viernes, 22 de enero de 2010

What causes AIDS?

AIDS is an infectious disease caused by a virus called Human Immunodeficiency Virus (HIV or HIV) or AIDS virus. It belongs to the family of viruses known as the Retroviridae and are known at present two HIV virus, HIV-1 and HIV-2, both attack the immune apparatus invading T cells

Ways of transmitting the AIDS virus.
The AIDS virus is found in all fluids and secretions, but the epidemiology indicates that there is contagion, they have to contain high concentrations of it. Therefore, the scientific evidence established that its modes of transmission are:
• sexual contact through the male genital fluid (semen) and cervicovaginal secretions of women (discharge).
• injecting through blood transfusion or blood products (plasma, platelets), organ transplants, artificial insemination, surgery, dental treatment with use of sharps, sharp instruments maneuvers nonprofessional (sharing needles and syringes among drug users intravenous, practiced tattooing)
• the intrauterine or perinatal (called vertical transmission). The transmission of the AIDS virus from a pregnant woman to her child during pregnancy, childbirth or through breastfeeding
• It should be noted that there is no evidence to support the transmission of the virus by other routes of infection (tears, saliva, sweat, etc.).
The AIDS virus infection is followed by an asymptomatic period (without symptoms) that can extend from 2 to 9 years. There are few cases that cover this period much longer.
The specific antibody response occurs between 2 weeks and 3 months after infection and may be accompanied by transient signs compatible with infectious mononucleosis. The duration of this asymptomatic period depends among other factors:
• the magnitude of the inoculation
• the level of the host immune
• the route of infection
Once you have the symptoms and signs of the syndrome, begins a gradual deterioration that can lead to stillbirth in subsequent years, depending on the time of the early initiation of treatment. The AIDS virus can enter the body as free or more often incorporated into a cell infected. It will then be picked up by a macrophage, through which the virus begins its replication.

What are the AIDS risk behaviors?

Unsafe sex.

The most important route of transmission of HIV / AIDS in the world is sexual, homosexual or heterosexual. In general, the risk of sexual transmission depends on the prevalence of infection among the sexually active population.
Homosexual practices are associated with increased risk of infection especially ano-genital relations being the most exposed receptive partner. In practice the risk of heterosexual transmission of HIV-AIDS is bidirectional but the likelihood of male to female transmission could be 20 times larger than the female-male transmission.
In all cases the risk increases when you have a sexually transmitted disease (STD) and there The possibility to have multiple partners. Another factor to consider is the world of prostitution, especially in cases that do not have safe sex (without condoms), sumándosele in many cases their relationship with the consumption of intravenous narcotics, which is shared syringes.
It is now commonly observed risk behavior in the "sex tourism" and the relationship can be brought through the Internet, through a first finger contact, allowing contact with a potential risk bearer / ra's AIDS virus.
The risk of sexual transmission of AIDS virus decreases when:

• There are theoretically safer sex or safer.
• monogamous behavior is preserved.
• It prevents promiscuity and sex with strangers.
• You use a latex condom.
Sharing syringes

Within the mode of transmission via blood, the most common form of infection is the habit of sharing needles among intravenous drug users individuals.

Not only sharing syringes and needles poses a risk behavior, because the virus can be transmitted through any element used to prepare the drug. Finally, we must consider that in these individuals, the effect produced by intravenous drugs heterosexual transmission condition treated in most cases of "unsafe sexual contact" as the individual's ability to take the protection is affected by drug effect

How does HIV?

The AIDS virus enters the body through blood, semen and vaginal fluids and once incorporated attacks the immune system. This system consists of a set of components including cells, antibodies and circulating substances across any element that is recognized as foreign or strange. This is particularly the case with infectious agents including bacteria, fungi, viruses and parasites.

Faced with the presence of infectious agents the immune system mobilizes to defend cells called lymphocytes. Lymphocytes, to be invaded by the HIV virus lose their ability to recognize and deal with foreign agents, who take the opportunity this fall to proliferate immune surveillance. To multiply, the virus puts in place a specific mechanism by which retroviruses copy its genome (all the genetic information of a living being) of RNA, DNA Cell. The virus stimulates the reproductive activity of lymphocytes but since they have copied the HIV genome, rather than reproducing, viral cells multiply.

