Ebola Virus: A Review

 

Ravi Kumar1*, Sanjeev Saini2, Chatter Singh2, Bijander Singh2, Alimuddin Saifi3

1Department of Pharmacy, Bharat Institute of Technology, Meerut

2Mahaveer College of Pharmacy, Meerut

3Department of Pharmacy, Katyayani College of Education, Meerut

*Corresponding Author E-mail:

 

ABSTRACT:

Zaire ebolavirus, more commonly known as Ebola virus (EBOV), is one of six known species within the genus Ebolavirus. Four of the six identified ebolaviruses, including EBOV, cause a severe and often fatal hemorrhagic fever in humans and other mammals, known as Ebola virus disease (EVD). Ebola virus belonging to family Filoviridae is of mainly 5 types and has a high fatality rate in humans and nonhuman primates. Once the more virulent forms enter the human population, transmitted through contact with infected body fluids, can result in major epidemics. It is one of the most virulent pathogens among the viral haemorrhagic fevers, and has been reported up to 90% fatality rate. Mortality is the result of multi-organ failure and severe bleeding complications.

 

KEYWORDS: Ebola virus, Virology, EBOV, EVD.

 

 

 

INTRODUCTION:

Ebolavirus belongs to the genus Ebolavirus which together with the genus Marburgvirus forms the family of the Filoviridae.[1] Ebola virus disease may show multiple ,serial and nonspecific disease symptoms including high fever, headache, vomiting, diarrhea, and muscles spasm, and sometimes sever internal bleeding.[2] The imported ebola virus disease case in Nigeria that resulted in a relatively small outbr, effects that are abrogated by hydrophobic mutations.eak, and similar imported case in the USA and spain.[1] Mostly cases are shown in 2013-16 west African outbreak. This outbreak was unprecedented in scale, with more than 28,000 confirmed case and 11,000 deaths. These virus are mostly spread through the rural to the urban arias in Africa.[3]

 

Zaire, Sudan and Bundibugyo Ebola virus are accountable for most of the EHF (Ebola Hemorrhagic Fever).[4]

 

Types of Ebola Virus- The Ebola Disease is caused by five genetically distinct members.

 

1.     Zaire Ebola Virus (ZEBOV):

This is most fatal among all five and has the highest case fatality rate, upto 90% in some epidemics. The symptoms of Zaire Ebola Virus has like Malaria.[4]

 

2.     Sudan Virus (SUDV):

This virus also caused threaten effect to people who’s was working in cotton factory in Nzara, Sudan.[4]

 

3.     Tai Forest Virus (TAFV):

It was first discovered among chimpanzees from the Tai forest in Cote d Ivoire, Africa. The source of contamination was believed to be the meat of infected western Red Colobus monkeys.[4]

 

 

4.     Bundibugyo Virus (BDBV):

The name of BDBV is originated from Bundibugyo which is the name one of the town of Uganda Bundibugyo District, where it was first discovered.[4]

 

5.     Reston Virus (RESTV):

It is non-pathogenic to humans however hazardous in monkey. It is found in non-humans mammals and was also in swine suffering people with reproductive and respiratory disease syndrome.[4]

 

VIROLOGY:

The family Filoviridae comprises of one genus, Filovirus, which contains two species, morphologically identical but serologically distinct: Marburg virus and Ebola virus.[5] The prefix of the family name “filo” originates from the Latin word for thread or string. Virions have multiple morphological forms of very long filamentous rods or compact convoluted shapes (diameter around 80 nm, length 800-14000 nm).[6] These are linear, negativestranded, RNA viruses with a genome of approximately 19 kilobases. Morphologically, when studied under an electron microscope, the viral particles look like long stretched filaments with some particles tending to curve into an appearance looking like the number 6.[1] Their life cycle is thought to begin with a virion attaching to specific cell-surface receptors such as C-type lectins, DC-SIGN, or integrins, which is followed by fusion of the viral envelope with cellular membranes.[7] The EBOV genome is a single negative-sensed RNA, and these RNA encodes seven structural proteins: [major glycoprotein (GP), minor glycoprotein (VP30), matrix proteins (VP40 and VP24), nucleoprotein (NP), phosphoprotein VP35 and viral polymerase (L)] and two non-structural proteins [secreted glycoproteins (sGP) and small soluble glycoproteins (ssGP)].[8] The nucleocapsid consists of ssRNA, NP, VP35 and VP30 structural proteins and viral polymerase, forming the ribonucleoprotein complex (RNP), essential in viral transcription and replication. The VP40 and VP24 proteins establish bonds with the RNP and the inner surface of the viral envelope, respectively.[9][10]

