·
Acquired Immune
Deficiency Syndrome (AIDS) is a chronic, life threatening condition caused by
Human Immunodeficiency Virus (HIV).
·
Characterized by
generalized dysfunction of the immune system making individuals susceptible to
opportunistic infections & tumors.
·
Pneumocystis carinii pneumonia: most common opportunistic infection.
·
Incubation period
estimates range from 6 months to 9 years.
Pathophysiology:
·
HIV binds with
CD4+T cells and replicates by generating a DNA copy by reverse transcriptase.
·
HIV causes AIDS by
destroying CD4+T cells which leads to a weak immune system allowing
opportunistic infections.
Epidemiology:
·
5th
leading cause of death among ages 25-44 years in the US
·
In the US
·
Most HIV
infections occur in men due to homosexual contact but the incident is already
increasing among women who engage in unprotected sexual activities.
Mode of Transmission:
·
Horizontal
transmission: Sexual contact (oral, vaginal, anal sex); parenteral exposure to
blood or body fluid containing visible blood.
·
Vertical
(perinatal) transmission: HIV infected pregnant woman passes the infection to
fetus during pregnancy, delivery or breastfeeding.
Clinicl Stages
of HIV/AIDS
|
Signs &
Symptoms
|
Stage I.
Asymptomatic/Primary HIV
infection
|
Flu-like symptoms
ü Fever
ü Myalgia
ü Persistent generalized lymphadenopathy
ü Headache
|
Stage II.
|
ü Person may experience outbreak of herpes zoster
ü Recurrent respiratory tract infection
ü Chronic diarrhea for longer than 1 month
|
Stage III.
|
ü
Integumentary
problems
ü
Gynecological
problems
|
Stage IV.
|
ü HIV wasting syndrome
ü Development of opportunistic infections
|
Diagnostic Exams:
§ AIDS is present if there is 2 positive results of ELISA
confirmed with positive result on Western blot assay.
§ Enzyme –linked immunosorbent assay (ELISA)/ Enzyme
immunoassay (EIA)
o Identifies antibodies directed specifically to HIV.
o Useful in children older than 18 months.
§
Western blot assay
o Confirm HIV infection
Useful in children older than 18 months
§ Viral load tests: Reverse Transcriptase- Polymerase
Chain Reaction (RT-PCR) & Nucleic Acid Sequence-Based Amplification (NASBA)
o < 10,000 copies/mL = low risk AIDS
o > 100,000 copies/mL = High risk for AIDS. (+) viral activity
o Measures HIV RNA in the plasma.
o Measures response to treatment.
o RT-PCR detects HIV in high risk seronegative people
before antibodies are measurable, screen neonates, & confirm + EIA result.
§
CD4/CD8 Ratio
o Helper/ suppressor ratio = degree of immune
suppression.
o CD4 count of
<200/mm3: indicates AIDS
o Normal values depend on age (ratio 0.9 to 3.7 in
adults).
§
p24 antigen
o 2 or more positive results are diagnostic for HIV
infection
o Used o detect HIV antigen in children younger than 18
months.
§ Nonspecific markers of disease progression: blood
counts, albumin levels & ESR
§ Skin biopsy, serum chemistries and imaging studies are
indicated depending on organ/system involvement & disease progression.
Treatment:
·
There is no cure;
prevention is the only key to control.
·
Highly Active Antiretroviral Therapy (HAART): reduces the number of HIV particles in the blood
stream as measured by viral load test.
-
Combination of three
(3) drugs belonging to 2 types of antiretroviral agents.
-
Side effects include: lipodystrophy, dyslipidaemia,
diarrhea,
insulin resistance, an increase in cardiovascular
risks and birth defects.
-
n.b: Patient
problem with HAART: non-adherence with complex administration leads to drug
resistance development.
·
Antiretroviral drugs: inhibit the growth and replication of HIV at various stages of its life
cycle.
Types/Classes:
1.
