Transcript As HIV viral load increases CD4 cell count decreases and vise

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Heterosexual
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Bi-sexual
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Homosexual
Transmission Modes for HIV (2)
[Non-Sexual]
Blood and Blood Products
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Blood transfusion
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Tissue Transplantation e.g Kidney
Other
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Injections
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Contaminated instruments
Mother to Child
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During Pregnancy
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During labor (delivery)
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After birth (breastfeeding)
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High Viral load in the infecting person
Lowered Immune status of the recipient
Presence of genital ulcers, abrasions
Lack of circumcision (male)
Multiple sexual partners
Specific sexual practice – anal sex
Age of the recipient – very young and
very old
Type of the HIV strain infecting recipient
•Avoiding exposure (abstinence)
•Use of condoms during all sexual
encounters
•Treatment of concurrent Sexually
Transmitted Infections (STIs)
•Post-exposure prophylaxis
•Antiretroviral therapy to prevent
mother to child transmission
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Two types: HIV-1 and HIV-2, 40-60%
Amino Acid homology
HIV-1 is found worldwide, HIV-2 is found
primarily in West Africa
Subtypes (clades): M group (subtypes A-K)
and Subtype O (55-70% homology with M
subtypes), N (“new”) subtype
Diagnostic tests may preferentially detect a
specific type or subtype
Vaccines may need to be subtype specific
Leukocytes (WBCs) play major role:
◦ Neutrophils (form pus, phagocytic)
◦ Macrophages (phagocytic, secrete chemicals
that affect function of other cells)
◦ Lymphocytes
 B lymphocytes (make antibodies)
 T lymphocytes (secrete chemicals that affect
function of other cells)
 CD4+ ”helper” stimulate macrophages
 CD8+ “suppressor” cells
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HIV is an RNA virus  HIV RNA is what is
detected in blood
P24 antigen can be detected early in HIV
infection, before antibodies (6 – 8 wks
after)
Methods of testing HIV virus load:
Different sensitivities, range:
◦ “Undetectable”: <50 copies/ml or
<400 copies/ml
◦ > 750,000 copies/ml
Play important role in immune response
of healthy individual
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Activate B cells which produce antibodies
Important in the production of growth factors
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Stages of CD4 cell count in HIV infection
1.
2.
3.
4.
Before HIV infection: 800 – 1000/mm3
Sero-conversion illness: ~500/mm3
Adaptive immune response: ~700/mm3
AIDS: <200/mm3
◦ HIV binds to the CD4 receptor sites,
causing the CD4 cell to loose
immune function
◦ HIV disrupts the cell membrane of
the CD4 cell causing cell death
◦ Binding of HIV to the CD4 receptor
may result in the CD4 programming
its own death
HIV viral load ⍺
CD4
1
As HIV viral load increases CD4 cell
count decreases and vise-versa
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Play important role in controlling viruses
◦ Kill cells expressing these (foreign)
antigens
◦ Suppress HIV replication
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As HIV virus load increases, CD8 T cells
increase in a bid to fight /suppress HIV
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Syn. Sero-conversion illness
 Fever
 Lymphadenopath
y
 Pharyngitis
 Rash
 Myalgia /
arthralgia
 Diarrhoea
 Headache
 Nausea
&
vomiting
 Weight loss
 Thrush
 Neurologic
symptoms
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Clinical Stage One:
◦ Asymptomatic
◦ Persistent generalized lymphadenopathy
Performance scale 1: Asymptomatic, normal activity
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Clinical Stage Two:
◦ Weight loss < 10% of body weight
◦ Minor mucocutaneous manifestations
(seborrheic dermatitis, fungal nail infections,
recurrent oral ulcerations, angular chelitis)
◦ Herpes zoster within the past 5 years
◦ Recurrent upper respiratory tract infections
And/or performance scale 2: Symptomatic, normal
activity
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Clinical Stage Three:
◦ Weight loss > 10% of body weight
◦ Unexplained chronic diarrhea (> 1 month)
◦ Unexplained prolonged fever (intermittent or
constant) > 1 month
◦ Oral candidiasis (thrush)
◦ Oral hairy leukoplakia
◦ Pulmonary tuberculosis within the past year
◦ Severe bacterial infection (pneumonia, pyomyositis)
And/or performance scale 3: bed-ridden < 50% of
the day during the past month
Candidiasis
 Fungal infection caused by C. albicans.
 Commonly found in people with HIV
infection
 Occurs commonly in stages 3 & 4 of HIV
disease
 Other factors may predispose to candidiasis:
Extremes of age, antibiotics, diabetes, other
immunosuppressive states.
Rx. Topical antifungals: clotrimazole,
Nystatin
Systemic: Ketoconazole, Fluconazole
Pulmonary Tuberculosis (PTB)
 Bacterial infection caused by
Myco.tuberculosis.
 Found in late HIV disease (stage 3 & 4)
 Symptoms mimic those of HIV infection:
 Weight loss
 Night sweats
 Chronic fevers
 H/o contact may not be revealing
 Diagnosis is simple: Sputums, CXR
Rx. 2RHZE/6HE
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Clinical Stage Four:
HIV wasting syndrome
Pneumocystis carinii pneumonia
CNS toxoplasmosis
Cryptosporidiosis with diarrhea > 1 month
Extrapulmonary cryptococcosis
Cytomegalovirus (CMV) disease of an organ
other than liver, spleen, or lymph nodes
◦ Visceral Herpes simplex virus (HSV) infection
or mucocutaneous HSV infection > 1 month
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HIV-Associated Wasting
Definition: “Weight loss of at least 10% in
1.Disorders in food absorption
the presence of diarrhoea or chronic
weakness and documented fever for at
least 30 days, that is not attributable to a
concurrent condition other than HIV
infection itself”.
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Rapid weight loss associated with acute
infections
Depletion of fat and lean tissue
Reasons for weight loss:
1. Metabolic abnormalities
2. Decreased intake
3. Production of some immune factors
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Nutritional assessment
Diet history
Identify factors interfering with food intake
Estimate current energy intake
Interventions
Treat any underlying infection
Institute ARVs where possible (gain: 0.40.8kg/month)
Increase intake of protein to 1.5 g/kg
Supplement micronutrients: Vitamin A, B1,2,6
Appetite stimulators: Cyproheptadine
(Periactin®), Tres Orix F®
Exercise
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Clinical Stage Four, continued:
◦ Progressive multifocal leukencephalopathy (PML)
◦ Any disseminated endemic mycosis (e.g. histoplasmosis,
coccidiodomycosis)
◦ Candidiasis of the esophagus, trachea, bronchi or lungs
◦ Disseminated atypical mycobacterium
◦ Non-typhoid Salmonella septicemia
◦ Extrapulmonary tuberculosis
◦ Lymphoma
◦ Kaposi’s sarcoma
◦ HIV encephalopathy
And/or performance scale 4: bed-ridden > 50% of the day during the last
month