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:2/12/2016)... (PRWEB) , ... February 12, 2016 , ... CDRH Enforcement Trends: , Back to the ... , As Winston Churchill said, “Those who don’t learn from history are ... what to expect when they come knocking this year. But that takes time. , ...
(Date:2/12/2016)... , ... February 12, 2016 , ... Each year, the ... be held in Anaheim, CA at the Anaheim Convention Center. Almost 10,000 physical therapists ... new therapy products in action, learn more about their chosen field and network with ...
(Date:2/12/2016)... ... 12, 2016 , ... Coco Libre, the maker of coconut water beverages with ... Style Lounge Event. Coco Libre will offer musicians and celebrities the company’s signature Organic ... The invitation-only gifting suite, held this year at the W Hollywood Hotel, has become ...
(Date:2/12/2016)... ... February 12, 2016 , ... The ThedaCare ... San Francisco General Hospital on April 5-7. The series is a multi-day, multi-workshop ... habits. The workshops cover a broad range of topics, including coaching skills, the ...
(Date:2/12/2016)... , ... February 12, 2016 , ... Every winter, someone ... This winter the West Penn Burn Center, part of the Allegheny Health ... to bring you the “Space Heaters Need Space” campaign. , “Space ...
Breaking Medicine News(10 mins):
(Date:2/12/2016)... 2016 /PRNewswire/ - Demers Ambulances announces its first delivery in the ... Okaloosa County Emergency Medical Services (EMS) consisting of ... LT2 van. Quality Emergency Vehicles in Lecanto, FL ... sale.  This is the latest in Demers, ongoing expansion of ... at Demers. --> Benoit LaFortune , Executive Vice ...
(Date:2/12/2016)... HOUSTON , Feb. 12, 2016  Memorial Hermann ... center Dwight Howard to bring a one-of-a-kind ... Hospital . Using cutting-edge technologies such as 360-degree video ... kids both virtually, then literally – giving the patients ... – and it was all caught on video ...
(Date:2/12/2016)... 2016  Aralez Pharmaceuticals Inc. (Nasdaq: ARLZ ) ... will ring the Nasdaq Closing Bell at the Nasdaq ... at 4:00 p.m. ET on Tuesday, February 16, ... Adrian Adams , will perform the honorary bell ... p.m. ET.  A live webcast will be available at: ...
Breaking Medicine Technology: