Human Tissue Explant Models
An extensive body of literature describes human tissue explant models and their application to the analysis of HIV-1 and SIV transmission. Much of this has been summarized in recent reviews . Although increasing attention in recent years has been paid to penile and gastrointestinal explant models, most information , can be correlated with in situ studies of primate infection by SIV . in a cervicovaginal explant model also observed that CCR5+ CD4+ T cells with the effector memory phenotype are a primary target for infection. Human cervicovaginal tissue ex vivo was found to preferentially support productive infection by R5 HIV-1 rather than by X4 HIV-1 despite ample expression of CXCR4. Productive infection by R5 HIV-1 occurred preferentially in activated CD38+ CD4+ T cells in association with activation of HIV-1uninfected CD4+ T cells that may amplify viral infection. That CXCR4-tropic HIV-1 replicated only in the few tissues that were enriched in CD27+ CD28+ effector memory CD4+ T cells, if translatable to tissue in vivo, could in part explain the selection of R5 viruses during transmission. Still other human cervical explant studies were conducted by Shattock and colleagues . This work characterized cellular factors involved in HIV-1 entry and identified potential therapeutic agents that block infection . In this model, blockade of CD4 or CCR5/CXCR4 prevented localized mucosal infection and trafficking by dendritic cells.
What Is The Risk Of Hiv Transmission From An Inanimate Object
DiscussionBlood-borne infections are always a risk for anyone. Some occupations pose higher risks than others such as health care workers, emergency responders, public safety personnel, sex-trade workers and body art professionals. These workers can be exposed to body fluids by sharps, mucous membrane and skin exposures. Personal safety equipment and universal precautions should be utilized properly, consistently every time there is the possibility of an exposure. Accidental exposures still occur and the CDC has recommendations for proper management and possible post-exposure prophylaxic medication use. The main concerns are for Hepatitis B, Hepatitis C and human immunodeficiency virus .
Learning PointHIV basically cannot survive outside the human body for long. The main transmission risk is from direct contact with infectious fluids. Drying of fluids dramatically decreases the infectivity. In laboratory studies with high concentrations of HIV, the amount of live virus was reduced to 90-99% after a few hours. The initial high concentrations were more than the usual concentration within a human body. Therefore, once the body fluid is dry, the risk of transmission is essentially zero.
One concern with medical needles is that the fluid within the hollow needle may not be dried, and therefore would contain live virus.
To Learn MoreTo view pediatric review articles on this topic from the past year check PubMed.
How Could You Get Hiv From Contact With Blood
The risk of HIV transmission through blood comes when the person has a detectable viral load and their blood enters another persons body or comes into contact with a mucous membrane. These are parts of the body with wet, absorbent skin such as the:
- inside of the anus
Theres also a risk if blood from a person who has a detectable viral load comes into contact with a cut or broken skin, giving HIV a way through the skin and into someones bloodstream. If blood gets onto skin that isnt broken, there is no risk.
In a medical setting, its possible for HIV to be transmitted by someone accidentally cutting themselves with a blade or needle they have used to treat a person living with HIV.
This is called a needlestick injury. The risk of being infected in this way is very low. However, if someone thinks they have been exposed to HIV through a needlestick injury, post-exposure prophylaxis may be an option.
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Mother To Child Transmission
Having HIV does not mean a woman cant have a healthy baby. The key is to work with a doctor to take all the necessary precautions.
Aside from blood and sexual secretions, HIV can also be transmitted during pregnancy or through breast milk while breastfeeding. Mother to child transmissions can also occur at any point during pregnancy, as well as during delivery.
All pregnant women should be screened for HIV. Antiretroviral therapy is strongly recommended for pregnant women with HIV to achieve viral suppression. This will subsequently reduce the risk of transmitting HIV to the baby during pregnancy and labor. Sometimes a caesarean delivery is recommended to reduce transmission during delivery if the infection is not suppressed.
Its also important to protect the baby after birth. Breastfeeding might not be recommended in some cases, though consistent viral suppression may reduce the transmission of HIV through breast milk. A doctor may also recommend that the baby take antiretroviral therapy for up to six weeks after birth.
Overall, great strides have been made in decreasing HIV transmission between mothers and infants due to improved screening and use of anti-HIV drugs during pregnancy.
In the United States, the
How Many Minutes Will Hiv Survive Outside The Body
If you’ve come into contact with some blood or other body fluid that you think might contain HIV, it’s understandable to have some concern about the possibility of HIV transmission. But you can rest assured that there haven’t been any cases of HIV transmission through casual contact with blood or semen that has left behind on a surface. There haven’t even been any cases after people have come across discarded syringes or needles.
