak, Charles Perrings of Arizona State University, A. Marm Kilpatrick of the University of California at Santa Cruz, and colleagues show that economic epidemiology has the potential to improve predictions of the course of infectious diseases, and to support new approaches to management of such diseases.

Environmental change causing increase in number of new diseases

Ebola. West Nile virus. Lyme disease. All are infectious diseases spreading in animals, and in humans. Is our interaction with the environment somehow responsible for the increase in incidence of these diseases?

With 60 percent of all human diseases and 75 percent of all emerging infectious diseases involving animal-to-human transmission, the underlying factors that contribute to disease outbreaks are mostly related to environmental changes to global ecosystems, the scientists found. Deforestation and illegal wildlife trade are two culprits.

Large-scale environmental events alter the risks of emergence of viral, parasitic and bacterial diseases in humans and animals.

"Virtually all the world's terrestrial and aquatic communities have undergone dramatic changes in biodiversity due primarily to habitat transformations such as deforestation and agricultural intensification, invasions of exotic species, chemical contamination, and climate change events," says Sam Scheiner, National Science Foundation (NSF) program director for the joint NSF-NIH-USDA Ecology and Evolution of Infectious Diseases (EEID) Program, which funded the research.

Ebola epidemic highlights need to address infectious disease threats

"The current Ebola epidemic highlights the need to anticipate possible health threats from these changes," says Scheiner. "This study shows that the long-term economic benefits outweigh the short-term costs, not to mention the human benefits of preventing the next pandemic."

Rapid changes to the environment are resulting in a continuous year-by-year increase in the number of new diseases emerging, the researchers found.

"With continued pressure causing diseases to rise, we need to analyze the ecological and economic foundations of the risk, and identify economically effective strategies to reduce it," says David Finnoff, an economist at the University of Wyoming and co-author of the PNAS paper.

The paper highlights WHO International Health Regulations goals, and points out that the global capacity to achieve such targets needs to be addressed to deal with the continuous rise in the rate of new diseases.

Five new diseases each year into the future

"We show that we can expect more than five new emerging diseases each year into the future," says Daszak.

"With this continuous rise in the pandemic threat, and our increasing global connectivity, we are at a critical moment in history to act."

-- Cheryl Dybas, NSF

NSF FUNDS RESEARCH ON CRUSTACEAN PATHOGENS

FROM:  NATIONAL SCIENCE FOUNDATION 

Summer brings crab feasts--and concerns for Chesapeake blue crabs

Infectious diseases play a part in crab population declines

It's almost summer. Seafood restaurants from coast-to-coast are serving platter after platter of steaming crabs, ready for hammering and picking. The supply seems endless, but is it?

Not if we're talking about blue crabs from Chesapeake Bay.

The bay's iconic blue crab population has dropped to levels not seen since before restrictions were placed on the fishery more than five years ago. What's to blame?

A long and, by Mid-Atlantic standards, brutal winter has been fingered as one culprit. In one of the worst die-offs in recent history, more than a quarter of the Chesapeake's blue crabs perished in the frigid waters.

More than cold water to blame

But that's not the only factor, says disease ecologist Jeff Shields of the Virginia Institute of Marine Sciences in Gloucester Point, Va.

"Several commercially important crustacean populations, including blue crabs, have had declines linked to diseases," says Shields. "In most cases, though, the underlying causes have been difficult to pinpoint because crustacean pathogens [infectious agents] aren't very well known."

To help determine what's infecting Chesapeake blue crabs and other crustaceans, the National Science Foundation (NSF) awarded Shields a grant through the joint NSF-NIH Ecology and Evolution of Infectious Diseases Program.

"We know very little about how disease affects populations of marine invertebrates and even less about how disease might interact with other stressors, such as overfishing," says Dave Garrison, director of NSF's Biological Oceanography Program, which also funded the research.

"This study is a major step toward discovering new ways of wisely managing our coastal resources."

One Chesapeake Bay blue crab killer may be a single-celled parasitic dinoflagellate named Hematodinium, a scourge that infects blue crabs and is of concern in fisheries not only in the Chesapeake, but around the world.

Outbreak in the crab pot and the shedding house

The parasite was first reported along the U.S. East Coast in the 1970s and found in the Chesapeake's blue crabs in the 1990s.

In a Hematodinium outbreak, some 50 percent of crabs caught in fishing pots may die. That number jumps to 75 percent in "shedding houses" where crabs molt their shells, then are collected for the soft-shell industry.

"Infection is almost always fatal--for the crabs," says Shields, who adds that the disease isn't harmful to humans.

In a breakthrough for blue crabs, Shields and colleagues recently succeeded in their effort to uncover the life history of Hematodinium.

"Describing the entire life cycle of Hematodinium is an important step toward controlling the infection," says Shields. "With all the parasite's stages in culture in the lab, we can learn when Hematodinium is most infectious."

