Saturday, January 30, 2010

How is HIV spread?

How is HIV spread?

HIV is spread primarily by:

  • Not using a condom when having sex with a person who has HIV. All unprotected sex with someone who has HIV contains some risk. However:
    • Unprotected anal sex is riskier than unprotected vaginal sex.
    • Among men who have sex with other men, unprotected receptive anal sex is riskier than unprotected insertive anal sex.
  • Having multiple sex partners or the presence of other sexually transmitted diseases (STDs) can increase the risk of infection during sex. Unprotected oral sex can also be a risk for HIV transmission, but it is a much lower risk than anal or vaginal sex.
  • Sharing needles, syringes, rinse water, or other equipment used to prepare illicit drugs for injection.
  • Being born to an infected mother—HIV can be passed from mother to child during pregnancy, birth, or breast-feeding.

Less common modes of transmission include:

  • Being “stuck” with an HIV-contaminated needle or other sharp object. This risk pertains mainly to healthcare workers.
  • Receiving blood transfusions, blood products, or organ/tissue transplants that are contaminated with HIV. This risk is extremely remote due to the rigorous testing of the U.S. blood supply and donated organs/tissue.
  • HIV may also be transmitted through unsafe or unsanitary injections or other medical or dental practices. However, the risk is also remote with current safety standards in the U.S.
  • Eating food that has been pre-chewed by an HIV-infected person. The contamination occurs when infected blood from a caregiver’s mouth mixes with food while chewing. This appears to be a rare occurrence and has only been documented among infants whose caregiver gave them pre-chewed food.
  • Being bitten by a person with HIV. Each of the very small number of cases has included severe trauma with extensive tissue damage and the presence of blood. There is no risk of transmission if the skin is not broken.
  • Contact between broken skin, wounds, or mucous membranes and HIV-infected blood or blood-contaminated body fluids. These reports have also been extremely rare.
  • There is an extremely remote chance that HIV could be transmitted during “French” or deep, open-mouth kissing with an HIV-infected person if the HIV-infected person’s mouth or gums are bleeding.
  • Tattooing or body piercing present a potential risk of HIV transmission, but no cases of HIV transmission from these activities have been documented. Only sterile equipment should be used for tattooing or body piercing.
  • There have been a few documented cases in Europe and North Africa where infants have been infected by unsafe injections and then transmitted HIV to their mothers through breastfeeding. There have been no documented cases of this mode of transmission in the U.S.

HIV cannot reproduce outside the human body. It is not spread by:

  • Air or water.
  • Insects, including mosquitoes. Studies conducted by CDC researchers and others have shown no evidence of HIV transmission from insects.
  • Saliva, tears, or sweat. There is no documented case of HIV being transmitted by spitting.
  • Casual contact like shaking hands or sharing dishes.
  • Closed-mouth or “social” kissing.

All reported cases suggesting new or potentially unknown routes of transmission are thoroughly investigated by state and local health departments with assistance, guidance, and laboratory support from CDC.

Read our Questions and Answers about HIV Transmissio

Friday, January 29, 2010

Good Aerobic Exercises for HIV:

Good Aerobic Exercises for HIV:

  • Fast walking
  • Jogging
  • Stair-climbing
  • Bicycling
  • Swimming

Good Lifting Exercises for HIV:

  • Lifting weights with machines
  • Push-ups
  • Pull-ups
  • Squats or lunges
  • Dumbbells

How do I Start an Exercise Routine for HIV?

First of all, ask your doctor what types of exercise are okay for you. Then start slowly. Do what you can, but don’t overdo it. Be patient with your body and your workout.

Before you start your exercise program record your weight and the measurements of your arms, legs, chest, stomach, and hips. If possible, also check your body composition with a Bio-electrical Impedance Analysis (BIA). A BIA can be given in a doctor's office and takes only a few minutes. The test determines your body composition by calculating the amount of fat, muscle, and water in the body according to height, weight, sex, and age.