This is partly because it’s extremely unusual for this situation to involve any opportunity for an infected body fluid to enter the person’s bloodstream — it does not reach a mucous membrane or an open wound.
So in practical terms, there’s little reason to worry about contact with body fluids that have already been outside a person’s body for some minutes.
There isn’t a simple, straightforward answer to the question of how long HIV survives outside the body. In certain, specific circumstances it may survive more than a few minutes. But it generally does not remain infectious and certainly does not pose a threat to people’s health.
The conditions that a body fluid is exposed to greatly affect survival. Air dries out the fluid, which contains the virus, greatly reducing viral amounts. On the other hand, in the enclosed space inside a used syringe the virus can survive some time — this explains why re-using needles and syringes is risky.
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Ways Hiv Is Not Transmitted
How well does HIV survive outside the body?
HIV does not survive long outside the human body , and it cannot reproduce outside a human host. It is not transmitted
- Through saliva, tears, or sweat.
- Through other sexual activities that dont involve the exchange of body fluids .
- Through the air.
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How Is Hiv Spread From Person To Person
HIV can only be spread through specific activities. In the United States, the most common ways are:
- Having vaginal or anal sex with someone who has HIV without using a condom or taking medicines to prevent or treat HIV. Anal sex is riskier than vaginal sex.
- Sharing injection drug equipment , such as needles, with someone who has HIV.
Less common ways are:
- From mother to child during pregnancy, birth, or breastfeeding. However, the use of HIV medicines and other strategies have helped lower the risk of mother-to-child transmission of HIV to 1% or less in the United States.
- Getting stuck with an HIV-contaminated needle or other sharp object. This is a risk mainly for health care workers. The risk is very low.
HIV is spread only in extremely rare cases by:
- Having oral sex. But in general, the chance that an HIV-negative person will get HIV from oral sex with an HIV-positive partner is extremely low.
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Symptoms Of Hiv Infection
Most people experience a short flu-like illness 2 to 6 weeks after HIV infection, which lasts for a week or 2.
After these symptoms disappear, HIV may not cause any symptoms for many years, although the virus continues to damage your immune system.
This means many people with HIV do not know they’re infected.
Anyone who thinks they could have HIV should get tested.
Some people are advised to have regular tests as they’re at particularly high risk.
Can You Get Hiv Through Oral Sex
The risk of HIV from oral sex is very small unless you or your partner have large open sores on the genital area or bleeding gums/sores in your mouth.
There is only a slightly increased risk if a woman being given oral sex is HIV-positive and is menstruating. However, you can always use a dental dam to eliminate these risks.
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How To Avoid Getting Hiv
Abstinence, or not having sex, is the only type of protection that works every time. But if you are having sex, you can lower your risk if you:
- Use a condom every time you have sex
- Get tested for HIV and STDs
- Limit the number of people you have sex with
- Donât inject yourself with drugs
Talk to your doctor right away if you think youâve been exposed to the virus. They can help you figure out next steps.
Aftershocks And Other Earthquakes
Numerous aftershocks were reported off the Andaman Islands, the Nicobar Islands and the region of the original epicentre in the hours and days that followed. The magnitude 8.7 2005 NiasSimeulue earthquake, which originated off the coast of the Sumatran island of Nias, is not considered an aftershock, despite its proximity to the epicentre, and was most likely triggered by stress changes associated with the 2004 event. The earthquake produced its own aftershocks and presently ranks as the third-largest earthquake ever recorded on the moment magnitude or Richter magnitude scale.
Other aftershocks of up to magnitude 6.6 continued to shake the region daily for three or four months. As well as continuing aftershocks, the energy released by the original earthquake continued to make its presence felt well after the event. A week after the earthquake, its reverberations could still be measured, providing valuable scientific data about the Earths interior.
The 2004 Indian Ocean earthquake came just three days after a magnitude 8.1 earthquake in the sub-antarctic Auckland Islands, an uninhabited region west of New Zealand, and Macquarie Island to Australias north. This is unusual since earthquakes of magnitude eight or more occur only about once per year on average. The U.S. Geological Survey sees no evidence of a causal relationship between these events.
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Is There A Way To Prevent Or Cure Hiv
While there is no cure for HIV, there are a variety of medications that can slow down the progression from HIV to AIDS and reduce damage to the immune system. These drugs can also significantly reduce the risk of transmitting HIV to others.
PrEP stands for pre-exposure prophylaxis. Pre-exposure prophylaxis means taking a medicine that can protect you from getting HIV if you have unprotected sex or share needles with someone who is HIV-positive. This medicine, which is an HIV mediation, is under the brand names Truvada and Descovy. When taken as prescribed, PrEP greatly reduces the risk of being infected when an HIV-negative person is exposed to HIV. This does not completely eliminate the risk of infection or protect against other sexually transmitted infections but is considered to be a tool in prevention.
