prof. dalia m. mohsen prof. in microbiology. is a disease of the human immune system. types: it have...

Medical Virology

Dr. Dalia M. Mohsen Prof. In Microbiology CLS 413

Lecture (5)

Prof. Dalia M. Mohsen Prof. In Microbiology


Human immunodeficiency virus infection / acquired immunodeficiency syndrome (HIV/AIDS)

• Is a disease of the human immune system.

• Types:

• It have two type (HIV-1 and HIV-2 )

• HIV-1 and HIV-2 differ in genome organization.

• The proteins of HIV-2 are only identical to those of HIV-1


Transmission of HIV/ AIDS

HIV is transmitted by three main routes:

• Sexually

• blood and blood products.

• Mother-to-child


Pathogenesis

Target site:

• Lymphocytes

• Macrophages

• Dendritic cell

Symptoms

•This lead to drop of total number of CD4T- cells

•The immune function become deficient.


Hepatitis Virus

• Some viruses cause hepatitis as part of a general infection but the main

targets of the true hepatitis viruses are the hepatocyte themselves.

• These hepatitis viruses include:

• Hepatitis A Virus (HAV)

• Hepatitis B Virus (HBV)

• Hepatitis C Virus (HCV)


Hepatitis A Virus (HAV)

General characteristic:

• It is a non enveloped .

• Single strand-RNA virus.

• Icosahedral virus.

• It is pathogenic to man and .

• Incubation period is 2-6 weeks.


Hepatitis A Virus (HAV)

METHOD OF TRANSMISSION:

• It is transmitted by contaminated food.

• The virus is found in the stool 2 weeks before and 2 weeks after the

jaundice appears.

SYMPTOMS:

• Jaundice

• Fever

• Abdominal pain


Hepatitis B Virus (HBV)

HBV infected liver of human and chimpanzees only.

HBV infection is characterized by a long incubation period.

STRUCTURE:

• HBV is a small, enveloped DNA virus.

• The genome is a small circular double-stranded DNA

• HBV is surrounded by an icosahedral capsid



• SYMPTOMS OF ACUTE INFECTION:

• Fever

• Anorexia

• Nausea,

• Vomiting.

• The classic symptoms of liver damage

(Jaundice, dark urine ).



SYMPTOMS OF CHRONIC INFECTION:

Chronic infection characterized by distraction of the liver

leading to scarring of the liver, cirrhosis and liver failure.

Chronically infected people are the major source for spread of

the virus.



• DAIGNOSIS:

• Elevated liver enzyme level on a routine blood chemistry

profile.

• ELISA

• PCR


Hepatitis C Virus (HCV)

GENERAL CHARACTERISTIC:

• HCV is 30 to 60 nm in diameter

• positive sense RNA genome

• Enveloped.

HOST:

HCV infect only human and chimpanzees.


Hepatitis C Virus (HCV)

TARGET SITE:

• hepatocyte

• lymphocytes

MODE OF TRANSMSSION:

• HCV is transmitted primarily in infected blood and sexually

• Almost all HIV –infected people who are or were intravenous drug users

are infected with HCV


Hepatitis C virus (HCV)

CLINICAL SYMPTOMS:

• The chronic persistent disease often progresses to chronic active

hepatitis within 10 to 15 year and to cirrhosis and liver failure

after 20 years.

• HCV promotes the development of hepatocellular carcinoma in

chronically infected patients.


Mumps virus

• It is an acute disease

characterized by non-

supportive enlargement of the

parotid glands

• The virus has a single serotype


Pathogenesis of Mumps virus

• Infection occurs by respiratory droplets.

• Primary multiplication occurs in the respiratory mucosa followed by viraemia

and localization of virus in the parotids and other salivary glands.

• It may affect the testes, ovaries, pancreas and the CNS.

• Some cases are subclinical.

• The incubation period is 18 days Followed by fever, malaise, anorexia, and

swelling of parotid gland.

• Meningitis may complicate some cases.

• Immunity is permanent after a single infection.

Thank you


prof. dalia m. mohsen prof. in microbiology. is a disease of the human immune system. types: it have...

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