Tests for latent infections: which ones are included and how to prepare

In modern medicine, the term "latent infections" is not an official diagnosis. It typically refers to asymptomatic sexually transmitted infections—that is, situations where a person does not complain of symptoms, but the pathogen is already present and can be transmitted further or cause complications. In 2025, the World Health Organization specifically emphasized that many such infections remain undetected, especially in women and in non-urethral locations, such as the pharynx and rectum. [1]

This is an important clarification, because the common expression "test for latent infections" often suggests a universal panel. In practice, such a panel does not exist. The modern approach is built around three questions: are there symptoms, was there a risky exposure, and is the person in a group for which regular screening is recommended. These are the factors that determine what to actually look for. [2]

The main infections for which evidence-based recommendations for asymptomatic screening exist are chlamydia, gonorrhea, syphilis, human immunodeficiency virus, hepatitis B, and hepatitis C. For some groups, trichomoniasis and human papillomavirus screening are also important as part of cervical cancer prevention. This list alone demonstrates that "hidden infections" are not a single disease, but a collection of different conditions with different tests and different screening guidelines. [3]

It's crucial to distinguish truly recommended screening from unnecessary testing. For example, an asymptomatic individual with no elevated risk will not benefit from endless "everything" panels, especially if they include tests with low specificity or microorganisms that often simply colonize the mucous membranes and do not require treatment. This is especially true for commercial packages, where both necessary and unnecessary tests are often bundled under a catchy name. [4]

Therefore, a modern article on this topic should answer not the question "what can be tested in general," but rather "what really makes sense to test specifically for asymptomatic screening." This approach reduces the number of false positives, unnecessary courses of antibiotics, anxiety, and unnecessary expenses. [5]

What is commonly referred to as modern asymptomatic screening?	What is often mistakenly included in "broad panels" without sufficient justification
Chlamydia trachomatis	Routine serology for asymptomatic genital herpes
Neisseria gonorrhoeae	Mycoplasma genitalium in asymptomatic individuals
Syphilis	Ureaplasma urealyticum, Ureaplasma parvum
Human immunodeficiency virus	Mycoplasma hominis
Viral hepatitis B	Gardnerella vaginalis as a stand-alone "screening test for latent infection"
Viral hepatitis C	Bacterial vaginosis in asymptomatic patients as part of a general panel
Human papillomavirus in people with cervical cancer screening guidelines	Any "panels for everything" without reference to risk and anatomical contact zone

The table is compiled based on recommendations from the World Health Organization, the US Centers for Disease Control and Prevention, the US Preventive Services Task Force, and the European Council on Guidelines on Sexually Transmitted Infections. [6]

Which infections are actually screened and for whom?

For chlamydia and gonorrhea, proven screening primarily applies to sexually active women 24 years and younger, as well as women 25 years and older at increased risk. The U.S. Preventive Services Task Force notes that the benefits of screening are proven for these groups. For low-risk men, evidence of the benefits of routine screening is insufficient, so a more selective approach is used. [7]

For men who have sex with men, the recommendations are more stringent. The US Centers for Disease Control and Prevention recommends annual screening for chlamydia and gonorrhea at points of contact, that is, the urethra, rectum, and pharynx, regardless of condom use. For those with increased risk, testing is recommended more frequently—every 3-6 months. This is one of the most important modern advances: screening is based not only on gender but also on the anatomical site of contact. [8]

Syphilis is not screened for "everyone." The U.S. Preventive Services Task Force recommends testing asymptomatic adolescents and adults outside of pregnancy only in those at increased risk. These situations include, but are not limited to, men who have sex with men, people with human immunodeficiency virus (HIV), people with other sexually transmitted infections, people with a history of sex work, substance use, or incarceration. [9]

Testing for human immunodeficiency virus and viral hepatitis is structured differently. The U.S. Centers for Disease Control and Prevention recommends testing for human immunodeficiency virus at least once a year for all people aged 13-64 years, and at least once a year if at risk remains. For viral hepatitis B, at least one screening is recommended for all adults aged 18 years and older using a triple panel. For viral hepatitis C, the U.S. Preventive Services Task Force recommends one-time screening for all adults aged 18-79 years, including pregnant women. [10]