As the virus replicates, the body becomes increasingly vulnerable to diseases against which, in normal times can be defended. These diseases are called opportunistic diseases. The collapse of the defenses is not massive, but allows even more likely the emergence of certain diseases: infections (the most common are lung, and others produced by various viruses, bacteria, fungi and parasites), and different types of cancer (the most common are that affect the skin and lymph nodes).

One of the clearest indicators of the progress of the infection and the development of AIDS, is the emergence of these "opportunistic infections". That is why they are considered "markers" or "tracer". Mark the presence and progression of the infection. They are compounded by the direct effects of virus in the body, including, among others, nervous system and digestive system. When the HIV status develops this set of conditions is considered an AIDS victim.

As discussed above, that HIV can happen once entered the body remains "at rest" within invaded cells. In this situation, the patient has no symptoms, so it is called asymptomatic carrier. Although no asymptomatic carrier symptoms can infect others unknowingly.

What is AIDS?

AIDS is an advanced stage of infection with Human Immunodeficiency Virus (HIV). It is a retrovirus that attacks the body's defenses and impairs the ability to defend against diseases caused by other viruses, bacteria, parasites and fungi. The immune system includes several types of cells, including white blood cells responsible for fighting against external aggressors. HIV kills a particular cell type, CD4 cells that make up the immune system. What does the word AIDS?

The word AIDS is formed from the initials of the term "Acquired Immune Deficiency Syndrome."

Syndrome: A set of signs and symptoms.

Immune mean on the system of defenses.

Deficiency: decrease.

Acquired: refers to non-congenital.

This means that AIDS has developed only when there is a set of signs and symptoms indicating that defenses are diminished because they caught the virus. It is possible to be infected with HIV, ie, being HIV positive or carrier of the virus and have not yet developed AIDS. From the moment the virus enters the body until symptoms appear may be a long time, between 10 and 12 years, which may be extended if treatment is started early. However, it is necessary to take into account that this is global average periods vary from country to country and modify substantially by the development of the epidemic in each place and with the development of treatments.

INTRODUCTION ON AIDS

One in 100 adults aged 15 to 40 years are infected by HIV, the virus that causes AIDS. Only 1 in 10 people know they are infected. It is estimated that currently over 30 million people living with HIV infection. For the current year is expected to rise to 40 million.

Since the beginning of the epidemic is estimated that 3.8 million children under age 15 have been infected with HIV and 2.7 million have died. Over 90% of these children have contracted the virus through their mothers with HIV before or during birth or through breastfeeding. More than 8 million children have lost their mother to AIDS before age 15, and many have also lost their father. It is estimated that this figure will nearly double for 2000.

AIDS became a major epidemic of the twentieth century and the future projection on the spread of this disease becomes a considerable burden on overstretched health care systems of most affected countries.

Many factors are affected by the impact of AIDS. This impact is not limited exclusively to health statistics. Also poses a serious economic problem, given the high cost of medical care of patients. In turn, AIDS has a social impact, and has changed behaviors and habits.

The poor living conditions, the difficulties in providing seamless access to health systems and lack of education for much of the population, favor the continued growth of the epidemic.

From a scientific point of view must be acknowledged that progress has been made in understanding the pathophysiology of infection, the mechanisms of immune damage, clinical forms, their evolution over time and the prevention and treatment of many opportunistic infections that are the usual cause of death of patients. The use of antiretroviral drugs has improved and prolonged the survival of many patients.

But reality shows us that the disease still has no cure, and for this reason, the fight should focus on appropriate prevention tasks in the fight against AIDS. And education is the key to prevention in the fight against AIDS, and should act as reinforcement in health systems.

Those countries that did not implement media campaigns at the onset of the first cases of the disease are paying a high price in lives lost. The campaigns have placed special emphasis on the preventive aspects. The campaigns should take people a clear and direct message that leaves no doubt about risk behaviors that can be exposed to HIV, and what is the way around.

You could say that at present the only vaccine is good information and that only slightly more dangerous than AIDS: Ignorance.

