specific investigations of hiv infections 1

7/28/2019 Specific Investigations of HIV Infections 1

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Specific Investigations of HIV

Infections1. Antigen Detection: The detection of HIV p24 antigen in serum or CSF

is the key to early diagnosis. The p24 antigen is a soluble protein fromcore of virus. Its level increases during first few weeks and leveldetected upto six weeks time. The antigen is not detected duringasymptomatic silent phase for a period of ten years or more. Thereappearance of p24 antigen precedes onset of symtomatic phase of

AIDS.

2. Antibody Test: Detection of the IgG antibody to envelop componentsgp 120 and its sub units is the commonly employed marker ofinfection with HIV. It is detected in the patient serum using enzyme-linked immunosorbent assay (ELISA). This test is highly sensitive (>99.5%) and quite specific.


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3. Western Blot (Immunoblotting): The confirmation of positive ELISA

test by this is mandatory. It detects the presence of antibodies in thepatients serum against HIV antigen. The criteria for the positiveinterpretation of western blot test are the presence of any two ofthree bands;

i, anti p24

ii, anti gp41 andiii, anti gp 120 or gp 160

4. Polymerase Chain Reaction: It detects very low level of viral DNAintegrated into the host genome. It is useful test in patients with +veor intermediate ELISA test.

5. Virus Isolation: HIV can be cultured from tissue peripheral bloodcells or plasma but this is mostly done in research settings.


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6. CT Scan or MRI: It is a advanced investigated procedure done in

patients with headache or neurological science so as to excludeintracerebral lesions before a lumber puncture is performed.

7. HIV Genotypic or Phenotypic Resistance Test: It is useful in decidingthe choice of antiretroviral regimen in treatment of HIV infection.

8. CD4 + T-cell Count: During the course of HIV disease there isgradual reduction in the CD4 cells in the peripheral blood while theCD8 cell count remains unchanged. The CD4 cell count is animportant criteria as its level falls below 200/L, patient should be

placed on regimen for pneumocystis carinii infection prophylaxis.


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TREATMENT

General principles of patient management includecounselling psychological support and screening forHIV infection. The general guidelines for treatment of

adults are as follows: Stage 1: Acute HIV Syndrome

1,,Symtomatic treatment of illness

2, Appropriate diagnostic test for TB, hepatitis B,

syphilis

3, Vaccination and immunization


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Stage 2: Chronic asymtomatic infection; Antiretroviral therapy;

The corner stone of medical management of HIV infection isantiretroviral therapy. Suppression of HIV replication isimportant component in prolonging life and improving qualityof life of patients with HIV infection

A. Nucleoside Analogues:

1. Zidovudine (AZT, 3-azido, 2-3 dideoxythymidine)

Doses: 200mg tid or 300mg bidIt inhibit reverse transcriptase and act as DNA chainterminator


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2. Didanosine (dideoxyinosine)Doses: 200mg bid for patients > 60kg and

100mg bid for patients < 60kg

3. Zalcitabine (dideoxycytidine)

Doses: 0.75mg tid

4. Stavudine (didehydro-3-deoxy-thymidine)

Doses: 40mg bid5. Lamivudine

Doses: 150mg bid


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B. Nonnucleoside reverse transcriptase inhibitors:These interfere with function of HIV reversetranscriptase by binding two regions outside theactive side and cause confirmation changes in

enzymes and make it inactive.

Nevirapine and Delavirdine are currently availablefor clinical use.

Doses: Nevirapine 200mg/day for 1 week then200mg bid; Delavirdine 400mg tid.


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C. Protease Inhibitors: These drugs are potent andselective inhibitors of HIV1 protease enzymes.

Saquinavir: It was first protease inhibitors

Doses: 600mg qds.

Ritonavir:

Doses: Initially 300mg bid and can be increased tofull dosage of 600mg bid.

Indinavir:Doses: 800mg qds

Nelfinavir: 750mg tid.


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Stage 3. Early symtomatic disease:1. Fever: Long term use of NS AIDS

2. Night sweats: Use of antipyratic agents

3. Chronic diarrhoea: Loperamid, Diphenoxylate HCl

4. Fatigue: Evaluate for thyroid or adrenal insufficiency,neuropathy, miopathy and treat if detective

5. Minor oral infections: treated with chlorohexidine

6. Headache: treatment with NSAIDS7. Continue treatment with antiretroviral agents

8. Nutritional defc.: Iron, Vit. B12


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Stage 4. Late Symptoma.1. Continue treatment with antiretroviral agents

2. Continue treatment of symtomatic complaints

Stage 5. Advance Disease

these patients need more frequent clinicalexamination

Diagnosis andImmediate treatment


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2. In the operating room

a, operating table is covered with a single sheet ofpolythene

b, the number of theatre personnel is reduced tominimum

c, the staff with abrasion or laceration on their hands arenot allowed inside the theatre

d, staff who entered the theatre should wear over shoes,gloves and disposable water resistant gowns and eye

protection glasses.


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E. Surgical Techniques:

1. Avoid sharp injury

2. Prefer scissors or diathermy to the scalpal

3. Use skin clips

4. Avoid needle stick injuries

5. Proper auto claving at the end of surgery6. AZT-Zidovudine, lamivudine and indinavir should be

given for health workers falling exposures of susceptibleareas to infected material from AIDS patients.

Rohit Sharma 69 pre-final year

Department of Oral Medicine and Radiology

specific investigations of hiv infections 1

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