What Are The Tests For Detecting Hiv
Various tests may be used for HIV detection:
- HIV antibody test: This test detects the antibodies produced in the body in response to HIV.
- Antigen test: This test can be done at an earlier stage than an HIV antibody test. It measures a protein called p24 antigen, present in the virus and produced in high amounts after the infection.
- Nucleic acid test : It is also called an RNA test. It is a very specific test that looks for the virus itself and can detect HIV as early as about 10 days of infections.
- In-home test kits: Although less accurate than the laboratory-based tests, home-based kits have the advantage of testing in the privacy and comfort of the home. Only FDA approved home-based kits should be used.
- Viral culture: This involves using the patients sample and growing the virus in the lab. It takes longer to get the results and is not the most preferred test for HIV.
What Is A Retrovirus
rather than as DNA DNA Genes are segments of deoxyribonucleic acid that contain the code for a specific protein that functions in one or more types of cells in the body. Chromosomes are structures within cells… read more .
When HIV enters a human cell, it releases its RNA, and an enzyme called reverse transcriptase makes a DNA copy of the HIV RNA. The resulting HIV DNA is integrated into the infected cells DNA. This process is the reverse of that used by human cells, which make an RNA copy of DNA. Thus, HIV is called a retrovirus, referring to the reversed process.
Other RNA viruses , unlike retroviruses, do not make DNA copies after they invade cells. They simply make RNA copies of their original RNA.
Each time an HIV-infected cell divides, it makes a new copy of the integrated HIV DNA as well as its own genes. The HIV DNA copy is either
HIV-1 originated in Central Africa during the first half of the 20th century when a closely related chimpanzee virus first infected people. The global spread of HIV-1 began in the late 1970s, and AIDS was first recognized in 1981.
What Are The Signs & Symptoms Of Hiv And Aids
When first infected with HIV, a person may have:
- increased number of infections
- infections that are more severe than is typical
Without treatment, HIV can lead to a very weakened immune system and progress to AIDS. Illnesses that happen in AIDS are called “AIDS-defining conditions.”
AIDS-defining conditions include:
- very fast and severe weight loss
- a lung infection called pneumocystis pneumonia
- Kaposi sarcoma
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Expected Outcomes Of Early Therapy
Typical responses of virus load to treatment in patients with chronic HIV-1 infection show decreases to undetectable levels during an 820-week period of potent ART. Time to virus suppression in patients with PHI has not been well characterized. Higher initial virus loads in patients with acute infection may prolong the time to virus suppression. Alternatively, a relatively intact immune system and a lower total body virus burden in patients with early-stage infection may decrease time to suppression. The pattern and potency of individual immunologic responses likely reflect a number of host factors, including HLA class I type, initial antibody response, CTL and T helper cell responses, and chemokine receptor polymorphisms.
How Is Hiv Spread
The spread of HIV from person to person is called HIV transmission. HIV is spread only through certain body fluids from a person who has HIV. These body fluids include:
- Rectal fluids
- Breast milk
HIV transmission is only possible through contact with HIV-infected body fluids. In the United States, HIV is spread mainly by:
- Having anal or vaginal sex with someone who has HIV without using a condom or taking medicines to prevent or treat HIV
- Sharing injection drug equipment , such as needles or syringes, with someone who has HIV
The spread of HIV from a woman with HIV to her child during pregnancy, childbirth, or breastfeeding is called perinatal transmission of HIV. For more information, read the HIVinfo fact sheet on Preventing Perinatal Transmission of HIV.
You cannot get HIV by shaking hands or hugging a person who has HIV. You also cannot get HIV from contact with objects, such as dishes, toilet seats, or doorknobs, used by a person with HIV. HIV is not spread through the air or water or by mosquitoes, ticks, or other blood-sucking insects. Use the HIVinfo You Can Safely ShareWith Someone With HIV infographic to spread this message.
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Suspected Or Known Exposure To Hiv But No Symptoms
If you have not been tested for HIV, call your doctor if:
- You suspect that you have been exposed to HIV.
- You have engaged in high-risk behaviour and are concerned that you were exposed to HIV.
- Your sex partner engages in high-risk behaviour.
- Your sex partner may have been exposed to HIV.
- Your sex partner has HIV.
- You have any of the symptoms listed above.
Getting tested for HIV can be scary, but the condition can be managed with treatment. So it is important to get tested if you think you have been exposed.
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
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Preventive Treatment After Exposure
People who have been exposed to HIV from a blood splash, needlestick, or sexual contact may reduce the chance of infection by taking antiretroviral drugs for 4 weeks. These drugs are more effective when they are started as soon as possible after the exposure. Taking two or more drugs is currently recommended.
