December 1 World AIDS Day
Given my interest in the medical field and my feelings on this topic, I decided to post few lines on this terrible disease.
The Acquired Immunodeficiency Syndrome, otherwise known as AIDS represents the terminal clinical stage of infection by the human immunodeficiency virus (HIV).
HIV is an RNA virus that belongs to a particular virus family, that of retroviruses, has a unique replication mechanism. Thanks to a specific enzyme, reverse transcriptase, retroviruses are able to transform their genetic heritage to a double-stranded RNA into DNA. This is inserted in the DNA of the infected cell (called "host cell") and from there to conduct the production of new viral particles.
In the specific case of HIV, the target cells are special cells in the immune system, CD4 T cells, which are essential in the adaptive response against a variety of pathogens. The HIV infection then causes a progressive weakening of the immune system (immunosuppression), increasing the risk of infections and diseases - more or less serious - from viruses, bacteria, protozoa and fungi, potentially lethal to the long distance, and that in normal conditions could be treated more easily.
After coming into contact with HIV, a person can become infected with HIV and begin them to produce antibodies directed specifically against the virus, undetectable in the blood. This implies that HIV infection is ongoing and it is therefore possible to transmit the virus to others. The appearance of antibodies, however, is not immediate. The time that elapses between the time of infection and the appearance in the blood of antibodies against HIV is called "window period" and lasts an average of 4-6 weeks, but may extend up to 6 months. During this period, even if the person is HIV-negative can still transmit the infection.
from HIV, you can live for years without noticing any symptoms of infection and only the outbreak of a disease. Undergo the test of anti-HIV antibodies is, therefore, the only way to discover the infection.
The incubation period can last several years, until the disease becomes clinically overt due to the onset of one or more infections so-called "opportunistic." To cause disease agents that are normally unable to infect healthy people, but only people with seriously compromised immune systems.
During full-blown AIDS may develop various forms of cancer, particularly lymphomas and Kaposi's sarcoma.
Vie transmission
There are three different modes of transmission dell’Hiv: per via ematica, per via sessuale e per via materno-fetale.
La trasmissione per via ematica avviene con stretto e diretto contatto fra ferite aperte e sanguinanti e scambio di siringhe con un sieropositivo. Durante le prime fasi dell’epidemia, quando erano minori anche l conoscenze sui sistemi di diffusione del virus, diverse persone sono state contagiate dall'Hiv in seguito a trasfusioni di sangue o alla somministrazione di suoi derivati. A partire dal 1985 questo tipo di trasmissione dell'infezione è stato praticamente eliminato, grazie a un maggiore controllo delle unità di sangue, al trattamento con calore degli emoderivati e alla selezione dei donatori, ma anche a un minor ricorso a trasfusioni inutili e ad un maggiore utilizzo dell’autotrasfusione.
La trasmissione attraverso il sangue rappresenta, invece, la principale modalità di contagio responsabile della diffusione dell’infezione nella popolazione dedita all’uso di droga per via endovenosa. L’infezione avviene a causa della pratica, diffusa tra i tossicodipendenti, di scambio della siringa contenente sangue infetto. Possono essere infatti veicolo di trasmissione dell’Hiv anche aghi usati, e in questo senso sarebbe opportuno sottoporsi ad agopuntura, mesoterapia, tatuaggi e piercing utilizzando aghi monouso e sterili. Con la stessa modalità è possibile la trasmissione sia dell’Hiv che di altri virus tra i quali quelli responsabili dell’epatite B e C, infezioni anch’esse very common among drug users.
Sexual transmission is the world's most common mode of transmission of HIV infection. Sexual intercourse, both heterosexual and homosexual, are not protected by the condom can result in transmission of infection. Transmission occurs through contact between infected fluids (vaginal secretions, pre-ejaculatory fluid, semen, blood) and mucous membranes during sexual intercourse. The transmission is possible even if the mucous membranes are intact. The
unprotected sex can cause not only of HIV transmission. Indeed, there are over 30 sexually transmitted diseases.
Hiv e gravidanza
La trasmissione da madre a figlio, o verticale, può avvenire durante la gravidanza, durante il parto, o con l’allattamento. Il rischio per una donna sieropositiva di trasmettere l’infezione al feto è circa il 20%. Oggi è possibile ridurlo al di sotto del 4% somministrando zidovudina (Azt, primo farmaco usato contro l’Hiv) alla madre durante la gravidanza e al neonato per le prime sei settimane di vita. Per stabilire se è avvenuto il contagio il bambino deve essere sottoposto a controlli in strutture specializzate per almeno i primi due anni di vita. Tutti i bambini nascono con gli anticorpi materni. Per questa ragione, il test Hiv effettuato sul sangue di un bambino nato da una donna sieropositiva risulta sempre positivo. Anche se il bambino non ha contratto l’Hiv, gli anticorpi materni possono rimanere nel sangue fino al diciottesimo mese di vita, al più tardi entro i due anni. Il bambino viene sottoposto a test supplementari per verificare se è veramente portatore del virus o se ha ricevuto solo gli anticorpi materni.
