Category Archives: Virus

eLife — Filovirus receptor NPC1 contributes to species-specific patterns of ebolavirus susceptibility in bats –

Melinda Ng, Esther Ndungo, Maria E Kaczmarek, Andrew S Herbert, Tabea Binger, Ana I Kuehne, Rohit K Jangra, John A Hawkins, Robert J Gifford, Rohan Biswas, Ann Demogines, Rebekah M James, Meng Yu, Thijn R Brummelkamp, Christian Drosten, Lin-Fa Wang, Jens H Kuhn, Marcel A Müller, John M Dye, Sara L Sawyer, Kartik Chandran

Abstract

Biological factors that influence the host range and spillover of Ebola virus (EBOV) and other filoviruses remain enigmatic. While filoviruses infect diverse mammalian cell lines, we report that cells from African straw-colored fruit bats (Eidolon helvum) are refractory to EBOV infection. This could be explained by a single amino acid change in the filovirus receptor, NPC1, which greatly reduces the affinity of EBOV-NPC1 interaction. We found signatures of positive selection in bat NPC1 concentrated at the virus-receptor interface, with the strongest signal at the same residue that controls EBOV infection in Eidolon helvum cells. Our work identifies NPC1 as a genetic determinant of filovirus susceptibility in bats, and suggests that some NPC1 variations reflect host adaptations to reduce filovirus replication and virulence. A single viral mutation afforded escape from receptor control, revealing a pathway for compensatory viral evolution and a potential avenue for expansion of filovirus host range in nature.
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Bats and Rodents Shape Mammalian Retroviral Phylogeny

Bats and Rodents Shape Mammalian Retroviral Phylogeny
Jie Cui, Gilda Tachedjian & Lin-Fa Wang

Scientific Reports 5, Article number: 16561 (2015)
doi:10.1038/srep16561

Abstract
Endogenous retroviruses (ERVs) represent past retroviral infections and accordingly can provide an ideal framework to infer virus-host interaction over their evolutionary history. In this study, we target high quality Pol sequences from 7,994 Class I and 8,119 Class II ERVs from 69 mammalian genomes and surprisingly find that retroviruses harbored by bats and rodents combined occupy the major phylogenetic diversity of both classes. By analyzing transmission patterns of 30 well-defined ERV clades, we corroborate the previously published observation that rodents are more competent as originators of mammalian retroviruses and reveal that bats are more capable of receiving retroviruses from non-bat mammalian origins. The powerful retroviral hosting ability of bats is further supported by a detailed analysis revealing that the novel bat gammaretrovirus, Rhinolophus ferrumequinum retrovirus, likely originated from tree shrews. Taken together, this study advances our understanding of host-shaped mammalian retroviral evolution in general.

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Click on the Link below to access the complete paper:
http://www.nature.com/articles/srep16561

Emerging Infectious Disease: Filovirus RNA in Fruit Bats, China

“…
Phylogenetic analysis showed that the Bt-DH04 strain is placed, together with LLOV, at basal position and intermediate between EBOV and MARV (Figure). It is divergent from all known filoviruses, with F1 sharing the highest nucleotide identities (46%–49%) to members of the genus Ebolavirus, followed by 44% to LLOV and <40% to MARV (Figure, panel A). The L gene is the most conserved region of filoviruses, and F2 of Bt-DH04 strain shared relatively closer 66%–68% nt identities with members of the genus Ebolavirus, followed by 64% with LLOV and ≈60% with MARV (Figure, panel B). This sequence diversity is likely the main factor for unsuccessful amplification of the full genome of Bt-DH04."

Click on the Link to access the complete letter:
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4550138/

ABC Australia — Hendra virus fears prompt cancellation of Aberdeen campdraft

Updated Mon at 5:32pm

Aberdeen Bushmen’s Campdraft cancelled

Fears thousands of bats may be carrying the deadly hendra virus have forced the cancellation of a Hunter Valley campdraft event.

Organisers of the Aberdeen Bushmen’s Campdraft say the annual event was scheduled for the last weekend of this month, but could take place in September instead.

Hendra has killed four people and 90 horses since it was discovered in Brisbane in 1994.

Event secretary Scott Ryan said organisers will meet in four weeks to determine whether the bats have moved on.

“We’ve got some bat problems up there at the moment, and they look like they’re here to stay for a little while,” he said.

“Just with the hendra virus going around at the moment, more up in the Queensland area, but everyone’s a bit worried about putting horses under bats.

“You know, they get really sick and have to be put down, and it can also be passed on to vets or anyone who has come into contact with a horse.

“People can die from it as well, so it’s pretty scary stuff.”

Mr Ryan said last month’s super storm has been blamed for the bats moving into the area.

“There’s thousands of bats down there,” he said.

“Supposedly, they’ve come from the coast, but because of the recent cyclonic weather on the coast they’ve come up the Hunter Valley, is what we’ve been told.

“It’s down on the river bank, this local government property.

“These bats are in all the trees where all the competitors will be camping.”