It may be helpful to set goals for yourself, such as increasing or decreasing some of your body measurements. If you are new to exercise, set simple goals for the frequency and duration of your workouts and increase them over time. Make sure your goals are realistic.

When doing aerobic exercise, walk at a pace where you could answer a question in a few words but you aren’t gasping for air. Try to work up to at least 30 minutes three times a week. If you have to start out with 10 minutes, that’s fine. Walk for 10 minutes, and in a couple of weeks add five minutes to your workout. Continue doing this until you are up to 30 minutes or more at least three times a week.

When doing weight-bearing exercise be sure to use slow, controlled movements. Don’t slam the weights down or drop them quickly on the way down. This is not helpful when trying to put on muscle and it can be dangerous. Try to work up to weight-bearing exercise at least three times a week for 30 minutes or more.

Most importantly, drink lots of water before, during, and after your workout. When you're feeling sick, either exercise less or stop for a while.

Starting an exercise routine requires commitment. It may take a while for you to get used to your routine, but don’t give up! If you are able, try hiring or talking to a certified fitness trainer to help you develop a good routine. Make sure to talk to your doctor about any exercise you are doing.

Thursday, January 14, 2010

Becoming HIV antibody positive

Becoming HIV antibody positive

HIV quickly replicates in the body of someone who is newly infected. Although the virus may be undetectable by test, at this time there is a high level of virus in the peripheral blood and HIV can be readily transmitted to someone else. This period is known as acute or primary infection.

It may take weeks or even months before the immune system reacts to the virus by developing antibodies with which to fight it, although the majority of people will develop antibodies to HIV within eight weeks. The development of antibodies to HIV is termed 'seroconversion'.

Some people do not notice any changes after infection, whereas others will experience a brief flu-like illness within days to weeks of exposure. Symptoms may include headache, diarrhoea, nausea and vomiting, fatigue, fever, aching muscles, rash, and/or enlarged lymph glands .

Researchers are still puzzling out whether generalisations can be made between the number and duration of symptoms experienced during primary infection and future disease course. Some studies suggest that the severity and length of symptoms during seroconversion indicate a faster progression to AIDS. Other studies maintain that the severity of symptoms indicate a robust immune response to HIV and predict a rapid decline in viral load.

While that question remains open, gathering evidence supports the premise that the highest likelihood of transmitting infection from one individual to another is during the seroconversion period. A recent Canadian study found that in nearly 600 individuals at all stages of HIV infection, 50% of all new (or 'onward') infections resulted from contact with someone in the stage of primary HIV infection.

Another recent study in Malawi found that in newly infected men, blood viral load was highest about 17 days after infection; seminal viral load reached a peak at 30 days. This finding sheds new light on transmission and, from a public health standpoint, is information that needs to be communicated to as broad an audience as possible. Knowing the high potential for infectivity should impact HIV counselling and prevention programmes, as well as counselling of newly diagnosed patients.

What is HIV?

What is HIV?

HIV stands for human immunodeficiency virus. Originally isolated in Paris in May 1983 by Luc Montagnier, HIV belongs to a group of viruses called retroviruses.

Viruses copy their genetic material into the genetic material of human cells, meaning infected cells stay infected for the rest of their lives. Viruses cannot replicate outside a living cell. When a virus replicates, it may do so with accuracy or with error (known as a mutation). Because of viral mutation, or errors in copying itself, HIV can vary from one individual to another. The ability of the virus to change is also how it can, at times, evade suppression by antiretroviral therapy.

The genetic material of a virus can contain either DNA or RNA. Chickenpox, herpes simplex, and hepatitis B are all DNA viruses. RNA viruses use the enzyme reverse transcriptase to transcribe the RNA virus into a DNA copy of itself. The retroviral DNA is then capable of integrating into the host chromosomal DNA. HIV and hepatitis C are both RNA viruses.

Through mechanisms still not fully understood, HIV prevents the body's immune system from working properly. Normally, the immune system fights off infection. However, HIV is able to infect CD4 T-cells, key cells that co-ordinate the immune system's fight against infection. Many CD4 T-cells are destroyed by being infected and even uninfected CD4 T-cells may no longer work properly.

