HIV

AIDS or Acquired Immunodeficiency Syndrome is caused by HIV (Human Immunodeficiency Virus), which targets cells of the immune system. Its action presents with the reduction of the body’s defences and thus the development of opportunistic infections in the course of the disease.

Appearing in the 1920s in the Democratic Republic of Congo, particularly in the capital, the virus continued to spread throughout Africa and then the rest of the world for sixty years. It was not until 1981 that the existence of a new disease began to be suspected. The virus was identified in 1983, by Luc Montagnier and Francoise Barrè-Sinoussi of the Pasteur Institute in Paris, who were awarded the Nobel Prize in Medicine in 2008 for this very discovery.

CAUSES

The infection is caused by a human retrovirus, consisting of ribonucleic acid (RNA). Humans are the only known species affected by HIV-1.

Based on HIV sequences, HIV-1 is the one found in most patients, while HIV-2, whose DNA has 40-60% homology to HIV-1 DNA, is common in West Africa.

Humans are not the only animals to be infected with immunodeficiency virus: chimpanzees and cats are equally affected by the retroviruses called SIV and FIV, of which the former is the progenitor of HIV1 and HIV2.

TRANSMISSION

HIV is usually found in pre-ejaculatory fluid, semen, vaginal secretions, breast milk and, of course, blood.

One can come into contact with infected blood through the exchange of contaminated syringes, through the promiscuous use of scissors, toothbrushes, or razors, and also through instruments used for tattoos that have not undergone optimal sterilization.

Sexually, transmission can occur during vaginal, oral or anal intercourse between a positive and a healthy person. In these cases, the risk is aggravated by the presence of blood (menstrual cycle, bleeding gums or blood loss from anal trauma).

During pregnancy, childbirth, and natural lactation, direct transfer of infection takes place from mother to baby.

The use of toilets, gyms or showers shared by several people and the promiscuous use of glasses and cutlery are not considered infectious agents. Saliva, sneezing, coughing, kidney excretions and fecal material do not carry the HIV infection and neither do handshakes and kisses.

GEOGRAPHICAL DISTRIBUTION

On the European continent, HIV incidence is divided into three groups: high, intermediate, and low.

The average incidence is close to 30%, and the most affected countries are Poland, Latvia and the Netherlands around 40-50%.

Those with low incidence are Denmark and Switzerland, while Italy has intermediate incidence like France, UK and Germany around 25%.

According to 2011 data, 75% of cases are found in men with an incidence rate of 6 cases per 100,000 residents. 80% of positive cases are due to sexual intercourse, with the average age of those infected being 38 for men and 34 for women. One third of all cases are among immigrant foreigners who then receive a late diagnosis.

SYMPTOMS

An important feature of AIDS is the asymptomatic nature of the HIV-positive individual, especially in the early period after infection. Non-specific symptoms may alternately occur, such as loss of appetite, nausea, pain along the colon with diarrhea, joint pain, sweating, fever, and lymph nodes increasing in volume.

These glands can be affected by significant swellings, reaching more than a centimetre in diameter, in extra-inguinal sites.

Other symptoms such as fatigue, weight loss, mucosal and skin objectification such as severe SD (seborrheic dermatitis), precancerous lesions (oral villous leukoplakia), candidiasis of the oral cavity, Kaposi's sarcoma, and genito-anal condylomas make this early phase characterized by various symptoms.

Opportunistic infections such as Pneumocystis jirovecii (formerly Pneumocystis Carinii) pneumonia and associated diseases: hepatitis B and C, syphilis etc. may then arise.

DIAGNOSIS

Infection can be confirmed by blood tests for the detection of specific antibodies, such as:

• Elisa test (enzyme immunoassay) that detects targeted antibodies for HIV and if positive must be confirmed by another test (Western Blot).
• The test for the p24 antigen in blood indicates infection in the first few weeks after exposure to the virus, even before antibody production (average 16 days after infection then ELISA test after 3 months).
• The fourth-generation serological test (Combo test) simultaneously searches for HIV antibodies and the p24 antigen (the viral protein).
• The Nucleic Acid Test (NAT) for the presence of HIV-RNA genetic/viral material in blood.
• HIV rapid test

Today, rapid tests on saliva or blood are available as an alternative to traditional tests. These tests are capable of detecting the presence of the HIV antibodies, have an appreciable level of sensitivity and specificity, and can be performed even in the absence of trained health care personnel.

