Download ACQUIRED IMMUNODEFICIENCY SYNDROME (HIV infection, AIDS)

ACQUIRED
IMMUNODEFICIENCY
SYNDROME
(HIV infection, AIDS)
Dr. Rasha Salama
PhD. Community Medicine
Suez Canal University
Egypt

Globally, AIDS caused an estimated 3.1
million deaths in 2003 (2.5–3.5 million)

The epidemic has continued growing, with
estimates of 5 million new infections (4.2–
5.8 million) and 2.5 million children (2.1–2.9
million) living with HIV/AIDS.
Identification

Emergence was in 1981 of a cluster of
diseases associated with loss of cellular
immunity in adults who had no obvious
reason for presenting such immune
deficiencies.

Within several weeks to several months
after infection with HIV, many persons
develop an acute self-limited
mononucleosis-like illness lasting for a week
or two. They may then be free of clinical
signs or symptoms for months or years
before other clinical manifestations develop.
AIDS Associated Disease Categories
1. Gastrointestinal: Cause most of illness and
death of late AIDS.
Symptoms:

Diarrhea

Wasting (extreme weight loss)

Abdominal pain

Infections of the mouth and esophagus.
Pathogens: Candida albicans,
cytomegalovirus, Microsporidia, and
Cryptosporidia.
AIDS Associated Disease Categories
2. Respiratory: 70% of AIDS patients develop
serious respiratory problems.
Partial list of respiratory problems associated with
AIDS:

Bronchitis

Pneumonia

Tuberculosis

Lung cancer

Sinusitis

Pneumonitis
AIDS Associated Disease Categories
3. Neurological: Opportunistic diseases and
tumors of central nervous system.
Symptoms many include: Headaches,
peripheral nerve problems, and AIDS
dementia complex (Memory loss, motor
problems, difficulty concentration, and
paralysis).
AIDS Associated Disease Categories
4. Skin Disorders: 90% of AIDS patients
develop skin or mucous membrane
disorders.

Kaposi’s sarcoma




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
1/3 male AIDS patients develop KS
Most common type of cancer in AIDS patients
Herpes zoster (shingles)
Herpes simplex
Thrush
Invasive cervical carcinoma
5. Eye Infections: 50-75% patients develop
eye conditions.



CMV retinitis
Conjunctivitis
Dry eye syndrome
Extensive tumor lesions of Kaposis’s sarcoma in AIDS patient.
Source: AIDS, 1997
Infectious agent





Human immunodeficiency virus (HIV),
Retrovirus.
Two serologically and geographically distinct
types with similar epidemiological
characteristics, HIV-1 and HIV-2, have been
identified.
The pathogenicity of HIV-2 may be lower
than that of HIV-1
lower rates of mother-to-child transmission
for HIV-2.
Structure of the Human Immunodeficiency Virus
HIV is a Retrovirus
Occurrence

AIDS was first recognized as a distinct clinical entity
in 1981;, however, isolated cases appear to have
occurred during the 1970s and even earlier in
several areas (Africa, Europe, Haiti, USA).

Of the estimated 40 million persons (34–46 million)
living with HIV infection or AIDS (HIV/AIDS)
worldwide in 2003, the largest elements were
estimated at 25–28.2 million in sub-Saharan Africa,
4.6–8.2 million in south and southeastern Asia, 13–
1.9 million in Latin America and 800 000–1 million in
North America.
People Living with HIV/AIDS by End of 2001
North America
950,000
Western Europe
560,000
East Europe & Central Asia
1’000,000
East Asia & Pacific
1’000,000
Caribbean
420,000 North Africa &
Middle East
500,000
South/South East Asia
5.6 million
Latin America
1.5 million
Sub-Saharan Africa
28.5 million
Australia &
New Zealand
15,000
Total: 40 million people


HIV-1 is the most prevalent HIV type
throughout the world;
HIV-2 has been found in Africa
Reservoir


Humans.
HIV is thought to have recently
evolved from chimpanzee viruses.
Mode of transmission

Person to person transmission through
unprotected (heterosexual or homosexual)
intercourse;

Contact of abraded skin or mucosa with
body secretions such as blood, CSF or
semen;

The use of HIV-contaminated needles and
syringes, including sharing by intravenous
drug users; transfusion of infected blood or
its components
Mode of transmission (cont.)

Transplantation of HIV-infected tissues or
organs.

The presence of a concurrent sexually
transmitted disease, especially an ulcerative
one, can facilitate HIV transmission.

Unprotected intercourse (no condom—
unprotected sex) with many concurrent or
overlapping sexual partners.
Mode of transmission (cont.)

HIV can be transmitted from mother to child (MTCT
or vertical transmission).

From 15% to 35% of infants born to HIV-positive mothers
are infected through placental processes at birth.

HIV-infected women can transmit infection to their infants
through breastfeeding and this can account for up to half
of mother-to-child HIV transmission.

Giving pregnant women antiretrovirals such as zidovudine
results in a marked reduction of MTCT.
Mode of transmission (cont.)


After direct exposure of health care workers
to HIV-infected blood through injury with
needles and other sharp objects, the rate of
seroconversion is less than 0.5%, much
lower than the risk of hepatitis B virus
infection after similar exposures (about
25%).
Unsafe injections may account for up to 5%
of transmission.
Mode of transmission (cont.)

While the virus has occasionally been found
in saliva, tears, urine and bronchial
secretions, transmission after contact with
these secretions has not been reported.

