Hiv Can Spread Through Sexual Contact Between Women
During the study, the team gave the couples condoms and taught them other ways to prevent passing along HIV to their partner. But in 137 couples, transmission did occur sometime during the decade. In these cases, the team compared the viruses of the newly infected person with those of the partner.
They found that HIV was most likely to be transmitted when its genetic code had a particular pattern. These versions of the HIV genes seem to make the virus good at initially infecting and replicating within a person.
Turned out, this pattern is the average DNA sequence that scientists find when they examine HIV strains in people from around the globe. “The average sequence in the population is probably average because it works best, and we found that that is true,” says Jonathan Carlson, a computational biologist at Microsoft Research, who contributed to the study.
To establish a long-term infection through sexual contact, an HIV virus must first infect a single cell on the genitals. Then the virus multiples and spreads to adjacent cells. “Fitter” viruses are more efficient at infecting new cells and then replicating themselves, Carlson says.
And the higher the initial barrier to this initial infection, the fitter the virus has to be to complete this process.
“What was most striking was that risk factors that were known to affect the risk of transmission affected the selection,” says Eric Hunter, a virologist at Emory University, who also contributed to the study.
How To Prevent The Spread Of Hiv
People living with HIV can use the following to prevent transmitting it to others:
- Pre-exposure prophylaxis : This is a daily pill that contains two antivirals called tenofovir and emtricitabine. When a person takes it daily, PrEP can reduce the risk of acquiring HIV through sex by
- of a recent potential HIV exposure.
All Exposures Are Not Equal
The results of several meta-analyses suggest that some types of sex carry on average a higher risk of HIV transmission than others. Below are estimates from meta-analyses that have combined the results of studies conducted in high-income countries. For types of sex where meta-analysis estimates do not exist, numbers from individual studies are provided.
Anal sex
A meta-analysis exploring the risk of HIV transmission through unprotected anal sex was published in 2010.1;The analysis, based on the results of four studies, estimated the risk through receptive anal sex to be 1.4%. This risk was similar regardless of whether the receptive partner was a man or woman.
No meta-analysis estimates currently exist for insertive anal sex but two individual studies were conducted to calculate this risk. The first, published in 1999, calculated the risk to be 0.06% .2;However, due to the design of the study, this number likely underestimated the risk of HIV transmission. The second study, published in 2010, was better designed and estimated the risk to be 0.11% for circumcised men and 0.62% for uncircumcised men.3
Vaginal sex
A meta-analysis of 10 studies exploring the risk of transmission through vaginal sex was published in 2009.4;It is estimated the risk of HIV transmission through receptive vaginal sex to be 0.08% .
A meta-analysis of three studies exploring the risk from insertive vaginal sex was estimated to be 0.04% .4
Oral sex
Don’t Miss: How Can Hiv Be Controlled
How Is Hiv Not Transmitted
Any fluids that were not mentioned above do not carry enough HIV to transmit the infection. HIV cannot be transmitted by: shaking hands, sharing food, hugging and kissing, coughs and sneezes, spit, insects, etc.
All Canadian blood products in Canada have been checked for HIV since 1985 and there has not been a single case of transmission through blood products since that time.
Why Do Gay Men Have An Increased Risk Of Hiv
In the United States, gay men are at a disproportionately high risk of getting HIV;and AIDS. In 2016, 68% of all HIV infections in the U.S. affected men who have sex with men. The risk is even higher for gay black men. Why are gay men more likely to get HIV?
There are several reasons why gay and bisexual men are at higher risk of HIV than their straight counterparts. Some of the reasons are based on certain types of sex that result in greater risk of infection due to how HIV is biologically transmitted. Other reasons reflect social realities about how;men who have sex with men live in the world and are treated by society.
Recommended Reading: Does Walgreens Do Hiv Testing
How Is Hiv Transmitted Through Needles
HIV isnt transmitted only through sexual contact. Sharing needles also puts a person at higher risk of contracting HIV.
When a needle is injected into a persons body, it breaks the skin barrier. If the needle has already been injected into another person, it can carry traces of their blood, along with any infections they have. The contaminated needle can introduce these infections into the second persons body.
Researchers dont know if having an undetectable viral load reduces the risk of HIV transmission through shared needles, but its reasonable to assume it may provide some risk reduction.
HIV can affect anyone. Whatever their age, gender, sexuality, ethnicity, or race, everyone should take steps to protect themselves. But due to socioeconomic factors, some demographic groups have higher HIV transmission rates and generally are more affected by HIV.
According to the CDC , the general demographic traits most affected by HIV are:
Transgender women are also highly impacted by HIV transmissions as a population, reports the CDC .
These groups are disproportionately affected by HIV, but they arent inherently at greater risk of contracting HIV. An individuals personal risk depends on their behaviors, not on their age, gender, sexuality, ethnicity, race, or any other demographic factor.
What Should I Do If I Need To Clean Up Blood
HIV does not usually survive long outside of the body, but contact with blood should be avoided.;
Hepatitis C can survive in dried blood at room temperature for several weeks, and hepatitis B can survive in dried blood for around a week outside the body.
