Ways In Which Hiv Is Transmitted
Looking at the third condition for transmission , there are three primary ways in which this can happen:
- Unprotected sexual contact
- Direct blood contact, including injection drug needles, blood transfusions, accidents in health care settings or certain blood products
- Mother to baby
Sexual Routes of Transmission
Sexually, the three main ways that HIV is transmitted are:
- vaginal sex
- anal sex
- oral sex
Vaginal and anal intercourse: For the receptive partner , the mucous membranes of the anus and vagina are very efficient routes into the bloodstream. HIV may also enter either through routine, minute tearing caused during intercourse .
Anal sex is riskier than vaginal sex, because the membranes are thinner, tearing happens more easily, and there is no natural lubrication. But both are efficient routes for the virus.
It is speculated that for the penetrative partner , HIV may infect through the mucous membranes in the meatus . It is believed that uncircumcised men may be at greater risk for HIV for a variety of reasons. For instance, they may not have been told how to correctly use a condom. Because an uncircumcised man has a foreskin and a circumcised man doesn’t have a foreskin, each has to put on a condom differently. Uncircumcised men must pull back on their foreskin before rolling on the condom. Neglecting to pull back the foreskin may make condom failure more likely, although no clear evidence supports this idea.
Non-Sexual Routes of Transmission
Mother to Child Transmission
Tattoos And Body Piercings
- There are no known cases in the United States of anyone getting HIV this way.
- However, it is possible to get HIV from tattooing or body piercing if the equipment used for these procedures has someone elses blood in it or if the ink is shared. This is more likely to happen when the person doing the procedure is unlicensed because of the potential for unsanitary practices such as sharing needles or ink.
- If you get a tattoo or a body piercing, be sure that the person doing the procedure is properly licensed and that they use only new or sterilized needles, ink, and other supplies.
How Hiv Is Transmitted
HIV is not passed on easily from one person to another. The virus does not spread through the air like cold and flu viruses.
HIV lives in the blood and in some body fluids. To get HIV, 1 of these fluids from someone with HIV has to get into your blood.
The body fluids that contain enough HIV to infect someone are:
- vaginal fluids, including menstrual blood
- breast milk
- contact with animals or insects;like mosquitoes
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How Do You Get Or Transmit Hiv
You can only get HIV by coming into direct contact with certain body fluids from a person with HIV who has a detectable viral load. These fluids are:
- Semen and pre-seminal fluid
- Rectal fluids
- Vaginal fluids
- Breast milk
For transmission to occur, the HIV in these fluids must get into the bloodstream of an HIV-negative person through a mucous membrane ; open cuts or sores; or by direct injection.
People with HIV who take HIV medicine daily as prescribed and get and keep an undetectable viral load have effectively no risk of sexually transmitting HIV to their HIV-negative partners.
What Is The Connection Between The Hiv Life Cycle And Hiv Medicines
Antiretroviral therapy is the use of HIV medicines to treat HIV infection. People on ART take a combination of HIV medicines every day. HIV medicines protect the immune system by blocking HIV at different stages of the HIV life cycle.
HIV medicines are grouped into different drug classes according to how they fight HIV. Each class of drugs is designed to target a specific step in the HIV life cycle.
Because an HIV regimen includes HIV medicines from at least two different HIV drug classes, ART is very effective at preventing HIV from multiplying. Having less HIV in the body protects the immune system and prevents HIV from advancing to AIDS.
ART cant cure HIV, but HIV medicines help people with HIV live longer, healthier lives. HIV medicines also reduce the risk of HIV transmission .
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What Is Necessary For Hiv Transmission To Occur
For HIV transmission to occur there are three necessary components: a fluid, a route and an activity or event. Sufficient virus in a fluid containing HIV needs to get into the body of an HIV-negative person. This can happen only through a limited number of activities.
The amount of virus in the blood and other bodily fluids of a person with HIV is known as the viral load. It is measured as the number of copies of the virus per millilitre of blood . Most viral load tests used in Canada cannot detect HIV in the blood if there are fewer than 40 to 50 copies/ml, though some newer tests can detect as few as 20 copies/ml. People who have a lower concentration of the virus than these thresholds are said to have an undetectable viral load. When a person takes HIV treatment consistently, their viral load can become undetectable within about three to six months. Having an undetectable viral load greatly lowers or eliminates the chance of passing HIV. A person with HIV will have a higher viral load right after contracting the virus, which can be reduced to the undetectable level if they take effective treatment. ;
What Does Viral Suppression Mean
The terms viral suppression and undetectable viral load are used interchangeably to mean the same thing. This is when antiretroviral drugs reduces a persons viral load to an undetectable level. Viral suppression does not mean a person is cured; HIV still remains in the body. If ARVs are discontinued, the persons viral load will likely return to a detectable level and they will no longer be virally suppressed.