Human papillomavirus (HPV) is also an asymptomatic infection, but it is not tested as part of a "genital panel" but rather as part of cervical cancer prevention in people with a cervical cancer. The US Centers for Disease Control and Prevention and the US Preventive Services Task Force recommend cytology screening every 3 years from age 21 to 29, and from age 30 to 65, either cytology every 3 years, an HPV test every 5 years, or a combination every 5 years. Annual screening is not recommended for those at average risk. [11]

Infection	Who is screening most often recommended for?	Comment
Chlamydia trachomatis	Sexually active women 24 years and younger, women 25 years and older at increased risk	For men at low risk, there is insufficient evidence to support the benefit of routine screening.
Neisseria gonorrhoeae	The same groups as for chlamydia	Often screened at the same time as chlamydia
Syphilis	People not at increased risk during pregnancy	Screening is based on risk, not on the desire to “check everything.”
Human immunodeficiency virus	All people aged 13-64 years at least once, then more often with ongoing risk	If the risk is elevated, repeat testing is required.
Viral hepatitis B	All adults 18 years and older at least once	Use a triple panel
Viral hepatitis C	All adults 18-79 years old	Then repeat according to risk factors

The table is compiled based on recommendations from the US Centers for Disease Control and Prevention and the US Preventive Services Task Force. [12]

What tests are used and from what material are they taken?

For chlamydia and gonorrhea, nucleic acid amplification tests, including polymerase chain reaction, are currently considered the primary methods. The US Centers for Disease Control and Prevention (CDC) recommends that the optimal urogenital specimen for chlamydia is the first portion of urine in men and a vaginal swab in women. The logic is the same for gonococcus, and the exact sampling site depends on the anatomical site of contact. [13]

For women, a self-collected vaginal swab is considered an acceptable option and is comparable in sensitivity and specificity to specimens collected by a clinician. This is an important practical detail, as this format increases accessibility to testing. Nucleic acid amplification tests are also used for the rectum and pharynx if these areas were involved in sexual contact. [14]

For syphilis, serological blood tests are used, not a swab or urine sample. Current laboratory guidelines from the US Centers for Disease Control and Prevention (CDC) indicate that if a treponemal screening test is positive, the laboratory should automatically perform a quantitative non-treponemal titer test. If it is negative, a second treponemal test of a different type should be performed to confirm the result. In other words, syphilis is detected not by a single test, but by an algorithm. [15]

Blood is also used for human immunodeficiency virus (HIV), hepatitis B virus (HBV), and hepatitis C virus (HCV), but the tests differ. For HBV, antigen and antibody tests are used, and for some recent exposures, a nucleic acid test may be necessary. For HBV, the Centers for Disease Control and Prevention (CDC) recommends a triple panel, while for HCV, it recommends antibodies with nucleic acid confirmation. [16]

For trichomoniasis, the most sensitive methods are also based on nucleic acid amplification, but asymptomatic screening is not necessary for everyone. The US Centers for Disease Control and Prevention recommends it primarily for sexually active women with human immunodeficiency virus (HIV) at their initial visit and then annually thereafter. Routine serological testing is not recommended for asymptomatic herpes because false-positive results are too common, and the clinical benefit of such a widespread approach is low. [17]

Infection	Main material	The most typical method
Chlamydia trachomatis	Vaginal smear in women, first urine sample in men, and, if indicated, smears from the rectum and pharynx	Nucleic acid amplification test
Neisseria gonorrhoeae	The same materials as for chlamydia	Nucleic acid amplification test
Syphilis	Venous blood	Treponemal and non-treponemal serological tests according to the algorithm
Human immunodeficiency virus	Venous blood, sometimes a rapid test from capillary blood	Antigen and antibody tests, sometimes nucleic acid tests
Viral hepatitis B	Venous blood	Triple panel
Viral hepatitis C	Venous blood	Nucleic acid-confirmed antibodies
Trichomonas vaginalis	Vaginal material, sometimes urine and other materials as needed	Nucleic acid amplification test

The table is compiled from materials from the US Centers for Disease Control and Prevention, MedlinePlus, and the US Preventive Services Task Force. [18]

What was the contact zone?	What is important not to miss
Vaginal sex only	Urogenital material
Receptive anal contact	Rectal smear
Oral contact	Throat swab
Several types of contact	A fence with several zones is needed.
No symptoms, but there was a risk	The contact point is still important for material selection.