To clean up blood that has been spilled, wear rubber gloves and mop up the liquid using bleach and warm water . Use warm, soapy water to clean away blood spilled on someones body.
Put the waste, used gloves and bloodied clothes in a plastic bag, seal and throw away.
Recommended Reading: How Fast Does Hiv Spread In The Body
Implications For Hiv Transmission And Prevention
Anal sex is a common practice among men who have sex with men, heterosexual men and women, and transgender individuals and is a known risk factor for HIV infection and transmission.11,12,13,14 In a recent nationally representative survey of almost 6,000 men and women in the United States , approximately 20% of women between the ages of 18 to 39 reported engaging in anal sex in the past year, as did approximately 25% of men between the ages of 25 to 49.15
HIV transmission
Rectal fluid has implications for HIV transmission through anal sex when the HIV-negative person is the insertive partner . Research show that this type of anal sex can carry a significant risk of HIV transmission. In fact, the average risk of HIV infection through a single act of condomless insertive anal sex with an HIV-positive partner is slightly higher than through vaginal sex but much lower than if the HIV-negative person takes the receptive role during anal sex.16,17
Rectal fluid undoubtedly contributes to the risk of HIV transmission through anal sex where the insertive partner is HIV negative. We know that for HIV transmission to be possible, a fluid that contains HIV must come into contact with specific parts of the body that are vulnerable to HIV infection. If an HIV-negative person has insertive anal sex with an HIV-positive partner, rectal fluid containing HIV can come into contact with the urethra and/or the penis foreskin. Both the urethra and foreskin are vulnerable to HIV infection.
Safe Disposal Of Needles
Discarding needles in regular household trash bins endangers children, pets, janitors, and waste management services personnel; therefore, needles should be properly disposed of in a FDA-cleared sharps container that is both puncture- and leak-resistant. It is important to properly dispose of used needles because it can be difficult to tell if a needle has ever been used before. By not disposing of needles in a safe way, users may expose others or themselves to a needle stick injury. If a sharps container is not available, needles can often be brought to local law enforcement, hospitals, or drug stores for safe collection and disposal. In addition, needles can be mailed in specialized containers to a mail-back program for safe disposal. Moreover, needles can be utilized and disposed of properly in supervised injection sites. In the health care setting, use of blunt-end needles can minimize the risk of needle stick injuries.
You May Like: Does Hiv Cause Hair Loss
Risk Of Other Infections
In addition to HIV, a person can get other sexually transmitted diseases like chlamydia and gonorrhea from anal sex without condoms. Even if a condom is used, some STDs can still be transmitted through skin-to-skin contact . One can also get hepatitis A, B, and C; parasites like Giardia and intestinal amoebas; and bacteria like Shigella, Salmonella, Campylobacter, and E. coli from anal sex without a condom because they’re transmitted through feces. Getting tested and treated for STDs reduces a person’s chances of getting or transmitting HIV through anal sex. If one has never had hepatitis A or B, there are vaccines to prevent them. A health care provider can make recommendations about vaccines.
How Long Can Hiv Survive Outside The Body
Once outside the body, HIV usually cant survive for very long. Coming into contact with blood or semen that has been outside the body doesnt generally pose a risk for HIV transmission.
Similarly, the risk of passing on HIV to someone else if you have a detectable viral load and cut yourself is also very low. Wash away any blood with soap and hot water and cover the wound with a sticking plaster or dressing.
Don’t Miss: Can You Get Hiv Through Kissing
Interpreting The Numberswhat Additional Information Needs To Be Provided
Some clients may see these numbers and think their risk of HIV transmission is low. Therefore, caution is needed when interpreting them. If these numbers are provided to clients, they should be accompanied by information that helps shed light on why the risk may be higher than it seems.
Transmission can occur after one exposure.
It is important to emphasize that a person could become infected from having unprotected sex once or a person could have unprotected sex many times and not become infected, regardless of how low or high the risk per exposure is.
A risk of 1% would mean that an average of one infection would occur if 100 HIV-negative people were exposed to HIV through a certain type of sex. It does not mean that a person needs to be exposed 100 times for HIV infection to occur.
These are estimates of average risk in the absence of biological factors that increase risk.
The numbers in the table above are rough estimates. They are averages and do not represent the risk from all exposures to HIV through a certain type of sex.
The risk of HIV transmission may be much higher than these averages if biological risk factors are present. For example, research shows that STIs and some vaginal conditions, such as bacterial vaginosis, can increase the risk of HIV transmission by up to 8 times.6,7,8;As a result, the risk of an HIV-negative woman becoming infected through unprotected receptive vaginal sex could be closer to 1% if she has a vaginal STI.