Doctors and the person who was exposed typically decide together whether to use these preventive drugs. They base the decision on the estimated risk of infection and the possible side effects of the drugs. If they do not know whether the source is infected with HIV, they consider how likely the source is to be infected. However, even when the source of the exposure is known to be infected with HIV, the risk of infection after exposure varies, depending on the type of exposure. For example, risk from a blood splash is less than that from a needlestick.
Immediately after exposure to HIV infection, what is done depends on the type of exposure:
If skin is exposed, it is cleaned with soap and water.
Puncture wounds are cleaned with antiseptic.
If mucous membranes are exposed, they are flushed with large amounts of water.
Symptom : Nausea Vomiting And Diarrhoea
Many people experience digestive system problems as a symptom of the early stages of HIV. However, nausea, vomiting and diarrhoea can also appear in later stages of infection, usually as the result of an opportunistic infection.
It is important to stay hydrated. Diarrhoea that is unremitting and not responding to usual therapy might be an indication of HIV.
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Cancers Common In People With Hiv Infection
Kaposi sarcoma Kaposi Sarcoma Kaposi sarcoma is a skin cancer that causes multiple flat pink, red, or purple patches or bumps on the skin. It is caused by human herpesvirus type 8 infection. One or a few spots may appear… read more , a cancer caused by a sexually transmitted herpesvirus, appears as painless, red to purple, raised patches on the skin. It occurs mainly in men who have sex with men.
Cancers of the immune system . Often, lymph nodes in the neck, under the arms, or in the groin enlarge rapidly and painlessly… read more ) may develop, sometimes first appearing in the brain. When the brain is affected, these cancers can cause weakness of an arm or a leg, headache, confusion, or personality changes.
Having AIDS increases the risk of other cancers. They include cancer of the cervix, anus, testes, and lungs as well as melanoma and other skin cancers. Men who have sex with men are prone to developing cancer of the rectum due to the same human papillomaviruses Human Papillomavirus Infection Human papillomavirus causes warts. Some types of HPV cause skin warts, and other types cause genital warts . Infection with some HPV… read more that cause cancer of the cervix in women.
How Is Hiv Treated
There are many treatments that can help people with HIV, and current treatments are very effective and safe. As a result, most people with HIV are living long and healthy lives. Treatment is recommended for everyone with HIV infection, and generally should be started as early as possible.
Medicines slow the growth of the virus or stop it from making copies of itself. Although these drugs don’t eliminate the virus from the body, they keep the amount of virus in the blood low. This protects the health of the person with HIV and also can prevent HIV from passing to sex partners.
The amount of virus in the blood is called the viral load, and it can be measured by a test.
There are several types of anti-HIV drugs. Each type attacks the virus in a specific way.
Pop question: True or false. HIV medicines eliminate virus from the body.
Pop question: True or false. HIV medicines eliminate virus from the body.
Answer: FALSE. HIV drugs cannot eliminate HIV virus from the body, but they can reduce it to very, very low levels. The main goal of HIV drugs is to reduce viral load as much as possible for as long as possible.
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Unresolved Questions About Hiv Origins And Emergence
The discovery of the main HIV / SIV phylogenetic relationships permits explaining broad HIV biogeography: the early centres of the HIV-1 groups were in Central Africa, where the primate reservoirs of the related SIVcpz and SIVgor viruses exist similarly, the HIV-2 groups had their centres in West Africa, where sooty mangabeys, which harbour the related SIVsmm virus, exist. However, these relationships do not explain more detailed patterns of biogeography, such as why epidemic HIV-2 groups only evolved in the Ivory Coast, which is one of only six countries harbouring the sooty mangabey. It is also unclear why the SIVcpz endemic in the chimpanzee subspecies Pan troglodytes schweinfurthii did not spawn an epidemic HIV-1 strain to humans, while the Democratic Republic of Congo was the main centre of HIV-1 group M, a virus descended from SIVcpz strains of a subspecies that does not exist in this country. It is clear that the several HIV-1 and HIV-2 strains descend from SIVcpz, SIVgor, and SIVsmm viruses, and that bushmeat practice provides the most plausible cause of cross-species transfer to humans. However, some loose ends remain.
It is not yet explained why only four HIV groups spread considerably in human populations, despite bushmeat practices being widespread in Central and West Africa, and the resulting human SIV infections being common.
