Download MBBS General Medicine PPT 6 Dna Viruses Lecture Notes

Download MBBS (Bachelor of Medicine, Bachelor of Surgery) General Medicine 2022 PPT 6 Dna Viruses Lecture Notes


Infectious diseases

4/5th Semester Classes on Infectious Diseases, 8-9AM, Tuesdays (LT-1)

Topics

1

Approach to Infectious Diseases and their prevention

2

Antibiotic stewardship practices

3

Community-Acquired Infections

4

Health Care?Associated Infections

5

Gram-Positive Bacteria (part-1)

6

Gram-Positive Bacteria (part-2)

7

Gram-Negative Bacteria (part-1)

8

Gram-Negative Bacteria (part-2)

9

Spirochetal Diseases

10

Diseases Caused by Atypical/Miscel aneous Bacterial Infections

11

Revision-cum-exam on bacteria (Must to know type)

1

12

Infections Due to DNA Viruses

13

Infections Due to RNA Viruses (part 1)

14

Infections Due to RNA Viruses (part 2)

15

HIV/AIDS ? part 1

16

HIV/AIDS ? part 2

17

Fungal Infections

18

Parasitic Infections (part 1)

19

Parasitic Infections (part 2)

20

Revision-cum-exam on Virus, Fungal, and Parasite (Must to know type)

? Viruses are obligate intracellular parasites

? Virusoids are nucleic acids that depend on cells and helper viruses for

packaging their nucleic acids into virus-like particles.

? Viroids are naked, cyclical, mostly double-strand small RNAs that appear to

be restricted to plants, spread from cell to cell, and are replicated by cellular

RNA polymerase II.

? Prions are abnormal proteins that propagate and cause disease by altering

the structure of a normal cell protein.



Herpes Simplex Virus Infections

? Herpes simplex viruses (HSV-1, HSV-2; Herpesvirus hominis) produce a variety of

infections involving mucocutaneous surfaces, the central nervous system
(CNS), and--on occasion--visceral organs

? The clinical manifestations and course of HSV infection depend on the

anatomic site involved, the age and immune status of the host, and the
antigenic type of the virus.

? Genital HSV-2 infection is twice as likely to reactivate and recurs 8?10 times

more frequently than genital HSV-1 infection. Conversely, oral-labial HSV-1
infection recurs more frequently than oral-labial HSV-2 infection.


Varicella-Zoster Virus Infections

? VZV causes two distinct clinical entities: varicella (chickenpox) and herpes

zoster (shingles).

? Chickenpox, a ubiquitous and extremely contagious infection, is usually a

benign illness of childhood characterized by an exanthematous vesicular rash.

? With reactivation of latent VZV (which is most common after the sixth decade

of life), herpes zoster presents as a dermatomal vesicular rash, usually

associated with severe pain.

? Humans are the only known reservoir for VZV.


Varicella pneumonia, the most serious complication following chickenpox,

develops more often in adults (up to 20% of cases) than in children and is
particularly severe in pregnant women. Pneumonia usually has its onset 3?5
days into the illness

Medical management of chickenpox in the immunologically

normal host is directed toward the prevention of avoidable
complications

Acyclovir (800 mg by mouth five times daily), valacyclovir (1

g three times daily), or famciclovir (250 mg three times
daily) for 5?7 days is recommended for adolescents and
adults with chickenpox of 24 h duration.

Three methods are used for the prevention of VZV infections.

? First, a live attenuated varicella vaccine (Oka)

? to administer varicella-zoster immune globulin (VZIG)

? antiviral therapy can be given as prophylaxis to

individuals at high risk who are ineligible for vaccine or
who are beyond the 96-h window after direct contact.


Epstein-Barr Virus Infections

EBV is the cause of heterophile-positive infectious mononucleosis (IM), which is

characterized by fever, sore throat, lymphadenopathy, and atypical
lymphocytosis.

EBV is also associated with several tumors, including nasopharyngeal and

gastric carcinoma, Burkitt's lymphoma, Hodgkin's disease, and (in patients
with immunodeficiencies) B cell lymphoma.

EBV is spread by contact with oral secretions


? Therapy for IM consists of supportive measures, with rest and analgesia.

? Prednisone (40?60 mg/d for 2?3 days, with subsequent tapering of the

dose over 1?2 weeks) has been used for the prevention of airway
obstruction in patients with severe tonsillar hypertrophy, for autoimmune
hemolytic anemia, for hemophagocytic lymphohistiocytosis, and for
severe thrombocytopenia.

? Glucocorticoids have also been administered to rare patients with severe

malaise and fever and to patients with severe CNS or cardiac disease.


Cytomegalovirus and Human
Herpesvirus Types 6, 7, and 8

Cytomegalovirus (CMV); In addition to inducing severe birth defects, CMV

causes a wide spectrum of disorders in older children and adults, ranging
from an asymptomatic subclinical infection to a mononucleosis syndrome in
healthy individuals to disseminated disease in immunocompromised
patients. Human CMV is one of severa related species-specific viruses that
cause similar diseases in various animals.

All are associated with the production of characteristic enlarged cells--

hence the name cytomegalovirus. CMV, a -herpesvirus, has double-
stranded


Parvovirus Infections

Thank you

This post was last modified on 05 April 2022