Ebola virus: Difference between revisions

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==Transmission==
==Transmission==
<br>Ebola is transmitted through bodily fluids and/or direct contact with infected individuals. It is believed to spread to human populations through contact with infected primates, as opposed to from natural reservoirs. The suspected natural sources of the virus are species of fruit bats. They have been found to carry the virus, but they themselves are asymptomatic, making them good candidates for natural reservoirs.<br>Outbreaks of Ebola virus are often traced to an individual that has handled a gorilla or chimpanzee carcass. It is common for the virus to then spread to family members or hospital workers. The virus spreads to people that come into contact with these patients’ blood or contaminated medical equipment. Because Ebola kills its victims so quickly and the outbreaks usually occur in isolated areas, the disease does not typically spread very far. Also, Ebola has an incubation period of up to 21 days, but is normally closer to 10 days; so infected persons do not have time to carry the disease very far. It is highly unlikely that Ebola could turn into an epidemic.  <br> Oftentimes Ebola outbreaks are mistakenly classified initially as outbreaks of malaria, dysentery, influenza, typhoid fever or other bacterial infections because the early symptoms are similar and these infections are common in the areas. This misinterpretation of symptoms can lead to spread of the virus within medical centers because necessary precautions are not taken.  
<br>Ebola is transmitted through bodily fluids and/or direct contact with infected individuals. It is believed to spread to human populations through contact with infected primates, as opposed to from natural reservoirs. The suspected natural sources of the virus are species of fruit bats. They have been found to carry the virus, but they themselves are asymptomatic, making them good candidates for natural reservoirs.<br><br>Outbreaks of Ebola virus are often traced to an individual that has handled a gorilla or chimpanzee carcass. It is common for the virus to then spread to family members or hospital workers. The virus spreads to people that come into contact with these patients’ blood or contaminated medical equipment. Because Ebola kills its victims so quickly and the outbreaks usually occur in isolated areas, the disease does not typically spread very far. Also, Ebola has an incubation period of up to 21 days, but is normally closer to 10 days; so infected persons do not have time to carry the disease very far. It is highly unlikely that Ebola could turn into an epidemic.  <br> <br> Oftentimes Ebola outbreaks are mistakenly classified initially as outbreaks of malaria, dysentery, influenza, typhoid fever or other bacterial infections because the early symptoms are similar and these infections are common in the areas. This misinterpretation of symptoms can lead to spread of the virus within medical centers because necessary precautions are not taken.<br><br>
Transmission of Ebola virus among non-human animals is a little different. It is proposed that fruit bats drop partially eaten fruits that carry viruses in the bat saliva. Gorillas or other monkeys then eat the fruit, and therefore the virus as well.  Gorilla carcasses have been found to contain multiple strains of Ebola virus. Decomposing bodies only remain infectious for three to four days after death, and gorillas do not typically interact among different groups, which means the victims were probably infected by several animal host reservoirs.<br>
Transmission of Ebola virus among non-human animals is a little different. It is proposed that fruit bats drop partially eaten fruits that carry viruses in the bat saliva. Gorillas or other monkeys then eat the fruit, and therefore the virus as well.  Gorilla carcasses have been found to contain multiple strains of Ebola virus. Decomposing bodies only remain infectious for three to four days after death, and gorillas do not typically interact among different groups, which means the victims were probably infected by several animal host reservoirs.<br>



Revision as of 04:53, 8 December 2009

Introduction


Ebola virus is a member of the Filoviridae viral family of RNA viruses, which are characterized by the long, thin filaments seen in micrograph images. It is named after the Ebola River where the virus was first discovered.
The virus causes Ebola hemorrhagic fever, which is a serious and usually fatal disease for those who contract it. It damages the endothelial cells that make up the lining of the blood vessels and creates difficulty in coagulation of the infected individual’s blood. As the vessel walls become more damaged, and the platelets cannot coagulate, the individual undergoes hypovolemic shock, or a dramatic decrease in blood pressure. Depending on the type of virus, Ebola can have up to a 90 percent mortality rate for those infected.
Ebola hemorrhagic fever has been reported in humans only in Africa.

There are several different types of Ebola virus that effect humans. Currently they are Zaire, Sudan, and Ivory Coast Ebola virus, named for the respective regions in Africa in which the strain was found. Reston Ebola virus is a type of Ebola that only infects non-human primates. It was first discovered in an outbreak in Reston, Virginia. Outbreaks of Ebola are sometimes caused by new strains of the virus; so more types can and are being discovered. For example, in 2007 there was an outbreak of Ebola hemorrhagic fever in the Bundibugyo District of Uganda where a new strain of the virus, as classified according to the Center for Disease Control, was found to be the cause.
Ebola virus is a large concern of public and global health because very few humans have been found that are immune to the disease and it has such a high mortality rate that it is a very dangerous virus and a potential bioterrorism agent.

