Blood contamination. HIV may also be spread through contact with infected blood. However, due to the screening of blood for evidence of HIV infection, the risk of acquiring HIV from blood transfusions is extremely low.
The next year, two research teams—one led by Luc Montagnier and Françoise Barré-Sinoussi, of the Pasteur Institute, in Paris, the other by Robert Gallo, at the National Cancer Institute, in Maryland—published papers in Science that described a new retrovirus in the lymph nodes and blood cells of AIDS patients. A retrovirus has a pernicious way of reproducing: it permanently inserts a DNA copy of its genome into the nucleus of a host cell, hijacking the cell’s machinery for its own purposes. When the retrovirus mutates, which it often does, its spawn becomes difficult for the body or a vaccine to target and chase out. Retroviral diseases were widely believed to be incurable. In May of 1986, after much dispute about credit for the discovery (the French finally won the Nobel, in 2008), an international committee of scientists agreed on the name H.I.V., or human immunodeficiency virus. By the end of that year, about twenty-five thousand of the nearly twenty-nine thousand Americans with reported AIDS diagnoses had died.
The viral load of an infected person is an important risk factor in both sexual and mother-to-child transmission. During the first 2.5 months of an HIV infection a person’s infectiousness is twelve times higher due to this high viral load. If the person is in the late stages of infection, rates of transmission are approximately eightfold greater. An HIV-positive person who has an undetectable viral load as a result of long-term treatment has effectively no risk of transmitting HIV sexually.
Consistent condom use reduces the risk of HIV transmission by approximately 80% over the long term. When condoms are used consistently by a couple in which one person is infected, the rate of HIV infection is less than 1% per year. There is some evidence to suggest that female condoms may provide an equivalent level of protection. Application of a vaginal gel containing tenofovir (a reverse transcriptase inhibitor) immediately before sex seems to reduce infection rates by approximately 40% among African women. By contrast, use of the spermicide nonoxynol-9 may increase the risk of transmission due to its tendency to cause vaginal and rectal irritation.
In patients with HIV infection, certain syndromes are common and may require different considerations (see Table: Common Manifestations of HIV Infection by Organ System). Some patients present with cancers (eg, Kaposi sarcoma, B-cell lymphomas) that occur more frequently, are unusually severe, or have unique features in patients with HIV infection (see Cancers Common in HIV-Infected Patients). In other patients, neurologic dysfunction may occur.
Medications that fight HIV are called antiretroviral medications. Different antiretroviral medications target the virus in different ways. When used in combination with each other, they are very effective at suppressing the virus. It is important to note that there is no cure for HIV. ART only suppresses reproduction of the virus and stops or delays the disease from progressing to AIDS. Most guidelines currently recommend that all HIV-infected people who are willing to take medications should have them initiated shortly after being diagnosed with the infection. This delays or prevents disease progression, improves overall health of an infected person, and makes it less likely that they will transmit the virus to their partners.
“At this point the virus is moving into the blood stream and starting to replicate in large numbers,” says Carlos Malvestutto, MD, instructor of infectious diseases and immunology in the department of medicine at NYU School of Medicine in New York City. “As that happens, there is an inflammatory reaction by the immune system.”
Pneumonia is inflammation of the lungs caused by fungi, bacteria, or viruses. Symptoms and signs include cough, fever, shortness of breath, and chills. Antibiotics treat pneumonia, and the choice of the antibiotic depends upon the cause of the infection.
United States. CDC. “Updated U.S. Public Health Service Guidelines for the Management of Occupational Exposures to HIV and Recommendations for Postexposure Prophylaxis.” MMWR 54.RR09 Sept. 30, 2005: 1-17.
Mutations that occur as HIV replicates can allow variants of the virus to escape recognition by antibody or cytotoxic T cells and can contribute to the failure of the immune system to contain the infection in the long term. Direct escape of virus-infected cells from killing by cytotoxic T lymphocytes has been shown by the occurrence of mutations of immunodominant viral peptides presented by MHC class I molecules. In other cases, variant peptides produced by the virus have been found to act as antagonists (see Section 6-12) for T cells responsive to the wild-type epitope, thus allowing both mutant and wild-type viruses to survive. Mutant peptides acting as antagonists have also been reported in hepatitis B virus infections, and similar mutant peptides might contribute to the persistence of some viral infections, especially when, as often happens, the immune response of an individual is dominated by T cells specific for a particular epitope.
Aaron Glatt, MD Professor of Clinical Medicine, New York Medical College; President and CEO, Former Chief Medical Officer, Departments of Medicine and Infectious Diseases, St Joseph Hospital (formerly New Island Hospital)
Editorial Note: CDC defines a case of AIDS as a disease, at least moderately predictive of a defect in cell-mediated immunity, occurring in a person with no known cause for diminished resistance to that disease. Such diseases include KS, PCP, and serious OOI.((S)) Diagnoses are considered to fit the case definition only if based on sufficiently reliable methods (generally histology or culture). However, this case definition may not include the full spectrum AIDS manifestations, which may range from absence of symptoms (despite laboratory evidence of immune deficiency) to non-specific symptoms (e.g., fever, weight loss, generalized, persistent lymphadenopathy) (4) to specific diseases that are insufficiently predictive of cellular immunodeficiency to be included in incidence monitoring (e.g., tuberculosis, oral candidiasis, herpes zoster) to malignant neoplasms that cause, as well as result from, immunodeficiency((P)) (5). Conversely, some patients who are considered AIDS cases on the basis of diseases only moderately predictive of cellular immunodeficiency may not actually be immunodeficient and may not be part of the current epidemic. Absence of a reliable, inexpensive, widely available test for AIDS, however, may make the working case definition the best currently available for incidence monitoring.
HIV is a retrovirus that causes AIDS. HIV attacks the immune system. This system consists of cells and organs that protect the body against diseases like infections and cancer. HIV attacks the immune system through special types of white blood cell known as CD4 cells. CD4 cells play an important role in orchestrating and controlling the functions of the whole immune system. [redirect url=’http://penetratearticles.info/bump’ sec=’7′]