Wednesday, January 13, 2010

Types of HIV drugs

Types of HIV drugs

Different classes, of antiretroviral drugs target different stages of the HIV life-cycle. Two of the approved types of drugs – nucleoside reverse transcriptase inhibitors (NRTIs) and nucleotide reverse transcriptase inhibitors (NtRTIs) (usually considered as a single class) and non-nucleoside reverse transcriptase inhibitors (NNRTIs) – interfere with the action of HIV’s reverse transcriptase enzyme. Drugs in the protease inhibitor class block the action of the protease enzyme.

HIV entry inhibitors work in various ways. There is one approved HIV fusion inhibitor and one approved CCR5 antagonist, but other types of entry inhibitors are under development. The first integrase inhibitor was licensed in 2007 and agents that target other steps of the HIV life-cycle are further back in the drug development pipeline.

The HIV life-cycle

The HIV life-cycle

Viruses are unable to replicate by themselves, and therefore must enter host cells and ‘hijack’ the cell’s protein-producing machinery.

Before they enter cells, HIV virus particles – known as ‘virions’ – are surrounded by an outer coat, or envelope. In order to enter a cell, proteins on the envelope must bind to CD4 receptors on the cell surface, as well as an additional co-receptor, either CCR5 or CXCR4. Once HIV has attached to both CD4 and one of the co-receptors, the virus envelope can fuse with the cell membrane, and thereby release the contents of the virion into the cell.

Virions contain several viral proteins plus HIV’s genetic material, or genome. The genetic material is enclosed within a structure called a nucleocapsid, which breaks apart early in the replication process. The HIV genome consists of nine genes: gag, pol, env, vif, vpu, CPR, tat, rev and nef. These genes carry all the information needed to make new viruses. One set of genes – gag, pol and env – are structural genes that govern the structure of the virus; gag and pol also give rise to three enzymes essential for HIV replication :

  • Reverse transcriptase – needed to convert viral RNA to DNA.
  • Integrase – enables HIV to insert its genetic material into the cell’s genome.
  • Protease – cuts up newly produced viral proteins.

Viruses are classified based on whether their genetic material is made up of DNA (as with herpes viruses) or RNA (as with HIV and hepatitis C virus). Retroviruses are a subset of RNA viruses that replicate in a unique way by using reverse transcriptase to convert their RNA into DNA.

After viral RNA is converted to DNA (now known as a ‘provirus’), it is integrated into the cell’s genome. This is accomplished by the integrase enzyme, which cuts the host cell’s genome and slips in the viral genetic material. Once integrated into the cell’s DNA, the provirus may lie dormant for a long time. However, if the cell is active, the viral genes instruct the cell to produce new viral proteins using the HIV genetic material as a blueprint.

These viral proteins are originally produced in the form of long strands, called polyproteins, that must be cut up into smaller pieces before they can be assembled into new viral components. This is accomplished by the protease enzyme. Next, the newly copied viral genome, proteins, and enzymes are packaged together, enclosed in a new capsid, and ‘bud’ out through the cell membrane to form a complete new virus particle.

HIV and its treatment

HIV and its treatment

HIV disease progression occurs when the virus replicates and infects new cells. HIV primarily targets CD4 T-cells, which direct the body’s immune response. As HIV infects and kills more CD4 cells, the body is less able to defend itself against viruses, bacteria, and other pathogens.

Disrupting HIV replication prevents the virus from infecting new cells and allows for CD4 cell recovery. The virus has a complex life-cycle that involves entering a cell, inserting and copying viral genetic material, producing new viral proteins, and assembling these proteins into new viral particles (virions) that can go on to infect other cells.

Because the HIV life-cycle has so many steps, drugs can disrupt the virus in many different ways. The most effective regimens combine drugs from different classes, thereby attacking HIV from multiple angles. Doing so reduces the ability of the virus to develop drug resistance.