The biologists made their discovery by looking at many parasite generations over a year-long period.

Answers under a microscope

Through the research, scientists now know that Hematodinium takes some 40 to 50 days to develop. "That matches what we see in the field," he says. "We think infection is linked with blue crabs' molting cycles."

Hematodinium usually infects young crabs. Some 50 to 70 percent of juvenile blue crabs along the Virginia coast carry the pathogen, "and it's prevalent in bays and inlets along the entire U.S. East Coast," says Shields.

The high cost--to the crab population and to the humans that depend on it--comes in the deaths of young blue crabs before they can make their way from coastal spawning grounds to brackish tributaries, where they become large enough to legally catch.

"Imagine a harvest with 50 percent more crabs," says Shields. "The toll exacted by Hematodinium is very clear."

The parasite is after more than blue crabs, however.

"You can't fish out the blue crabs somewhere and hope this pathogen will be gone," says Shields. "It's also in many other crustaceans, including spider crabs, rock crabs and other swimming crabs."

Insights from the bay's shape

Outbreaks of Hematodinium are linked with certain geographic features, such as shallow bays, lagoons and fjords. "Such features are ideal for the growth and spread of pathogens, as they serve to focus transmissive stages or retain them within the system," writes Shields in a paper published in the Journal of Invertebrate Pathology.

Four factors may facilitate epidemics of Hematodinium and other pathogens: relatively "closed" host (crab) populations, with little immigration and emigration of juveniles and adults; bays with restricted water exchange with the open ocean, which hold in pathogens; stressful environmental conditions, such as overfishing and seasonal hypoxia, or "dead zones"; and pathogens that can rapidly multiply.

"The Chesapeake has several of these features," Shields says.

Managing for pathogens

Shields and colleagues are working to understand how Hematodinium is transmitted in wild crustacean populations and at shrimp farms and other aquaculture operations. "We hope to develop 'best practices' for managing, in particular, the Chesapeake's wild blue crabs."

Diseases can have serious effects on commercial fisheries, Shields says. "But there's a perception among resource managers and fishers that diseases aren't important to the fishing industry, or that little can be done to manage them."

Too few fishery models use information like disease prevalence and distribution, according to Shields, and fisheries management decisions often don't consider disease.

"Estimates of disease-induced effects such as mortality or 'negative marketability' can be incorporated into existing models to improve stock assessment and management," Shields writes in the Journal of Invertebrate Pathology.

Disease may be the sleeper in the decline of the Chesapeake Bay blue crab.

Hard-hit by freezing temperatures, low-oxygen waters and overfishing, unless disease is taken into account, believes Shields, the next blue crabs caught may be headed not to your dinner table, but to the crustacean equivalent of the ICU.

-- Cheryl Dybas, NSF
Investigators
Harry Wang
Kimberly Reece
Jeffrey Shields
Related Institutions/Organizations

UPDATE: MENINGOCOCCAL DISEASE

FROM:  CENTERS FOR DISEASE CONTROL AND PREVENTION 

Meningococcal Disease Update

On Monday, March 10, a Drexel University student tragically died from serogroup B meningococcal disease. CDC’s laboratory analysis shows that the strain in Princeton University’s serogroup B meningococcal disease outbreak matches the strain in the Drexel University case by “genetic fingerprinting.” This information suggests that the outbreak strain may still be present in the Princeton University community and we need to be vigilant for additional cases.

As with all cases of meningococcal disease, the local health department quickly and thoroughly investigated who has been in close contact with the Drexel University student prior to illness onset. Antibiotic prophylaxis to prevent additional cases of meningococcal disease was recommended and administered to those who had or may have had close contact. To date, no related cases among Drexel University students have been reported.

The public health investigation of the Drexel University student revealed that the student had been in close contact with students from Princeton University about a week before becoming ill. Princeton University has been experiencing a serogroup B meningococcal disease outbreak.

A high percentage of Princeton University undergraduates and eligible graduate students received 2 doses of the investigational serogroup B vaccine as part of a recent vaccination effort at Princeton University. There are currently no serogroup B vaccines licensed (approved) in the United States. Those who have received the investigational vaccine have likely protected themselves from getting sick (there have been no new cases among Princeton University students since the vaccination campaign began on December 9, 2013). Available data show most adolescents that get 2 doses of this vaccine are protected from getting meningococcal disease. However, vaccinated individuals may still be able to carry the bacteria in their throats, which could infect others through close contact.

The local health department and Drexel University are taking all the recommended steps to prevent additional cases. Because Drexel University is not experiencing an outbreak of serogroup B meningococcal disease, members of that community are not considered to be at increased risk.  The investigational serogroup B vaccine is not currently available to the Drexel University community.