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Can I Get Hiv From Tattooing Piercing Acupuncture Electrolysis Or Shaving
Any procedure in which a needle or razor is used on more than one person involves a theoretical risk of HIV transmission because of the possibility of infected blood on the instrument. However, the risk can be reduced or eliminated through routine sterilization procedures. There have been no documented cases in the United States of someone becoming infected through tattooing or piercing.
Tattoo artists, piercers, hairdressers and barbers, massage therapists, manicurists and pedicurists, and acupuncturists are all defined by the Centers for Disease Control as “personal service workers” . The CDC has established universal precautions for PSWs, similar to those for health care workers, which are designed to protect both the workers and their customers from HIV and other blood-borne illnesses such as hepatitis B and C. The guidelines state that any instruments designed to penetrate the skin such as tattoo or acupuncture needles either should be used only once and discarded, or should be thoroughly cleaned and sterilized after each use.
If you are worried about the risks of such procedures, you should discuss infection control precautions with the provider. In the case of tattoos and acupuncture, you may also provide your own fresh needles to ensure sterility.
In California, establishments that provide personal services may be regulated locally, so anyone who has further concerns about the procedures in an establishment should call the local department of public health.
Hiv Invasion Of Immune Cells
HIV infects T cells via high-affinity interaction between the virion envelope glycoprotein and the CD4 molecule. The infection of T cells is assisted by the T-cell co-receptor called CXCR4 while HIV infects monocytes by interacting with CCR5 co-receptor . As illustrated in Figure 2, after gp120 binds to CD4 on the T cell . Nucleocapsids containing viral genome and enzymes enters the target cell . Following the release of viral genome and enzymes from the core protein, viral reverse transcriptase catalyses reverse transcription of ssRNA to form RNA-DNA hybrids . To yield HIV dsDNA the viral RNA template is partially degraded by ribonuclease H and the second DNA strand is synthesized . The viral dsDNA is translocated into the nucleus and integrated into the host genome by the viral integrase enzyme . Transcription factors transcribe the proviral DNA into genomic ssRNA , which is exported to cytoplasm . In the cytoplasm, host-cell ribosomes catalyse synthesis of viral precursor proteins . The viral precursor proteins are cleaved into viral proteins by viral proteases . HIV ssRNA and proteins assemble beneath the host-cell plasma membrane forming virion buds from it . Maturation occurs either in the forming buds or after budding from the host cell . During maturation, HIV proteases cleave the poly-proteins into individual functional HIV proteins. The mature virions are able to infect another host cell.
Figure 1. Figure 2.
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What Should I Do If I Forget To Take My Arvs
Taking your HIV medication every day, exactly the way your health care provider tells you to will help keep your viral load low. If you skip doses, even now and then, you are giving HIV the chance to multiply rapidly. This could weaken your immune system, and you could become sick.
In most cases, if you realize you missed a dose, take the medicines as soon as you can, then take the next dose at your usual scheduled time .
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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Can I Get Hiv From Kissing
You cannot get HIV from kissing an infected person on the cheek. Where saliva is exchanged, it is unlikely that the virus will be transmitted. This is because one would have to swallow one gallon of the saliva from an infected person in order to contract the disease. However, the risk increases if an uninfected person has a sore or cut in the mouth.
Is Someone Who Takes Hiv Drugs Able To Transmit Hiv
Some people believe that taking antiretrovirals or having an “undetectable viral load” means that they can’t transmit HIV to their sexual partners. That is not true. A person who takes HIV treatments — even those who have “undetectable” viral load counts — can still transmit HIV.
Effective drugs, taken properly, can significantly decrease viral load . It is known that the higher one’s viral load, the more likely one is to transmit the virus and the lower one’s viral load, the less likely one is to transmit the virus. But, regardless, HIV can still be transmitted. It is also important to note that viral load can change from day to day, so one can never be certain of their viral load count at a particular time. In addition, viral load tests only reflect the amount of virus in the blood, not necessarily the level of virus in other bodily fluids, such as semen and vaginal fluid.
