1. medical community was unsure of how



We Will Write a Custom Essay Specifically
For You For Only $13.90/page!

order now




Ebola virus is a relatively recently discovered virus, that when it infectshumans, caries with it a 50-90% fatality rate. Symptoms of this deadly virusinclude Sudden Fever, Weakness, Muscle Pain, Headache, Sore Throat, Vomiting,Diarrhea, Rash. Internal results include Limited Kidney Function, Limited LiverFunction, and Internal and External Bleeding.

The incubation period for the Ebola virus ranges from 2 to 21 days, dependingupon the method of infection. A direct inoculation of the virus into the bloodstream ofa human will bring about symptoms markedly faster than other forms of less directcontact. The virus is present in the male’s reproductive fluids, and can be transmittedthrough sexual contact for up to 7 weeks after clinical recovery from the Ebola virus.The Ebola virus can be diagnosed with laboratory testing of blood specimensunder maximum containment conditions – because of the high risk of infection to thosehandling infected blood.

There is currently no treatment or vaccination available for the Ebola virus.Transmission of the Ebola virus occurs by direct contact with the bodily fluidsof patients infected with the virus. The handling of chimpanzees that are either ill orhave died from the Ebola virus can also transmit the virus. Any suspicion of infection with the Ebola virus should be treated with extremecaution: immediate isolation from other patients and strict barrier nursing techniquesmust be practiced. All instruments, clothing, or biological matter must be eitherdisposed of or thoroughly disinfected immediately.The initial outbreaks of the Ebola virus occurred in 1976.

Springing forth fromunknown origins, this virus held the nations of Zaire in fear as it quickly claimed the livesof many of it’s citizens. As this was the first recorded outbreak of the Ebola virus, themedical community was unsure of how to handle Ebola. The level of care in Zaire duringthis outbreak was very low, and as a result of the many infected victims congregated inpublic areas, the virus continued to spread among the denizens of Zaire. The interveningyears have slowly produced scientific data on the nature of the virus – yet treatment is stillunavailable for those infected.

The first outbreak, as stated earlier, occurred in Zaire in 1976. This first outbreakwas followed by one in western Sudan, also in 1976. In total, these two outbreaks havebeen traced to the deaths of 340 people – resulting from the 550 plus cases that wereidentified in these two nations.After lying dormant for several years the Ebola virus onceagain made it’s presence known in 1979. Once again, no cause was identified as 34 casesof Ebola were identified in Sudan. This occurrence brought the deaths of 22 patients -showing a fatality rate of more than 60%, just as in the 1976 outbreaks. The next instance of humans contracting the Ebola virus occurred in 1995. TheEbola Zaire strain was discovered once again on April 10, 1995 when a patienthospitalized for what was believed to be Malaria infected the surgical team during anoperation.

Those involved with the operation developed symptoms indicating a viralhaemorrhagic fever disease. This outbreak occurred in the city of Kikwit, Zaire. Althoughthe virus was spreading at a rapid rate, a coordinated effort of international health serviceswas able to contain the outbreak. Present in this coalition of health organizations was theCenters for Disease Control and Prevention (the CDC) and the World Health Organization- aided by members of the medical community from France, Belgium, and several southernAfrican nations. In this most recent epidemic (defined as all cases occurring from 1 July1995), approximately 233 deaths have been caused, and 293 cases identified as Ebola -bringing the fatality rate to nearly 80% in the outbreak of 1995) Ebola was also detected in the United States in 1989, but this strain of the virus, known asEbola Reston, is not harmful to the Homo Sapien population. In 1989 a shipment ofAfrican Green and Rhesus Monkeys arrived in Reston, Virginia from the Philippines.These monkeys were infected with the Ebola virus, yet no human cases were documented.

149 workers came into contact with these monkeys in Reston, Virginia and not onebecame ill – although two did develop antibodies for Ebola Reston. A recent outbreak of the Ebola Virus occurred in November of 1995. There hadbeen a rash of deaths in the population of chimpanzees living within the Tai Forest.

On 24November 1995, a Swiss researcher on the Cote d’Ivore of West Africa contracted thedisease from an infected chimpanzee in the Tai Forest. The researcher was rushed to aSwiss hospital where she recovered. After an autopsy of the chimpanzee indicated that itwas showing effects similar to those visible in human patients, a search began for thelocale the virus is indigenous to. However, the Tai Forest comprises over 4200 squarekilometers, and field researchers were unable to locate the virus. The Ebola virus has not been very researchable. Part of the difficulty is that thevirus is so communicable, research must be conducted in very strictly controlledsettings requiring safeguards and equipment that are beyond the reach of manylaboratories. Also, because of the Ebola virus’ very lethal tendencies, it isextraordinarily difficult to obtain a specimen for research. The most concentrated research efforts to date have been performed by theWorld Health Organization and the Centers for Disease Control and Prevention.