Rapid tests are an aid in early detection of the virus: they can be purchased at pharmacies and can be performed on your own by carefully following the recommendations provided with the kit. However, they are not considered diagnostic and in the case of a positive result still require confirmation through traditional laboratory testing.

Rapid kits are immunochromatographic tests for the qualitative detection of HIV type 1, 2, and subtype 0 antibodies in whole blood, serum, or plasma with a fingertip swab of the hand. The blood sample (whole, serum or plasma) reacts with particles coated with the HIV antigen (recombinant) in the test line.

If the sample contains HIV-1 antibodies and/or subtype 0 or HIV-2, a coloured line appears in the area of the test line. If, on the other hand, the sample contains no antibodies, no line appears and therefore the result is negative.

This self-test is reliable for determining HIV infections developed at least three months prior to testing (window period). It does not detect recent infections and its qualitative nature cannot provide quantitative news nor the increase in antibodies.

You can perform this type of test if you have casual intercourse on a periodic basis, all the more so if such intercourse is frequent.

TREATMENT

Current antiretroviral therapy suppresses HIV replication, preserves or restores CD4 (a type of white blood cell) cell counts and immune function, reduces morbidity and mortality, and prolongs survival based on that of the general population.

Current treatment guidelines worldwide recommend starting therapy for anyone infected with the virus, regardless of previous illness, symptoms, signs, HIV RNA levels, or CD4 cell count.

Current first-line therapeutic regimens consist of three antiretroviral drugs, often formulated as a single solution, allowing an oral treatment regimen in a single daily pill. These regimens (called HAART, Highly Active Antiretroviral Therapy) result in virologic suppression for more than 80 percent of HIV-infected patients.

Virus-specific enzymes required for multiplication in target cells (CD4+ lymphocytes) such as integrase, reverse transcriptase, protease are blocked by drugs such as:

• Integrase inhibitors (enzyme for integration of virus genome within human cell DNA).
• Reverse transcriptase inhibitors.
• Protease inhibitors (enzyme that can break down proteins).
• Fusion inhibitors (which stop the virus from entering CD4+).

These drugs should be used together with multiple antiretrovirals.

Therapy is unable to eliminate the virus from the body because the virus remains in infected cells. However, the goal of HAART is to stop the multiplication of the virus, thus preventing progression of the infection.

PREVENTION

Risky sexual behavior should be avoided, especially if it involves a large number of partners of unknown states of health. Exchange of syringes, shared use of toothbrushes, scissors and razors, and general contact with infected blood should be avoided. Using a condom reduces the risk of infection.

Substantial progress has also been made in developing strategies to prevent HIV transmission and acquisition.

In 2016, the United Nations General Assembly agreed that rapid action is needed to eliminate AIDS by 2030 and reduce new HIV infections to less than 500,000 cases per year by 2020 worldwide.

The answer is mainly through continued progress toward the 90-90-90 target: that is, by 2020,

• 90% of all people living with HIV will know their HIV status,
• 90% of those diagnosed will receive antiretroviral therapy
• 90% will have viral suppression through therapeutic treatments

PrEP

Pre-Exposure Prophylaxis (PREP) is a new biomedical HIV prevention intervention that involves the use of daily (or sporadic) antiretroviral drugs to reduce the risk of HIV acquisition if exposure occurs. This type of prophylaxis involves the combination of two drugs and has been shown to be effective in preventing the transmission of HIV infection.

As early as the mid-1990s, it was shown that prophylaxis with antiretrovirals during pregnancy can effectively reduce the risk of maternal-fetal transmission, now estimated at less than 1% in the presence of appropriate treatment of the pregnant woman.

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