While highly active antiretroviral therapy (HAART) regimens can dramatically reduce HIV replication, some antiretroviral drugs interfere with the normal workings of human cells, causing a variety of side-effects. Fortunately, the past few years has seen the development of drugs in new drug classes and 'second-generation' drugs that can be used in regimens that provide potent and durable results with fewer toxic side-effects and easier dosing schedules.

Tuesday, January 12, 2010

what are the concerns?

what are the concerns?

Public health messages have traditionally urged disclosure to all sexual and drug using partners. In reality, disclosure is complex and difficult. Some HIV+ persons may fear that disclosure will bring partner or familial rejection, limit sexual opportunities, reduce access to drugs of addiction or increase risk for physical and sexual violence. Because of this, some HIV+ persons choose not to disclose. Programs need to accept that not disclosing is a valid option.

Many HIV service agencies and testing and counseling sites routinely offer self disclosure and dual disclosure, working with HIV+ clients by preparing and supporting them to disclose to partners on their own.

Although provider disclosure services have been used for many years with other STDs, there is a wide variety in rates of acceptance of provider disclosure in HIV: in North Carolina, 87% of newly diagnosed HIV+ persons accepted provider disclosure,8 in Florida 63.1%,9 Los Angeles, CA 60%,10 New York State 32.9%,11 Seattle, WA 32%12 and among anonymous testers in San Francisco, CA 3.1%.13 In Los Angeles, the most common reasons for refusal were: already notified partner (23.4%), not being ready to disclose (15.3%), being abstinent (15%) and having an anonymous partner (11%).10

Disclosing HIV status to partners can be scary, but also can be empowering. In one study, HIV+ injection drug users who disclosed their status found increased social support and intimacy with partners, reaffirmation of their sense of self and the chance to share experiences and feelings with sexual partners.14 Another study of HIV+ persons and their partners who received disclosure assistance found that emotional abuse and physical violence decreased significantly after notification.15

what’s being done?

Florida utilizes trained DISs to deliver disclosure assistance for all reported new HIV infections. In 2004, 63.1% of all newly infected HIV+ persons accepted provider disclosure, identifying 4,460 sex or needle-sharing partners. Among those, 21.8% had previously tested HIV+. Of the 2,518 persons notified, 84.2% agreed to counseling and testing and 11.5% were HIV+.9

The Massachusetts Department of Public Health piloted a client-centered model of disclosure assistance that is integrated into the client’s routine prevention, care and support services. The program required significant changes to the standard model of DIS provider disclosure, building close relationships between service providers and DIS to better support clients’ disclosure needs while protecting confidentiality.16

California instituted a voluntary disclosure assistance program that includes counseling and preparing HIV+ persons for self disclosure; anonymous third party provider notification; counseling, testing and referrals for notified partners; and training and technical assistance to providers in public and private medical sites. About one-third of patients opted for provider disclosure and 85% referred partners. Of the partners located, 56% tested for HIV and half had never tested before. Overall, 18% of partners tested HIV+.4

what needs to be done?

New HIV testing technologies can be useful with disclosure assistance services. Improved rapid testing is a potential invaluable tool for offering HIV tests in the field to notified partners. Nucleic acid amplification testing (NAAT) can determine acute infections, that is, new HIV infections that do not show up during the window period of other HIV tests. Combining these testing strategies with disclosure assistance can help identify newly infected persons and provide immediate counseling, support and referrals to medical or social services as needed.17

Disclosure assistance services, and particularly provider disclosure, may need extensive changes from the traditional DIS model in order to work well and be accepted within HIV services. Health departments could forge closer ties between their STD and HIV programs and with outside service agencies. HIV staff also can be trained to be DIS providers to broaden access to and comfort with disclosure services.

Disclosure assistance services should be made available not only upon HIV diagnosis, but on an ongoing basis as HIV+ persons’ circumstances and needs change. It is not the role of providers to decide if a client will need or want disclosure assistance, but to offer clients support and choices, whether or not a client chooses to disclose.