Although some understanding of the virus has occurred, much of the informationneeded to develop a treatment and vaccine still remains elusive to researchers.Research has led to a better understanding of the pattern of symptoms whichthe Ebola virus causes in humans. Most patients arrive overtly ill, dehydrated,apathetic, and disoriented – further medical investigation quickly shows othersymptoms indicating an infection with the Ebola virus. The Ebola virus is best knownfor the extraordinary amount of bleeding, both internal and external, that it causes init’s victims. The death of the patient usually occurs within 7 to 16 days, with thespecific cause being shock – often accompanied with severe blood loss.

As early as 10-14 days after infection with either the Marburg or Ebola viruses,an immune response can be detected. The primary response of the immune system is toproduce antibodies against the surface glycoproteins. This response is relativelyineffective in that the Ebola still flourishes within the human body and is fatal to mostinfected persons. There is also little known about the cell-mediated response to theseviruses.

The pathology of the Ebola virus produces lesions found in liver, spleen, andkidney. They are characterized by focal hepatic necrosis and by follicular necrosis ofthe lymph nodes and spleen. As the disease progress into it’s later stages, hemorrhageoccurs in the gastrointestinal track, pleural, pericardinal, and peritoneal spaces.Abnormalities in the coagulation occur(blood), suggesting that disseminatedcoagulation is a terminal event. Research also points out that macrophages andfibroblasts appear to be the initial and also preferred site of replication by Ebola.

Experimental treatments have included human interferon, human convalescentplasma and anticoagulation therapy. These treatments, however, have met with mixedresults and any success is quite controversial. The only effective preventative measurecurrently known is to crate a physical barrier of some sort – surgical masks, quarantinewards, et cetera – that is capable of blocking the transmission of the virus to currentlyuninfected patients.As stated previously, past research has been significantly slowed as a result of theextreme pathogenicity of the Ebola virus, as well as the Marburg virus. Recombinant DNAtechnology holds hope in that the molecular structure of the virus is beginning to beunderstood. This type of research will also lead to an understanding of the way in whichthis virus replicates itself and the interactions that occur between virus and host. The goalis to gain an understanding of the frequency, ways in which it is transmitted, and also toidentify where in nature the Ebola virus naturally resides – to identify it’s initial hostorganism. Ebola timeline/ Overview1.

Viral hemorrhagic fever in southern Sudan and Northern Zaire. Bowen et al., Lancet,’77, 1:571-573. 2. Management of patients with suspected viral hemorrhagic fever. CDC-Morbidity andMortality Weekly Report, Supp. 37/S-3:1-16, 1988. 3.

Update: Ebola-related filovirus infection in nonhuman primates and interim guidelinesfor handling nonhuman primates during transit and quarantine. CDC- MMWR,39(2):22-4,29-30,1990 4. Biosafety in Microbiological and Biomedical Laboratories. CDC/NIH, HHS PublicationNo.

CDC-1993, 3rd Edition. 5. Epidemiologic investigation of Marburg virus disease, Southern Africa, 1975. Conrad,et al., Am. J.Trop. Med.

Hyg.,’78, 27:1210-1215. 6.

Molecular biology and evolution of filoviruses. Feldmann et al., Arch.Virol (supp)1993;7:81-100. 7. Association of Ebola-related Reston virus particles and antigen with tissue lesions ofmonkeys imported to the United States, Geisbert et al., J. Comp.

Path., ’92, 106:137-152. 8. Preliminary Report: isolation of Ebola virus from monkeys imported to USA, Jahrlinget al., Lancet, ’90, 335:502-05. 9. Isolation and partial characterization of a new virus causing acute hemorrhagic fever inZaire.

Johnson, et al., Lancet, ’77, 1:569-571. 10. Agent of disease contracted from green monkeys. Kissling et al., ’68, Science, , 160,888-890.

11. Pathology of Ebola virus infection. Murphy, F.

A.. in: Ebola Virus Hemorrhagic fever,ed.Pattyn, pp 37-42.

1978. Elesvier/North Holland, Amsterdam. 12. Marburg virus morphology and taxonomy. Murphy, F.A.

(in same text as above). pp61-82. 13.

Marburg virus infection in monkeys. Murphy et al. Lab.

invest., ’71, 24:279-291. 14.Filorviruses. Peters CJ et al. in: Emerging Viruses. S.Morse, Ed.

, pp 159-75. OxfordUniversity Press, New York. 1991.

15. Filoviruses as emerging pathogens. Peters CJ et al. Seminars in Virology, ‘94,5:147-154. 16. Sequence analysis of the Ebola virus genome: organization, genetic elements, andcomparison with Marburg. Sanchez et al.

, Virus Res. ’93, 29:215-240. 17.

Firsthand clinical observations of Ebola hemorrhagic fever in Zaire. Rev. Inf.

Dis., ‘89,11:S-790-793.


I'm Mary!

Would you like to get a custom essay? How about receiving a customized one?

Check it out