Lec.2 Flashcards
(49 cards)
Viral Growth is detected by?
- Cytopathogenic
- Inclusion Bodies
- Hemadsorption
- Interference
- Fluorescent anti-body staining
- Detection of viral Antigens by
serology
Cytopathogenic
cell death (poliovirus), cluster formation
(adenovirus), giant cell formation (measles and mumps viruses) or cell
transformation (tumor viruses).
Inclusion Bodies
observed by light microscope. They are aggregates or just sites of
replication of the virus e.g. cytoplasmic Negri bodies in brain cells of rabies
infected animal, cytoplasmic Guarnieri′s bodies of poxvirus or nuclear bodies of
adenovirus or nuclear and cytoplasmic bodies in case of cytomegalovirus.
Hemadsorption
viruses which contain hemagglutinin spikes are
able to form clumps of RBCs if added to the tissue culture.
Interference
Host cells infected with a virus may acquire resistance to infection by a
second virus, of the same type or another one. Some viruses do not
produce CPE, however, their growth can be proved by their ability to interfere
with another CPE producing virus e.g. rubella and ECHO virus.
Local Infections
- Skin
- Respiratory Tract Infection affecting the mucos membrane
- Alimentary Tract
more than 60% of
diarrhea in infants are caused by
Rotavirus
The virus passes through lymphatics, blood (viremia), tissues or nerves, reaching the target tissue (tropism),
Systemic Infection
What should one take to prevent/before viremic phase
Administration of
neutralizing antibodies before the viremic phase could prevent the development of
the disease.
are characterized by short incubation period and short lasting
immunity
Local Infections
are characterized by long incubation period and
long lasting immunity
Systemic Infections
the virus remain hidden most of the time with intermittent
reactivation and development of the disease
Latent Infections
the virus usually has long incubation period and is always
shedding
Chronic Infection
are viruses with long incubation period and slow multiplication
Slow Infection
many viruses penetrate the placenta during
pregnancy causing congenital defect in the embryo.
Congential/Teratogenic Infection
resulting in transformation of infected cells.Viral
genes become integrated into host cell chromosome
Oncogenicity (tumor causing)
s, viral RNA acts as a template for synthesis
of viral DNA- through the action of reverse transcriptase. The DNA copy of the
viral RNA is integrated into the host cell chromosome
RNA tumor viruses
Epidemiology of viral Infections?
- Direct contact ( sexual transmission)
- Droplet Infection ( respiratory)
- Oral Fecal Infection (feces-flies-food-finger - 4F)
- Skin Puncture
Skin puncture through?
- Injection Hepatitis B
- Anthropods Yellow Fever
- Animal Bites Rabies Virus
- Agents preventing attachment
- Agent preventing uncoating
- Agents inhibiting the replication
- Agents preventing attachment (ie. neutralizing antibodies)
- Agent preventing uncoating (Amantadine and Rimantadine)
- Agents inhibiting the replication (—– &Interferons)
Inteferons are all non-specific except?
gamma which is specific.
They are species specific
Human Interferons
MOA Interfons?
They act by inhibiting the translation of viral mRNA, without affecting
the translation of human cellular mRNA, by attaching to certain cell surface
receptors triggering the formation of intracellular kinase.
Used mainly for prophylaxis in hepatitis B to delay the appearance of liver
cancer
Interferons
