Genetic Predisposition and Environmental Conditions
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HIV is an acronym that stands for Human Immunodeficiency Virus. Just like bacteria, viruses are also infectious agents. The difference between these two agents is that viruses are much smaller and are also not self-sufficient. Though viruses can exist by themselves, they usually require a host especially for their reproduction. HIV is normally found to exist in the human immune system’s macrophages and in a number of T-helper cells. This paper wishes to examine the interconnection between genetic predisposition and environmental conditions that trigger the onset of various modern diseases, in this case HIV.
Viruses are known to replicate themselves once they have entered a host cell by the use of the host cell’s machinery. They eventually destroy it so that when it bursts open or during budding they get released. Within the human immune system, the most vulnerable cell that the HIV normally enters is the CD4 T-lymphocyte, a type of white blood cell known to perform very important roles within the immune system (HIS-CPSH, 2004). These immune cells get steadily and very slowly destroyed so that the body is weakened to be able to defend any disease that attacks the individual. When the CD4 cells are significantly reduced in number such that they fall below a given number, usually less than two hundred per cubic millimeter of blood the individual moves to the critical AIDS stage.
In its history, the Human Immunodeficiency Virus was discovered as a strange disease among the gay community in North America. The victims would mysteriously fall sick and thereby develop certain tumors and infections that were unusual. Pneumocystic carinii was established to be one of the infectious agents. Though it had been known to be harmless, this micro-organism would make people and other organisms to experience fatal pneumonia especially in situations of abnormal weakness. Kaposi’s sarcoma was a tumor that was seen in these victims and was initially characterized by bluish red skin lesions on lower legs and feet. This was a cancer and was very aggressive. Its lesions would not only spread up one’s body but also internally to lymph nodes (Goudsmit, 1997).
Treatment of these gay men by physicians established that they had great immunodeficiency marked by a severe drop in T-helper cells. The CD4-positive cells are vital in the defense of the body against certain disease causing micro-organisms and thus by the action of the HIV that led to their destruction this role was impaired. It was evident that this impairment did not originate from an individual’s own body, that is inborn, but it was acquired. This therefore made it to be known as acquired immunodeficiency syndrome (AIDS).
The functions of the CD4 cells in the body are the recognition of any intruders and using the available fighter cells to fight these intruders off. Ironically, HIV enters the cells via these CD4 molecules and end up destroying those cells (Jones, 2010). The effect of the HIV is not immediately felt since the cells it destroys get replenished. However in the long run, the virus’ steady destruction of the cells leads to the body’s immunodeficiency. The Human Immunodeficiency Virus may not have been a new virus but an old virus that acquired a new degree of virulence.
There exist more than one type, subtype and strains of the HIV. For example, HIV type 1 is mainly found within Europe and North America and is quickly spreading towards South America. Whenever this type of HIV enters a new person, it gains strength and becomes more virulent. The most unfortunate thing is that this cycling process appears to be a family trait of the virus. It is possible that it might have acquired the mutations to bring about human immunodeficiency lately.
People immune to HIV
Jones (2010) asserts that studies that have been carried out lately say that there are some people who are naturally immune to the HIV. Scientists in certain places, for example Dr Nicole Bernard believes that it is the simultaneous expression of specific versions of HLA-B*57 and KIR3DL1 genes that are responsible for this innate ability to resist infection by the Human Immunodeficiency Virus. They compared people experiencing primary level of HIV infection’s genetic profiles with those of individuals who are recurrently exposed to HIV but are not infected in their studies. It is alleged that KIR3DL1 gene codes belonging to a receptor found on the natural killer cells of the immune system’s surface get activated and thus are responsible for destroying the body’s infected cells.
It is hypothesized that these genetic mechanisms usually occur immediately after the virus begins infecting the cells in one’s body. Carriers of these versions of the genes are able to efficiently kill the cells that have been infected due to their exposure to HIV. It is said that after the KIR3DL1 has been activated the HLA-B*57 gene codes belonging to a protein present on body cells’ surfaces binds it and thus reducing the natural killer cells’ activity.