 

TRANSMISSION:

These virus are spread through the saliva of bat and some species of simians, the infected bats and simians are major infectious source of EBOV when handled or consumed by humans.[11] Transmission through the humans occurs via direct contact (mucosal surfaces or abraded skin) with the blood, organs and some body fluids like-( saliva, mucus, vomit, feces, sweat, tears, breast milk, urine, and semen)and infected people or contaminated surface with these fluids.[12],[13] Transmission through the skin is not clearly confirm.[14] Transmission from touching the diseased body is possible for at least seven days post-mortem.[15,16] Infection via the inhalation route are very common for transmission of any types of virus but there is no evidence for airborne transmission in humans.[17] [18]

 

COMPLICATIONS:

Fever:

The presenting symptom in approximately 90% of patients.[19] Wide variations in body temperature can be observed during the course of illness, especially in children,[20]

 

On Eyes:

The Uveitis is also common cause of Ebola, the main risk factor for developing uveitis in adjusted analysis was having had red/injectedeye during ETC hospitalization.[21]

 

On Circulatory System:

The Ebola virus are affect the circulatory system and caused the impaired blood clotting, in 40–50% bleeding from puncture sites and mucous membranes (e.g. mouth, gastrointestinal tract, nose, ears, vagina and gums), reddening of eyes and bloody vomit has also been reported.[4, 22]

 

On Liver:

Ebola are affect the functions of liver and causes infection and damage the endothelial cells hepatocytes.[23] As, the process of coagulation of platelets are completely diminish, this result in hypovolemic shock or decrease in blood pressure and death may also occur.[24]

 

On CVS:

Some cardiovascular disease are caused by ebola- valvulopathy, tachycardia, hypertensive cardiopathy, cardiac decompensation, palpitation, chest pain etc.[21]

 

On GIT:

Some gastrointestinal symptoms including anorexia, nausea, vomiting, diarrhea, and abdominal pain.[25]

 

On Respiratory System:

The Ebola virus are affect the respiratory system and shown the some symptom including nasal discharge, cough, and shortness of breath.[26]

 

On Blood:

In initial stages, as antigenemia increases, there is thrombocytopenia and leukopenia that is characterized by increased numbers of atypical lymphocytes. These are associated with fatal illness.[27]

 

On Kidney:

Renal function is not affect in the first week of infections and kidneys are perform the function normally.[28,29] After that, the end of the first week, patients may show a progressive decline in urine output and a rise in BUN and creatinine.[30,31] Renal failure is more common in fatal cases.[32]

 

CONCLUSION:

The filoviral infections are well defined, many aspects remain poorly characterized or incompletely documented. Some basic parameters that indicate the infections including cardiovascular function such as pulse, blood pressure, and urine output, and markers of physiologic status such as the serum electrolytes, glucose, lactate, and pH, but lacking information on changes in cardiovascular function and other data for patients with filoviral HF. Importantly, knowledge of the ecological activity of ebolaviruses in wildlife is still needed,because we are not carefully survive in our ecology system.

 

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Received on 08.02.2020            Modified on 05.03.2020

Accepted on 30.03.2020   ©Asian Pharma Press All Right Reserved

Asian J. Pharm. Res. 2020; 10(2):117-119.

DOI: 10.5958/2231-5691.2020.00022.2