Infection And Infectious Diseases
HIV is able to enter the body via intact mucous membranes, eczematous or injured skin or mucosa and by parenteral inoculation. When transmitted by sexual contact, HIV attaches first to dendritic cells or macrophages/monocytes HIV using CCR-5 as a co-receptor is then preferentially replicated . HIV is taken up by macrophages and replicated as shown for M cells in the mucosa . HIV exposure to blood cells can result in the direct infection of T helper cells and the transmission of R5 and X4 viruses . As mentioned above, 1 HID is equivalent to approximately 500-1,000 HIV particles, with a higher dose required for infection via mucous membranes compared to infection via the bloodstream, e.g. by needle stick injury. The majority of new HIV infections are still transmitted sexually. Another epidemiologically relevant route is parenteral administration of drugs and also snorting of drugs with epistaxis.
Transmission of HIV via blood or transplanted organs, including bone, is possible from about days 5-6 after infection of the donor. Mother-to-child transmission has been demonstrated from the 12th week of gestation, but transmission occurs predominantly in the final trimester and particularly shortly before or during birth . HIV can be transmitted via breast milk .
What Is The Treatment For Hiv
Individuals who are HIV positive will likely need to see a specialist. As with many other conditions, early detection offers more options for treatment. Today, there are medical treatments that can slow down the rate at which HIV weakens the immune system. However, there are other treatments that can prevent or cure the conditions associated with HIV. Anti-retroviral drug therapy may be given to a pregnant woman, which has proven to greatly reduce the chance of an infant developing HIV. A cesarean section may be recommended to reduce infant transmission from the birth canal. In the U.S., where other feeding options are available, an infected mother should be discouraged from breastfeeding her infant. Consult your child’s doctor for more information regarding various drug therapies.
The Timeline Of Hiv Infection
Treatments can now slow HIV from progressing to AIDS. However, treatment requires prompt testing and care after exposure to the virus. Despite improvements in treatment regimens, access to care remains a big problem. Even with the advent of multi-drug therapy, evidence reports that 680,000 people died from AIDS-related illness in 2020 alone.
When a person acquires HIV and does not receive treatment, the infection progresses through :
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Prevalence And Incidence Of Blood
Prior to the introduction of compulsory testing for HIV antibodies in May and October 1985, about 1,380 haemophiliacs and about 200 transfusion recipients were infected in Germany with HIV by blood donations and plasma derivatives . With the introduction of antibody screening tests and obligatory virus inactivation procedures in the production process of plasma derivatives, the number of HIV and hepatitis virus infections by transfusion declined significantly, especially in the first 2 years. Since 2004, HIV antibody testing and HIV NAT further reduced the potential HIV burden of the source material . Since 1990/1991 no HIV infections have been transmitted by plasma derivatives .
According to reports to the Paul Ehrlich Institute, 2 HIV transmissions by cellular blood components have occurred after the introduction of NAT screening in 2004 . Both transmissions were due to very recent infections and a failure of the NAT systems used. In the case of 2007, presumably a low viral load and mutations in the primer binding region were responsible for the false-negative test results . Regarding the transmission reported in 2009, the HIV-positive donor sample was repeatedly tested negative with the NAT system used .
As recommended for HIV-infected donors, plasma and lymphocytes of the HIV-infected recipient should also be stored in order to possibly clarify the origin of infection and the transmission using molecular methods .
The Origin Of Aids And Hiv May Not Be What You Have Learned
Most people believe that the origin of HIV, the AIDS virus, derives from some natural evolutionary event. Key among these HIV origin theories is the so called “cut hunter theory” in which a human, allegedly African native, received a bloody wound or infected splash while preparing a chimpanzee carrying a similar virus . Most recent research, along with the scientific consensus, holds that the origin of HIV and AIDS could never have happened this way.
In 2001, The Royal Society of London’s conference proceedings, which sought to determine the initial cause of AIDS and the origin of HIV, were published for the world to behold. The most highly respected scientists and academicians debated the possibility that HIV-1, the most widespread and deadly human AIDS virus, evolved from accidental vaccine contaminations and subsequent transmissions to mostly African villagers. The oral polio vaccine received the focus of interest here since that vaccine was partially derived from growing live polio viruses in monkey kidney cells that have historically proven to be contaminated with cancer viruses such as SV40 — the 40th monkey virus ever discovered. This virus, like HIV-1, is currently linked by medical scientists to widespread human cancers. By the end of the symposium, the esteemed delegates concluded HIV’s origin, and AIDS, was not likely to have come from polio vaccine transmissions as chimpanzees were not proven to have been used during the manufacture of this vaccine
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Hiv Natural History And Immunopathogenesis
The pathology of HIV infection can be generally characterised by declining peripheral blood CD4 lymphocyte counts, wasting disease and neurological disease. This latter feature of the AIDS syndrome is related to infection of macrophages and microglia. In primary HIV infection, only about 50% of infected individuals are symptomatic with fever and lymphadenopathy. After seroconversion , there follows an asymptomatic period of 2-15 years. During this period, viral replication is continuing at a high rate of up to 1010 infectious virions/day, leading to approximately 108-109 lymphocytes/day being infected, which are replaced almost as quickly. It is therefore remarkable that the rate of CD4 lymphocyte depletion is not more rapid than observed. This rapid turnover of HIV and its enormous diversity underlie the difficulty in producing antiretroviral drugs with long-term efficacy, and is one of many problems facing the development of an effective vaccine against HIV.
