The document discusses Ebola virus, which causes Ebola virus disease (EVD) or Ebola hemorrhagic fever. Ebola virus is a member of the filovirus family and is highly contagious, spreading through contact with bodily fluids. There are five types of Ebola virus that can infect humans. Symptoms include fever, muscle pain, and bleeding. While there is no proven treatment, supportive care such as rehydration can improve survival rates. Risk of transmission can be reduced by avoiding contact with infected wildlife or humans and through safe burial practices.
3. INTRODUCTION
• Ebola Virus is the member of
filoviridae family
• Filoviruses includes two members
Ebola and Marburg virus
• Filo viruses cause hemorrhagic fevers
4. DISEASE
• Ebola virus causes Ebola virus disease EBV
• Also known as Ebola hemorrhagic fever EHF (Because internal or
external bleeding)
• very high mortality (up to 90%)
• have been classified as Risk Group 4 Pathogens “biosafety level
4”
• One of the most virulent pathogen
5. FIVE TYPES
among which first four can cause infections in humans, namely
• Zaire ebolavirus
• Sudan ebolavirus
• Taï Forest Ebolavirus
• Bandibugyo ebolavirus
• Reston ebolavirus
6. EPIDEMIOLOGY
• The existence of filoviruses was first recognized in Marburg in 1967
Germany
• First time discovered in 1976 northern Zaire (Democratic Republic of
the Congo) and southern Sudan. Since 1976, there have been 885,343
confirmed cases West Africa making this part badly hit.
• The largest outbreak to date was the epidemic in West Africa, which
occurred from December 2013 to January 2016 with 28,616 cases and
11,310 deaths Other outbreaks in Africa began in the Democratic
Republic of the Congo in May 2017.
• Not reported in Pakistan
7.
8. EBOLA VIRUS STRUCTURE
• 80 nm in diameter, 970 nm long
• encoded glycoprotein (GP) projecting as 7-10 nm long spikes from
its lipid bilayer surface
• glycoprotein GP is the sole resident of the Ebolavirus surface and is
responsible for attaching to and entering new host cells
11. • VP30 is a transcription factor
• VP35 inhibits the production of interferon
• They cause extreme virulence
• VP24 protein blocks the STAT1 protein and IFN-stimulated genes.
• By inhibiting these immune responses, EBOV may quickly spread
throughout the body.
• A number of studies demonstrated that both VP35 and VP24 are
validated target for drug development
• NP codes for Nucleocapsid.
12. TARGET CELLS
• DC-SIGN also known as CD209 is a protein which in humans. DC-
SIGN is a lectin receptor present on the surface of both
macrophages and dendritic cells
• Neutrophils DC SIGNR
• It enters through Endocytosis.
14. REPLICATION CYCLE
• 1. Attachment
Host receptors through GP glycoprotein which is endocytosed into
vesicles in the host cell. Host DC-SIGN and DC-SIGNR play a role in
virion attachment.
• 2. Viral Entry (Penetration)
The virion enters early endosomes by Macropinocytosis or clathrin-
mediated endocytosis.
Macropinocytosis= Macropinocytosis is a process in which the
Eukaryotic host cells form macropinosomes, (segments of plasma
membranes that extend out from the cell approximately 0.2-10
µm, )in order to incorporate the virus into the cell
15.
16. 3. Sequential Transcription
During transcription, the RNA genome is transcribed into
seven monocistronic mRNAs whose length is determined by
highly conserved start and stop signals.
4. Replication
As viral protein levels rise, a switch occurs from translation to
replication. Using the negative-sense genomic RNA as a
template, a complementary +ssRNA is synthesized; this is then
used as a template for the synthesis of new genomic -ssRNA,
which is rapidly encapsidated.
17. SYMPTOMS
5. Budding
The newly formed nucleocapsids and envelope proteins
associate at the host cell’s plasma membrane; budding
occurs, destroying the cell.
Virus Recruit components of the cellular ESCRT
• Start within 2 days of contact with virus(infection)
• Incubation Period 2-21 days
18.
19. TRANSMISSION
• The Ebola virus is transmitted among humans through close and
direct physical contact with
• Infected bodily fluids, the most infectious being blood, feces
and vomit.
• Entry points for the virus include the nose, mouth, eyes, open
wounds, cuts and abrasions.
• Ebola may be spread through large droplets; however, this is
believed to occur only when a person is very sick
• Not through sweat
20.
21. DIAGNOSIS
It can be difficult to clinically distinguish EVD from other
infectious diseases such as malaria, typhoid fever and meningitis.
Confirmation that symptoms are caused by Ebola virus infection
are made using the following diagnostic methods:
• Antibody-capture Enzyme-linked Immunosorbent Assay (ELISA)
• Antigen-capture Detection Tests
• Serum Neutralization Test
• Reverse Transcriptase Polymerase Chain Reaction (RT-PCR)
Assay
• Electron Microscopy
• Virus Isolation By Cell Culture.
22. TREATMENT AND VACCINES
• No Proven Treatment Available For EVD
• Supportive care-rehydration with oral or intravenous fluids- and
treatment of specific symptoms, improves survival
• Favipiravir (avigan) antiviral drug appears to be useful
• Ribavirin shows delayed death in monkeys and rats
• Brincidofovir is under trials.
23. PREVENTION AND CONTROL
Risk reduction measures should include:
• Reducing the risk of wildlife-to-human transmission from contact
with infected fruit bats or monkeys/apes and the consumption of
their raw meat.
24. • Reducing the risk of human-to-human transmission from direct or
close contact with people with Ebola symptoms, particularly with
their bodily fluids.,
• Outbreak containment measures, including prompt and safe burial
of the dead
25. CONTROLLING INFECTION IN HEALTH-CARE SETTINGS
Health-care workers should always take standard precautions when
caring for patients, regardless of their presumed diagnosis.
These Include
• Basic Hand Hygiene,
• Respiratory Hygiene,
• Use Of Personal Protective Equipment (To Block Splashes Or Other
Contact With infected Materials),
• Safe Injection Practices
• Safe Burial Practices
