Mode of Transmission
Viruses enter into body by 4 ways:
- Ingestion:
Contaminated food and drink when ingested may cause infection
Example: Jaundice is caused by hepatitis viruses.
- Inhalation:
Dust, droplets etc when inhaled may causes infection.
- Inoculation:
When continuity of skin break, viruses usually enter into the cells and
causes infection.
ð Direct inoculation: By contaminated needle or sharp
instruments.
ð Insect borne: Such as mosquitoes.
ð Tran placental: From mother to fetus.
Example AIDS is caused by HIV.
Main portal of entry of important viral pathogens:
|
Portal
of entry
|
Virus
|
Disease
|
|
Respiratory
tract
|
Influenza
virus
Rhino
virus
Measles
virus
Mumps
virus
Adeno
virus
V aricella virus-Zoster virus
|
Influenza
Common
cold
Measles
Mumps
Rubella
Pneumonia
Chicken
pox
|
|
Gastrointestinal
tract
|
Hepatitis
A virus
Polio
virus
Rota
virus
|
Hepatitis
A
Poliomyelitis
Diarrhea
|
|
Skin
|
Rabies
virus
|
Rabies
|
|
|
Dengue
virus
|
Dengue
|
|
|
Human
papilloma virus
|
Papilloma(warts)
|
|
Genital
tract
|
HIV
|
AIDS
|
|
Blood
|
Hepatitis
B virus
|
Hepatitis
B
|
|
|
Hepatitis
D virus
|
Hepatitis
D
|
|
|
HIV
|
AIDS
|
|
Tran
placental
|
Cytomegalo
virus
Rubella
|
Congenital
abnormalities
Congenital
abnormalities
|
