This document provides information on various viral diseases including common cold, influenza, smallpox, chickenpox, measles, mumps, rabies, polio, dengue, hepatitis, COVID-19, Ebola, HIV/AIDS, and others. For each disease, it lists the pathogen, affected body parts, mode of infection, symptoms, complications, prevention and treatment methods. The document aims to comprehensively summarize the key details about multiple important viral diseases.

2. Viral Diseases – Tables
Disease Pathogen
Description
Genome
Part / s
Affected
Mode of
Infection
Type of Disease
+ Signs / Symptoms (s/s)
Compli
cations
Prevention /
Vaccine
Treatment
Common
Cold /
Rhinitis
Rhino v
RNA Virus
URT
(Upper
Resp Tract
Contagious
Air borne
Droplet, Fomites
Acute, Self resolving
S / s : Nasal discharge
Congestion, Sore throat
NEET NEET
Influenza Influenza
Virus
RNA
Retro virus
RT
+ Whole
body
Contagious
Air borne
Droplet, Fomites
+Aerosol
Acute, Self resolving;
sometimes severe/Fatal (0.1 %)
RTI (Resp Tract Infection)
+ Myalgia (muscle pain)
+ Arthralgia (joint pain)
-May cause pneumonia
(common cause of death)
Pneumo
-nia
Ear-
infection
(otitis)
Vaccine available;
But virus mutates
every season.
also changes ; hence,
not very effective
Small Pox
(Edward
Jenner)
Variola
virus
ds DNA
virus
URT
&
Skin
Most
Contagious
Air borne
-Droplet,
Fomites -
Discharge from
scabs
Acute URTI and skin disease
May be Fatal
Rash →vescicles→pustules
→scabs→ falls by 3 wks
Leave behind permenant poc
marks (deep pits / scars)
Blindness
-Otitis
media
-Death
Isolation
1st
Vaccination; by
Edward Jenner ;
1st
and only disease
eradicated from Earth
Chicken Pox
Varicella
zoster
virus
-ds DNA
URT
Skin
Most
Contagious
Air borne
-Droplet,
Fomites -
Discharge from
vesicles &
pustules
Acute self resolving, mild skin
diasease, esp in Kids
Rash (centrifugal)
-vescicles→pustules→scabs in
succession. Fall off by 3 wks
→ rarely permenant poc
marks
Herpes
Zoster /
Shingles
(neuritis
and
nerve
pain
-Isolation
-Vaccination
Available now;

3. Disease Pathogen
Description
Genome
Part / s
Affected
Mode of
Infection
Type of Disease
+ Signs / Symptoms (s/s)
Compli
cations
Prevention /
Vaccine
Treatment
Measles
(Rubeola)
(German
Measles
=Rubella)
Rubeola v
RNA v
URT
Skin
Air borne
Droplet
Fomites
Acute – mild disease of skin and
resp tract ; sometimes severe
-Can be fatal in immune-
compromised host
Esp Kids below 5 yrs
-Centripetal Rash on whole
body (Face, neck and
arms→trunk) + High Fever
Pneumo
nia,
-death in
malnouri
shed
kids
-MMR vaccine
After 6-9 months of
Birth
(Maternal Ig G
antibodies give
protection)
Mumps Mumps v
RNA v
Parotid
gland
Droplet-
Saliva
Acute, self resolving
Swelling behind cheeks
Pancrea-
titis
Orchitis
MMR vaccine
Rabies Rhabdo
virus
RNA
Lente (long
lasting)
virus
CNS
Encephal
itis.
Saliva, bite,
secretions
from infected
animals
Acute ; 100% fatal
Virus travels to brain from
bite site via nerves
s/s : Unprovoked Aggression &
Rage. Hydrophobia, fear of
water + Photophobia
Death
100%
RIG (immune globulins)
+ Vaccine : Multiple
doses but, useful only
in early phase +
Immunization of Pets
Polio -
myelitis
Infant Para-
lysis
ss RNA Spinal
Cord –
(Anterior
horn,
motor
neurons)
Enters by feco-
oral route.
Contamination
of food, water,
esp by stools
in drainage
water
-Chronic paralysis and
atrophy of muscles
-Rarely death
in / c/ o diaphragm involvement
- More in Kids.
Initially diarrhoea, fever, neck
stiffness followed by paralysis
of a limb (usually unilateral).
If diaphragm→death d/t
respiratory paralysis
No cure
Life long
paralysis
and then
stiffness
in limbs
Physiotherapy + rehab
-Polio is eradicated
except Pakistan
Vaccination :
-OPV (Sabin type -
attenuated)
Given from birth +
Multiple boosters till
5-13 yrs
IPV (killed)-Salk type
-More efficient, but,
less effective at
community level for
herd immunity

4. Disease Pathogen
Description
Genome
Part / s
Affected
Mode of
Infection
Type of Disease
+ Signs / Symptoms (s/s)
Compli
cations
Prevention /
Vaccine
Treatment
Dengue RNA
arbo-virus
Whole
body –
Multi-
systemic
+ blood
platelets,
liver ,
eyes,
kidney
Vector
(arthropod)
borne ds –
Mosquito
Aedes
aegypti
Classical Dengue is like usual
viral fever
Acute – severe Hemorrhagic
fever - can be Fatal
Hemorrhagic type – High
fever, Bodyache, conjunctival
H’ges, Hemorrhagic purpura
(tiny bleeding spots). Rash on
chest. Cough
Thrombo
cyto
Penia
→
Bleeding
→
death
-Tourniquet Test
-No cure
Rx (Treatment)
-Platlet Transfusion
-Anti-mosquito
measures-Cover
whole body, esp
during day;
-Clean water pods.
Avoid Aspirin
Herpes
HSV-1 &
HSV-2
Herpes
viridae
(dsDNA)
Multi-
system
STD
+ Contact
(herpein ="to creep" = hide ;
Can stay in body for many yrs
(latent recurring infections).
- oro-labial herpes & genital herpes)
No Treatment
Hepatitis
Causes of Hepatitis : viruses (Viral Hepatitis)
Drugs, toxins, alcohol, contamination,
Common symptoms of Hepatitis :
Jaundice, loss of appetite, fatty stools
Hepatitis A Hepatitis A
Virus (HAV)
ss RNA
Liver
+ Multi-
sysyemic
Feco-oral Acute, mild hepatitis; rarely
fatal
Rare
No Treatment
Hepatitis
B
Serum
Hepatitis
HBV
ds DNA
Blood, STD,
wound, tear,
saliva
Chronic, fatal
Life long Carrier state
Chronic hepatitis and liver
failure, (INCURABLE)
cirrhosis
hepatic
cancer,
Death
-2nd
Gen-rDNA Vaccine
-3rd
Gen DNA Vaccine
(under trial)
Hepatitis
C (Non AB)
HCV
ss RNA
Blood, STD SAME AS Hep B
No Treatment
Hepatitis D HDV
ss RNA
Blood, STD SAME AS Hep B
It is a Defective virus & requires co-infection with Hep B
in order to manifest
Hepatitis
E (Non AB)
HEV-
ss RNA
Feco-oral Severe Hepatitis and Death in Pregnant Ladies
For NEET - only Hepatitis A & Hepatitis B are important

5. Corona virus : These are Group of mammalian and bird (Zoonotic ) RNA Viruses which affect humans also.
Common Corona viruses are SARS, MERS, and COVID-19. There are no vaccines or antiviral drugs to prevent human infections .
Disease Pathogen
Description
Genome
Part / s
Affected
Mode of
Infection
Type of Disease
+ Signs / Symptoms (s/s)
Compli
cations
Prevention / Vaccine
Treatment
COVID -19
All are
RNA
viruses with
Nucleo-
plasmid +
Envelop and
protein
receptors for
infection
Upper
and
Lower
Resp
Tract +
Multi-
systemic
Reservoir =
bats
Mammal→Man
Man→ Man
Touch, fomites
and Droplets
-90% patients have no / mild
symptoms (Like mild flu)
-High fatality in Elderly & those
with underlying disease, esp due
to pneumonia
Severe Acute Resp Distress
Syndrome
Middle East resp Distress
Syndrome
Pneu-
monia
&
Death
For prevention :
Maintain Covid Care
No Vaccine or
Treatment Yet
(Isolation) + Mask +
frequent hand soap
wash ? alcohol based
sanitizers
SARS-Co V
MERS-Co V
Ebola virus
disease
(EVD),
Zaire Ebola
virus
Blood +
Multi-
systemic
+ Brain
Bats .
-Direct contact
with body
fluids-blood,
semen or
breast milk
is a viral haemorrhagic fever of
humans and
other primates caused
Death
(50%)
Bio-safety Level 4
Containment zones
(quarantine)
Epstein-Barr
virus (HSV)
DNA v (Infectious mononucleosis,
cancer
NA
cyto-megalo
virus CMV) –
HSV
DNA Fetus /
Lungs
Congenital deformities, Abortion
– if infection during pregnancy
NA
HPV Human
Papilloma V
DNA Cervix &
genitals
Sexual contact Cervical cancer of uterus and
Genital warts
Vaccine

6. Disease
Pathogen
Description
Genome
Part / s
Affected
Mode of
Infection
Type of Disease
+ Signs / Symptoms (s/s) &
Complications
Prevention / Vaccine
Treatment
HIV
Human
Immunodefic
iency
virus
HIV 1
(from chimp)
-global
-High
virulance
HIV 2
( from
meganbee)
-Only Africa
Both
enveloped
Retro Virus
Lente virus
With
2 copies of
ss RNA
infects
immune
cells
(initially
macropha
ges
Then T
cells
+
dendritic
cells
Gay,
homosexuals,
polygamic
heterosexuals
indulging un
unprotected
sex & drug
users
Blood, STD,
wound, tear,
saliva
breast milk
NOT BY
touch hug/kiss/
sharing food
-Begins with Usual Viral symptoms
Then
-2 months WINDOW PERIOD (ELISA –VE)
: Because, virus is multiplying in Macro or
dendritic cells
-Without treatment, average survival time
=9 to 11 years,
Invariably 100% FATAL
For Mass Screening
– ELISA which
detects HIV-1
antibodies ( -ve during
window period) -
Cheaper and faster
test
-For confirmation
reactive ELISA results
are retested by
western blot
or,
immuno-
fluorescence
assay (IFA)
But
100% diagnosis is by
nucleic acid testing
i.e.viral RNA by PCR
AIDS AIDS – few months to many years later
When T4 cells < 200/ml
progressive failure of immune system
→allowing life-threatening
-opportunistic infections and
-cancers
Complications : Opportunistic infections
-Pneumocystis carinii pneumonia (PCP),
- Mycoplasma infections
- Kaposi's sar coma (KS) d/t HSV.
-Toxoplasma gondii