Once the HIV (Human Immunodeficiency Virus) invades the immune system, it damages it part by part, until the person develops AIDS (Acquired Immunodeficiency Syndrome). CD4 cells are the immune systems' primary sentries that protect the body from infection. This deadly virus attacks these very cells, reducing their number to such an extent, that the affected person may be left with no protection against the mildest of illnesses. It takes generally about 10 years, for the HIV to progress to AIDS. By this time, the number of CD4 cells becomes lower than 200, leaving the person completely exposed to the mildest of infection. Although the disease has no cure, there are drugs that significantly slow down its progression, and extend the life expectancy of the patient. So, the sooner the treatment is begun, the better are the chances to manage the symptoms, and make living with the condition easier. Timely HIV testing and diagnosis is integral to the treatment of this condition. Diagnosis People go for testing if they suspect that they may have come in contact with the blood of an infected person, had unprotected sex, or used unsterilized syringes. This condition might be incidentally detected during medical checkups. One of the most important facts about the testing is that any test when done immediately after the infection, would provide an inaccurate or a negative result, even if the person has been infected by the virus. This is because, the body takes up to 3 months to develop antibodies in response to the invasion of the virus. This period is known as the HIV testing window period. In some cases, it has been found that this period might extend up to 6 months. Due to this, people are recommended to go for the test three months after they have been exposed to the virus. Also, another must-know fact is that from the moment a person is exposed to the virus, he can transmit the virus to others. The transmission can also occur during the window period. With the ongoing research studies on this condition, scientists have come to know that, once the virus infects the body, it produces a protein or an antigen. To detect this protein, experts have developed a newer type of test checks. These tests are known to produce confirmed diagnosis within days of infection. There are many centers which also provide free testing for people, and these results are kept confidential. Types of Tests The testing is done using a blood sample, or by obtaining a sample of cells taken from inside the cheek. This is to determine the presence of antibodies to the virus, once the window period is over. The types of testing procedures include:

• Enzyme-linked Immunosorbent Assay Test (ELISA) - Once this test confirms the presence of the antibodies, then the patient would have to undergo another test to confirm the presence of HIV proteins. Usually, it takes about a few days to a few weeks to get the results.
• Rapid HIV Testing - As the name suggests, this testing is known to provide accurate results, and all it takes is a mere 20 minutes.
• Home HIV Testing - Here, the subject has to mail a drop of his/her blood. He/she is then required to call up a toll-free number to get the results. The results are delivered within three to seven business days.

After Diagnosis Once the person has been diagnosed with this infection, he/she undergoes different test procedures so as to determine the stage of the disease.

• The first test includes the determination of the CD4 cells. If the test confirms the count to be somewhere around 500 - 1000, then the test is negative. However, if the count goes down to 200 or less, then the result would be otherwise.
• The next procedure is for determining the amount of virus in the blood. This is known as the viral load test.
• There is another test which helps in finding out if the strain of the HIV of the subject, has developed resistance to any anti-viral drugs.

The aforementioned testing methods help to determine how far the HIV infection has progressed. People, especially those who come in the high-risk groups, must get tested for it. Prevention is always better than cure, which is why, one must practice safe sex and take all possible preventive steps. Those who have been infected must take steps to prevent the transmission to others. Disclaimer: The information provided in this article is solely for educating the reader. It is not intended to be a substitute for the advice of a medical expert.