The table is based on recommendations from the World Health Organization and the US Centers for Disease Control and Prevention for asymptomatic infections and anatomical sites of exposure.[19]

What Shouldn't Typically Be Included in a Routine "Occult Infection Panel"

The first common example of unnecessary testing is genital herpes serology in asymptomatic individuals. Both the US Centers for Disease Control and Prevention and the US Preventive Services Task Force do not recommend routine serologic screening for herpes in asymptomatic individuals, including pregnant women. The main reason is the high probability of false positives and the lack of proven benefit of population screening. [20]

The second example is Mycoplasma genitalium in asymptomatic individuals. The US Centers for Disease Control and Prevention explicitly states that screening for asymptomatic infection in women and men, as well as extragenital testing for Mycoplasma genitalium, is not recommended. This pathogen is indeed important, but in a different setting—in recurrent nongonococcal urethritis in men, recurrent cervicitis in women, and some cases of pelvic inflammatory disease. [21]

A third example is Ureaplasma urealyticum, Ureaplasma parvum, and Mycoplasma hominis. The European Council on Guidelines on Sexually Transmitted Infections, in its 2018 position paper, stated that routine testing and treatment of both asymptomatic and many symptomatic individuals for these microorganisms is not recommended because asymptomatic carriage is common and the evidence base for the benefit of such screening is weak. This is a very important counterargument to commercial panels, where such tests are often at the forefront. [22]

A fourth example is bacterial vaginosis and Gardnerella vaginalis as a separate "test for hidden infections" in asymptomatic individuals. The US Centers for Disease Control and Prevention emphasizes that Gardnerella vaginalis culture is not recommended as a diagnostic tool because it is nonspecific, and routine screening for asymptomatic bacterial vaginosis is not recommended. This is an important reminder that not all vaginal microbiota should be considered an infection for mass screening. [23]

Finally, screening for sexually transmitted infections should not be confused with "all viruses in the blood" tests. For asymptomatic sexual screening, priority is currently given to those infections for which there is evidence of a benefit to detection and clear treatment, prevention, or monitoring pathways. Broad viral panels without a clinical question typically only increase the number of incidental findings and do not improve the quality of testing. [24]

Analysis	Why is it not usually included in routine asymptomatic screening?
Herpes in the blood without symptoms	Too many false positives, population benefit not proven
Mycoplasma genitalium without symptoms	Routine screening is not recommended.
Ureaplasma urealyticum, Ureaplasma parvum	Frequent asymptomatic carriage, no proven benefit of routine testing
Mycoplasma hominis	Similarly, routine testing is not recommended.
Gardnerella vaginalis culture	Non-specific
Bacterial vaginosis without symptoms	Routine screening is not recommended.

The table is compiled based on recommendations from the US Centers for Disease Control and Prevention, the US Preventive Services Task Force, and the European Council on Guidelines on Sexually Transmitted Infections. [25]

How to prepare for the examination and when to repeat tests

Preparation depends not on the trendy panel name, but on the specific test and material. Blood tests for human immunodeficiency virus, syphilis, and viral hepatitis typically do not require complex preparation. For urine tests for chlamydia and gonorrhea, it is important to provide the first portion of urine, not the "midstream" portion. For urogenital or rectal swabs, it is more important to follow the laboratory instructions and not change the rules on your own. [26]