Other scientists suggested that the generation of cytotoxic T-cells is the process responsible for the creation of the immunity against the Human Immunodeficiency Virus. This was after a research carried out by a group of researchers drawn from Japan, Gambia and England within a number of Gambian women who were apparently immune to infection by HIV. The women were prostitutes exposed to the risk of HIV infection for about five years but were free of any signs of the virus’ infection during that whole period.
These various researches all tend to concur on one thing; that there are a number of people within the human population that are immune to HIV infection. I agree with most of these and believe in the hypothesis that this ability to resist infection by HIV is because of the individual’s possession of CD8+ T-cells, immune cell types that are responsible for the identification and destruction of infected cells (Tatalovic, 2008). These cells’ mode of working whereby they created and then delivered perforin and granzyme B molecules that brought about immunity was the important aspect as far as this characteristic is concerned.
Relationship between HIV and AIDS
AIDS is the Acquired Immunodeficiency Syndrome and an individual is said to have this disease if he has a CD4+ cell count of less than two hundred per cubic millimeter of blood or one of twenty six specific illnesses with no other known cause of immune deficiency apart from HIV. There are numerous proofs that the Human Immunodeficiency Virus infection has an underlying responsibility for the occurrence of AIDS. Most of these are based on the virologic, epidemiologic and immunologic data available. The continuous destruction of CD4+ molecules causes acute immunosuppression, neurological complications as well as constitutional illnesses and along-the-way infections and neoplasms.
Treatments and prognoses
Currently, there are no available cures for people infected with the Human Immunodeficiency Virus; however, treatment options which have the ability to make persons living with this virus to live long and fulfilling lives exist. Post-exposure prophylaxis is a type of antiretroviral treatment that is administered to an individual within the period after he is exposed to the virus. The earlier one commences this type of treatment, the higher the reduction rate of the risk of HIV infection. Entry inhibitors are yet another type of treatment options available to patients. Complete HIV infection eradication has however not been possible despite various researches that have been carried out.
Scientists have established that the lack of treatment in an infected individual will make this person to have a net median period of survival of between nine and eleven years since the time of infection with the virus. In addition, a study that was conducted explains that without treatment; depending on the virus’ subtype an individual’s median survival period after being diagnosed with AIDS is six to nineteen months. This is specifically for areas with limited resources. The introduction of newer treatment options makes people’s survival time to also change with time.
Environments and conditions that help spread the virus
According to San Francisco AIDS Foundation (2008), the transmission of the HIV virus from person to person occurs in the condition that the HIV virus is present in a certain individual. It can not occur where none of the individuals in question possesses the virus. How concentrated one’s blood is with the virus as compared to other body fluids is also a necessary condition for infection. A slight concentration of this virus in the blood being passed from one individual to another will lead to the other person getting infected. However, for the spread of the infection to occur via body fluids there ought to be a larger concentration of this virus. HIV is transmitted in such instances as through contact with the anal mucous membrane, open wounds, eyes, genitals as well as the mouth. This is as long as the body fluids infected with HIV get access into an uninfected person’s body.
In African countries, apart from the other obvious factors that cause the spread of HIV, social factors such as political problems and oppressions, poverty problems, cultural factors, wars and psychological disorders among others tend to offer a basis for the illnesses’ proliferation. In many other parts of the world the prison environment exposes the prisoners to the risk of HIV infection through homosexuality and lesbian behaviors. In America and in other countries of the world where same sex relationships and marriages are legal people are exposed to the risk of HIV infection through sexual activities (Tatalovic, 2008).
In the case of HIV transmission, no genetic predispositions are involved in the process. Causes of the disease are mostly as a result of the exposure to bodily fluids that are infected as in the case of breast milk, semen, blood and vaginal secretions. Therefore, in an attempt to establish the interconnection between genetic predisposition and environmental conditions in triggering transmission of HIV, it is evident that HIV is transmitted solely through environmental conditions.
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