filovirus

Ebola, Marburg viruses edit genetic material during infection

Filoviruses like Ebola “edit” genetic material as they invade their hosts, according to a study published this week in mBio®, the online open-access journal of the American Society for Microbiology. The work, by researchers at the Icahn School of Medicine at Mount Sinai, the Galveston National Laboratory, and the J. Craig Venter Institute, could lead to a better understanding of these viruses, paving the way for new treatments down the road.

Using a laboratory technique called deep sequencing, investigators set out to investigate filovirus replication and transcription, processes involved in the virus life cycle. They studied the same Ebola virus species currently responsible for an outbreak in West Africa, and also analyzed a related filovirus, Marburg virus, that caused a large outbreak in Angola in 2005 and recently emerged in Uganda. The scientists infected both a monkey and human cell line with both viruses, and analyzed the genetic material produced by each virus, called RNA.

“Our study suggests that the Ebola virus is making forms of proteins previously undescribed,” said lead author Reed Shabman, PhD, an assistant professor at the J. Craig Venter Institute in Rockville, Md. Shabman was at Mount Sinai when the study was initiated. “Understanding the products of these viruses is critical to understanding how to target them.”

For you people worried about Ebola.

Earlier this summer ironically, I did a lot of research on the Ebola virus itself, after having a summer assignment for my AP Biology class that required me to read a novel entitled The Hot Zone by Richard Preston. So. I’m going to educate all of you to the best of my ability.

I noticed this morning how “Ebola” is trending on tumblr, and after a brief look at the tag I noticed that it was nothing but absolute panic about how everyone is going to die and how “people infected with the virus do not belong in the US”. Well let me tell you all a thing about the filovirus called Ebola. First of all, calm down. If you look at the facts about the outbreak, you’ll notice that the largest strain that is infecting people is Ebola Zaire, which guess what? It can’t travel through the air. The only way you will catch it is by coming in contact the the bodily fluids(blood, urine, etc.) of an infected person. Now I won’t lie, the fatality rate of the Ebola virus isn’t very pretty being 90%, BUT the major outbreak is in Africa, where they generally have outbreaks about once a year. 

Now for everyone who is whining about the Ebola infected people coming into the United States. If you honestly think they are going to put a deadly virus in one of your normal hospital rooms where you have easy access to the infected person you’re a little wrong and may want to think more about extreme biocontainment measures being taken. The United States understands how deadly this virus is, having had an outbreak of it in Virginia back in the 1980s. Even though that outbreak was of a different strain, Ebola Reston, and it was only fatal in monkeys; the US Military and the CDC fully understand what they are doing and I highly doubt we have anything to worry about.  In all honesty the virus will probably run it’s course and will probably go back into hiding in the rain forests of Africa, and we won’t have anything to worry about. It probably will not wipe out the United States population, the world won’t fall into nothingness, and we’re all going to live. Because in all honesty, how many of you guys leave your houses anyway?
Making sense of Ebola

Information and indeed misinformation about Ebola spread with speed and vigour comparable to the disease itself, but with such a deluge of often misleading news in light of the recent outbreaks in West Africa, it can be difficult to discern the valuable from the reactionary.

Classification

To fully appreciate both the threat of disease and the beauty of the etiologic agents, it is useful to start at the beginning. Ebola Virus disease (EVD), also known as Ebola hemorrhagic fever (EHF) first emerged in Yambuku, Zaire, home to the Ebola river after which the disease is named. Ebola viruses are Group V ((-)ssRNA) viruses; Order: Mononegavirales; Family: Filoviridae; Genus: Ebolavirus.

The Ebolavirus genus is comprised of 5 species each named after the location of their initial emergence. Of the 5, Zaire ebolavirus is the type species:

  • Species: Tai Forest ebolavirus
  • Virus: Tai Forest virus (formerly Cote d’Ivoire ebolavirus)
  • Species: Reston ebolavirus
  • Virus: Reston virus
  • Species: Sudan ebolavirus
  • Virus: Sudan virus
  • Species: Zaire ebolavirus 
  • Virus: Ebola virus
  • Species: Bundibugyo ebolavirus
  • Virus: Bundibugyo virus

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A virus species is defined as a polythetic class of viruses which constitute a replicating lineage, occupying a specific ecological niche. To contextualise this, the virus behind the recent ongoing Ebola outbreak in Guinea and elsewhere in West Africa is Ebola virus (Zaire ebolavirus) (found to be 97% identical to those found previously in the Congo and Gabon by Baize et al.) Whereas the virus responsible for the 2012 Ebola outbreak in Orientale Province, Democratic Republic of the Congo was Bundibugyo virus. Understandably, this can cause confusion among both the public and experts and can make it difficult to understand the epidemiology and virology of Ebola outbreaks.