Nucleotide
reverse transcriptase inhibitors/NtRTIs & Nucleoside analogue reverse transcriptase
inhibitors/NRTIs (“nukes”): inhibit the replication of an HIV enzyme called reverse
transcriptase.
E.g. idovudine
(Retrovir®) [formerly called AZT azidothymidine],
lamivudine (Epivir®) didanosine (Videx®), zalcitabine
(Hivid®), stavudine (Zerit®) and abacavir (Ziagen®)
2.
Protease
inhibitors (PIs): interfere
with an enzyme known as HIV protease. This causes HIV particles in your body to
become structurally disorganized and noninfectious.
e.g atazanavir/ATV (Reyataz®), darunavir/DRV (Prezista®), Fosamprenavir/FPV (Lexiva®), lopinavir + ritonavir (Kaletra®), saquinavir/SQV (Invirase®), tipranavir/TPV (Aptivus®)
3.
Non-nucleoside
reverse transcriptase inhibitors (NNRTIs): bind directly to the enzyme reverse transcriptase. E.g
efavirenz
(Sustiva®, Stocrin®);
nevirapine
(Viramune®); delavirdine (Rescriptor®); etravirine
(Intelence®)
1.
Fusion
inhibitors (entry inhibitors): suppress resistant strains of HIV. e.g maraviroc
(Selzentry®), enfuvirtide (Fuzeon®)
2.
Integrase
inhibitors: aims to treat those who become resistant to other treatments. e.g
raltegravir (Isentress®)
·
CCR5 antagonists: new
class of drugs used to treat a particular type of HIV infection called
CCR5-tropic HIV-1
E.g. maraviroc (Selzentry®)
Side effects: liver problems, postural hypotension, inflammation
response.
·
Oral Progesterone
(Megace®, Winstrol®):
stimulate appetite thereby assisting with the treatment of weight loss (HIV
Wasting Syndrome)& loss of taste perception
·
For disease
progression: Antibiotic therapy, chemotherapy, analgesic, antiemetic,
antifungal & appetite stimulants.
·
Supportive care
for chronic illness associated with HIV infection: O2 therapy, IV fluid,
electrolyte replacement and mechanical ventilation (end stage AIDS).
Prevention:
If HIV negative:
·
Know the HIV
status of your partner.
·
Provide client
education regarding safe & protected sex:
o Latex condom: vaginal or anal intercourse
o Dental dam: used for oral contact with the vagina or
rectum
o Avoid sexual contact with multiple partners.
·
Consider male
circumcision
·
Use sterile needle
& avoid needle sharing.
·
Be cautious about
blood products.
·
Get routine HIV
testing
If
HIV positive:
·
Follow safe sex
practices.
·
Tell your sexual
partner that you have HIV.
·
Don’t share
needles or syringes.
·
Don’t donate blood
or organ.
·
Don’t share
razors, toothbrush, sex toys or blood contaminated articles.
·
Drug users
interested in drug treatment programs must be referred.
·
Get immediate
medical care if pregnant.
·
Don’t breastfeed
the infant.
·
TB testing
For health workers:
·
Standard
precautions: apply to blood, body secretions & excretions.
Nursing Interventions:
·
Use of universal precautions
for all clients regardless of diagnosis.
·
Provide ongoing
coordination of health care team to afford client the best possible assistance.
·
Provide emotional
support, counseling and referral to support group.
·
Protect the client
from secondary infections; assess for early signs and report for treatment.
·
Maintain client
advocacy and confidentiality.
·
Refer to dietician
to analyze nutritional requirements & make recommendations to maintain
ideal body weight.
·
Provide
high-caloric, high protein diet to prevent weight loss.
·
Encourage intake
of foods rich in vitamins A, C & E.
·
Educate on:
o
Importance of
compliance to long-term treatment regimen.
o
Stress the need
for follow-up check-up & diagnostic tests to monitor response to treatment
& disease progression.
Discuss life issues with the client & support
system members as disease progresses & prognosis worsens