HIV Module 2

This second module deals with symptoms, diagnostic tests and laboratory confirmation of HIV infection.

When is HIV test performed?

1.     When signs and symptoms of HIV infection noticed.

2.     In all pregnant women, HIV test should be mandatorily performed during pregnancy because effective drugs are available now for preventing HIV transmission from mother to child.

3.     In all patients with confirmed TB. TB is a common condition seen in HIV positive individuals. Usually, an HIV infection gets detected soon after TB diagnosis.

4.     In blood donors. HIV test is performed in individuals who volunteer for blood donation. If samples of such donors turn out to be HIV positive, they will be informed by the blood bank maintaining confidentiality and secrecy. The collected blood will be safely discarded too. HIV test is also advised by doctors before major surgeries.

5.     Some individuals subject themselves to voluntary HIV testing. This practice needs to be encouraged as an early detection and prompt treatment enable HIV positive individuals to lead a healthy life for a longer period. It is always good to perform HIV test before marriage or during a periodical health check up.

Where is HIV test done?

HIV test is done for free at government hospitals. These centres are called Integrated Counselling and Testing Centre or ICTC and are located at Thaluk hospitals, district hospitals and medical colleges. These centres are also known as “Jyothis” in Kerala. Counselling sessions are given before and after HIV tests and facilities for clarification of doubts are also made available. Identity and test results of patients are kept confidential. Private laboratories also have testing facilities.

Signs and symptoms of HIV infection.

As mentioned before, HIV infected individuals might remain without any symptoms for several years. Some might just have large lymph nodes in different parts of the body (generalised lymphadenopathy) as symptom.

     Itchy lesions on skin which do not respond to treatment might be a symptom of HIV infection. Excessive skin reactions to insect bites also might point to a possible HIV infection. Recurrent episodes of herpes Zoster, oral fungal infections (oral candidacies) etc also are seen as a result of HIV induced immune suppression. All these conditions are grouped under WHO clinical stage-2.

Persistent fever for which a cause cannot be detected (over a month), prolonged diarrhoea or weight loss without reason (more than 10% of body weight) could be a signs of HIV infection. These symptoms are grouped under WHO category 3. Tuberculosis of lungs, severe anaemia, persistent oral fungal infections etc are also grouped under WHO category 3.

Severe emaciation of the body (HIV wasting syndrome), lung infections like PCP, fungal infection of oesophagus (food pipe), various infections affecting brain(TB, Meningitis, Toxoplasmosis), cancer of cervix in women, lymphomas, viral infections of retinal layer of eye (CMV retinitis) and TB of any organ other than lungs are classified as WHO stage 4.

On detecting above mentioned conditions an HIV test should be performed and treatment initiated.

Diagnostic Tests.

HIV ELISA (Enzyme Linked Immuno Sorbent Assay) is the test commonly used to detect HIV infection. This test can find antibodies produced by human body against HIV (Anti HIV antibodies) from blood samples. But human body might not produce enough antibodies in the early days (10 days to 3 months after contracting infection) for the ELISA to detect. This might give a negative HIV result in the initial period even though the individual is HIV positive and can transmit the infection. This period is called ‘window period’. Western Blot is the confirmatory test used in case of a doubtful result in ELISA test. The genetic material of HIV (RNA) can be detected in blood samples using PCR technique (polymerase Chain Reaction). In children less than 18 months, ELISA HIV test might not give an accurate result and hence DNA PCR test is used for confirmation. NAAT or Nucleic Acid Amplification Test can detect HIV infection in human body very early. These blood tests detect HIV infections after 7 to 15 days of entry of the virus into the body. Thus technology has advanced reducing the window period from three months to less than one week which is a great achievement.

Tests performed in HIV positive individuals.

There are two tests to assess the health status HIV positive individual.

a.      Direct method or HIV viral load method.

b.     Indirect method or CD4 test.

HIV viral load test tells us roughly the quantity of HIV in 1ml of human blood (Viral copies/ml). Those who take correct treatment for HIV infection will have undetectable levels of HIV in their blood (less than 50 copies/ml). In case of treatment failures, HIV viral load will be thousands or lacks/ml.

CD4 Test- To combat various diseases, human body has an elaborate immune system. A major component of the immune system is lymphocytes among which T cells is one group. HIV attacks these T cell lymphocytes and specifically a component called CD4 on T cells is targeted. On measuring this CD4, we can indirectly assess the extent of HIV infection in the individual. In a healthy person, CD4 count will range from 800 to 1200. In the initial years after contracting HIV, CD4 might be above 800 cells but as the HIV replicates in the body and increases its number, CD4 gradually comes down. When CD4 comes below 100-50 cells, stage 4 diseases start appearing.

Miscellaneous Tests.

1.     TB detection- in those individuals’ who are first detected to be HIV positive, intense TB screening should be performed. TB is a common manifestation of HIV induced immune suppression. Sputum Tests, FNAC (fine needle Aspiration Cytology) tests of the swelling of lymph nodes, scans of brain and abdomen, X-rays etc might be required.

2.     All baseline blood tests should be performed in HIV positive cases initially. Anaemia is very common in HIV infection. Long term HIV infection can affect heart and kidneys. Hence blood tests to assess function of kidneys (RFT) needs to be done.

Treatment of HIV infection, drugs used and care of HIV patients will be discussed in detail in the next module.