5. ANALYSIS OF HIV
What Is HIV?
To understand what HIV is, let’s break it down:
H – Human – This particular virus can only infect human
beings.
I- Immunodeficiency – HIV weakens your immune system
by destroying important cells that fight disease and
infection. A "deficient" immune system can't protect you.
V – Virus – A virus can only reproduce itself by taking
over a cell in the body of its host.
Human Immunodeficiency Virus is a lot like other Viruses,
but the difference is that, your immune system can clear
most viruses out of your body. But can not get rid of HIV.
Scientists are still trying to figure out why.
6. ANALYSIS OF AIDS
What Is AIDS?
To understand what AIDS is, let’s break it down:
A – Acquired – AIDS is not something you inherit from your parents. You
acquire AIDS after birth.
I – Immuno – Your body's immune system includes all the organs and cells that
work to fight off infection or disease.
D – Deficiency – You get AIDS when your immune system is "deficient," or isn't
working the way it should.
S – Syndrome – A syndrome is a collection of symptoms and signs of disease.
AIDS is a syndrome, rather than a single disease, because it is a complex
illness with a wide range of complications and symptoms.
Acquired Immunodeficiency Syndrome is the final stage of HIV infection. People
at this stage of HIV disease have badly damaged immune systems, which put
them at risk for opportunistic infections (OIs).
You will be diagnosed with AIDS if you have one or more specific OIs, certain
cancers, or a very low number of CD4 cells. If you have AIDS, you will need
medical intervention and treatment to prevent death.
7. Where Did HIV Come From?
Scientists believe HIV came from a
particular kind of chimpanzee in
Western Africa. Humans probably came
in contact with HIV when they hunted
and ate infected animals. Recent
studies indicate that HIV may have
jumped from monkeys to humans as far
back as the late 1800s.
8.
9. HIV COME
FROM
In the 1930s HIV
semms to
have
spread out of Africa
from the German &
Dutch Colonies of
Cameroon.
The First Cases of
HIV
were
PCP(Pnueumocystis
Carinii with CMV.
Now
Widespread….
10. Epidemiology
HIV-1(Distributed Worldwide ) and HIV2(Mainly endemic in West Africa) were
first isolated & associated with the disease
in 1982 and 1983.
AIDS was First recognized in 1981,
although retrospective studies suggest that
cases Occurred in Africa in the 1950’s and
in the U.S by the 1970’s
11. How Do you get HIV?
Modes of transmission :-
Sexual contact (Heterosexual (most common
means in the world) and Homosexual)
Blood or blood product transfusion (before
routine tasting)
Transplanted tissue (before routine testing)
IV drug use with shared needsles.
Transplacent (in utero) or by perinatal
infection of neonates (Breast milk).
13. Which Body Fluids Contain HIV?
HIV lives and reproduces in blood and other body fluids. We know that the
following fluids can contain high levels of HIV:
Blood
Semen (cum)
Pre-seminal fluid (pre-cum)
Breast milk
Vaginal fluids
Rectal (anal) mucous
Other body fluids and waste products—like feces, nasal fluid, saliva,
sweat, tears, urine, or vomit—don’t contain enough HIV to infect you,
unless they have blood mixed in them and you have significant and
direct contact with them.
14. CON…
Healthcare
workers may be
exposed to some
other body fluids
with high
concentrations of
HIV, including
Amniotic fluid
Cerebrospinal
fluid
Synovial fluid
15. How Is HIV Transmitted Through
Body Fluids?
HIV is transmitted through body fluids in very specific ways:
During sexual contact: When you have anal, oral, or vaginal
sex with a partner, you will usually have contact with your
partner’s body fluids. If your partner has HIV, those body
fluids can deliver the virus into your bloodstream through
microscopic breaks or rips in the delicate linings of your
vagina, vulva, penis, rectum, or mouth. Rips in these areas
are very common and mostly unnoticeable. HIV can also
enter through open sores, like those caused by herpes or
syphilis, if infected body fluids get in them.
You need to know that it’s much easier to get HIV (or to
give it to someone else), if you have a sexually transmitted
disease (STD).
16. Con…
During pregnancy, childbirth or breastfeeding: Babies have
constant contact with their mother’s body fluids-including amniotic
fluid and blood-throughout pregnancy and childbirth. After birth,
infants can get HIV from drinking infected breast milk.
As a result of injection drug use: Injecting drugs puts you in
contact with blood-your own and others, if you share needles and
“works”. Needles or drugs that are contaminated with HIV-infected
blood can deliver the virus directly into your body.
As a result of occupational exposure: Healthcare workers have the
greatest risk for this type of HIV transmission. If you work in a
healthcare setting, you can come into contact with infected blood or
other fluids through needle sticks or cuts.
As a result of a blood transfusion with infected blood or an
organ transplant from an infected donor: Screening
requirements make both of these forms of HIV transmission very rare
in the United States.
18. Ways through which HIV/AIDS is not
contacted
HIV cannot reproduce outside the human body. It is not
spread by:
Air or drinking water from the same pot with an infected
person.