AIDS does not get carried away by indifference.

Learn.

AIDS

Acquired immunodeficiency syndrome, most referred to by its acronym AIDS or AIDS is a disease that affects humans infected by HIV. They say a person has AIDS when his body due to the immunodeficiency caused by HIV, is not capable of providing an adequate immune response against infections that afflict humans.

Note the difference between being infected by HIV and suffering from AIDS. A person infected with HIV is HIV positive and goes on to develop a cadre of AIDS when their level of CD4 T cells that attack the virus, falls below 200 cells per milliliter of blood.

HIV is transmitted through the following body fluids: blood, semen, vaginal secretions and breast milk [1].

The World Day against AIDS is celebrated on December 1.

The Royal Spanish Academy (RAE) takes the word AIDS in the twenty-second edition of his dictionary, [2] which can be used in lower case and capital letters. [3] The use of lower case is recommended by the Pan American Health, health agency for the Americas United Nations [4].

¿Qué causa el SIDA?

El SIDA es una enfermedad infecciosa causada por un virus denominado Virus de la Inmunodeficiencia Humana (VIH o HIV) o virus del Sida. Pertenece a la familia de virus conocida como Retroviridae y se conocen en la actualidad dos Virus HIV, el HIV-1 y el HIV-2, ambos atacan al aparato inmunológico a invadiendo los linfocitos T.

FORMAS DE TRANSMISIÓN DEL VIRUS DEL SIDA.
El virus del Sida se encuentra en todos los fluidos y secreciones, sin embargo la epidemiología señala para que exista el contagio, éstos tienen que contener altas concentraciones del mismo. Por lo tanto, las evidencias científicas establecieron que sus formas de transmisión son las siguientes:
•por contacto sexual a través del fluido genital masculino (semen) y por las secreciones cervicovaginales de la mujer (flujo vaginal).
•por vía parenteral a través de la transfusión de sangre o hemoderivados (plasma, plaquetas), órganos transplantados, inseminación artificial, intervenciones quirúrgicas, tratamiento odontológico con uso de material punzante, maniobras con instrumentos punzocortantes no profesionales (compartir agujas y jeringas entre los drogadictos endovenosos, practicarse tatuajes)
•la intrauterina o perinatal (conocida como transmisión vertical). La transmisión del virus del Sida de una mujer embarazada a su hijo, durantes la gestación, en el parto o por medio de la lactancia
•Debe destacarse que no hay evidencia que sustente la transmisión del virus por otras vías de contagio (lágrimas, saliva, sudor, etc.)
La infección por virus del Sida está seguida por un período asintomático (sin síntomas) que se puede extender entre 2 y 9 años. Hay pocos casos que este período abarcan mucho más años.
La respuesta humoral específica aparece entre las 2 semanas y 3 meses post-infección y puede estar acompañada de signos transitorios compatibles con una mononucleosis infecciosa. La duración de éste período asintomático depende entre otros factores de :
•la magnitud de la inoculación
•del nivel inmunológico del huésped
•de la vía de infección
Una vez que se presentan los síntomas y signos del síndrome, se inicia un deterioro progresivo que puede llevar al óbito en los años siguientes, dependiendo el tiempo de la pronta iniciación del tratamiento. El virus del Sida puede ingresar al organismo como libre o más frecuentemente incorporado dentro de una célula infectada. Posteriormente será captado por un macrófago, a través del cual el virus comenzará su replicación.

¿Cuáles son las conductas de riesgo del Sida?

Relacion sexual no segura.