Symptoms Of Hiv/aids And Stages
Many people donât have symptoms at first, and sometimes even for years or decades. But there are signs that can happen, such as flu-like symptoms soon after you become infected with HIV. Even if you donât feel sick, HIV damages the immune system. It hijacks infection-fighting white blood cells called CD4 cells and uses them to churn out thousands of copies of itself. Without treatment, HIV destroys so many of these cells that your body canât protect you from life-threatening infections. If your CD4 count drops below 200, you have AIDS.
There are three stages of HIV infection:
Stage 1: This the earliest stage. You may also hear it called the âacuteâ stage. You might have a fever, rash, fatigue, chills, and other flu-like symptoms. But you might not have any symptoms. If you do, they may start 2-4 weeks after youâre infected. During this time, the virus quickly makes many copies of itself.
Stage 2: During this stage, HIV continues to reproduce, and it slowly damages your immune system over time. You might not feel sick or have symptoms. But HIV isnât gone, and you can still spread it to other people. This stage can last for years or even decades.
Stage 3: This is when you have AIDS. Your immune system has been severely damaged, leaving you vulnerable to other illnesses. With AIDS, many people have symptoms such as chills, fever, sweats, swollen lymph glands, weakness, and weight loss.
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Hiv Originated With Monkeys Not Chimps Study Finds
Researchers have found new clues to the deadly disease’s origins.
Scientists now say that the simian immunodeficiency virus in chimpanzees , which is believed to have been transmitted to humans to become HIV-1the virus that causes AIDSdidn’t start its life in chimps.
Instead, it was a product of separate viruses jumping from different monkey species into chimps, where they recombined to form a hybrid virus, according to a new study.
Researchers believe the chimpanzee virus is a hybrid of the SIVs naturally infecting two different monkeys, the red-capped mangabey and the greater spot-nosed monkey . Chimps eat monkeys, which is likely how they acquired the monkey viruses. The hybrid virus then spread through the chimpanzee species, and was later transmitted to humans to become HIV-1.
The study suggests striking parallels between SIV infection of chimps and HIV infection of humans. Just as chimps acquired viruses from two different sources, humans are infected by two distinct AIDS viruses: HIV-1 and the less virulent HIV-2, which humans acquired from sooty mangabey monkeys.
“Because of the similarity between chimpanzees and humans, any virus that successfully adapts to spreading among chimps would be a candidate for a further jump to humansa potential HIV-3,” said Paul Sharp of the Institute of Genetics at University of Nottingham in England, who led the study.
Testing Positive For Hiv
If you test positive, your doctor will complete a medical history and physical examination.
He or she may order several lab tests to check your overall health, including:
- A complete blood count , to identify the numbers and types of cells in your blood.
- A chemistry screen, to measure the blood levels of certain substances and to see how well your liver and kidneys are working.
Other tests may be done to check for current or past infections that may become worse because of HIV. You may be tested for:
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How Hiv Is Not Spread
The virus doesn’t survive well outside the body. So HIV cannot be spread through casual contact with an infected person, such as by sharing drinking glasses, by casual kissing, or by coming into contact with the person’s sweat or urine.
It is now extremely rare in Canada or the United States for HIV to be transmitted by blood transfusions or organ transplants.
How Are The Drugs Taken
Most people who are getting treated for HIV take 3 or more drugs. This is called combination therapy or “the cocktail.” It also has a longer name: antiretroviral therapy or highly active antiretroviral therapy . Combination therapy is the most effective treatment for HIV.
People with HIV need to work closely with their providers to decide which drugs to take. Several coformulations are available, and for most patients, HIV treatment involves taking just 1 or 2 pills per day.
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Can Hiv Be Prevented
To reduce the risk of getting HIV, people who are sexually active should:
- use a condom every time they have sex
- get tested for HIV and make sure all partners do too
- reduce their number of sexual partners
- get tested and treated for STDs having an STD increases the risk of HIV infection
- consider taking a medicine every day if they are at very high risk of getting infected
- Do not inject drugs or share any kind of needle.
- Do not share razors or other personal objects that may touch blood.
- Do not touch anyone else’s blood from a cut or sore.
How Is Hiv Spread Through Blood
You can become infected if you have contact with the blood of someone who has HIV. Blood-borne infection with HIV can occur through:
- sharing injection equipment when using drugs
- getting tattoos or body piercings with unsterilized needles
- accidental needle sticks
- splashing blood in your eyes
HIV is NOT spread by blood passed through insect bites.
If you inject drugs, the best thing to do is to use new or sterilized injection equipment every time. You can also take a daily medication called pre-exposure prophylaxis to lower your risk of HIV. Learn more about PrEP.
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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.