Ask the experts: Sexually transmitted Infections : I Wanna Know

Below are some of the questions people like you have sent us about sexual transmitted infections (STIs).

Click the question to see answers from our experts.

As a gay man I hear a lot about testing for HIV and hepatitis; what about other STIs? Please tell me what tests I should be thinking about.

The Centers for Disease Control and Prevention (CDC) recommend the following tests at least once each for men who have sex with men (MSM):

HIV
Syphilis
Gonorrhea and chlamydia of the urethra (tube in the penis)
Gonorrhea and chlamydia of the rectum for those who had insertive anal sex in the last year
Gonorrhea of the throat for anyone who performed oral sex in the last year

MSM are also recommended to be tested for hepatitis B, and to get vaccines against hepatitis A and hepatitis B. Additionally, HPV vaccines are recommended for both males and females up to age 26.

Depending on your own risk factors, more frequent testing may be recommended. Talk to your healthcare provider about sexual health, and ask them what tests they think you should have. For help finding a clinic in tune with your needs, visit the Gay and Lesbian Medical Association online.

--The STI Resource Center Staff

I am a 23-year old woman, one steady partner now but a couple of lovers in the last year or so. I had a urine test for chlamydia that was (thankfully) okay and said I don’t have it. I’ve had anal sex, too, and didn’t mention that to the people at the clinic. Would the test I had also pick up on chlamydia in the anus or rectum?

Chlamydia is perhaps the most commonly reported infectious disease in the U.S., with over a million cases reported to the CDC annually. In reality, many cases of chlamydia are undiagnosed and unreported, so the true number of new cases each year (known as “incidence”) is probably closer to 3 million.

This bacterial infection is especially common in young women and is also common in young men. Sexually active adults with multiple sex partners and those who do not use condoms regularly also have increased rates of infection. Usually there are no tell-tale signs nor symptoms of infection to let you know, so you were smart to get tested. In fact, it’s recommended that all sexually active females under age 26 be tested each year for chlamydia.

We now have very accurate swab and urine tests for chlamydia using Nucleic Acid Amplification Technology (NAAT). However, a urine test will only detect chlamydia infection of the urethra or genital tract; to check for chlamydia infection in someone who has had receptive anal intercourse, a swab sample must be taken from the rectum which can be done easily and with little or no discomfort. The same NAAT test can be used to test this swab and tell you if you have a rectal infection. A different swab can also be used to test the throat to see if there is a chlamydia infection due to oral sex if you have had that exposure as well.

It can be hard, I know, but it would be a good idea to let your healthcare providers know you’ve had anal sex and/or oral sex (believe me, you won’t be the first to tell them that!) so additional tests can be ordered. Also, an HIV test is always a good idea for anyone who’s sexually active, for example.

--Gary Richwald, MD, MPH

My doctor tested me for trich by taking a swab from my vagina, and then tested my urine for chlamydia. I don’t understand why I needed two tests. My friend was tested for a bunch of STIs and said they used a swab for her to test for trich, chlamydia, and gonorrhea.

There are several ways to test for Trichomonas (“trich”) and different providers may use different methods. Trichomonas is a motile one-cell parasite which can be viewed in a “wet preparation” of a vaginal swab on a slide under the microscope by the clinician. It is diagnosed by its motion on the slide under the magnification of the microscope.

Another way to detect it is to take a vaginal swab and send it to the laboratory for culture, which is a method to grow it; it is a little more sensitive than viewing it directly on a wet prep.

Recently, there is a new molecular test that is much more sensitive (more accurate) than “wet prep” or culture that amplifies the DNA from the swab or urine or a liquid PAP specimen. This is much like PCR or polymerase chain reaction that is powerful method for diagnosing infections. Tests for chlamydia, gonorrhea, and trichomonas can all be performed from a single swab or from urine using the new molecular method. Your doctor may have needed a separate swab for trichomonas if she/he was using a wet prep or culture method. The number of swabs (or use of urine) all depends on the type test the doctor is using.

--Charlotte A. Gaydos, DrPH, MPH, MS

How does a person get hepatitis C? I thought it had to be inherited or you had to come into contact with someone who has it, like with an open wound. I was told I tested positive for hepatitis C but we have no family history of this infection?

You are correct you have to come in contact with someone who has it. There are several types of hepatitis and unlike some other conditions (such as high blood pressure or diabetes, for example) none of them –including hepatitis C - are infections you get because a family history makes you more susceptible. Because hepatitis C virus is a virus it can be transmitted through exposure to infected blood. For example, when injecting drug users share needles or syringes. The virus can be transmitted mother-to-child if a pregnant woman is infected. Rarely, hepatitis C is transmitted through sexual contact (hepatitis B is much more likely to be acquired sexually). It’s also possible to contract hepatitis C thorough blood or organ transplants, although this is rare in the U.S. since updated precautions went into place in the early 1990s.

Most individuals with hepatitis C (about 80%) do not have signs or symptoms. Hepatitis targets the liver. Liver disease progresses so slowly that a person can have hepatitis C for years without having symptoms. Many individuals with chronic hepatitis C have mild to moderate liver damage but do not feel sick. The possible symptoms for an acute infection (newly acquired or short-term) and a chronic (long-term or persistent) infection are different.

