Sexually transmitted diseases (STDs) are distressingly common in the United States, especially among younger people. In fact, according to the Centers for Disease Control and Prevention, the leading federal health agency, people between the ages of 15 to 24 account for about half of all new STD transmissions each year despite comprising only 25% of the total population.

STDs are common in the U.S., and they’re becoming even more prevalent, with rates of STDs like syphilis, chlamydia, gonorrhea and others rising for the past several years. One of the most important methods for combating the rise of STDs is through testing.

Federal guidelines call for all those between the ages of 13 and 64 to be tested at least once in their lives for HIV, and men and women who are sexually active, particularly those who are 25 or younger, should be tested for HIV and other STDs once a year. Sexually active gay and bisexual men may benefit from testing every three to six months, as they are at a statistically elevated risk of contracting many STDs.

While it’s possible to get tested for just a single STD, some populations will benefit from a broader test, called a 10-panel STD test, which checks for several diseases and infections at once. Here’s a look at the common STDs that are included in a typical 10-panel testing kit:

HIV-1

While public awareness of human immunodeficiency virus, or HIV, is generally pretty high, most people are likely unaware that there are actually several different types of HIV. The virus is grouped into two main types, HIV-1 and HIV-2, and HIV-1 is by far the most common type of HIV,  accounting for the vast majority of infections in the U.S. and around the world. HIV-1 is responsible for around 95% of all global HIV infections.

Both types of HIV are made up of multiple groups and subtypes, and most 10-panel HIV tests check for the HIV p24 antigen and antibodies to HIV-1 groups M and O. Group M accounts for as many as 90% of all HIV-1 cases, essentially driving the HIV/AIDS epidemic around the world.

High levels of p24 antigen are usually associated with new infections of HIV rather than long-established ones, as newly infected individuals spike their levels of this viral protein, and a process called seroconversion makes p24 antigen undetectable in most people. So a combined antigen/antibody test is useful in detecting both new and established infections.

HIV-2

HIV-2, while related to the main type of the virus, is still estimated to be about 55% genetically distinct from HIV-1. These differences mean that most infections of HIV-2 cannot be detected with a test that checks only for HIV-1.

It’s true that an HIV-1 test may be sufficient for most people, but there are several reasons why a 10-panel test that includes HIV-2 is preferrable:

  • A person who is displaying HIV infection symptoms could test negative on a test designed to check only for HIV-1 and still have HIV.
  • HIV-2 is more common in some parts of the world, and people from those countries may spread the infection to their sexual partners.
  • Testing for HIV-2 is crucial for people who may have lived in parts of the world where that type of the virus is common.

Antibody testing is generally preferred for HIV-2 infections because most patients have a low viral load with HIV-2, and the presence of antibodies is often easier to detect than the virus itself.

Herpes Simplex Virus Type 2

Herpes is another common STD, and it’s one that’s also split into several varieties. In fact, there are eight known herpes viruses that are known to infect people. The two main types of herpes, herpes simplex virus 1 and herpes simplex virus 2, are both incredibly common.

HSV-1, commonly called oral herpes, impacts about half of all Americans, and HSV-2, usually referred to as genital herpes, is estimated to affect about 1 in 6 people in the U.S., and it’s much more likely to transmit HSV-2 through sexual contact.

Some people who have been infected with HSV-2 will display open sores or lesions, and a physician can take a culture from the sore. But most people with HSV-2 don’t show obvious signs, so antibody testing can reveal the presence of the virus in the body even in a person who is asymptomatic.

Hepatitis C Virus

Hepatitis C is a potentially serious infection of the liver caused by the hepatitis C virus (HCV), and it’s most often transmitted through sharing drug-injection equipment, but it can also be passed through unprotected sexual contact.

Most 10-panel STD testing kits include a hep C test not only because the virus can be transmitted sexually but because having hep C increases a person’s risk of contracting HIV. Also, people who are infected with both HIV and hep C are likely to have high viral loads, which increases their risk of transmitting HIV through unprotected sex.

It’s also quite common not to be aware of a hep C infection, and many people who have it don’t become aware until major damage has been done to their livers.

Ten-panel STD testing kits search for HCV-fighting antibodies in the blood.

Syphilis

Syphilis is perhaps the most dangerous STD that’s also very common, with population-adjusted syphilis rates rising in the U.S. by more than 140% over the past decade. Untreated syphilis can lead to serious, potentially fatal complications. In fact, if left untreated, syphilis can essentially rot the brain and cause damage across a host of other organs and systems, including the nerves, eyes, heart, liver and bones.

