Hot answers tagged

101

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 ...


21

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 ...


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 ...


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

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

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 ...


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 ...


9

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 ...


9

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 ...


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

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

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 ...


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 ...


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 Edition, ...


7

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

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

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

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 ...


6

As referenced the publication you shared, other human corona viruses also infect, but do not replicate in T cells, so it's not "Big News" in the sense of being a novel or unexpected finding. This also differs from HIV, which actively replicates in CD4+ T Cells. However, it does seem like CoV-2 patients have reduced T-cells after recovery, and that reduced ...


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

Whether or not a mutation changes the 'amount' (meaning the size of the genome) of genetic information present in an individual depends on the type of mutation and is independent on which gene is affected. In general there are 3 types of mutations: point mutation: this is the change of one base pair to another (e.g. A to C). The total amount of information/...


4

Yes, you can transmit HIV with infected needles/syringes. This is a quite common mechanism of transmission when drug addicts share and re-use needles and syringes and also in third world hospitals with poor hygiene standards. A drop of blood is considered infectious at least until it has completely dried up (some research showed that it might be contagious ...


4

If you read this article, you will find that CD4+ and CD8+ T-cells are probably the major mediators of the immune response against M. tuberculosis. Since HIV severely depletes the number of CD4+ T-cells (and to a lesser extent other kinds of lymphocytes), it stands to reason that the frequency of infection and virulence will be substantially increased in ...


4

Others have already touched the important points. Consider this as a summary. What gives HIV the ability to mutate? All organisms mutate by two mechanisms: Replication errors Mutagenesis by physical/chemical agents that cause a chemical change (lesion) on DNA The main enzyme responsible for HIV replication is reverse transcriptase which makes a DNA ...


4

The standard protocol for treating a healthcare worker that accidentally comes in contact with HIV infected body fluid is to receive HAART treatment. HAART is an acronym that stands for Highly Active AntiRetroviral Therapy, and is a multi-drug cocktail that acts on a number of pathways to block the HIV virus from replicating. There are early inhibitors ...


4

Human Immunodeficiency Virus is a mutated form of Simian Immunodeficiency Virus. In simians (Apes and Monkeys, not including humans), SIV is not pathogenic, in most cases, however, when the mutated form made the jump to humans, it became highly contagious and virulent. You can find a basic description in the wikipedia article here: Simian Immunodeficiency ...


4

A congenital disorder or disease is a disorder that is present at birth. This term can be applied to many conditions, including some that are infections. More typically, the term is used for developmental birth defects such as spina bifida and cleft palate. Although HIV/AIDS can be congenital (since a mother has about a 25% chance of passing it to her ...


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