Unlike hepatitis B, there is no vaccine for hepatitis C. Treatment may differ depending on the stage of illness at the time treatment is sought. Your healthcare provider can help you make the best decisions about your treatment based upon your individual health needs. People with acute viral hepatitis experience a self-limited illness (one that runs a defined, short course) and go on to recover completely. Relatively few people seek medical care for acute HCV, since most individuals are have no symptoms or have only mild, flu-like symptoms. Contact your healthcare provider for more information.

--Versie Johnson-Mallard, PhD, RN, APRN, WHNP-BC

I just took the treatment for chlamydia yesterday (I think azithromycin). I forgot about the doctor’s instructions and drank a bit of beer, about half a cup. Is this going to affect the treatment?

The short answer to your question is that a small quantity of alcohol (beer) taken about the same time as a dose of azithromycin should not cause a problem or make the treatment less effective.

Azithromycin (common trade name, Zithromax® or Z-Pak) may be taken either with or without food, but should not be taken within 2 hours of using antacids that contain aluminum or magnesium.

Your concern and question are good because alcoholic beverages do cause interactions with some medications, and you should know this information and follow the instructions of your doctor or pharmacist carefully.

--James Allen, MD, MPH

I was reading a fact sheet on bacterial vaginosis (BV) and it said “BV can increase a woman’s susceptibility to other sexually transmitted infections (STIs) such as herpes, chlamydia and gonorrhea.” I don’t understand this–what does that mean?

One of the hallmarks of BV is the absence of a specific type of bacteria that defines the healthy vagina: certain species of lactobacillus (sometimes also called lactobacilli). The lactobacilli found in the healthy vagina are generally found only in humans (meaning you can't get them by eating or douching with dairy products, like yogurt!) and often produce chemicals that act like antibiotics to fend off foreign invaders, including STDs like chlamydia and gonorrhea. One of these chemicals is hydrogen peroxide.

In BV, the normally robust population of vaginal lactobacilli essentially disappear, for reasons that are not completely understood, and are replaced by large numbers of bacteria that characterize BV, including Gardnerella vaginalis. While we think that some behaviors probably increase a woman's risk of BV, including douching (which probably reduces the good lactobacilli if it's done frequently) and unprotected sex (sometimes with a specific partner, and especially between female sex partners), we don't really know what causes BV.

The best way to avoid getting BV is to avoid douching, use precautions to increase sexual safety as you would to protect yourself against any STD, and to seek care if you notice abnormal vaginal discharge or an unusual genital odor. BV usually responds well to antibiotic therapy, which can be given as oral medication (pills) or vaginal gel or cream for 5-7 days; however, many women will experience a repeat episode, and some might need to go on long-term suppressive therapy (usually vaginal antibiotic gel twice a week) to keep it at bay.

--Jeanne Marrazzo, MD, MPH

Would you please tell me how long a person can have trichomoniasis and carry it? Could it have been passed on almost three months with only light symptoms?

This is such a common question that it is surprising how little we know about the answer. No one knows exactly how long someone can have vaginal trichomoniasis with few or no symptoms. We do know that women can have this infection for at least three months without symptoms of any kind, and we know that it can be transmitted to a sex partner even when it is causing no symptoms.

The diagnosis of trichomoniasis often raises questions for couples about their partner's faithfulness. Although trichomonas is always transmitted by sexual contact, the fact that trichomonas can survive for several months, maybe even longer, means that an infection could have been acquired in a previous sexual relationship that ended several months earlier.

It's also important to remember that men can have trichomonas but almost never have symptoms. And, we know next to nothing about how long some men may have trichomonas. It's also important to know that making a diagnosis of trichomonas infection in men can be very difficult. Click here to learn more about trichomonas infection.

--J. Dennis Fortenberry, MD, MS

Somebody I was with told me he has chlamydia and that his clinic said I should be tested. I don’t have any symptoms and don’t want to spend the money to test for something I may not even have. Do I really need to get tested?

It’s always a good idea to get tested if you learn that a current or previous partner has been diagnosed with a sexually transmitted infection (STI). Testing is particularly important for chlamydia because it is a common STI, especially in younger people, and most women don’t experience symptoms, so there really is no way of knowing if you have it. For this reason ASHA, the CDC, and most experts recommend that women 26 years and younger have annual chlamydia screenings – or more frequently if they are at high risk for an STI (such as having unprotected sex, multiple partners, or even a new partner).

Testing for chlamydia is easy; most often the specimen is a urine sample or swab. Chlamydia is easily treated, but if it goes undiagnosed over time it can cause fertility problems - something you might not be thinking about right now but will want to protect for the future. Your partner's clinic was right to advise that you get tested, and you can be thankful that your partner told you he had been infected. You should also notify any other partners you have been with recently.

Please don’t let the costs of medical care stand in the way of taking care of yourself and your future. Your local health department probably has an STI clinic, or you may want to contact community resource centers to learn about free clinics or subsidized health services that can offer lower rates for these tests (you can search here). Also, prevention of chlamydia and other STIs continues to be important for you and your partner.

--James Allen, MD, MPH

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Below are some of the questions people like you have sent us about sexual transmitted infections (STIs).