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

4. Classification
Coronaviridae
Coronavirinae Toronavirinae
1) Alfa coronavirus
2) Beta coronavirus Infects animals.
3) Delta coronavirus
4) Gamma coronavirus Infects birds.

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

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

15. Pathogenesis of COVID 19

17. Clinical Manifestations
1) Fever
2) Cough
3) Shortness of breath
4) Sore throat
5) Rhinorrhea
6) Diarrhea Myalgia
7) B/L Pneumonia
8) ARDS, SIRS
9) Normal CT ratio
10) Multiorgan failure

18. Lab Diagnosis
Specimen : Nasopharyngeal swab
Oropharyngeal swab
Sputum
Use synthetic fibre swab with plastic shaft.
Don’t use calcium alginate swab
Antibody detection
IOC : RT-PCR for Gene N, E , RdRP

19. Treatment
Intra venous fluid therapy
NASAIDs
Remdesivir
Hydroxy chloroquine
Ritonavir
Tolicozumab
Ivermectin
Corticosteroids
Elective Mechanical Ventilation
Plasma Therapy

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

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.

24. Slow virus diseases
Conventional Slow virus Unconventional disease
1) Subacute sclerosing panencephalitis By Prions
2) Progressive multifocal leukocephalopathy
3) Visna and Mardi disease

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

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

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

39. Treatment
• No effective treatment

40. Thank You