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

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

Prof. Dalia M. Mohsen Prof. In Microbiology

Prof. Dalia M. Mohsen Prof. In Microbiology

Transmission of HIV/ AIDS

HIV is transmitted by three main routes:

• Sexually

• blood and blood products.

• Mother-to-child

Prof. Dalia M. Mohsen Prof. In Microbiology

Pathogenesis

Target site:

• Lymphocytes

• Macrophages

• Dendritic cell

Symptoms

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

•The immune function become deficient.

Prof. Dalia M. Mohsen Prof. In Microbiology

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)

Prof. Dalia M. Mohsen Prof. In Microbiology

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.

Prof. Dalia M. Mohsen Prof. In Microbiology

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

Prof. Dalia M. Mohsen Prof. In Microbiology

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

Prof. Dalia M. Mohsen Prof. In Microbiology

Hepatitis B Virus (HBV)

• SYMPTOMS OF ACUTE INFECTION:

• Fever

• Anorexia

• Nausea,

• Vomiting.

• The classic symptoms of liver damage

(Jaundice, dark urine ).

Prof. Dalia M. Mohsen Prof. In Microbiology

Hepatitis B Virus (HBV)

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.

Prof. Dalia M. Mohsen Prof. In Microbiology

Hepatitis B Virus (HBV)

• DAIGNOSIS:

• Elevated liver enzyme level on a routine blood chemistry

profile.

• ELISA

• PCR

Prof. Dalia M. Mohsen Prof. In Microbiology

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.

Prof. Dalia M. Mohsen Prof. In Microbiology

Prof. Dalia M. Mohsen Prof. In Microbiology

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

Prof. Dalia M. Mohsen Prof. In Microbiology

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.

Prof. Dalia M. Mohsen Prof. In Microbiology

Mumps virus

• It is an acute disease

characterized by non-

supportive enlargement of the

parotid glands

• The virus has a single serotype

Prof. Dalia M. Mohsen Prof. In Microbiology

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