Rapid HIV test (clinical analyzes)

Content

Introduction

Introduction

HIV (human immunodeficiency virus) infection tends to persist over time (chronic infection) and for many years may not cause any disturbance (symptoms) and can only be identified with specific blood tests (read the hoax ).

The "ascertainment (diagnosis) of any" infection is necessary in order to avoid its transmission to other people and to allow rapid access to treatments capable of preventing the progression of the infection and the onset of AIDS. Therefore, anyone who has had potentially risky behaviors (read the Hoax) must carry out the HIV test in the manner recommended by the Ministry of Health.

In particular, the detection of HIV infection is carried out by means of highly consolidated and standardized tests that search in the blood for the presence of antibodies against HIV-1 and HIV-2 (third generation tests) or the joint presence of antibodies and p24 antigen (combined IV generation tests).

In addition to the traditional blood test, rapid “do-it-yourself” tests are now available that can quickly detect the presence of anti-HIV antibodies in blood or saliva (rapid third generation tests). These tests, which have an appreciable level of sensitivity and specificity, can be easily carried out even in the absence of health personnel, but are not considered diagnostic as they require confirmation by means of the traditional test carried out in the laboratory.

A quick blood test can be purchased at a pharmacy and can be done yourself by carefully following the recommendations attached to the kit.

There are other rapid blood or saliva tests used by healthcare professionals in hospitals or in public spaces as part of initiatives aimed at facilitating access to the test for the general population.

The test

The test

Rapid tests for HIV are able to highlight the presence of antibodies against HIV in a small amount of blood or saliva.

The tests consist of a solid support in which there is an internal structure with a membrane inside that contains the HIV 1-2 proteins and a control substance (protein always recognized by antibodies).

When a drop of blood, taken by pricking the tip of a finger, or a small amount of saliva, taken by passing a spatula over the gums, is put in contact with this membrane, any antibodies present bind to the proteins, causing the formation, in the 15-30 minute ride, of a noticeable band.

The presence of the control band shows that the test was carried out correctly and the absence of the specific HIV band indicates the absence of anti-HIV antibodies (non-reactive or negative test).

The simultaneous presence of the control band and the specific HIV band signals the existence, in the sample, of anti-HIV antibodies (reactive or positive test), suggesting an infection.

Failure to develop the two bands indicates that the test was not carried out correctly and must be repeated (invalid test). The test must be carried out by carefully following the instructions and warnings contained in the package.

Results

Results

Rapid HIV tests are able to recognize only the presence of HIV antibodies and constitute 3rd generation test.

Based on their characteristics and the length of the period in which the infection is not detectable (window period), for a fully reliable response it is necessary to wait an interval of 90 days from the possible contagion. This period is necessary for the complete development of antibodies specific as a consequence of the infection.

Unlike the rapid blood test, which has a high sensitivity and specificity, the saliva test is slightly less sensitive and can be affected by inflammation of the mouth and by the intake of food and drink within a short period of time. of the test.

For this reason, rapid tests cannot be taken into consideration for the definitive ascertainment of HIV infection and, particularly in the case of salivary tests, it is always advisable to perform a traditional examination that confirms, or not, the presence of the infection. .

In consideration of the potential psychological implications associated with the outcome of the HIV test, it would be advisable to carry it out in the presence of health personnel adequately trained to provide professional and scientific support. Thanks to its simplicity, the rapid test can be performed alone, but, in the case of positive result, it is not possible to have an immediate reference for information and psychological support from qualified personnel.

However, the rapid test is a useful tool to facilitate access to HIV testing for people who may have difficulty in going to diagnostic centers.

In any case, it is important that the availability of the rapid test is accompanied by adequate information campaigns for the prevention of HIV and other sexually transmitted infections.

Bibliography

Bibliography

Pilcher CD, Louie B, Facente S, Keating S, Hackett Jr J, Vallari A, Hall C, Dowling T, Busch MP, Klausner JD, Hecht FM, Liska S, and Pandori MW. Performance of Rapid Point-of-Care and Laboratory Tests for Acute and Established HIV Infection in San Francisco. PLoS One. 2013; 8: e80629

U.S. Food and Drug Administration (FDA). Testing for HIV

U.S. Food and Drug Administration (FDA). HIV Home Test Kits

Link Further information

Link Further information

United Against AIDS (ISS). HIV / Aids test

Ministry of Health. Consensus document on offer policies and methods of carrying out the HIV test in Italy

Ministry of Health. HIV test

Editor'S Choice 2022

Pleurisy

Pleurisy

Pleurisy is an inflammation of the pleura, the membrane formed by two layers (one that lines the lungs and the other the inner wall of the thoracic cavity) separated by a space containing a very small amount of fluid with a lubricating function

!-- GDPR -->