We will continue to closely monitor the situation and determine next steps while local health authorities remain vigilant to recognizing and promptly treating any new cases. At this time, CDC does not recommend limiting social interactions or canceling travel plans as a preventive measure for meningococcal disease.

We recognize that when cases of meningococcal disease occur, there is increased concern about the potential spread of disease and desire to take appropriate steps to prevent additional cases. There is no evidence that family members and the community are at increased risk of getting meningococcal disease from casual contact with Princeton University students, faculty, or staff. Although transmission is from person-to-person, this organism is not highly contagious and requires sharing respiratory and oral secretions to spread. Those at highest risk for disease are people who have had close, prolonged, or face-to-face contact with someone who has meningococcal disease.

Students at both Universities should be especially vigilant to the signs and symptoms of meningococcal disease and seek urgent treatment if suspected. Symptoms may include sudden onset of a high fever, headache, stiff neck, nausea, vomiting, rapid breathing, or a rash. Handwashing and covering coughs and sneezes are also good practices to follow.

WHERE DISEASES AND CLIMATE CHANGE INTERSECT

Rat Eating Seeds.  Credit:  Wikimedia.

FROM:  NATIONAL SCIENCE FOUNDATION

Infectious diseases and climate change intersect with no simple answers
Climate change is already affecting the spread of infectious diseases--and human health and biodiversity worldwide--according to disease ecologists reporting research results in this week's issue of the journal Science.

Modeling disease outcomes from host and parasite responses to climate variables, they say, could help public health officials and environmental managers address the challenges posed by the changing landscape of infectious disease.

"Earth's changing climate and the global spread of infectious diseases are threatening human health, agriculture and wildlife," said Sam Scheiner, National Science Foundation (NSF) program director for the joint NSF-National Institutes of Health Ecology and Evolution of Infectious Diseases Program, which funded the research.

"Solving these problems requires a comprehensive approach that unites scientists from biology, the geosciences and the social sciences."

According to lead author Sonia Altizer of the University of Georgia, the issue of climate change and disease has provoked intense debate over the last decade, particularly in the case of diseases that affect humans.

In the Science paper, Altizer and her colleagues--Richard Ostfeld of the Cary Institute of Ecosystem Studies; Pieter Johnson of the University of Colorado; Susan Kutz of the University of Calgary and Canadian Cooperative Wildlife Health Centre; and Drew Harvell of Cornell University--laid out an agenda for future research and action.

"For a lot of human diseases, responses to climate change depend on the wealth of nations, healthcare infrastructure, and the ability to take mitigating measures," Altizer said.

"The climate signal, in many cases, is hard to tease apart from other factors like vector control, and vaccine and drug availability."

In diseases affecting wildlife and agricultural ecosystems, however, findings show that climate warming is already causing changes.

"In many cases, we're seeing an increase in disease and parasitism," Altizer said. "But the effect of climate change on these disease relationships depends on the physiology of the organisms and on the structure of natural communities."

At the organism level, climate change can alter the physiology of parasites. Some of the clearest examples are found in the Arctic, where temperatures are rising rapidly. Parasites are developing faster as a result. A lungworm that affects muskoxen, for instance, may be transmitted over a longer period each summer, making it a more serious problem for the populations it infects.

Climate change is also affecting entire plant and animal communities.

Community-level responses to rising temperatures are evident in tropical marine environments such as the coral reef ecosystems of the Caribbean. Warmer water temperatures have directly stressed corals and facilitated infections by pathogenic fungi and bacteria. When corals succumb, other species that depend on them are affected.

The potential consequences of these changes are serious. The combination of warmer temperatures and altered disease patterns is placing growing numbers of species at risk of extinction, the scientists say.

In human health, there is a direct risk from pathogens like dengue, malaria and cholera. All are linked to warmer temperatures.

Indirect risks also exist in threats to agricultural systems and game species that are crucial for subsistence and cultural activities.

The scientists recommend building on and expanding data on the physiological responses of hosts and parasites to temperature change. Those mechanisms may offer clues to how a system will respond to climate warming.

"We'd like to be able to predict, for example, that if the climate warms by a certain amount, then in a particular host-parasite system we might see an increase from one to two disease transmission cycles each year," Altizer said.

"But we'd also like to try to tie these predictions to actions that might be taken."

Some of those actions might involve more monitoring and surveillance, adjusting the timing of vector control measures and adopting new management measures.

These could include, for instance, closing coral reefs to human activity if a disease outbreak is predicted, or changing the planting strategy for crops to compensate for unusually high risks of certain diseases.

The researchers also point out that certain local human communities, such as those of indigenous peoples in the Arctic, could be disproportionately affected by climate-disease interactions.

Predicting where these local-scale effects might be most intense would allow societies to take measures to address issues such as health and food security.

"Involving local communities in disease surveillance," said Altizer, "could become essential."