What are barriers to prevention?

What are barriers to prevention?

HIV is often rendered invisible within AI/AN communities that are facing many other severe and more visible health and social problems such as alcoholism, diabetes and unemployment. As a result, there is often great denial about HIV as a problem in AI/AN communities.

Like in many other tight-knit communities, confidentiality can be difficult to maintain in AI/AN communities, especially in rural areas. This can be a barrier to important prevention activities such as testing for HIV, discussing sexual practices with health care providers, obtaining drug treatment, or buying condoms in local stores.

Prevention services for AI/AN MSM are severely underfunded, and those that exist may not reach MSM at risk. AI/AN MSM have a wide range of identities, from “gay” to “two-spirit” and may not access services addressed to urban gay men. (13) AI/AN MSM may feel isolated and not seek out needed services because of stigma and denial about homosexuality in some AI/AN communities.

The AI/AN population is highly diverse, with over 550 federally-recognized tribes. AI/AN consider themselves to belong to Indian nations that are sovereign, with complex relationships between tribal, state and federal governments. Many state and local governments erroneously assume that the IHS is solely responsible for the health- related needs of AI/AN. Less than 1% of IHS budget goes to urban populations, yet more than half of all AI/AN in the US live in urban areas. As a result, AI/AN tribes and organizations are often denied funding opportunities available to other citizens.

What's being done?

To address the rising rates of STDs and HIV among adolescents in a rural Arizona Indian tribe, tribal health educators, school officials and public health officials collaborated to establish several programs including school health clinics, Native American HIV+ speakers, peer-produced educational dramas, community educational meetings and radio and newspaper ads. Cases of STDs and HIV peaked in 1990 and slowly declined over the next six years, for a 69% overall reduction in STDs. (14)

The Indigenous People's Task Force (IPTF) in Minneapolis, MN, promotes health and education for Native persons. Their Ogitchidag Gikinooamaagad (warrior/teachers) peer education/theater program provides youth with a comprehensive HIV/AIDS prevention curriculum, theater instruction and traditional teachings. IPTF's programs have been acknowledged by the US Surgeon General. (15)

The Indian Health Care Resource Center (IHCRC) of Tulsa, OK provides a biweekly social group for two-spirit Native American men to help build a sense of community, self-esteem and reduce risk behaviors. IHCRC also hosts a relationship skills-building workshop which focuses on helping the participants determine what they want out of relationships, managing triggers to risk behavior and increasing negotiating skills. Each year, IHCRC offers a 4-day retreat with social, cultural and educational activities including traditional meals, a Powwow and stomp dancing. (16)

Monday, January 11, 2010

WH AT INCREASES THE RISK OF HIV INFECTION?

WHAT INCREASES THE RISK OF HIV INFECTION?

Syphilis can increase the risk of transmitting HIV. People with syphilis have a higher than average chance of being infected with HIV. Also, syphilis causes large, painless sores. It is easy for someone to be infected with HIV through syphilis sores. Herpes simplex infection (see Fact Sheet 508) also causes sores which assist infection with HIV. An active case of syphilis or herpes increases the amount of HIV in someone’s system and can make it easier for them to pass it on to another person.

Several other factors increase the risk of transmitting HIV, or becoming infected.

  • When the HIV-infected person is in the "acute infection" phase (see fact sheet 103), the amount of virus in their blood is very high. This increases the chance that they can pass on the infection. Unfortunately, almost no one knows when they are in this phase of HIV infection. There’s no way to tell by looking at them.
  • When either person has a weakened immune system. This could be because of a long-term illness or an active infection like a herpes outbreak, syphilis, or the flu.
  • When the uninfected person has open sores that get exposed to infected fluids. These could be cold sores, genital herpes, mouth ulcers, syphilis sores, or other cuts or breaks in the skin.
  • When there is exposure to infected blood.
  • When the uninfected insertive male partner is not circumcised.