A Hunter Valley equine vet is urging Upper Hunter horse owners to make themselves aware of the health impacts flying foxes can have on them and their animals.
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Click HERE for the complete article.
http://www.abc.net.au/news/2015-05-12/hendra-virus-fears-prompt-cancellation-of-aberdeen-campdraft/6462042

Economic & Political Weekly — Bat Hunts and Disease Outbreaks

Traditional Bat Hunting in Nagaland

Vol – L No. 18, May 02, 2015 | Pilot Dovih

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There are various factors why infectious agents from wildlife jump over to humans causing illness and death. One of the significant causes are factors that bring wildlife and humans in close contact with each other. One such important human-wildlife interface is bush meat hunting; this combined with various other factors such as a rapidly growing human population, unsustainable natural resource consumption, biodiversity loss and habitat fragmentation have increasingly pushed wildlife and humans in close contact with each other, resulting in increased incidence of disease spillover and outbreaks during recent years.

Such factors have increasingly exposed us and our domesticated animals to viruses that earlier lacked such numerous opportunities for viral spillover. As we rapidly alter natural landscapes, converting them into farmland or other development projects, we alter habitats, changing the interaction between wildlife and humans. Bushmeat hunting provides one of the most intimate contacts between humans and wildlife, providing ample opportunities for the virus to jump over to humans. Very high bushmeat hunting has been documented in West Africa (David S 1998), which might have been the reason for high occurrence of zoonotic diseases there (Wolfe et al 2005). Though there have been very few such studies in India, one study shows high quantity of bushmeat consumption in Northeast India (Hilaluddin 2005).

Bushmeat hunters are exposed to lethal viruses, as they cut open the animal and are directly exposed to body fluids such as blood, saliva, urine and faeces. One of best known examples for disease spillover from wildlife to humans is acquired immunodeficiency syndrome (AIDS), which is thought to have jumped to humans from non-human primates through bushmeat in Africa. The SARS outbreak of 2002 is known to have originated from a wet market in China, where live wild animals are regularly slaughtered and kept in close contact with each other and humans. Other infections which are thought to have originated from wildlife include Ebola virus, Nipah virus, West Nile virus, SARS-CoV; a large number of these viruses have also been detected in bats.

The Longpfurii Yimchungii, a Naga sub-tribe, living in Mimi village in Nagaland, participate in a unique, annual bat harvesting festival in mid-October. The village is situated along the Indo-Myanmar border and comprises around 200 households, mainly occupied by 3 clans namely Bomrr, Whourr and Mer.
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Click HERE for the complete article.
http://www.epw.in/web-exclusives/bat-hunts-and-disease-outbreaks.html

Bloomberg — Ebola Antibodies in Zambia Bats Match West African Virus

By Matthew Hill

(Bloomberg) — Ebola antibodies found in bats in Zambia seem to show that the species of the disease they have been exposed to match outbreaks as far as 5,000 kilometers (3,100 miles) away, including the one that’s killed more than 10,000 people in West Africa.

A study, conducted by scientists including Hokkaido University’s Professor Ayato Takada and published in the Journal of Infectious Diseases last week, found the transition of the antibodies for the virus family that includes Ebola coincided with flare-ups in humans from 2005 to 2013. Data for 2014 is still being analyzed.
Scientists are still analyzing samples from last year so they cannot definitively say they coincide with the latest Ebola outbreak, Takada said.

The study explores the theory that straw-colored fruitbats become infected with Ebola from natural reservoirs in central Africa but don’t carry the actual virus to Zambia. Alternatively, it hypothesizes that the bats themselves act as the reservoirs from which outbreaks into human populations periodically occur. In addition to primates, filoviruses such as Ebola can infect dogs, pigs and duikers, a small species of antelope. Conclusive evidence of either of the hypotheses wasn’t found.

Jungle Reservoir
“I do not believe that this bat species serves as a natural reservoir of filoviruses, but our serology data suggest that they can be infected,” Takada said in reply to e-mailed questions on Thursday. “This further suggests that they might have a chance to contact with authentic natural hosts of filoviruses somewhere central Africa.”

Click HERE for the complete article.
http://www.bloomberg.com/news/articles/2015-03-27/ebola-antibodies-in-zambia-bats-match-west-african-virus-species

Sky News Australia — Deadly bat lyssavirus detected in NT

Northern Territory residents and visitors are being warned not to handle bats after a flying fox tested positive to the deadly Australian bat lyssavirus.

This is the second bat to test positive in a matter of months and only the third case for the Northern Territory since the first was detected in 1997.

Found Australia-wide, the virus is very similar to rabies, and symptoms include severe headaches and convulsions, before it paralyses breathing and causes a fatal brain inflammation.

All three people who have contracted the virus, in Queensland, have died.

The infected flying fox was under the care of a bat carer when it became sick and died, said Malcolm Anderson, the NT’s chief veterinary officer.

‘The disease, like rabies, can have a very long incubation period, so it can be in an animal for a long time before they show signs … six months or 12 months,’ he said.

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Click HERE for the complete article.
http://www.skynews.com.au/news/local/darwin/2015/03/11/deadly-bat-lyssavirus-detected-in-nt.html