Depletion of HIV-infected lymphocytes occurs through several mechanisms, viz: direct cytopathic effect of HIV, including the formation of syncytia by SI X4 HIV lymphotropic strains, immune destruction of HIV-infected cells by cytotoxic CD8 T lymphocytes that recognise HIV antigens presented on major histocompatibility complex molecules, apoptosis due to lymphocyte activation in the presence of specific cytokines.
Donor History Questionnaire And Donor Interview
According to the haemotherapy guidelines, the state of health and pre-existing relevant diseases have to be assessed by using a donor history questionnaire and a confidential interview. This can help to identify and defer persons whose donation could represent a health risk to themselves or could be associated with the risk of transmitting a disease to others. For further queries and explanations a physician has to be available. The medical history should cover all issues of the donor selection criteria of the haemotherapy guidelines. These constitute a legally binding basis for decision-making in selecting donors. Since 2015 an updated standardised donor history questionnaire is available , and its application is recommended by Vote 41 of the German Advisory Committee Blood .
Perinatally HIV-infected children who since birth have been effectively treated with antiviral drugs for years may be antibody-negative due to early suppression of HIV replication and could theoretically become potential blood donors. They may have no measurable viral load in plasma but HIV DNA in their blood cells . By declaration of the HIV infection and/or disclosure of the continuous use of anti-retroviral drugs they are excluded from donating blood.
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Ways Hiv Cannot Be Spread
HIV is not spread by:
- Air or water
- Mosquitoes, ticks or other insects
- Saliva, tears, or sweat that is not mixed with the blood of a person with HIV
- Shaking hands hugging sharing toilets sharing dishes, silverware, or drinking glasses or engaging in closed-mouth or social kissing with a person with HIV
- Drinking fountains
However Dr Gallo Has Been Confronted Several Times For The Alleged Duty Of Undertaking On Creating The Deadly Virus Intending To Destroy Black People And Gay Men In 1970s
After many years of trying out different vaccines, this time around Dr Gallo has announced the beginning of the first human clinical trials of his new discovered HIV vaccine known as Just another protein which was made to produce a new type of anti-body to kill the infection in the first place.
IHV researchers led by announce start of #HIV vaccine human clinical trials
Dr. Robert Gallo
It took 15 years to reach this stage and the most important thing is to prove that the vaccine is safe in man if we carryout the first and the second phases, am very excited this moment, it has been a journey, Dr Gallo said.
He continued and said 60 volunteers will be needed in the first phase were by the first person will be injected late this month and second phase will be to link-up with other peoples vaccines.
Many people still ask themselves what his real intention was in creating the deadly virus, was he paid to do such a thing? others think that may be a certain organisation hired him to take part in such a dengerous thing, but according to Dr Gallo himself, its like people miss understood what he really did.
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Frequency Of Administration Type And Amount Of Blood Products
Blood components: Since 2004 only 2 HIV transmissions through blood components have been reported in Germany . HIV is transmitted if 1 HID is present in the administered blood component . There is evidence that immediate initiation of HIV post exposure prophylaxis can prevent an infection after needle stick injury in individual cases .
Plasma derivatives: Transmission of HIV by plasma derivatives occurred between 1979 and 1989 primarily via factor VIII, factor IX and prothrombin complex concentrates . HIV has never been transmitted via albumin, antithrombin III and i.m. or i.v. immunoglobulin preparations, not even before the introduction of specific process steps for the depletion and inactivation of viruses. The implementation of donor selection, antibody screening and inactivation procedures has made a transmission of enveloped viruses no longer possible.
Structure And Genome Of Hiv
The genome and proteins of HIV have been the subject of extensive research since the discovery of the virus in 1983. “In the search for the causative agent, it was initially believed that the virus was a form of the Human T-cell leukemia virus , which was known at the time to affect the human immune system and cause certain leukemias. However, researchers at the Pasteur Institute in Paris isolated a previously unknown and genetically distinct retrovirus in patients with AIDS which was later named HIV.” Each virion comprises a viral envelope and associated matrix enclosing a capsid, which itself encloses two copies of the single-stranded RNA genome and several enzymes. The discovery of the virus itself occurred two years following the report of the first major cases of AIDS-associated illnesses.
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Screening And Diagnostic Tests
If doctors suspect exposure to HIV infection, they do a screening test for HIV. Doctors also recommend that all adults and adolescents, particularly pregnant women, have a screening test regardless of what their risk appears to be. Anyone who is concerned about being infected with HIV can request to be tested. Such testing is confidential and often free of charge.
