Veterinary researchers discover first U.S. strains of hepatitis E virus from rabbits | ScienceBlog.com

Researchers in the Virginia-Maryland Regional College of Veterinary Medicine at Virginia Tech have identified the first strains of hepatitis E virus from farmed rabbits in the United States.

It is unknown whether the virus can spread from rabbits to humans.

Caitlin Cossaboom of Salisbury, Md., a second-year student in the combined Doctor of Veterinary Medicine and Ph.D. program in the Department of Biomedical Sciences and Pathobiology, is the first author of a publication entitled “Hepatitis E Virus in Rabbits, Virginia, USA” in the November issue of Emerging Infectious Diseases, published by the U.S. Centers for Disease Control and Prevention.

“Although researchers found hepatitis E virus in rabbits in China in 2009, this is the first time the virus has been identified in rabbits in the United States or anywhere outside of China,” Cossaboom said.

Dr. X.J. Meng, professor of biomedical sciences and pathobiology in the veterinary college, Cossaboom’s graduate advisor, and senior author of the study, identified the first animal strains of hepatitis E virus — swine hepatitis E virus from pigs — in 1997.

Following the landmark study on swine hepatitis E virus by Meng and his colleagues at the National Institutes of Health’s National Institute of Allergy and Infectious Diseases, researchers began to consider hepatitis E virus a zoonotic virus.

“Since 1997, researchers have found hepatitis E virus in pigs essentially in every swine-producing country and shown that the virus from pigs can infect humans,” said Meng.

He added that his lab also identified avian hepatitis E virus from chickens in the United States and that other researchers later discovered strains of the virus in other animal species, including rats, mongoose, deer, and wild boars.

Hepatitis E is an acute hepatic disease caused by infection with an RNA virus that has a fecal-oral transmission route.

The disease is mainly prevalent in developing countries, though sporadic cases have been reported in industrialized countries such as the United States.

The mortality rate associated with hepatitis E virus infection in humans is generally less than 1 percent, but it can reach up to 28 percent in infected pregnant women.

The virus has at least four distinct genotypes. Genotypes 1 and 2 infect only humans and typically occur in developing countries with poor sanitation conditions.

Meanwhile, genotypes 3 and 4 are zoonotic, can spread from animals to humans, and are found in both industrialised and developing countries.

“It is worth noting that the strains of the virus found in rabbits in the U.S. and China closely relate to genotype 3, a genotype that has been shown to transfer from animals to humans,” Meng said.

“The question is, ‘Do the strains of hepatitis E virus in rabbits infect humans?’ We don’t know, but the possibility is there and more research is needed to address this potential concern.”

She added that pigs can serve as “animal reservoirs” for genotypes 3 and 4 hepatitis E virus. In other words, the pigs can carry and shed the virus, and occasionally the virus may transmit to humans.

“However, it is unknown if the virus from rabbits can infect across species or serve as a reservoir,” Cossaboom said.

There are five known types of viral hepatitis: Hepatitis A transmits from person to person from ingesting contaminated food and water. Hepatitis B and C spread by blood-to-blood contact; the hepatitis C virus can also cause chronic infection and, in some cases, liver cancer.

Hepatitis D occurs in individuals who already have hepatitis B. Although all of these viruses, including hepatitis E virus, target the liver, none of them are genetically related.

The Finless porpoise - Neophocaena phocaenoides

You are probably aware of most river dolphins but today it's time to learn more about the lesser known 'river pig' or finless porpoise (Neophocaena phocaenoides).

The charming finless porpoise is very much a coastal species, predominantly found in salt water areas of the Indo-Pacific region. However, a small and endangered population of the porpoise inhabits the infamous Yangtze River and its tributaries.

Very little is known of the species, as is common with most of the cetaceans covered in this series of blogs, but the plight of the baiji (Yangtze river dolphin) from the Yangtze River has drawn obvious attention towards the oddly named “river pig”.

As its name suggests, it is the "finless" porpoise

Much debate has occurred over recent years over the genetic distinction of a number of sub-species of finless porpoise. Many populations are geographically isolated and this has led to the rise of the currently recognised three sub-species. Of which, the Chinese population of freshwater dwelling porpoises is one – Neophocaena phocaenoides asiaeorientalis.

As with other species of porpoise, N. phocaenoides is not known to be overly acrobatic and shies away from boats and human disturbance. The tragedy of the Yangtze River population is that the levels of human disturbance and boat traffic in the region are so high that many individuals now readily approach boats. They have therefore become more vulnerable to the usual suspects of by-catch in fishing gear and direct boat collision.

Unfortunately, their ‘cute’ looks and approachable behaviour have also led to the river population being exploited for the aquarium trade. In conjunction with all the same impacts that pushed the baiji to extinction in recent years, this represents some the most irresponsible of practices the aquarium trade takes part in worldwide.

The finless porpoise is one of the only species of cetacean not to have a dorsal fin.

However, the lack of action and consequent tragic loss of the baiji has spurned more rapid action in conserving the finless porpoise population of the Yangtze River. The Tian-e-Zhou Oxbow Nature Reserve, an area of wetland in the Yangtze basin near Shishou City, was originally intended for the baiji.

More recently it has been adopted as a ‘safe haven’ for the finless porpoise in which 28 individuals live. Chinese conservationists wish to follow this example, in the fight to conserve the river dwelling populations, by using other sanctuaries and reserves that were previously set up for the baiji.

The Tian-e-Zhou population is by no means a strong population and with the only other ‘stronghold’ of finless porpoises in China (in Poyang Lake) coming under threat from dredging activities, their future looks bleak.

Chinese conservationists have, however, insisted that the population can be saved if sufficient action is taken immediately. Sand dredging in Poyang Lake has provided a quick and sizeable cash injection into the area.

Whilst the lake holds a quarter of all finless porpoises found in China, the boats are the primary cause of an extremely high porpoise death toll. If sufficient protection is put in place for the porpoises and the dredging activities are more strictly controlled, the future of the Poyang finless porpoises may well be restored.

As with many other species of cetacean, their future may rely on tourist revenue replacing the income streams created from the impacting practices, such as sand dredging and fishing.

Taiwan Farmers Potty Train their Pigs to Reduce Pollution

Farmers in southern Taiwan have started to potty-train their pigs in response to a planned water pollution fee, breeders and officials said Monday.
To keep their livestock from defecating into nearby rivers, a growing number of farms have established special "toilets" smeared with faeces and urine to attract the pigs -- and farmers say the results have been very encouraging.

"The pig toilets on my farm help me collect about 95 percent of all pig waste, making cleaning much, much easier," Chang Chung-tou, a pig farmer in Yunlin county, told AFP.

The Environmental Protection Administration, which will introduce a new fee on water pollution in the middle of 2010, plans to encourage other pig breeders to begin potty training.

"Apart from Yunlin, we have launched trial pig toilets in Changhua county (in central Taiwan). We are evaluating the results," an official from the administration said.

Taiwan has a total of about six million pigs, most of them raised on farms in the centre and the south.

One in five complaints about water pollution received by the administration is about waste from livestock farms.