La vía más importante de transmisión del VIH-Sida en el mundo es la sexual, tanto homosexual como heterosexual. En general, el riesgo de transmisión sexual depende de la prevalencia de la infección en la población sexualmente activa.
Las prácticas homosexuales son las que se asocian con mayor riesgo de padecer la infección sobre todo las relaciones ano-genitales siendo el compañero receptivo el más expuesto. En las prácticas heterosexuales el riesgo de contagio del VIH-Sida es bidireccional pero la probabilidad de transmisión hombre-mujer podría ser hasta 20 veces mayor que la de transmisión mujer-hombre.
En todos los casos el riesgo se incrementa cuando se padece alguna enfermedad de transmisión sexual (ETS) y existe la posibilitad de tener múltiples parejas. Otro factor a tener en cuenta es el mundo de la prostitución, especialmente en los casos que no se tiene sexo seguro (sin el uso de preservativos), sumándosele en muchos casos su relación con el consumo de narcóticos intravenosos, donde se comparte jeringas.
En la actualidad es frecuente observar el comportamiento de riesgo en el denominado “turismo sexual” y la relación que se puede entablar por medio de Internet, a través de un primer contacto digital, que posibilita un contacto de riesgo con un posible portador/ra del virus del Sida.
El riesgo de transmisión sexual del virus del Sida decrece cuando:

•Existen prácticas sexuales seguras o teóricamente seguras.
•Se preserva la conducta monogámica.
•Se evita la promiscuidad y las relaciones sexuales con desconocidos.
•Se utilizan preservativos de látex.
Uso compartido de jeringas

Dentro de la forma de transmisión por vía sanguínea, la forma más común de contagio es el hábito de compartir jeringas entre los individuos drogadictos intravenosos.

No sólo compartir las jeringas y agujas entraña un comportamiento de riesgo; ya que el virus se puede transmitir por medio de cualquier elemento utilizado para preparar la droga. Finalmente hay que considerar, que en éstos individuos, el efecto que producen las drogas intravenosas condicionan la transmisión heterosexual por tratarse en la mayoría de los casos de “contactos sexuales no seguros”, ya que la capacidad del individuo a tomar protección esta afectada por el efecto de la droga.

¿Como actua el VIH?

El virus del SIDA ingresa al organismo a través de la sangre, el semen y los fluidos vaginales y una vez incorporado ataca el sistema inmunológico. Este sistema está constituido por un conjunto de componentes que incluyen células, anticuerpos y sustancias circulantes que enfrente a todo elemento que sea reconocido como ajeno o extraño. Esto sucede, especialmente con los agentes infecciosos como bacterias, hongos, virus y parásitos.

Frente a la presencia de agentes infecciosos el sistema inmunológico moviliza para defenderse células llamadas linfocitos. Los linfocitos, al ser invadidos por el virus VIH pierden su capacidad para reconocer y enfrentar a los agentes extraños, los que aprovechan la oportunidad de esta caída de la vigilancia inmunológica para proliferar. Para multiplicarse, el virus pone en funcionamiento un mecanismo específico de los retrovirus por el cual copia su genoma (conjunto de información genética de un ser vivo) de ARN, en el ADN de la célula. La presencia del virus estimula la actividad reproductiva de los linfocitos pero, dado que tienen copiado el genoma del VIH, en vez de reproducirse, multiplican células virales.

A medida que el virus se reproduce, el organismo se hace cada vez más vulnerable ante enfermedades contra las cuales, en tiempos normales puede defenderse. A estas enfermedades se las denomina enfermedades oportunistas. La caída de las defensas no es masiva y uniforme sino que permite con mayor probabilidad la aparición de ciertas enfermedades: infecciones (las más frecuentes son las pulmonares, y también otras producidas por diversos virus, bacterias, hongos y parásitos), y distintos tipos de cáncer (los más comunes son lo que afectan la piel y los ganglios linfáticos).

Uno de los indicadores más evidentes del avance de la infección y del desarrollo del SIDA, es la aparición de estas "enfermedades oportunistas". Por eso se las considera "marcadoras" o "trazadoras". Marcan la presencia y evolución de la infección. A ellas se suman los efectos directos del virus en el organismo, que incluyen, entre otros, trastornos del sistema nervioso y del aparato digestivo. Cuando el portador del VIH desarrolla este conjunto de afecciones se lo considera un enfermo de SIDA.

Como se expuso anteriormente, puede suceder que el VIH, una vez ingresado al organismo permanezca "en reposo" dentro de los linfocitos invadidos. En esta situación, el paciente no tiene síntomas, por eso se lo llama portador asintomático. Sin bien no presenta síntomas el portador asintomático puede contagiar a otras personas sin saberlo.