AIDS

CHARACTERISTIC FEATURES OF HIV

       *Long incubation period

           ( 3 months to 10 years ) followed by slow progression

Hemopoietic and nerve tissue tropism

Cytopathic effects

Immunosuppression 

MODE OF TRANSMISSION OF AIDS

HIV is present in blood , semen and other body fluids , such as breast milk and saliva

Exposure to infected fluid leads to a risk of contracting infection, which is dependent on the

            ÜIntegrity of the exposed sites

          Ü Types and volumes of body fluids

         ÜViral load

HIV can be transmitted mainly by 3 ways

 1. Sexual route  ( Heterosexual / Homosexual )

 2. Parenteral route through blood or blood product,     transfusion injecting drugs, occupational injury

3. Mother to child  transmission: During pregnancy,     through placenta,  at birth during delivery and through          breast feeding

DIAGNOSIS OF AIDS (According to WHO )

For the purposes of AIDS surveillance  an adult or adolescent (>12 years of age) is considered to have AIDS if at least 2 of the following  major signs are present in combination with at least 1 of the minor signs  listed below

Major signs :¤ weight loss ³ 10% of body weight

¤Chronic diarrhea >1 month      

¤Prolonged fever >1 month (intermittent or constant)

Minor signs : vPersistent cough > 1 month

v Generalized pruritic dermatitis vH/O Herpes zoster vOropharyngeal candidiasis vCh. Progressive or  disseminated  herpes simplex  infection vGeneralized lymphadenopathy  * * The presence of either Kaposis sarcoma or cryptococcal  meningitis  is sufficient  for the diagnosis of AIDS

Investigations:

Test for HIV specific antibody

Screening test ÊSerum specimen – PAT, ELISA, ÊSaliva /         Urine,/ vaginal secretion/ specimen- IFA

Confirmatory test: Serum – Western blot assay

 P24 (Viral core protein) gp 41 (envelop glycoprotein)

F Most of the Ab titre may be detected after at least 2 weeks    of exposure history

Test for detection of HIV antigen (confirmatory)

YPCR  YVirus isolation and lymphocyte culture very expensive lab. support) YDetection of HIV specific core Ag – * indicates HIV replication * tends to be positive  prior to seroconversion and advancement of disease

Tests for evaluation of immunological status

CD4  Cell count

b2   microglobulin ( Polyclonal hyper globulinemia

            (rapid progression indicative of     macrophage monocytic  stimulation)

Others

Hb %              Anemia

 TC, DC        Lymphocytopenia, thrombocytopenia

 ESR  

PREVENTIVE STRATEGIES / MEASURES FOR HIV TRANSMISSION

Until a vaccine or cure for AIDS is found the only means at present available is prevention

Sexual

FComprehensive school sex education program

 Public awareness for HIV

F Safe sex practice à avoiding  indiscriminate sex  and using condom

 Control of sexually transmitted diseases

 Avoiding infected women to become pregnant

Parenteral

Routine screening of donated blood

Avoid sharing needles or syringes during  blood transfusion , saline infusion, drug injection, blood collection etc.

 Avoid shared razors and tooth brushes

 Occupational universal precaution  à need stick injury

v Post-exposure prophylaxis should be started within hours of exposure (occupationalà health    workers)

            Zidovudine + Lamivudin + Indinavir for 28 days

MEASURES TO REDUCE VERTICAL TRANSMISSION

ÊCounseling about the  risk of pregnancy  (Infected mother)

Highly Active Anti-Retroviral  Therapy (HAART) during pregnancy.

 Caesarean Section.

Zidivudin Treatment  in Neonates.

 Avoid breast Feeding.