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Tuesday, May 11, 2010

0 HIV Infections


DEFINITIONS
Infection with HIV (Human Immunodeficiency Virus) is an infection by one of two types of virus that progressively damage the white blood cells called lymphocytes, causes AIDS (Acquired Immunodeficiency Syndrome) and other illnesses as a result of immune disorders.

In early 1980, the researchers found a sudden increase of two kinds of disease among homosexuals in America.
Both diseases were Kaposi's sarcoma (a rare form of cancer) and pneumonia pneumokista (a type of pneumonia that only occurs in people with immune system disorders).

The failure of the immune system, resulting in two types of this rare disease which is now known as AIDS.
The failure of the immune system are also found on the users of illegal drugs are injected, hemophiliacs, recipients of blood transfusions and bisexual men.
Some time later the syndrome was also started in the heterosexual non-drug user, not a hemophiliac and does not accept blood transfusions.

AIDS has become epidemic in the United States with more than 500,000 people were infected and 300,000 died until October 1995.
WHO estimates that 30-40 million people worldwide will be infected with HIV in 2000.

CAUSE
There are two types of the virus that causes AIDS, namely HIV-1 and HIV-2.
HIV-1 is most common in the western region, Europe, Asia and Central Africa, South and East. HIV-2 is found predominantly in West Africa.

TRAVEL SICKNESS

To be infected, the virus must enter the cell, in this case white blood cells called lymphocytes.
Viral genetic material is inserted into the DNA of infected cells.
Inside the cell, the virus reproduce and eventually destroy the cells and release of new virus particles.
The new virus particles then infect other lymphocytes and destroy it.

Viruses attached to the lymphocytes which have a receptor protein called CD4, which is located in the outer membrane.
Cells that have receptors called CD4 cells are usually CD4 + or helper T lymphocytes.
Activate helper T lymphocyte functions and regulate other cells of the immune system (such as B lymphocytes, macrophages and cytotoxic T lymphocytes), which all help to destroy malignant cells and foreign organisms.
HIV infection causes destruction of helper T lymphocytes, resulting in weakness of body systems in protecting themselves against infection and cancer.

A person infected by HIV will lose the helper T lymphocytes through three stages over several months or years:


  1. A healthy person has a CD4 + T lymphocytes were 800-1300 cells / ml blood. In the first few months after becoming infected with HIV, the numbers decreased by 40-50%. During these months the patient can transmit HIV to others because a lot of virus particles present in the blood. Although the body tries to fight the virus, but the body is not able to relieve the infection
  2. After about six months, the number of virus particles in the blood reaches a stable level, which varies in each patient. The destruction of CD4 + cells and transmission of the disease to others continues.High levels of viral particles and CD4 + lymphocyte levels are low to help the physician in determining the people who suffer AIDS at a higher risk.
  3. 1-2 years prior to AIDS, the number of CD4 + lymphocytes are usually dropped dramatically. If levels reach 200 cells / mL blood, the patient becomes susceptible to infection.
HIV infection also causes interference with the function of B lymphocytes (lymphocytes that produce antibodies) and often causes excessive antibody production.
These antibodies are primarily intended to fight HIV and infections suffered by patients, but these antibodies are not much help in fighting a variety of opportunistic infections in AIDS.
At the same time, the destruction of CD4 + lymphocytes by the virus decreases the ability of the immune system in the organism and identify new targets to be attacked.

Transmission

HIV transmission occurs through contact with body fluids containing infected cells or virus particles.
What is meant here with body fluids are blood, semen, vaginal fluid, cerebrospinal fluid and breast milk. In smaller concentrations, the virus is also present in tears, and saliva kemihi.

SYMPTOMS
Some patients showed symptoms resembling mononucleosis infeksiosa within a few weeks after infection.
Symptoms include fever, rashes, swollen lymph nodes and malaise that lasts for 3-14 days. Most symptoms will disappear, though still enlarged lymph nodes.

For several years, no other symptoms appear. But a large number of viruses will be found in blood and other bodily fluids, so the patient can transmit the disease.
Within a few months after infection, patients may experience symptoms which are recurrent ringn not really show any AIDS.

Patients may show symptoms of HIV infection within a few years before the occurrence of infection or a tumor unique to AIDS.
Symptoms include:
- Swollen lymph nodes
- Weight loss
- The fever is gone-arising
- Feeling unwell
- Tired
- Recurrent diarrhea
- Anemia
- Thrush (a fungal infection in the mouth).

By definition, AIDS begins with a low number of CD4 + lymphocytes (less than 200 cells / mL blood) or the occurrence of opportunistic infections (infection by the organism in people with good immune system does not cause disease).
Cancer can also occur, such as Kaposi's sarcoma and non-Hodgkin's lymphoma.

The symptoms of AIDS itself derived from their HIV infection and opportunistic infections and cancers.
But only a few people with AIDS who died from direct effects of HIV infection. Usually death occurs because the cumulative effect of various opportunistic infections or tumors. Organisms and diseases that normally cause only little effect on healthy people, in people with AIDS can cause death immediately, especially if the number of CD4 + lymphocytes reached 50 cells / mL blood.

DIAGNOSIS
Examination is relatively simple and accurate blood test called the ELISA test.
With this examination can detect the existence of antibodies against HIV, the test results are routinely reinforced with a more accurate test.

