Lecture 4

AIDS

HIV

Lecture 4

CAUSATIVE ORGANISM

AIDS

• Acquired immunodeficiency syndrome (AIDS) is a syndrome (a complex of

symptoms) caused by HIV virus.

Causative agent

• Human immunodeficiency virus (HIV) is the causative agent for AIDS.

• HIV attacks the body’s immune

system (specifically the CD4+ T cells).

HIV virus

• Two distinct types have been identified:

• HIV-1

• HIV-2

• HIV-1 is the most prevalent HIV type worldwide; HIV-2 has been found primarily in western Africa.

• HIV-2 is less easily transmitte

HIV

HIV2 HIV1

The burden of the HIV vary

considerably between countries and regions.

African region remains most severely affected, with nearly two- thirds of the people living with HIV worldwide.

Distribution

CLINICAL DISEASE

Stages of HIV

• Without treatment with HIV medicines, HIV infection advances in stages:

1. Acute syndrome 2. Clinical Latency 3. AIDS

Stages of HIV

ACUTE INFECTION

• Around two to four weeks after HIV infection,

• Flu-like symptoms.

CLINICAL LATENCY

• People in this stage may not have any HIV-

related symptoms, but they can still spread HIV to others.

• Without

treatment this period lasts an average 10 years.

AIDS

• HIV has severely damaged the immune system,

• The body can’t resist

opportunistic infections.

• Without

treatment, people with AIDS typically survive about 3 years.

1. Acute HIV syndrome

Within several weeks after infection with HIV, many persons develop an acute self-limited

non-specific illness

:

• fever,

• malaise, myalgia,

• lymphadenopathy,

• Pharyngitis

• Skin rash

2. Clinical Latency period

• During this period of the disease, few or no clinical manifestations of the HIV infection are present.

•

Clinical latency

lasts an average of 10 years without antiretroviral therapy.

3. AIDS

• AIDS occurs when the immune system has been severely

damaged.

• Patients with AIDS become more likely to develop

opportunistic infections.

• Opportunistic infections are infections by organisms that usually don’t cause illness in people with normal immunity.

TRANSMISSION

Reservoir

• Humans are the only reservoir of HIV.

Transmission

1. Unprotected (heterosexual or homosexual) sex.

2. The use of HIV-contaminated needles and

syringes, including sharing by intravenous drug users.

Transmission

3. Transfusion of infected blood or its

components; screening of blood donors has reduced the number of transfusion related cases of AIDS.

4. From mother to child during pregnancy, birth, or breastfeeding

Transmission

5. By being stuck with an HIV-contaminated needle or other sharp object. This is a risk mainly for health care workers.

6. Contact between broken skin, wounds, or mucous membranes and HIV-infected

blood.

HIV is not transmitted by

• Coughing, sneezing

• Insect bites

• Touching, hugging

• Water, food

• Kissing

Coughing

Insects

food

Kissing

HIV is not transmitted by

• Public bathrooms, toilet seats

• Handshakes

• Using telephones

• Work or school contact

• Sharing cups, glasses, plates, or other eating utensils.

Handshakes toilet seats

telephones

eating utensils

PREVENTION

HIV testing and counselling (HTC)

HIV testing and counselling (HTC) is a public health intervention

whereby an individual, couple, or family receives HIV testing and counselling on HIV prevention,

treatment, care, and support.

HIV testing and counselling (HTC)

HTC must adhere to the five Cs—Consent, Confidentiality, Counselling, Correct test results and linkage to Care.

• HTC services are Confidential

• Persons receiving HTC must give informed Consent.

• HTC must be accompanied by pre-test information and post-test Counselling.

• HTC should provide high-quality testing services to ensure Correct test results.

• HTC should provide Connections to prevention, care, and treatment services.

Safe Practice

2. Safer sex

• The practice of "

safer sex

" to avoid contracting HIV infection and to avoid spreading infection.

• E.g. by use if condoms.

3. Drug users

• Avoidance of sharing of needles among injection drug users.

Screening of blood or blood products

Transmission of HIV via transfused blood or blood products has been decreased dramatically by

screening

of

all blood donors for HIV infection.

Preventing vertical transmission

Treatment of an HIV-infected mother with

antiretroviral therapy

during pregnancy and the infant during the first weeks following

birth has proven very

effective

in

dramatically decreasing mother to child transmission of HIV.

Preventing vertical transmission

HIV can be transmitted via breast milk and colostrum.

Therefore, breast-feeding from an infected mother should be avoided.

Health care workers

• Health care workers should wear latex gloves, eye protection and other personal protective

equipment in order to avoid

contact with blood or other body fluids.

• Care must be taken in handling, using and disposing of needles or other sharp instruments.

CONTROL

A. Control of HIV cases

Report to local health authority

Isolation of the HIV-positive person is unnecessary,

ineffective and unjustified.

Of equipment contaminated with blood or body fluids.

Report

Isolation

Concurrent disinfection

Treatment of cases (ART)

• There is no cure for HIV infection.

• HIV treatment^{, also called}

antiretroviral therapy (ART), works by controlling the replication of HIV in the body – that is, it reduces HIV's ability to make copies ^{of itself.}

• ART can decrease the rate of transmission of infection.

• The treatment must be lifelong.

• Adherence is critical for the success of the treatment.

Short Notes

• Enumerate methods of transmission of HIV

1. The most affected region with HIV in the world

A. Africa

B. North America C. Europe

D. Middle east E. Southeast Asia

2. HIV can be transmitted by:

A. Coughing, sneezing B. Insect bites

C. Kissing

D. Contaminated needles

3. HIV can be transmitted by:

A. Transfusion of infected blood

B. From mother to child during pregnancy C. The use of HIV-contaminated needles D. Unprotected sex.

E. All of the above

4. HIV is not transmitted by _______?

A. From mother to child during pregnancy B. The use of HIV-contaminated needles C. Unprotected sex

D. Insect bites

5. HIV patients develop

opportunistic infections

during ______

stage?

A. Acute INFECTION B. CLINICAL LATENCY C. AIDS

D. All of the above

6. HIV virus attacks

_______

A. Liver B. Kidney C. Lung

D. Immune System

7. Regarding types of HIV virus _____

A. HIV-2 is the most prevalent HIV type worldwide

B. HIV-1 is less easily transmitted

C. HIV-2 is less pathogenic

D. None of the above

8. HIV

treatment is taken for

_____ duration

A. 6 months B. 10 days

C. Life long

D. None of the above