1) Corona viruses are a large group of RNA viruses that commonly infect animals but sometimes humans, causing illnesses ranging from the common cold to SARS, MERS, and COVID-19.
2) SARS-CoV and MERS-CoV are two dangerous corona viruses that have caused outbreaks in the past, while the current pandemic is caused by SARS-CoV-2 which emerged in 2019.
3) Slow viruses and prions are infectious agents that cause long incubation periods and neurodegenerative diseases like Creutzfeldt-Jakob disease through direct neuronal damage rather than immune responses. They lack nucleic acids and are resistant to sterilization.
1. CORONA VIRUS , SLOW VIRUS
& PRIONS
Made By : Niteesh Kumar
2. Corona Virus
It is large group of single stranded positive sense RNA virus which is
enveloped and helical in structure.
Affects mainly animals and rarely human.
Disease caused by corona virus ranges from common cold to SARS ,
MERS , COVID-19.
Its has crown like/petal/club shaped peplomer spike which gives it
appearance of solar corona.
It belongs to Coronaviridae family.
3. Morphology
1) Enveloped
2) Club shaped/petal/crown like spikes
3) 120-160 nm in size
4) Helical symmetry present
5) Linear , positive sense ssRNA.
6) Non segmented genome
5. Human Coronavirus
Human coronavirus are :-
1) 229E
2) NL63 Alfa coronavirus
3) OC-43
4) HKU1
5) SARS-CoV Beta coronavirus
6) MERS-CoV
7) COVID-19
6.
7. Severe Acute Respiratory Syndrome - CoV
First seen in China in 2003.
Epidemiology :- During 2003, 29 countries , 8098 cases and more than
774 deaths. Since 2004; no new case is seen.
Source :- Monkeys ,
Himalayan palm civets,
Raccoon dogs ,
Cats , rodents
8. Clinical Features
• Severe lower respiratory tract infection
• Myalgia
• Headache
• Sore throat and fever
• Cough
• Dyspnoea
• Pneumonia
9. Middle East Respiratory Syndrome - CoV
• First reported in Saudi Arabia in 2012.
• Epidemiology : During 2012-18 ; 27 countries, 2143 cases , 750 deaths.
Mortality rate : 30%
Yet no case in India.
Source of infection is unknown but camels & bats are
suspected as source.
Incubation period : 2-14 days
10. Clinical Manifestations
• ARDS
• Myalgia
• Headache
• Sore throat and fever
• Cough
• Dyspnoea
• Pneumonia
• GIT symptoms – Diarrhoea, nausea , vomiting
• Kidney failure may be seen
11. Lab Diagnosis
• Antibody detection
• Detection upE and ORF1b gene in real time RT-PCR.
• ELISA based detection of nucleocapsid protein in nasopharyngeal
aspirate.
12. COVID 19
Origin : 31 December 2019 Wuhan , Hubei , China as pneumonia of
unknown etiology
7 January 2020 : Causative agent identified as nCoV.
9 January 2020 : 1st death due to nCoV.
13 January 2020 : 1st case of nCoV outside China –Thailand
30 January 2020 : First Case in Kerala in India , PHEIC declared
11 February 2020 : nCoV named as COVID-19 ( SARS-CoV - 2)
11 March 2020 : COVID-19 Pandemic declared
13. Till Date ………..
WORLD INDIA Uttar Pradesh
Total case : 31,777,987 56,43,481 3,64,543
Active case : 7,407,671 9,68,232 63,148
Recovered : 23,394,845 45,84,392 2,96,183
Death : 975,471 90,050 5,212
20. 1. Mild cases: Supportive treatments (Antihistamine & Analgesics)
2. Moderate cases:
a. Oseltamivir (150 mg BID for 5 days)
b. Hydroxychloroquine, Chloroquine (500 mg BID for 14 days) or Ribavirin
(for 5 days)
3. Severe cases:
a. Oseltamivir (150 mg BID for 5 days)
b. Kaletra (Lopinavir/Ritonavir) (for 5 days)
c. Hydroxychloroquine, Chloroquine (500 mg BID for 14 days) or Ribavirin (for
5 days)
4. Critical cases:
a. Oseltamivir (150 mg BID for 5 days)
b. Kaletra (Lopinavir/Ritonavir) (for 5 days)
c. Ribavirin (for 5 days)
d. Hydroxychloroquine or Chloroquine (for 14 days)
21. Prevention
• Hand washing : With soap and water for >20 sec
Alcohol based hand sanitizer >60% alcohol
Avoid T- zone to touch.
Respiratory Hygiene :
1) Cover with tissue or by elbow sleeve while coughing/sneenzing.
2) Use of mask
Self isolation and self quarantine
Social distancing
22.
23. Slow viruses and Prions
Slow virus diseases including prion diseases are a group of
neurodegenerative conditions affecting both human and animals’
characterized by :
1) Long incubation period
2) Predilection for CNS
3) Lack of immune response , INF production against viral proteins and
lack of associated inflammation.
25. Subacute Sclerosing Panencephalitis ( SSPE)
• Rare disease of young adults
• By defective measles virus
• Slow progressive demyelination of CNS leading to chronic sclerosing
panencephalitis
Diagnosed by high anti measles antibodies in CSF
26. Progressive Multifocal
Leukoencephalopathy
1) By JC Virus of Polyomaviridae family.
2) Infect oligodendrocytes and causes demyelination of CNS
3) Occurs in 5% patients with AIDS or other immunosuppressed
conditions
27. Visna & Maedi Disease
• Disease of sheep
• Visna – Demyelination of CNS in sheep
• Maedi virus – Slow progressive fatal hemorrhagic pneumonia of
sheep.
28. Slow Virus disease Due to Unconventional
viruses or Prion Disease
Prions are infectious protein particle which –
1) Lack nucleic acid
2) Filterable
3) Resistant to many agents of sterilisation
Prions proteins have two isoforms : PrPc and PrPsc
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34. Creutzfeldt-Jacob disease
It is a subacute encephalopathy characterized by
Progressive inco-ordination, dementia & fatal termination.
Two forms
1) Gerstamann-Straussler- Scheinker’s syndrome
2) Fatal familial insomnia
can occur after
I. corneal transplant
II. contaminated injection of pituitary growth hormone
III. Cadaveric human dura grafts used in head injury
35. Kuru
Characterised by :-
1) Progressive cerebellar ataxia, tremors
2) Terminates fatally in 3-6 months
IP- 5-10 years
- Infections believed to be due to cannibalism & Sorcery
- A tribal custom of eating dead bodies of relatives after ritual non
sterilising cooking
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38. Lab Diagnosis
Measurement of PrPsc
Brain MRI
Neuropathological examination : Spongiform degeneration
Astrocytic gliosis
Sequencing pf PRNP gene
Stress protein 14-3-3 is elevated in CSF
Abnormal EEG