There was a period (several weeks or more after infection with HI) where the antibody has not been positive. In this period a very sensitive examination to detect the virus, namely p24 antigen.
P24 antigen was recently used to menyaringan donated blood for transfusion purposes.

If the ELISA test results showed the existence of HIV infection, then at the same blood samples carried out to confirm the ELISA test.
If the second ELISA test is also positive, then the next step is to confirm the diagnosis with a blood test more accurate and more expensive, that is, Western smear tests. This test also bisam enentukan presence of antibodies to HIV, but more specific than ELISA. If Western is also a positive test result, it can be ascertained that person is infected with HIV.

TREATMENT
At the moment, there are many drugs that can be used to treat HIV infection:

1. Nucleoside reverse transcriptase inhibitor
- AZT (zidovudin)
- DdI (didanosin)
- DdC (zalsitabin)
- D4T (stavudin)
- 3TC (lamivudin)
- Abakavir
2. Non-nucleoside reverse transcriptase inhibitor
- Nevirapin
- Delavirdin
- Efavirenz
3. Protease inhibitors
- Saquinavir
- Ritonavir
- Indinavir
- Nelfinavir.

All the drugs are intended to prevent the reproduction of the virus thus slowing disease progression.
HIV will soon form a resistance to these drugs when used singly. The most effective treatment is the combination of two or more drugs, the drug combination can slow the emergence of AIDS in HIV-positive patients and prolong survival.
Doctors sometimes difficult to determine when the commencement of these drugs. But patients with high levels of virus in the blood must be treated immediately even though his CD4 + levels are still high and the patient did not show any symptoms.

AZT, ddI, d4T and ddC cause side effects such as abdominal pain, nausea and headache (especially AZT).
Use of continuous AZT can damage bone marrow and cause anemia.
ddI, ddC and d4T can damage peripheral nerves. ddI can damage the pancreas.
In the nucleoside group, 3TC seems to have at least mild side effects.

All three protease inhibitors cause side effects of nausea and vomiting, diarrhea and stomach upsets.
Indinavir causes a mild increase in liver enzyme levels, are reversible and causes no symptoms, also cause severe back pain (renal colic), which is similar to pain caused by kidney stones.
Ritonavir effects on the liver caused by the increase or decrease in blood levels of other drugs.
Group of protease inhibitors cause many metabolic changes such as increased blood glucose and lipid levels, and changes in body fat distribution (protease paunch).

AIDS patients are given drugs to prevent infection ooportunistik.
Patients with CD4 + lymphocyte levels less than 200 cells / mL of blood to get a combination of trimethoprim and sulfamethoxazole to prevent pneumonia and infection of Toxoplasma pneumokistik to the brain.
Patients with CD4 + lymphocyte less than 100 cells / mL of blood to get azithromycin once a week or Mycobacterium avium.
Patients who recover from cryptococcal meningitis or candida infection fluconazole long term gain.
Patients with recurrent herpes simplex infection may require long-term acyclovir treatment.

Antibiotics

Exposure to HIV does not always lead to infection, some people are exposed to HIV over the years can not become infected. On the other hand someone who is infected may not show symptoms for more than 10 years old.
Without treatment, HIV infection has a 1-2% risk for AIDS menjdi the first few years. This risk is increased by 5% in each subsequent year.

Risk of getting AIDS within 10-11 years after HIV infection reaches 50%.
Prior to the latest drugs discovered, in the end all will become AIDS cases.

AIDS treatment has been successful in reducing rates of opportunistic infections and improve patient life expectancy.
Combination of several types of drugs can reduce the amount of virus in the blood until it can be detected. But there has not been proven to heal patients.

Technique of counting the number of HIV virus (plasma RNA) in blood, such as polymerase chain reaction (PCR) and branched deoxyribonucleid acid (bDNA) test helps doctors to monitor the effects of treatment and help assessing patient prognosis.
This virus levels will vary from less than a few hundred to over a million viral RNA / mL plasma.

In the early discovery of the HIV virus, patients with decreased quality of life immediately after being treated in hospital. Almost all patients will die within two years after contracting AIDS.
With the development of antiviral drugs and new treatment methods and prevention of opportunistic infections continue to be updated, the patient can maintain his physical and mental abilities until years after exposure to AIDS. So at this moment to say that AIDS has been handled, although no known cure.

PREVENTION
HIV prevention programs have focused primarily on educating the public about the transmission of HIV, with the aim of changing the habits of people who are at high risk for contagion.
Ways of preventing this are:

1. For healthy people
- Abstinens (no sexual intercourse)
- Sex is safe (shielded)
2. For HIV-positive patients
- Abstinens
- Safe sex
- Do not donate blood or organs
- Prevent pregnancy
- Notifying sexual partners before and after being infected by
3. To abuse drugs
- Stopping the use of injections or used together
- Following the rehabilitation program
4. For health professionals
- Use latex gloves at every contact with body fluids
- Using a disposable needle

Various vaccines have been tested for preventing and slowing the progression of the disease, but so far no one has succeeded.
Hospitals usually do not isolating people with HIV unless the patient suffering from infectious diseases like tuberculosis.
Surfaces contaminated with HIV can be easily cleaned and disinfected because the virus is destroyed by heat and fluids commonly used disinfectants such as hydrogen peroxide and alcohol.

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