1. Are HIV and AIDS the Same Thing?
No. HIV is a virus, while AIDS is a stage of advanced infection. Specifically, HIV, or the human immunodeficiency virus, is an infectious virus that gradually breaks down a person’s immune system, leaving the body less able to defend itself against viruses, bacteria, fungi, and parasites. These infections, which are called “opportunistic,” tend to be mild in the early stages and can become progressively worse as the immune system is depleted. AIDS, or acquired immunodeficiency syndrome, is the stage of the disease when the immune system is weakened by the loss of CD4 cells (also called T-helper or T-4 cells) — white blood cells that help fend off harmful pathogens in the body. Without these defenses, a person will be at high risk for serious illnesses that a healthy person would be able to fight off. AIDS is diagnosed when a person has a CD4 count of less than 200 (meaning less than 200 cells per cubic millimeter of blood) or has at least one of 27 AIDS-defining conditions outlined by the Centers for Disease Control and Prevention (CDC), such as recurrent pneumonia and some lymphomas.
2. Can HIV Live Outside the Body?
Not for very long. Compared with other types of viruses, such as influenza or chicken pox, HIV is relatively fragile: It does not thrive at room temperature (68 degrees F), when exposed to ultraviolet (UV) radiation from the sun, or at pH levels that are dissimilar to that of blood. Even if a small amount of virus does manage to survive for a short period of time, the odds that it will infect you are next to zero. For example, there have been no confirmed cases of HIV caused by a blood-tainted needle in a public place to date. Even in a healthcare setting, the risk of infection from a needlestick injury is only around 0.3 percent. “Just because a person comes into contact with tiny quantities of HIV in blood or semen doesn’t mean that an infection will occur,” says Dennis Sifris, a physician and HIV specialist with the Lifesense Disease Management Group in Johannesburg, South Africa.
3. Which Activities Are Most Likely to Transmit HIV?
The three main routes of HIV infection in the United States are anal sex, vaginal sex, and shared needles. Of these, unprotected anal sex poses the highest risk. Here is the estimated probability of acquiring HIV from an infected source, per exposure act, according to the CDC:
Receptive anal sex: 1 in 72Shared injection drug use: 1 in 159Insertive anal sex: 1 in 909Receptive penile-vaginal sex: 1 in 1,250Insertive penile-vaginal sex: 1 in 2,500
The more you engage in these activities, the more likely you are to contract the virus. “The simple truth is that people can and do get infected after a single exposure,” says Dr. Sifris. “Identifying your personal risk, therefore, allows you to take the steps needed to protect yourself and others.”
4. Can You Get HIV From Oral Sex?
While there is a possible risk of getting HIV from oral sex, the documented risk remains extremely low. The CDC says that the risk is hard to quantify, because a lot of people who have oral sex have anal or vaginal sex, too. Still, there are certain factors that may increase the potential for infection. These include coexisting sexually transmitted diseases (STDs) and bleeding gums. Even then, it’s unlikely that a person will be infected by having oral sex. Using a condom or dental dam can further reduce the already low risk, as can taking medicine to prevent or treat HIV.
5. How Common Are False Negatives and False Positives?
Thanks to the use of next-generation technologies, the accuracy of HIV testing in healthcare settings has never been greater. Still, false positives and false negatives have been known to occur, albeit infrequently. Today, the false negative rate in the United States is only around 0.003 percent (or roughly three out of every 100,000 tests). False positive rates are even lower — between 0.0004 percent and 0.0007 percent — due in large part to the practice of confirming a positive result with a secondary test. If a false negative does occur, it is often the result of premature testing during the so-called window period. This is the period of time following infection when the body has not yet produced enough protective proteins (called antibodies) to register an accurate result. If this happens, a person may believe that they haven’t been infected. While newer, combination HIV tests have significantly reduced this window period, a person will still need to wait at least three to four weeks after being exposed to the virus to get a reliable result.
6. How Accurate Are In-Home HIV Tests?
Currently there is only one in-home HIV test available in the United States, OraQuick, promoted as a means to ensure privacy for those who might otherwise avoid getting tested. It is easy to use, requiring only a simple saliva swab, and can return a result in as little as 20 minutes. Because antibody levels in saliva are lower than they are in blood, this test can fall short in its ability to detect early-stage (acute) infection. According to the CDC, OraQuick tests have a 7 percent false negative rate, meaning that roughly one out of every 12 tests will deliver an incorrect all-clear sign.
7. Can a Pap Smear Detect HIV?
A Pap smear is valuable for many things, but HIV detection isn’t one of them. The aim of a Pap smear is to identify cell changes that may indicate cervical cancer, not to check for the presence of HIV, which can be identified only with a blood- or saliva-based HIV test. That said, Pap smears are especially important for women who have HIV; these women are at least five times more likely to develop invasive cervical cancer than women who don’t have HIV. The test can also be used to screen for anal cancer and the human papillomavirus (HPV).
8. How Long Does It Take for HIV Symptoms to Appear?
An estimated 40 to 90 percent of newly infected people experience symptoms during the early (acute) stage of HIV infection. These generally develop within two to four weeks of exposure and resemble symptoms of the flu, such as fever, fatigue, sore throat, headache, and muscle and joint pain. One of the more telling signs of acute infection is lymphadenopathy, the sometimes painful swelling of the lymph nodes, specifically on the neck, behind the ears, under the armpits, and in the upper groin. A maculopapular rash (characterized by small, pink-to-red bumps, mostly on the upper body) can also appear. While flu-like symptoms can last anywhere from a few days to several weeks, lymphadenopathy can persist for months and even years and may improve only after the start of HIV treatment.
9. Do HIV Symptoms Differ in Women and Men?
The HIV symptoms in men and women don’t differ very much. Women, however, can experience symptoms in the genital tract, including bacterial vaginosis and candidiasis, a common fungal infection that can manifest as a vaginal yeast infection. (Oral thrush, a fungal infection, can appear in both women and men.) Women with HIV also have an increased risk for recurrent and hard-to-treat pelvic inflammatory disease (PID), and can experience irregular periods, cramping, and unusual discharge. In the later stages of HIV, women who also have HPV are more likely to have an increased risk of cervical cancer; gay and bisexual men with HPV are more likely to develop anal cancer. But beyond these differences, the disease varies more by the individual than by sex. Other factors, like genetics, age, treatment history, and lifestyle habits such as smoking, diet, and exercise also play a role.
10. How Long Can I Wait Before Starting Treatment?
Ideally, you shouldn’t wait at all. In the past, doctors would delay treatment until a person’s CD4 count fell below 500 — largely because of concerns about the long-term effects of HIV treatment and the premature development of a drug-resistant virus — but that’s no longer the case. “Today, things are different,” says Linda-Gail Bekker, PhD, a physician and infectious-disease specialist in South Africa and a past president of the International AIDS Society. “Newer-generation drugs have overcome many of these concerns. Moreover, if [treated] properly, a person with HIV can now expect to enjoy near-normal life expectancy.” The focus, therefore, is no longer just on life extension; it’s on preserving quality of life. In 2015, landmark research funded by the National Institutes of Health and published in the New England Journal of Medicine confirmed that early HIV treatment (started at CD4 counts above 500) reduced the risk of serious illness by 53 percent compared with delayed treatment. As a result of these findings, the Department of Health and Human Services now recommends that HIV treatment begin at the time of diagnosis, irrespective of age, race, income, or health status.