The current combination screening test tests for two things that suggest HIV infection:
Antibodies are proteins produced by the immune system to help defend the body against a particular attack, such as that by HIV. Antigens are foreign substances that can trigger an immune response.
The body takes several weeks to produce enough antibodies to be detected by the test, so results of the antibody test are negative during the first few weeks after the virus enters the body . However, results of the p24 antigen test can be positive as early as 2 weeks after the initial infection. The combination tests can be done quickly by a laboratory. Also, a version of these tests can be done in a doctor’s office or clinic . If results are positive, doctors do a test to distinguish HIV-1 from HIV-2 and a test to detect the amount of HIV RNA in the blood .
Other, older rapid bedside tests are also available. These tests can be done using a sample of blood or saliva. If results of these rapid screening tests are positive, they are confirmed by ELISA or by repetition of one or more other rapid tests.
Diagnosis Of Hiv Infection
Tests to detect antibodies to the HIV virus in a sample of blood or saliva
Tests to detect HIV RNA in a sample of blood
Early diagnosis of HIV infection is important because it makes early treatment possible. Early treatment enables infected people to live longer, be healthier, and be less likely to transmit HIV to other people.
Doctors usually ask about risk factors for HIV infection Transmission of HIV Infection Human immunodeficiency virus infection is a viral infection that progressively destroys certain white blood cells and can cause acquired immunodeficiency syndrome . HIV is transmitted… read more and about symptoms .
Doctors also do a complete physical examination to check for signs of opportunistic infections, such as swollen lymph nodes and white patches inside the mouth , and for signs of Kaposi sarcoma of the skin or mouth.
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Through Needles Or Other Instruments
Health care workers who are accidentally pricked with an HIV-contaminated needle have about a 1 in 300 chance of contracting HIV unless they are treated as soon as possible after exposure. Such treatment reduces the chance of infection to less than 1 in 1,500. The risk increases if the needle penetrates deeply or if the needle is hollow and contains HIV-contaminated blood rather than simply being coated with blood .
Infected fluid splashing into the mouth or eyes has less than a 1 in 1,000 chance of causing infection.
Why Is Hiv So Evasive What Is The Hiv Reservoir
Although HIV can be controlled by antiretroviral therapy, it cannot be eliminated from the body. This is because HIV evades the normal immune system mechanisms for getting rid of cells infected by viruses.
HIV integrates itself into the DNA of human immune system cells and only replicates when the cell is stimulated to respond to an infection. These cells are called latently-infected cells. These cells are not recognised as infected by the immune system and killed off, allowing them to persist for as long as the cell lives.17
Some of the cells infected by HIV are very long-lasting memory T-cells. Reservoirs of latently- infected cells become established in the lymph nodes, the spleen and the gut. HIV also infects cells in the brain, but it is unclear if HIV can pass from the brain to other parts of the body. HIV may also persist for many years in macrophages immune cells found largely in tissues and in dendritic cells, which recognise infectious agents and alert other immune cells to remove them.
Latently-infected cells can proliferate without being activated and HIV may also pass from cell to cell within tissues in the gut and other reservoirs. 18 This means they evade the immune system and are not suppressed by antiretroviral drugs before infecting other cells.
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Why Does The Immune System Fail To Fight The Hiv Virus
There are various reasons which can contribute to the failure of the immune system to control HIV infection and prevent AIDS development. By infecting CD4+ T cells, HIV is able to replicate predominantly in activated T cells and paralyse one of the main components of adaptive immune system. HIV can also establish latent infection in CD4+ T cells and remain invisible to CD8+ T cells and therefore replication can occur later in the infection and generate new virions. Antigenic mutation within the T-cell epitopes can affect the binding capacity of MHC molecules to the viral peptides, resulting in the inability of the TCRs to recognise the MHC-peptide complex. Finally, HIV is able to hide from anti-HIV antibodies by expressing non-immunogenic glycans on key antibody epitopes.
What Are The Factors That Affect Disease Progression
The most important factor affecting HIV progression is the ability to achieve viral suppression. Taking antiretroviral therapy regularly helps many people slow the progression of HIV and reach viral suppression.
However, a variety of factors affect HIV progression, and some people progress through the phases of HIV more quickly than others.
Factors that affect HIV progression can include:
- Ability to achieve viral suppression. Whether someone can take their antiretroviral medications and achieve viral suppression is the most important factor by far.
- Age when symptoms start. Being older can result in faster progression of HIV.
- Health before treatment. If a person had other diseases, such as tuberculosis, hepatitis C, or other sexually transmitted diseases , it can affect their overall health.
- Timing of diagnosis. Another important factor is how soon a person was diagnosed after they contracted HIV. The longer between their diagnosis and treatment, the more time the disease has to progress unchecked.
- Lifestyle. Practicing an unhealthy lifestyle, such as having a poor diet and experiencing severe stress, can cause HIV to progress more quickly.
- Genetic history. Some people seem to progress more quickly through their disease given their genetic makeup.
Some factors can delay or slow the progression of HIV. These include:
Living a healthy lifestyle and seeing a healthcare provider regularly can make a big difference in a persons overall health.
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