Hot answers tagged

95

No, this is not possible. There are a few reasons for that, but most important are that the only thing a mosquito injects is its own saliva, while the blood is sucked into the stomach where it is digested. To be able to infect other people HIV would need to be able to leave the gut intact and then also be able to replicate in the mosquitos which it cannot ...


33

HIV was identified as an infectious disease through classical epidemiology, and the virus was identified through classical virology. I won't get into the epidemiology, but briefly it went pretty much as you'd expect -- a cluster of symptoms were identified, patient characteristics were analyzed, the contagious nature of the symptoms were recognized, all ...


18

The reasons why HIV is "incurable" (a misnomer) are legion: HIV is a retrovirus, which means it inserts its own genome into the host cell's genome. You must therefore kill each and every infected cell to rid the body of the virus. HIV is a lentivirus, which means it has a long incubation period, so it can "lay low" before symptoms are readily detected. HIV ...


17

I think no one can really deny the existence of HIV or AIDS, just a search on google scholar will show >1,500,000 hits for each of those terms, and ask (hopefully any) doctor and they will say it does, though AIDS denialists do debate whether HIV causes AIDS. This paper explains the process of HIV causing AIDS. Further, AIDS denialists have not offered up ...


17

Doctors would recommend the use of barrier protection for couples where both partners are HIV+ because the virus can mutate. Mutated forms of the virus can become resistant to Highly Active Antiretroviral Therapy (HAART) treatments, rendering them ineffective. The use of barrier protection reduces the risk that a resistant mutant strain of HIV is ...


13

Alright, having read the citation linked, and doing a little poking of my own, here's my approach at an answer: Some human herpes virus infections may compete with HIV infection. Essentially, some strains (not the ones you normally think of) infect CD4 cells - the same cells targeted by HIV. These strains down regulate transcription in CD4 cells, which in ...


12

nope - the test contains antibodies to HIV proteins, but nothing from HIV itself. The 'antigen test' tests for antigens, it doesn't itself contain any antigens. Antibodies are proteins that animals (like humans) produce to fight of viral and bacterial infections, they don't come from viruses. Even if the test did contain HIV proteins, it could not ...


12

I am not a medical doctor but in my view this is within the realms of possibility. The probability has been estimated by Princeton at 1 in 10 million. This is per bite, assuming - I presume - that the mosquito that bit you was just feeding on an HIV-infected person of sufficiently high viral load. It is not against the laws of Physics that blood cells can ...


11

Usually an antibody test against HIV is positive three month after the infection. Before this time a test can only be done with molecular biology methods as PCR. However, it is possible, that patients which have definitely been tested in an early phase using molecular biology methods and which afterwards receive a antiretroviral therapy (ART) that these ...


10

I'm not sure if I should be posting this as an answer, but I think a very approachable and accurate account of the history of HIV can be found from Dinis de Sousa et al.. I agree with what has been posted above. On the theory that a picture is worth a thousands words, you might also introduce skeptics to the cryo-electron microscopy images of the virus (...


10

There are many other things inside the HIV capsid besides RNA. The ssRNA is bound to the p7 nucleocapsid protein, the p6 late assembly protein, as well as integrase and reverse transcriptase, both of which are vital for infectivity. Also enclosed within the virion are Vif (Viral Infectivity Factor), protease, Nef (Negative Regulatory Factor), Tat (HIV ...


9

You read right: it can only come from people already infected through: sexual contact contact with an infected person's body fluids (blood transfusions), although not all fluids carry HIV (saliva, tears) from mother to child (pregnancy, breast feeding) Having unprotected sex with multiple partners statistically increases the risk of stumbling upon someone ...


8

HIV hides in a number of known cells and unknown cells. Although most of the damage of HIV is caused by its infection of shorter lived cells, long lived cells which it infects includes anything with adequate receptors including memory T cells, dendritic cells, macrophages and some glial cells too. These cells are found widespread in the body from tissues to ...


8

Being HIV+ and having AIDS are slightly different terminologies: If the virus is detectable in an individual by existing medical techniques he/she is called HIV+. A HIV+ person is said to have progressed to AIDS only when the CD4+ T-lymphocyte count drops below 200 cells per ml of blood. Cornelius has nicely summarized the infection routes so I wont ...


8

Yes, it is possible and the chances are pretty high. According to the WHO paper linked below, the rate of partially or completely breastfed children which get infected by this route is about 20-35%, while the rate of children which are not infected and doesn't get breatfed is zero (no surprise here). The mechanism by which this infection occurs is ...