Electron micrograph of the Ebola Zaire virus. This was the first photo ever taken of the virus, on 10/13/1976. By Dr. F.A. Murphy, now at U.C. Davis, then at the CDC.


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History


Ebola virus was first discovered in 1976 when an outbreak of Ebola hemorrhagic fever occurred in Zaire and another later that year in Sudan. Each outbreak had about 300 victims, but did not spread much larger than that because of the remoteness of the areas in which they occurred. The Zaire Ebola virus has one of the highest fatality rates of any pathogenic virus affecting humans. In the 1976 outbreak, it killed 88 percent of patients, 81 percent in 1995, 73 percent in 1996, 80 percent in 2001-2002, and 90 percent in 2003, although none of these outbreaks were as large as the original.
Sudan Ebola virus has a lower, yet still very dangerous, fatality rate of 53 percent in 1976, 65 percent in 1979, 53 percent in the over 400 patients infected in 2000, and 41 percent in 2004.
Ivory Coast Ebola virus was first discovered in 1994 when a scientist conducting autopsies on chimpanzees contracted Ebola hemorrhagic fever. This strain found was different than the Zaire or Sudan strains. However, this has been the only case of Ivory Coast Ebola known to have occurred in humans.

Most Ebola virus outbreaks have originated in Africa and have traveled only to other countries through shipment of non-human primates or through accidental contamination in testing facilities. Crab-eating macque that were imported from the Philippines to Reston, Virginia in 1989 were found to have a virus similar to Ebola. Over 150 animal handlers were all tested for Ebola and only 6 were found to have developed antibodies to it, none of which actually developed Ebola hemorrhagic fever. The Center for Disease Control concluded that this strain had a low infection rate for humans and it was later classified as its own strain named Reston Ebola virus.

For a complete list of Ebola cases throughout history see: Known Cases and Outbreaks of Ebola Hemorrhagic Fever, in Chronological Order compiled by the CDC.

Transmission


Ebola is transmitted through bodily fluids and/or direct contact with infected individuals. It is believed to spread to human populations through contact with infected primates, as opposed to from natural reservoirs. The suspected natural sources of the virus are species of fruit bats. They have been found to carry the virus, but they themselves are asymptomatic, making them good candidates for natural reservoirs.

Outbreaks of Ebola virus are often traced to an individual that has handled a gorilla or chimpanzee carcass. It is common for the virus to then spread to family members or hospital workers. The virus spreads to people that come into contact with these patients’ blood or contaminated medical equipment. Because Ebola kills its victims so quickly and the outbreaks usually occur in isolated areas, the disease does not typically spread very far. Also, Ebola has an incubation period of up to 21 days, but is normally closer to 10 days; so infected persons do not have time to carry the disease very far. It is highly unlikely that Ebola could turn into an epidemic.

Oftentimes Ebola outbreaks are mistakenly classified initially as outbreaks of malaria, dysentery, influenza, typhoid fever or other bacterial infections because the early symptoms are similar and these infections are common in the areas. This misinterpretation of symptoms can lead to spread of the virus within medical centers because necessary precautions are not taken.

Transmission of Ebola virus among non-human animals is a little different. It is proposed that fruit bats drop partially eaten fruits that carry viruses in the bat saliva. Gorillas or other monkeys then eat the fruit, and therefore the virus as well. Gorilla carcasses have been found to contain multiple strains of Ebola virus. Decomposing bodies only remain infectious for three to four days after death, and gorillas do not typically interact among different groups, which means the victims were probably infected by several animal host reservoirs.

Symptoms


Include some current research in each section.

Prevention and Treatment


There is currently no treatment or vaccine for Ebola.

Prevalence and Relation to Global Health


Ebola has mainly occured in Africa, with the exception of the outbreak in Virginia.

Conclusion


Overall paper length should be approximately 2,000 to 2,500 words.
Include at least two data figures.
Use professional sources, including at least two research studies.
This page was created by Andie Asimes.

References

[Sample reference] Takai, K., Sugai, A., Itoh, T., and Horikoshi, K. "Palaeococcus ferrophilus gen. nov., sp. nov., a barophilic, hyperthermophilic archaeon from a deep-sea hydrothermal vent chimney". International Journal of Systematic and Evolutionary Microbiology. 2000. Volume 50. p. 489-500.

Edited by student of Joan Slonczewski for BIOL 191 Microbiology, 2009, Kenyon College.