Insects: including mosquitoes. Studies conducted by
researchers have shown no evidence of HIV transmission
from insects.
Saliva, tears, or sweat. There is no documented case of
HIV being transmitted by spitting.
Casual contact like shaking hands or sharing dishes.
Closed-mouth or “social” kissing.
20. Symptoms and Signs of HIV
Within weeks of infection, many people will develop the
varied symptoms of primary or acute infection which typically
have been described as a "mononucleosis" or "influenza" like
illness but can range from minimal fever, aches, and pains to
very severe symptoms.
The most common symptoms of primary HIV infection are:
fever,
aching muscles and joints,
sore throat and
swollen glands (lymph nodes) in the neck.
Ulcers in the mouth
24. How Do You Get AIDS?
AIDS is the late stage of HIV infection, when a
person’s immune system is severely damaged
and has difficulty fighting diseases and certain
cancers. Before the development of certain
medications, people with HIV could progress to
AIDS in just a few years. Currently, people can
live much longer - even decades - with HIV
before they develop AIDS. This is because of
“highly active” combinations of medications that
were introduced in the mid 1990s.
26. Stages of disease development
Stage 1:-Acute Viral
Infection (1-3 Wks.)
No Symptoms, or any or all
of the following
“Mononucleosis like
Symptoms”
(Fever,headache,malaise,mya
lgia,arthralgia
lymphadenopathy
hepatosplenomegaly
meningitis, encephalitis rash)
small pink papules or
macules over much of the
body.
Stage 1 ends with the
production of high titers
of anti-HIV antibodies at
2-3 months,postinfection.
Anti-HIV antibodies are
usually detectable by
ELISA by the 3-4 .Weeks
27. Stage 2:-Completely Assymptomatic
Lasts for 6 or more years in65-85% of cases.
Patients produce large amounts anti-HIV antibody.
HIV is detectable in blood, semen,& cervical secretions.
New PCR procedures show that as many as 1 in10 peripheral CD4+ cells
are infected.
HIV-antibody-complement
complexes
are
trapped
nodes,tonsils,spleen,etc. by follicular dendritic cells(FDC).
in
lymph
CD4+ T cells disappear from the blood because they are sequestered in
the lymph nodes(numbers are 5-10X higher then in the peripheral
blood).
Follicular Dendritic Cells(FDC) facilitate HIV transmission to uninfected T
cells.
when peripheral CD4+ cells number 500-200/hl,the FDC are dying
and the internal structure of the lymph node is breaks down;HIV spills
over into the blood.
28. Stage 3- Overt Disease
Severity is directly related to the decline of CD4+
T cells , which causes diminished function by
TC,B cells,
(Hypogammaglobinemia), macrophages and NK
cells, and leads to opportunistic infections and
spontaneous neoplasms.
29. Other disorders of AIDS
Patients
Lymphoid organs
-Deterioration due to Compromised CD4+ function.
Nervous system
-Infection of endothelial cells leads to break-down of the blood –brain
barrier & infiltration of infected cells.
-encephalitis and dementia
GI system
- Tissue macrophages infected—diarrhea and malabsorption “ slim
disease”-often combined with CMV infection.
Cancer
-Kaposi’s sarcoma and B cell lymphomas (HHV-8 & Epstein-Barr virus
(EBV)).
Toxoplasmosis
-Reactivation of Toxoplasma cysts in the brain
30. AIDS: Signs and Symptoms
When HIV infection progresses to AIDS, many
people begin to suffer from fatigue, diarrhea,
nausea, vomiting, fever, chills, night sweats,
and even wasting syndrome at late stages.
Many of the signs and symptoms of AIDS
come from opportunistic infections which
occur in patients with a damaged immune
system.
32. Diagnosis
Test
ELISA
Agglutination test
Purpose
Initial Screening test
Western blot
Immunofluorescence test
Confirmatory test
P24 antigen
Early marker of Infection
Detection of a recent
infection
To confirm treatment
efficacy Detection of recent
infection
Staging the disease and to
confirm treatment efficacy
Virion RNA –RT PCR
CD4 CD8 ratio
Viral Isolation
36. The Global HIV/AIDS Crisis
Today
HIV, the virus that causes AIDS, has become one of the world’s most
serious health and development challenges:
33.4 million are currently living with HIV/AIDS.
More than 25 million people have died of AIDS worldwide since the
first cases were reported in 1981.
In 2008, 2 million people died due to HIV/AIDS, and another 2.7
million were newly infected.
While cases have been reported in all regions of the world, almost all
those living with HIV (97%) reside in low- and middle-income
countries, particularly in sub-Saharan Africa.
According to the World Health Organization (WHO), most people
living with HIV or at risk for HIV do not have access to prevention,
care, and treatment, and there is still no cure.
37. PREVENTION OF HIV/AIDS
Safe sex ,safe use of needles and more effective
early screening. Treat HIV-1 infected pregnant
women as indicated above to prevent
infection of the Fetus/Infant.
VACCINES :- No Vaccine
is currently
approved by FDA. Clinical trials are currently
being conducted with a number of different
vaccines.