Screening and diagnosis for HIV
There are number of good reasons why people should get tested for HIV.
There are number of good reasons why people should get tested for HIV. Access to testing for HIV helps those in need to start antiretroviral treatment (ART). Even though HIV is still not a curable disease, ART helps people living with HIV live longer, healthier lives without AIDS. Another reason for people to get tested is that access to testing contributes to prevention of new infections. People who are aware that they are living with the virustend to change their behaviour to avoid transmitting the virus to others.
Also, access to ARV treatment reduces the risk of transmission. People living with HIV who have undetectable viral loads due to effective treatment cannot transmit the virus to others. In communities, the more people access ART, the fewer new infections there are. Another reason for HIV testing is that mother-to-child transmission can be prevented as mothers who know they are HIV positive can take ART. The probability that a mother living with HIV who is not on ART would transmit the virus to her child during pregnancy and/or delivery is approximately 20%.If a mother living with HIV mother is taking ART the probability of transmitting the virus to the child decreases to one percent. Finally, starting treatment early is more cost-effective than starting treatment later due to its benefits for the health of individuals taking treatment and to its impact on preventing transmission of the virus.
Acute primary HIV infection cannot be diagnosed from the symptoms which may start 2-6 weeks after transmission and last 1 to 4 weeks. Only 30-50 % of infected persons show symptoms.
Symptoms can include fever, sore throat, fatigue, diarrhoea, headache, joint and muscle aches and swollen lymph nodes. Once HIV enters to the body, it infects CD4 cells and starts replicating. During this acute or primary phase of infection, the blood contains a number of viral particles that spread throughout the body, seeding various organs, particularly the lymphoid organs. At the same time, the body starts to produce antibodies against
HIV. If a person has HIV-RNA (the virus genome), HIV-antigens or antibodies to HIV in his or her body, this indicates that the person is infected with HIV. HIV is usually diagnosed through the detection of antibodies against to HIV and/or the HIV p24 antigen rather than direct detection of the viral genome. Preliminary HIV-tests search for antibodies to HIV. They are enzyme immunoassays used in laboratories or rapid tests often used in low threshold services. All preliminary positive HIV-test results must be confirmed from a second sample with a confirmatory test done in a laboratory.