The family Filoviridae to which Ebolaviruses belong are so named due to their characteristic thread-like appearance and are not a welcome sight for any virologist, even those operating within the stringent confines of a Biosafety Level-4 containment facility. These images and indeed the catastrophic symptoms they herald in those infected have crystallised Ebola in the nightmares of many. 

Symptoms

A staggering 90% of those suffering with Ebola die within days of the onset of symptoms and there are no treatments or preventative measures beyond containment due to the relative rarity of outbreaks. On July 6, 2014, the Guinea Ministry of Health announced a total of 408 suspect and confirmed cases of Ebola hemorrhagic fever (EHF), including 307 fatal cases.

Incubation periods of Ebola hemorrhagic fever may range from as little as one day to several weeks, making it wildly unpredictable and difficult to control. Furthermore, initial symptoms of Ebola are ambiguous and similar to those observed in other tropical fevers, including headaches, joint and muscle pain and a high fever; this further serves to delay control efforts and quarantines. For the unfortunate majority, these initial stages generally progress to the catastrophic haemorrhagic stage for which the disease is infamous. Victims frequently suffer from bloody vomit and diarrhoea as well as a haemorrhagic rash which covers the skin, eyes and mucous membranes. Dramatic blood loss occurs from every orifice and this disastrous final stage leads to death from exsanguination and multiple organ failure within hours.

This dramatic haemorrhaging is not entirely under the control of the virus but rather results from the hosts immune response to the disease. Host antibodies flood the circulation, clogging the blood stream and attacking blood vessels leading to sustained, heavy internal bleeding.

Vectors and Transmission

Both the dead and the surviving Ebola victims remain contagious for over a month, shedding the viruses in their tears, blood, saliva, faeces and even semen. It is for this reason that outbreaks of Ebola are not considered to be over unless there have been no further cases for a 2 month period following the death or recovery of the last victim.

Little is known about the natural reservoirs of Ebolaviruses, nor is there any clear evidence to suggest a definitive vector. With each outbreak of the disease scientists are able to learn more, but certainly in the case of the most recent outbreak, the virus, as ever, appears without constraint and several steps ahead as we scramble to keep up.

Further information

A team of international researchers has discovered a new Ebola-like virus – Lloviu virus – in bats from northern Spain. Lloviu virus is the first known filovirus native to Europe, they report in a study published in the journal PLOS Pathogens.

The study was a collaboration among scientists at the Center for Infection and Immunity (CII) at Columbia University’s Mailman School of Public Health, the Instituto de Salud Carlos III (ISCIII) in Spain, Roche Life Sciences, Centro de Investigación Príncipe Felipe, Grupo Asturiano para el Estudio y Conservación de los Murciélagos, Consejo Suerior de Investigaciones Científicas and the Complutense University in Spain.

Filoviruses, which include well-known viruses like Ebola and Marburg, are among the deadliest pathogens in humans and non-human primates, and are generally found in East Africa and the Philippines. The findings thus expand the natural geographical distribution of filoviruses.

Primary source: PLoS Pathogens

((this is kind of frightening!  O_O))

Ebolavirus (EBOV)

Seriously, today is E and I am talking about viruses; how could I not choose Ebola? Well this nasty little Filovirus causes Ebola Hemorrhagic Fever, the mortality of which can be from 50-89%, depending on what species you have attacking your endothelial cells. EBOV is kept at a biosafety level 4, right up there with smallpox and all those other highly lethal aerosol-transmitted pathogens.  EBOV is also considered to be a prime target for biological weaponization.  If this ever happens, I want to die as one of the 15% of people that displayed hiccups as a symptom.

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