Most 10-panel STD testing kits search for antibodies to Treponema pallidum, which is the bacteria that causes syphilis. Syphilis infections proceed in several stages — primary, secondary, latent and tertiary, and antibodies can be detected at all phases.

However, it’s important to note that once someone undergoes successful treatment for syphilis, the presence of these antibodies may remain for life, so this type of test can’t separate from an active or cured case of syphilis.

Chlamydia

The most common reportable STD in the U.S. is chlamydia, which is caused by the bacteria Chlamydia trachomatis. Chlamydia infection rates in the U.S. have risen by about 33% over the past decade, and the overall infection rate for chlamydia is highest among the reportable common STDs for which the CDC gathers data — chlamydia (539.9 per 100,000 people), gonorrhea (179.1 per 100,000 people) and syphilis (35.3 per 100,000 people).

Chlamydia often does not produce any symptoms, but for those who do experience signs, the most common signals of a chlamydia infection include painful sex, burning when urinating, abnormal vaginal discharge and burning or itching near the opening of the penis.

Typically, STD testing kits require the use of a urine specimen to check for chlamydia, and the test is done at the molecular level, checking for signs of the DNA of Chlamydia trachomatis as opposed to searching only for antibodies. This process is the same as testing for gonorrhea and another common STD, trichomoniasis, or trich, since the infections all often produce similar symptoms.

Gonorrhea

Caused by the Neisseria gonorrhoeae bacteria, gonorrhea is among the most common STDs in the U.S., and infection rates here have jumped by 82% over the past 10 years. Rates of the disease peaked in the 1970s, but the national infection rate has risen for the past five straight years.

While some people who become infected with gonorrhea will show no signs, common signals of infection include painful urination, increased vaginal discharge, pain or swelling in the testicles and uncomfortable sex.

Ten-panel STD testing kits check for gonorrhea through a urine sample, and the lab will use the nucleic acid amplification testing method (NAAT) to detect the DNA of Neisseria gonorrhoeae instead of looking for antibodies to the bacteria. As with chlamydia, healthcare providers generally recommend testing for gonorrhea along with chlamydia and trich, as the three produce quite similar outward signs.

Trichomoniasis

Trichomoniasis is more commonly known by its nickname, trich (pronounced “trick”). It’s caused by an infection of the protozoan parasite Trichomonas vaginalis. Trich is the single most common curable STD, affecting an estimated 3.7 million Americans.

Fewer than 1 in 3 people infected with trich ever develop obvious symptoms, but signs include itching or irritation in the penis, unusual genital discharge and painful or uncomfortable urination. Women are more likely than men to have trich, and pregnant women who are infected are more likely to have preterm births.

Detection of trich in 10-panel STD testing is done using NAAT examination of a subject’s urine sample, checking for the DNA of Trichomonas vaginalis.

Bacterial Vaginosis

Bacterial vaginosis, or BV, is the most common vaginal infection that women between 15 and 44 experience. The precise cause of BV is largely unknown, but the infection occurs when too much of a certain bacteria is present in the vagina, changing the vagina’s normal bacterial balance.

Sexually active women are more likely to develop BV, and it rarely affects women who have never had sex. For women who do display symptoms, the  most common are discharge, pain and a strong fishy odor.

STD testing panels usually diagnose BV through DNA detection of the bacteria Mycoplasma hominis, Mycoplasma genitalium, Ureaplasma urealyticum and Ureaplasma parvum using a subject’s urine sample.

Human Papillomavirus (HPV)

Human papillomavirus, or HPV, is far and away the most common sexually transmitted infection. It’s so common, in fact, that almost every adult will get at least one strain of the virus at some point in their lifetimes, and currently an estimated 80 million Americans have HPV.

Most cases of HPV go away on their own, and usually the only outward sign of HPV is the appearance of genital warts. However, some strains of HPV are incredibly dangerous, with several types of HPV causing cancer. In fact, about 90% of cervical and anal cancers, 70% of throat and vaginal cancers and 60% of penile cancers are likely caused by HPV.

Ten-panel STD tests use the NAAT method to examine vaginal swabs and male urine samples to check for the DNA of 14 high-risk HPV types, 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 66 and 68.

Conclusion

Making progress in the fight against sexually transmitted infections starts with each individual. Knowing your STD status empowers you to make better decisions about your sexual health and practices. Fortunately, commonly available 10-panel STD tests can help arm you with the necessary information.

Additional References

  • Centers for Disease Control and Prevention, Sexually Transmitted Disease Surveillance 2018, Table 1. Sexually Transmitted Diseases — Reported Cases and Rates of Reported Cases*, United States, 1941–2018. (2019.)
  • Avert.org, HIV strains and types. (2019.) Retrieved from https://www.avert.org/professionals/hiv-science/types-strains