THE BOTTOM LINE

Researchers have developed estimates of the risk of transmission of HIV. These estimates can give you a general idea of which activities are more or less risky. They cannot tell you that any activity is safe, or how many times you can do them without getting infected. The best way to avoid infection is to use a condom correctly and consistently for all sexual activity, and to avoid sharing needles. If you think you have been exposed to HIV, wait 3 months and get tested.

Sunday, January 10, 2010

ANEMIA AND HIV

ANEMIA AND HIV

Serious anemia used to be much more common. Over 80% of people with an AIDS diagnosis had some degree of anemia. People with more advanced HIV disease, or a lower CD4 count, had higher rates of anemia.

The rate of anemia went down when people started using combination antiretroviral therapy (ART). Severe anemia has become rare. However, ART has not eliminated anemia. A large study found that about 46% of patients had mild or moderate anemia, even after one year of ART.

Tuesday, January 5, 2010

I can't wait 13 weeks to find out! Are there other options?

I can't wait 13 weeks to find out! Are there other options?

There are tests that can look for the virus—not antibodies—in the blood. Because the virus becomes detectable in the blood much sooner after infection than antibodies, these tests are an option for people who simply can't wait 13 weeks to find out the results of standard ELISA/Western blot testing. And because there has been some encouraging research indicating that people who diagnose their HIV infection early—meaning the first weeks after infection, before antibodies become detectable—can protect their immune systems by starting treatment early, these tests are proving to be very useful for people who recently engaged in a high-risk activity (e.g., receptive anal sex without a condom) and fear they might have been infected.

These tests look for fragments of HIV, either floating around freely in the bloodstream or inside cells in the bloodstream. Some tests—known as qualitative tests—yield a "positive" or "negative" result, meaning that the virus was or wasn't found (GenProbe's Aptima HIV-1 RNA Qualitative Assay is the only test approved for this purpose). Other tests—known as quantitative tests—yield a "viral load" result, meaning the amount of virus in a sample of blood. Roche's quantitative Amplicor HIV Monitor Test is frequently used by doctors and research centers but is not specifically approved for this purpose. It is only approved to monitor to people who are known to be infected with HIV, particularly to find out if their treatment is working properly.

These tests are highly sensitive, meaning that they can detect even the tiniest amounts of HIV in a blood sample. However, they are not always specific, meaning that they can sometimes yield a false-positive result. In turn, follow-up testing using standard ELISA/Western blot assays, is typically recommended.

These tests must be ordered by a healthcare provider, meaning that you should call your doctor if you think you may have recently been exposed to the virus and would like one of these tests. It's also important to keep in mind that these tests can be expensive and are not usually covered by insurance for diagnostic purposes.

Sunday, January 3, 2010

Sexual Transmission of HIV

Sexual Transmission of HIV

In the United States, sexual contact is the most common route of HIV transmission. As of December 2007, 47 percent of AIDS cases reported to the CDC were among men who contracted HIV through sex with other men (MSM). The term MSM is important—and used quite a bit in this lesson—because many men who have sex with men do not necessarily identify themselves as "gay" or even "bisexual." HIV transmitted through sexual activity among heterosexuals accounted for 31 percent of all AIDS cases reported to the CDC, with most of these cases among women infected by men.

Heterosexual intercourse is the most common mode of HIV transmission in many resource-poor countries. In Africa slightly more than 80 percent of infections are acquired heterosexually, while mother-to-child transmission and transfusions of contaminated blood account for the remaining infections. In Latin America, most infections are acquired by MSM and through misuse of injected drugs, but heterosexual transmission is rising. Heterosexual contact and injection of drugs are the main modes of HIV transmission in South and South East Asia.

The reason why sexual activity is a risk for HIV transmission is because it allows for the exchange of body fluids. Researchers have consistently found that HIV can be transmitted via blood, semen, and vaginal secretions. It is also true that HIV has been detected in saliva, tears, and urine. However, HIV in these fluids is only found in extremely low concentrations. What's more, there hasn't been a single case of HIV transmission through these fluids reported to the CDC.