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How Is Hiv Passed Through Needles And Other Drug Use Or Body Work Equipment
HIV can be passed through blood that remains in used needles or other drug injection equipment, even if the amount of blood is so small it cant be seen. When a used needle containing blood with HIV breaks the skin of another person, HIV can get directly into their bloodstream. Once inside the bloodstream it can then cause a permanent infection. In the same way, HIV can be passed on by reusing unsterilized equipment for tattooing or piercing and through accidental needlestick injuries.
Sharing needles or other equipment used to inject drugs is the most common way that HIV is transmitted through broken skin. When a person injects drugs, blood can get into the needle/syringe or on other equipment they are using to inject or prepare their drugs. When someone uses a needle/syringe that has already been used by another person, there is a possibility that blood containing HIV is present. When a person prepares and injects drugs using shared equipment, blood that may contain HIV can directly enter their bloodstream through the broken skin. This is an efficient mode of transmission because the immune cells are the only natural defence against this type of HIV transmission. A larger amount of residual blood in the needle/syringe or other equipment and a higher amount of HIV in the blood can both increase the risk of injection-related HIV transmission.
How Can Hiv Be Passed Through Infant Feeding
HIV can be passed to an infant through breast milk, and HIV has also reportedly been passed to young children through food that was prechewed by a parent or caregiver who has HIV.
We know that breast milk can contain high levels of HIV but we dont perfectly understand how HIV transmission happens through breastfeeding . Transmission of HIV through breastfeeding is thought to occur when HIV in breast milk enters an infants body through the mucous membranes that line the back of the babys throat and gut. Newborn babies are vulnerable to getting HIV in this way because of the frequency of their exposure to HIV in their parents breast milk and the fact that their immune systems and their bodies are still underdeveloped.
There is a 5% to 20% chance that a baby will get HIV through breastfeeding if the lactating parent is not on successful HIV treatment. In addition, there is still a small chance of transmission even with an undetectable viral load.
Feeding an infant prechewed food has been reported as a possible route of HIV transmission in only three cases where young children acquired HIV after being born HIV negative. Although none were breastfed, all three were fed food that had been prechewed by a parent or caregiver with HIV . Oral bleeding was reportedly present in two of these cases, which may have increased the risk of transmission.
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How Hiv Infects The Body
HIV infects;the immune system,;causing progressive damage and eventually making it unable to fight off infections.
The virus attaches itself to immune system cells;called CD4 lymphocyte cells, which protect the body against various bacteria, viruses and other germs.
Once attached, it enters the CD4 cells and uses it;to make thousands of copies of itself. These copies then leave the CD4 cells, killing them in the process.
This process continues until eventually the number of CD4 cells, also called your;CD4 count, drops so low that your immune system stops working.
This process may take up to 10 years, during which time you’ll feel and appear well.;
Page last reviewed: 22 April 2021 Next review due: 22 April 2024
How Long Do Side Effects Last
People have different experiences with side effects. For some it is mild and does not last for more than a few days while others may experience side effects for a few weeks. In general side effects from taking ARVs should not last more than 2-3 weeks. Talk to your doctor or Adherence Counsellor about managing side effects.
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What Is The Hiv Life Cycle
HIV attacks and destroys the CD4 cells of the immune system. CD4 cells are a type of white blood cell that play a major role in protecting the body from infection. HIV uses the machinery of the CD4 cells to multiply and spread throughout the body. This process, which is carried out in seven steps or stages,;is called the HIV life cycle.
Stages Of The Hiv Lifecycle
Binding and fusion
HIV attaches to a T-helper cell. It then fuses to it and releases its genetic information into the cell.
The types of drugs that stop this stage of the lifecycle are called fusion or entry inhibitor drugs because they stop HIV from entering the cell.
Reverse transcription and integration
Once inside the T-helper cell, HIV converts its genetic material into HIV DNA, a process called reverse transcription. The new HIV DNA then enters the nucleus of the host cell and takes control of it.
The types of drugs that stop this stage of the lifecycle are called NRTIs , NNRTIs and integrase inhibitor drugs.
Transcription and translation
The infected T-helper cell then produces HIV proteins that are used to produce more HIV particles inside the cell.
Assembly, budding and maturation
The new HIV is put together and then released from the T-helper cell into the bloodstream to infect other cells; and so the process begins again.
The type of drugs that stop this stage of the lifecycle are called protease inhibitor drugs.
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