No laboratory or epidemiological evidence
suggests that biting insects have transmitted
HIV infection.
HIV Transmission in United States and
Rest of the World
Drugs Against HIV


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Reverse Transcriptase Inhibitors:
Competitive enzyme inhibitors. Example:
AZT, ddI, ddC.
Protease Inhibitors: Inhibit the viral
proteases. Prevent viral maturation.
Problem with individual drug treatments:
Resistance.
Drug combinations: A combination of:



One or two reverse transcriptase inhibitors
One or two protease inhibitors.
Drug cocktails have been very effective in
suppressing HIV replication and prolonging
the life of HIV infected individuals, but long
term effectiveness is not clear.
Incubation period

Variable.

Although the time from infection to the
development of detectable antibodies is
generally 1–3 months, the time from HIV
infection to diagnosis of AIDS has an
observed range of less than 1 year to 15
years or longer.

The median incubation period in infected
infants is shorter than in adults.
Period of Communicability

Not known precisely; begins early after
onset of HIV infection and presumably
extends throughout life.

Infectivity during the first months is
considered to be high; it increases with viral
load, with worsening clinical status and with
the presence of other STIs.
Susceptibility

The presence of other STIs, especially
if ulcerative, increases susceptibility,
as may the fact of not being
circumcised for males, a factor
possibly related to the general level of
penile hygiene.
Interactions between HIV and
other infectious disease agents
Mycobacterium tuberculosis infection:

Persons with latent tuberculous infection who are
also infected with HIV develop clinical tuberculosis
at an increased rate, with a lifetime risk of
developing tuberculosis that is multiplied by a factor
of 6–8.

This interaction has resulted in a parallel pandemic
of tuberculosis.

in some urban sub-Saharan African populations
where 10%–15% of the adult population have dual
infection (Mycobacterium tuberculosis and HIV),

Other adverse interactions with HIV
infection include pneumococcal
infection, non-Typhi salmonellosis,
falciparum malaria and visceral
leishmaniasis.
Methods of control
A. Preventive measures:
 HIV/AIDS prevention programs can be
effective only with full community and
political commitment to change and/or
reduce high HIV-risk behaviours.
Methods of control (cont.)

Public and school health education
must stress that having multiple and
especially concurrent and/or
overlapping sexual partners or sharing
drug paraphernalia both increase the
risk of HIV infection.
Methods of control (cont.)

The only absolutely sure way to avoid
infection through sex is to abstain from
sexual intercourse or to engage in mutually
monogamous sexual intercourse only with
someone known.

In other situations, latex condoms must be
used correctly every time a person has
sexual intercourse.
Methods of control (cont.)

Expansion of facilities for treating drug users
reduces HIV transmission.

HIV testing and counselling is an important
intervention for raising awareness of HIV status,
promoting behavioural change and diagnosing HIV
infection. HIV testing and counselling can be
undertaken for:



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a) persons who are ill or involved in high-risk behaviours,
b) attenders at antenatal clinics, to diagnose maternal
infection and prevent vertical transmission;
c) couple counselling (marital or premarital);
d) anonymous and/or confidential HIV counselling and
testing for the “worried well”.
Methods of control (cont.)

All pregnant women must be counselled
about HIV early in pregnancy and
encouraged to undertake an HIV test as a
routine part of standard antenatal care.

Those found to be HIV-positive take a
course of ARV treatment, to reduce the risk
of their infant being infected.
Methods of control (cont.)

All donated units of blood must be tested for
HIV antibody; only donations testing
negative can be used.

People who have engaged in behaviours
that place them at increased risk of HIV
infection should not donate plasma, blood,
organs for transplantation, tissue or cells
(including semen for artificial insemination).

Only clotting factor products that have been
screened and treated to inactivate HIV must
be used.
Methods of control (cont.)

Care must be taken in handling, using and
disposing of needles or other sharp
instruments.

Health care workers should wear latex
gloves, eye protection and other personal
protective equipment in order to avoid
contact with blood or with fluids.
Methods of control (cont.)

WHO recommends immunization of
asymptomatic HIVinfected children with the
EPI vaccines; those who are symptomatic
should not receive BCG vaccine.

Live Measles-Mumps-Rubella and polio
vaccines are recommended for all HIVinfected children.
B. Control of patient, contacts and
the immediate environment:


1) Report to local health authority:
Official reporting of AIDS cases is
obligatory in most countries.
Official reporting of HIV infections is
required in some areas, Class 2

2) Isolation: Isolation of the HIVpositive person is unnecessary,
ineffective and unjustified.

Universal precautions apply to all
hospitalized patients.

3) Concurrent disinfection: Of
equipment contaminated with blood or
body fluids and with excretions and
secretions visibly contaminated with
blood and body fluids by using bleach
solution or germicides

4) Quarantine: Not applicable.

5) Immunization of contacts: Not applicable.

6) Notification of contacts and source of
infection: The infected patient should ensure
notification of sexual and needlesharing
partners whenever possible.
Management

AIDS must be managed as a chronic
disease; antiretroviral treatment is complex,
involving a combination of drugs: resistance
will rapidly appear if a single drug is used.

The drugs are toxic and treatment must be
lifelong.

In addition; treatment of other additional
associated conditions

C. Epidemic measures: HIV is currently
pandemic, with large numbers of infections
reported in the Africa, the Americas,
southeastern Asia, and Europe.

D. Disaster implications: Emergency
personnel should follow the same universal
precautions as health workers.

International measures: The United
Nations Joint Programme on HIV/AIDS
(UNAIDS), which coordinates UN
activities, and WHO do not endorse
measures such as requirements for
AIDS or HIV examinations for foreign
travellers prior to entry.
Thank You