Strategie di prevenzione
Poche semplici precauzioni possono ridurre, o addirittura annullare, il rischio di infezione da Hiv. Per evitare la trasmissione dell’infezione per via ematica:
- evitare l’uso in comune syringes and needles for injecting drugs
- not undergo acupuncture, mesotherapy, tattoos and piercings if the needles used are not disposable or have not been sterilized
- for health professionals, be careful when handling and use needles and other sharp objects
- for doctors, encouraging the use of autotransfusion and adhere rigidly to the indications for transfusion of blood, blood donations are always tested for HIV, nor should they give blood, plasma, sperm, organs for transplant, tissue or cell or persons who have had high-risk behavior.
To avoid transmission of infection through the blood, sexual
- mutually monogamous sexual relations with a partner who is not infected
- possibly abstain from sexual intercourse
- in occasional case reports ( vaginal or anal orogenital), use a condom.
The correct use of condoms can, in fact cancel the risk of infection during any kind of sexual relationship with each partner. During intercourse the condom is the only real barrier to defend themselves from HIV. Even a single unprotected sexual intercourse could be due of infection.
As the virus is not transmitted
The virus is not transmitted through:
- handshakes, hugs, kisses
- clothes, saliva, bites, scratches, cough, tears, sweat, mucus, urine and feces
- glasses, cutlery, plates, sheets and towels
- insect bites
The virus is not transmitted by attending:
- gym swimming pool, showers, saunas and toilets
- schools, kindergartens and places Working
- restaurants, bars, cinemas and public places
- transportation.
The HIV test
To find out if you have been infected with HIV, it is sufficient to take the test for the detection of specific antibodies against HIV that is done through a standard blood test. The anti-HIV tests can identify the presence of specific antibodies that the body produces when it comes into contact with this virus. If there were high-risk behavior is good to take the test at the end of the sixth month since the risk of infection (window period), because anti-HIV antibodies can also occur within six months after exposure to contagio.Bisogna keep in mind that during the "window period" (period of time from the moment of infection to that of the induction of antibodies) may be possible transmit the virus while not test positive.
Italian law (135, June 1990) ensures that the test is carried out only with the consent of the person. The test is not mandatory, but if there were risk behaviors should be effettuarlo.Per test, in most health services do not need a prescription, it's free and anonymous. Early to know to be HIV positive to HIV testing allows for timely drug therapy that enables today to improve the quality of life and live longer.
therapies
Today doctors offering therapy (HAART higly Active Anti-Retroviral Therapy) against HIV infection for people living with HIV, based on the so-called "values" of CD4 lymphocytes (cells of the system immune) and viral load (number of HIV particles in the blood), which measures the speed of replication of the infection.
therapy is usually composed of several antiretroviral drugs that reduce viral load and improve the immune system. Because of
strong tendency of HIV to mutate (reverse transcriptase is an enzyme that naturally introduces errors in the viral genome), it is necessary not only to find always new drugs, but also adopt combination therapies. In this way we try to minimize or at least delay the onset of multi-resistant viral strains.
In Western countries the therapeutic success against AIDS are largely due to the results obtained from scientific research that helped to identify drugs with potent antiviral activity.
However, keep in mind that current treatment strategies do not allow recovery from infection but allow you to keep it under control. It is therefore essential identify new therapeutic strategies with mechanisms other than those we have today.
The World Day against AIDS , held each year on 1 December , is dedicated to increase awareness of the epidemic World AIDS due to the spread of HIV . The recurrence was chosen as the first case of AIDS was diagnosed on 1 December 1981 . Since then, AIDS has killed more than 25 million people, becoming one of the most destructive epidemics in history. As recently access to treatment and antiretroviral drugs has improved in many regions of the world, the AIDS epidemic has claimed about 3.1 million victims in 2005 (estimates are between 2.9 to 3.3 million), more than half of which (570,000) were children.
The idea of \u200b\u200ba World AIDS Day originated at the World Summit of Ministers of Health on Programmes for AIDS prevention in 1988 and was later adopted by Governments, international organizations, professional associations worldwide.
