Navigation Links
Study predicts ranavirus as potential new culprit in amphibian extinctions
Date:7/9/2014

KNOXVILLEAmphibian declines and extinctions around the world have been linked to an emerging fungal disease called chytridiomycosis, but new research from the National Institute for Mathematical and Biological Synthesis (NIMBioS) shows that another pathogen, ranavirus, may also contribute.

In a series of mathematical models, researchers showed that ranavirus, which causes severe hemorrhage of internal organs in frogs, could cause extinction of isolated populations of wood frogs if they are exposed to the virus every few years, a scenario that has been documented in wild populations.

The most widely distributed amphibian species in North America, wood frogs have been shown to be highly susceptible to ranavirus infection, particularly as tadpoles. But little research has been done into how ranavirus affects frogs at all stages of their life cycle from egg to hatchling to tadpole to metamorph, the stage when they emerge as frogs. Little is also known about how the infection could hasten extinction in entire populations.

The study, published in the journal EcoHealth, investigates the effect of ranavirus on the entire life cycle of wood frogs in demographically isolated populations, where there is no movement of frogs into the population from surrounding areas.

The study used mathematical simulations based on long-term data sets from wild populations of wood frogs in eastern United States and laboratory data on the effects of ranavirus. It determined that the life stage during which a frog was exposed to ranavirus was one of the most important factors in determining extinction and declines.

Extinction was most likely to occur when the tadpole or metamorph was exposed to ranavirus at frequent intervals in small populations. Under the worst-case scenario, extinction could occur in as quickly as five years with exposure every year and 25-44 years with exposure every two years.

The egg stage had a 57 percent survival rate when exposed to ranavirus, which was high enough to prevent extinction. Scientists speculate that eggs have a greater survival rate than other stages because they are protected by a thick gelatinous membrane that may serve as a structural barrier or contain anti-viral properties.

"Just as the chytrid fungus has decimated frog populations, the results of our study suggest that ranavirus infection too could contribute to extinction of amphibian populations that are demographically isolated," said lead author and NIMBioS postdoctoral fellow Julia Earl.

Amphibians are already considered the most imperiled of vertebrates, and a third of amphibians are threatened or endangered, according to the International Union for Conservation of Nature, the main international body that assesses the conservation status of species.

Disease may be playing a role in amphibians' extinction. Since the 1990s, chytridiomycosis, which has been called the worst disease affecting vertebrate animals in recorded history, has caused massive die-offs and species extinctions across the world, particularly in Australia, the Caribbean, and North, Central, and South America.

Ranavirus infections in amphibians have been known since the 1960s, but it wasn't until the 1980s when they were associated with large-scale mortality and disease.

Once exposed to ranavirus, in susceptible species like wood frogs, mortality can be as quick as three days. Transmission can occur through water, direct contact and when tadpoles scavenge other dead and infected frogs. There is no cure or treatment for the disease.


'/>"/>

Contact: Catherine Crawley
ccrawley@nimbios.org
865-974-9350
National Institute for Mathematical and Biological Synthesis (NIMBioS)
Source:Eurekalert  

Related medicine news :

1. Study of dermatology on YouTube shows new ways science reaches public
2. Penn study finds living kidney donation does not increase risk of death or heart disease for older
3. Fit for the frontline? New study identifies the hearing requirements of British soldiers
4. Study finds kidney donation safe for healthy older adults
5. NCI study finds extreme obesity may shorten life expectancy up to 14 years
6. Study shows link between inflammation in maternal blood and schizophrenia in offspring
7. Study reveals protective role for specialized cells in intestinal and respiratory systems
8. Infant toenails reveal in utero exposure to low-level arsenic, Dartmouth study finds
9. $12.6 million NIH grant to study genetics of Alzheimers disease
10. New study reveals how tumors remodel their surroundings to grow
11. Study finds higher risk for celiac disease in some children
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Study predicts ranavirus as potential new culprit in amphibian extinctions
(Date:2/11/2016)... ... February 11, 2016 , ... "What holds ... author Ray Clarke poses a question as a challenge for his readers to ... "Being in the Being" (published by Partridge Singapore), Clarke explores the subject with ...
(Date:2/11/2016)... ... February 11, 2016 , ... Greenfield Insurance Group in ... to assist the people of their local community. The agency pledges to select ... leaders. Their hope is to bring awareness to important local causes with fundraising ...
(Date:2/11/2016)... , ... February 11, 2016 , ... ... practice Village Family Practice , will be presenting at the 2016 HIMSS ... Las Vegas, Nev. , During his session, “ Coding for Care: Using ...
(Date:2/11/2016)... ... February 11, 2016 , ... The annual list showcases the ... of DataPoint’s team dedication and commitment to the SharePoint ecosystem. A panel ... list. The panel’s goal is to recognize and promote technology entrepreneurship. , The ...
(Date:2/11/2016)... Washington, D.C. (PRWEB) , ... February 11, 2016 ... ... will be exhibiting at the American Academy of Dermatology Annual Meeting at ... Hidrex USA's goal is to raise awareness for both the condition of hyperhidrosis ...
Breaking Medicine News(10 mins):
(Date:2/11/2016)... 2016 Jeffrey Zucker , vice ... will present at this year,s Summit for Clinical Operations Executives ... Miami, FL. Zucker will discuss how ... execution, supporting SCOPE,s "Improving Site Study Activation and Performance" portion ... Feb. 25 at 11:05 a.m. --> ...
(Date:2/11/2016)... , Feb. 11, 2016 Exactus Pharmacy ... providing high-quality specialty pharmacy care for those suffering ... it has achieved full Specialty Pharmacy Accreditation from ... dedicated to promoting health care quality through accreditation, ... --> The URAC accreditation process demonstrates ...
(Date:2/11/2016)... 11, 2016 SI-BONE, Inc., a medical ... iFuse Implant System, a minimally invasive surgical (MIS) ... the sacroiliac (SI) joint, announced the publication of ... MIS SI joint fusion for patients suffering from ... or SI joint disruption.  In the first article, ...
Breaking Medicine Technology: