ATAL BIHARI VAJPAYEE GOVT. MEDICAL COLLEGE VIDISHA
DEPARTMENT OF MICROBIOLOGY
PATHOGENESIS OF VIRAL INFECTIONS
TRANSMISSION
SPREAD OF INFECTION
Portal of entry
MANIFESTATION OF VIRAL INFECTION
Shedding (Eg:Influenza virus)
IP
Infection
1.Respiratory route
(Influenza Virus)
2.Oral route
(Rotavirus)
3.Vector bite
Lymphnode/Blood
(multiplication)
Primary viremia
First symptom
Infection
Time
Blood stream
Reticuloendothelial Organs
(central foci of further multiplication)
b.Culex tritaeniorhynchus
(Japanese Encephalitis)
a.Aedes aegypti
(Dengue fever virus)
Secondary site
of replication
Endothelial
cells
c. Hard ticks
(Hemaphysalis spinigera (KFD)
Bone marrow
Secondary
viremia
Liver
Spleen
(non-specific symptoms)
Shedding (Eg: Hepatitis B virus)
VIRAL PATHOGENESIS AT CELLULAR LEVEL
4.Cutaneous route
(HIV)
5.Rabid Dog
(Rabies virus)
Target
organs
Lungs, salivary
glands, Kidney
Shedding
6.Blood transfusion
(Hepatitis B,C virus)
7.Transplacental route
(HSV)
8.Sexual route
9.Injection
Tropism
PRIMARY SITE OF REPLICATION
Two types
No viremia
No distant spread
Skin
Nasal and
oral mucosa
No Shedding
To respective cell type
10.Conjuctival
Replication at portal of entry
(multiply and produce
local disease)
Brain
Portal of entry
(silent local infection)
Viremia
Spread to distant sites
1. Lymphocytes
2. Monocytes and macrophages
3. Neutrophills
4.RBCs
Guide: DR. Sanjay Kirar
By: Namrata, Narendra,Naresh,Naval, Neeraj Gour,
Neeraj Solanki
Roll No. 91 to 96. (Batch-2019)
References:
1.Internal Jouranal of Molecular Medicine (web)
2.www.medscape.com (web)
3.Essential of Medical Microbiology (Apurba S. Sastry)
4.Textbook of Microbiology (Anantnarayan and Paniker’s)
5.Google Images and Adobe stock Images for illustrations