8

Retroviruses depend on being able to convert their RNA genome into a DNA copy, and have a reverse transcriptase enzyme to do that. This unique activity is not found in human cells, allowing for potential antiviral therapy if a drug can be used to inhibit the reverse transcriptase while not affecting the human enzymes. AZT is one such drug, by mimicking the ...


8

Posted due to certain inaccuracies in comments and answers provided to this question regarding the Human Immunodeficiency Virus. It should be noted that while it may not affect the ability for macrophages in the dermis to phagocytose the heavy metals found in the inks used in tattooing, and thus not interfere with the fixing of a tattoo in an HIV+ person, ...


8

Can people with AIDS/HIV be vaccinated? Yes. Immunization is an important part of the overall treatment strategy for HIV positive individuals. HIV infection is a risk factor for a number of vaccine preventable infectious diseases. Immunization in these patients is particularly important because of their increased risk of developing disease. (See Cecil ...


8

Important notes: I am not going into the ethical aspects of editing/removing CCR5 in human embryos, neither will I discuss potential effects of introducing that mutation into the human population. Both of these are very important issues, but out of the scope for this answer. As of now I'm not aware of any reliable sources of what was actually done in ...


7

Western Blot tests on young children are practically useless, since they test for antibodies. The child will likely have antibodies passed down by the HIV+ mother, regardless of whether the child has HIV. The test will show the antibodies, which may be mistaken for an active immune response from the child. As such, there will be a high false-positive rate on ...


7

This is an interesting question, which has not been answered yet. It is also questionable, if this protective effect is present at all. There are around 40 studies on the topic available which have subsequently undergone meta-analysis. In a meta-analysis all data from recent studies which meet certain quality criteria are analysed together. This gives a much ...


7

In Latin, lente means slow, so lentiviruses are retroviruses that are characterized by long periods of latency. lentivirus A group of retroviruses that include human immunodeficiency virus, HIV-1. They cause disease after a long incubation period. latency A state in which a virus infects a cell but does not replicate. -Janeway's Immunobiolgy, 8th ...


7

The CD4 receptor is vital for the proper functioning of the immune system. It is found not only on T-Lymphocytes, but also on macrophages and dendritic cells. Its function on T-cells is to stabilize the interaction between the T-Cell receptor and the MHC Class 2 (often known as HLA II in humans) antigen complex on antigen presenting cells and improves the ...


6

I am afraid your question is really not clear. You are asking one thing in the title of your question, another in the question body and a third in your comments. If you are asking (as you did in your comment above) what would happen if a virus with no enzymes were to infect a cell, see below. In the case of HIV (and other retroviruses) some of the most ...


6

Your answer is correct. HIV-1 encodes a single homodimeric aspartic protease, with each monomer containing the classic Asp-Thr-Gly motif, and the dimer's active site being formed with the two monomeric active sites creating a cleft where the proteolysis takes place. In it, water acts as a nucleophile in conjunction with the aspartic acid residue to hydrolyze ...


6

Short answer People with HIV can get tattoos. Background In Africa there are countries that tattoo people identified with HIV (Source: Kenya Today) and some people with HIV find comfort in tattooing biohazard symbols and related images on themselves to express their illness (Source: CNN). However, as rightly mentioned by @AMR, macrophages which are ...


6

Can people with HIV still be vaccinated? No (most of the time) if the vaccine is an attenuated vaccine, this means it contains living organisms that have been modified in order to reduce their virulence. The reduction would keep a healthy individual unharmed while still inducing an immune response to form antibodies, however it is considered dangerous to ...


6

This doesn't take much effort to answer! Googling "HIV mosquito" brings us straight to this blog post, which gives three main reasons (along with more details, links to other resources, etc.): Only saliva is injected into humans when a mosquito bites and thus HIV positive blood that a mosquito may have previously ingested is never transmitted to other ...


5

Cornelius covers Primary Infection and some of Dissemination. Wysiwyg covers some reasons when HIV cannot proceeds to AIDS. Little however is discussed yet exactly about the Pathogenesis - how HIV proceeds into AIDS. There are many stages: Primary infection Dissemination of virus to lymphoid organs Latency Increased HIV expression Constitutional ...


5

I would say no. Some HIV strains are X4-tropic and not R5 tropic. That means that the virus uses the CXCR4 coreceptor and not the CCR5 coreceptor for entry into the CD4-positive cell.


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