Infectiousness Of Ai For Heterosexuals And Msm
shows the per-act and per-partner summary estimates by exposure . Two per-act URAI estimates were based on studies among MSM, and two among heterosexual couples., The per-act summary estimate was 1.4% if Halperin et al.s abstract estimate is excluded due to lack of further detail on methods). No significant differences in per-act URAI estimates between heterosexual couples and MSM were found . However, while MSM estimates, were similar to each other , heterosexual estimates, were heterogeneous . Most per-partner estimates were derived from studies on MSM. Exceptions were the studies by Nicolosi et al. studying heterosexual couples, and Giesecke et al. who enrolled a small proportion of heterosexual participants. Cheingsong-Popov et al. did not describe study participants but it appears likely, given the 1984 publication date, that the acquired immunodeficiency syndrome and AIDS-related complex patients reporting AI were MSM. There was no evidence that the heterosexual combined URAIUIAI crude per-partner estimate was significantly different from the eight crude estimates from MSM .
Also Check: How Do You Find Out You Have Hiv
What Are My Chances Of Contracting Hiv
We include products we think are useful for our readers. If you buy through links on this page, we may earn a small commission. Heres our process.
What is HIV?
Human immunodeficiency virus attacks and weakens the immune system, making an individual more vulnerable to serious illness. Untreated HIV can lead to AIDS, which occurs when the immune system is so weak it becomes susceptible to serious infections and some cancers.
Theres an epidemic of HIV in the United States and around the world. According to the Centers for Disease Control and Prevention , more than 1.1 million people in the United States are living with HIV, and 1 in 7 of them arent aware of it. An estimated 39,782 people in the country were diagnosed with HIV in 2016 alone.
HIV transmission occurs in many different ways, including through condomless sex and by sharing needles. Risk of transmission varies depending on several factors including:
- sexual practices and the HIV status of sexual partners
- sharing needles for drug use or tattoos
- use of PrEP, PEP, condoms, or having an undetectable viral load
Its important to understand the risk level based on actual factors in preventing the transmission of HIV.
How Can You Get Hiv
HIV is found in the following bodily fluids of someone living with the virus:
- blood
- vaginal fluids
- breastmilk.
For you to get HIV, these bodily fluids need to get into your blood through a mucous membrane , via shared injecting equipment, or through broken;skin .
There is not enough HIV virus in other bodily fluids, like saliva, sweat or urine, to transmit it from one person to another.
Someone living with HIV who has;an undetectable viral load,;meaning effective treatment has lowered the amount of virus in their blood to levels where it cannot be detected by a normal blood test, cannot pass on HIV.
A person living with HIV with a detectable viral load can;pass the virus to others whether they have symptoms or not.
HIV is most infectious;in the first few weeks after infection.;At this time many;people are unaware of their status.
The main ways you can get HIV are:
Read Also: Can I Get Hiv From Spit
What Is Rectal Fluid
Rectal fluid is the mucus that lines the rectum. Mucus is a slippery secretion produced by certain parts of our body known as the mucous membranes. These membranes are located at the entrances into the body and line the internal passages of many of our organs, including the gastrointestinal tract , the vagina and cervix, and the foreskin and urethra.
Mucus has several functions. A major function is to protect the mucous membranes from germs . It does this by trapping germs and preventing them from coming into contact with the membranes. Mucus also contains substances that can to some extent kill germs.
For some membranes, mucus also acts as a lubricant that prevents friction and tearing of the mucous membrane tissue when objects pass through them. For example, mucus in the vagina reduces friction during sexual intercourse and mucus in the gastrointestinal tract facilitates the passage of food and feces. Mucus in the rectum also helps reduce friction during anal intercourse.
How To Be Safe When Coming Into Contact With Infected Blood
A condom will act as a barrier against any contact with blood during sex.;
As well as sex, sharing equipment for injecting drugs is a way blood can get into someones body. This can be avoided by using fresh needles and not sharing needles, syringes and other equipment.;
If a woman has HIV, her menstrual blood also carries a risk of transmission if she has a detectable viral load.;
If youre HIV negative and taking pre-exposure prophylaxis youll be protected against getting HIV if you come into contact with infectious blood.
Don’t Miss: Can Hiv Be Transferred Through Saliva
Are Hiv Medicines Used At Other Times To Prevent Hiv Transmission
Yes, HIV medicines are also used for post-exposure prophylaxis and to prevent mother-to-child transmission of HIV.
- Post-exposure prophylaxis ;PEP means taking HIV medicines within 72 hours after a possible exposure to HIV to prevent HIV infection. PEP should be used only in emergency situations. It is not meant for regular use by people who may be exposed to HIV frequently. For more information, read the ClinicalInfo fact sheet on Post-Exposure Prophylaxis .; ;
- Prevention of mother-to-child transmission of HIV;Pregnant women with HIV take HIV medicines for their own health and to prevent mother-to-child transmission of HIV. After birth, babies born to women with HIV receive HIV medicine to protect them from infection with any HIV that may have passed from mother to child during childbirth. For more information, read the ClinicalInfo fact sheet on Preventing Mother-to-Child Transmission of HIV.
How You Become Infected
There is HIV virus in body fluids like vaginal secretions and semen. If those fluids are present, they can enter the bloodstream of someone who doesn’t have HIV through an opening such as a mouth sore or a genital ulcer.
Your chances are higher of getting HIV if you:
- Have sores in your mouth, vagina, or penis
- Have another sexually transmitted disease
Recommended Reading: Can Hiv Positive Become Negative