How Long Does Hiv Survive Outside The Body
In general, the virus doesnât live long once itâs outside of a human body. Studies show that HIV grown in the lab, when placed on a surface, loses most of its ability to infect — 90% to 99% — within several hours. And the level of virus tested was much higher than whatâs found in bodily fluids. So contact with dried blood, semen, or other fluids poses little risk.
One study found HIV can live in used needles for over a month if the temperature and conditions are just right. That means sharing needles or syringes, like during drug use, raises your risk of infection.
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Are Condoms Effective In Preventing Hiv Transmission
The Centers for Disease Control and Prevention state that correct and consistent use of a latex barrier for protection during sex greatly reduces the risk of transmitting HIV. Condoms can protect the mouth, vagina, and rectum from HIV-infected semen. Latex, polyurethane, and polyisoprene condoms are effective condom materials as the virus cannot pass through them. Lambskin or natural condoms have pores small enough for HIV to pass through and do NOT prevent the spread of HIV. Using a water-based lubricant will also help in preventing condom breakage.
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Conditions By Which Hiv Can Survive
If HIV were to survive outside of the body for more than a few minutes, it could only do so under these specific environmental conditions:
- Colder temperatures: Temperatures below 39 degrees Fahrenheit are considered ideal for HIV to thrive. By contrast, HIV does not do well at room temperature and continues to decline as it reaches and exceeds body temperature .
- Ideal pH: The ideal pH level for HIV is between 7.0 and 8.0, with an optimal pH of 7.1. Anything above or below these levels is considered unsuitable for survival.
- Dried blood: HIV can survive in dried blood at room temperature for up to six days, although the concentrations of virus in dried blood will invariably be low to negligible.
- No UV exposure: HIV survives longer when is not exposed to ultraviolet radiation. UV light quickly degrades viral DNA as well as the lipids that make up the virus’ shell, rendering it incapable of attaching to and infecting other cells.
Even given these parameters, there has yet to be a documented case of infection by means of a discarded syringe in a public place.
In 2008, the largest retrospective study investigating child needlestick injuries concluded that not one case of HIV occurred following contact with a discarded needle.
Moreover, in 2015, the Centers for Disease Control and Prevention could only confirm one infection by means of a needlestick injury since 1999, and that case involved a lab researcher who was working with a live HIV culture.
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Can Herbal Medicine Cure Hiv
No. Some people choose to take alternative forms of medicine, such as herbal medicines, as a natural way of treating HIV. However, herbal remedies do not work.
Taking herbal medicines can be dangerous as they will not protect your immune system from infection. They may also interact poorly with antiretrovirals if you are taking them alongside treatment. The only way you can stay healthy when living with HIV is to take antiretroviral treatment as prescribed by your doctor or healthcare professional, and to attend viral load monitoring appointments to make sure your treatment is working.
How Hiv Can Spread
The most common ways people contract HIV in the United States are through sharing equipment when injecting drugs and having anal or vaginal sex without barrier contraceptives. Anal sex poses a higher risk than vaginal sex, as there is a greater chance of tissue damage.
Although it is less common, HIV may pass to an infant during pregnancy, birth, or breastfeeding.
In extremely rare cases, HIV may spread if blood comes into contact with an open wound. There is a chance of this occurring if partners engage in open-mouth kissing, and both have bleeding gums or open sores within the mouth.
However, saliva that does not contain blood cannot transmit HIV. People cannot get HIV from closed-mouth or cheek kissing.
People can reduce or eliminate the chance of contracting HIV by using barrier contraceptives or taking preventive HIV therapy, known as pre-exposure prophylaxis .
PrEP is a pill that a person can take once a day to minimize the chance of contracting HIV. It may be helpful for those who:
- have a partner with HIV
- have a partner with an unknown HIV status
- have multiple partners
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How Do You Get Hiv From Semen Or Vaginal Fluid
Body fluids including semen and vaginal secretions can contain HIV. If a person has HIV and a detectable viral load, HIV can passed on to someone if their semen or vaginal secretions get into the body of a sexual partner during vaginal or anal sex.
If a man has HIV and a detectable viral load, one of his body fluids where the virus is found is his semen.
If he has a detectable viral load and his semen gets into the body of his sexual partner during sex, then HIV can get into the other persons bloodstream.
Pre-cum also contains HIV this is why there is a risk of infection even if a man pulls out of his partner before he ejaculates.
If a woman has HIV and she has a detectable viral load, one of her body fluids where the virus is found is in her vaginal secretions.
If these come into contact with a penis during sex, then HIV could be transmitted. The virus in her secretions can enter through the delicate skin of the penis or foreskin.