For asymptomatic screening, the correct choice of sample is especially important. In women, a vaginal swab is usually more sensitive than urine for detecting chlamydia and gonorrhea, while in men, the first urine sample remains a convenient option. If there was anal or oral contact, a negative urogenital test does not rule out infection in the rectum or pharynx. This is why good screening begins with a discussion about the type of contact, rather than mechanically handing out the same panel to everyone. [27]

After a positive test, follow-up is also based on the specific infection. The US Centers for Disease Control and Prevention recommends repeat testing three months after a diagnosis of chlamydia, gonorrhea, or trichomoniasis to detect reinfection. Syphilis requires not just a "retest sometime," but serological surveillance according to specific protocols. Therefore, repeat testing is part of treatment and prevention, not an optional extra. [28]

Pregnancy requires a separate approach. For chlamydia during pregnancy, a cure confirmation test is required approximately 4 weeks after treatment, followed by a repeat test 3 months later and, if necessary, again in the third trimester or during labor. For gonorrhea, a repeat screening is also required 3 months after treatment. This is due not only to the risk for the pregnant woman but also for the newborn. [29]

If there was a very recent risky exposure, a negative result does not always immediately rule out infection, because different tests have a diagnostic window. For the human immunodeficiency virus, the US Centers for Disease Control and Prevention indicates that a nucleic acid test typically detects infection approximately 10-33 days after exposure, a laboratory test for antigen and antibodies after 18-45 days, and a pure antibody test after 23-90 days. This is a good example of why "getting everything tested the day after exposure" is not a definitive solution. [30]

Situation	What is important to remember
Urogenital screening in men	Usually the first portion of urine is needed
Urogenital screening in women	A vaginal smear is often preferred.
There was anal contact	A separate rectal swab is required.
There was oral contact	A separate throat swab is required.
Treatment for chlamydia, gonorrhea or trichomoniasis has been completed	Re-testing is recommended after 3 months.
Very recent exposure to human immunodeficiency virus risk	The diagnostic window must be taken into account

The table is based on materials from the US Centers for Disease Control and Prevention. [31]

Special situations: pregnancy, human immunodeficiency virus, men who have sex with men, and human papillomavirus screening

Pregnancy is a separate category, where the scope of screening is broader and more stringent. The US Centers for Disease Control and Prevention recommends that all pregnant women be tested for syphilis at their first prenatal visit, and, if at increased risk, again at 28 weeks and at delivery. Pregnant women under 25 are tested for chlamydia and gonorrhea, as are pregnant women 25 and older if at increased risk. Viral hepatitis B is also screened during every pregnancy, and viral hepatitis C, according to current recommendations, is screened for all adults aged 18-79, including pregnant women. [32]

Testing for human immunodeficiency virus (HIV) during pregnancy is also a mandatory part of modern prevention. The US Preventive Services Task Force recommends screening all pregnant women, including those who first present during labor and whose status is unknown. This is one of the most effective tools for preventing vertical transmission of infection. [33]

For men who have sex with men, the approach to asymptomatic infections differs significantly from that of the general population. The US Centers for Disease Control and Prevention recommends at least annual screening for chlamydia and gonorrhea at the anatomical contact sites, annual screening for syphilis and human immunodeficiency virus, and, in those at increased risk, repeat screening every 3-6 months for sexually active men who have sex with men. This is one group where "hidden infections" remain a common practical problem. [34]

People living with the human immunodeficiency virus (HIV) are also screened more actively for sexually transmitted infections (STIs). The U.S. Centers for Disease Control and Prevention (CDC) recommends screening sexually active people for syphilis, gonorrhea, and chlamydia at points of contact at the initial HIV visit and at least annually thereafter. For women with the HIV virus, trichomoniasis testing is also recommended at the initial visit and annually thereafter. [35]

Human papillomavirus (HPV) is a separate issue. It is not tested for as part of a "general panel after casual exposure." Screening for HPV is primarily a screening measure for cervical cancer in people with a cervix, based on age ranges. Furthermore, data are currently insufficient for routine mass screening for anal cancer using cytology in all risk groups outside of specialized programs, although digital anorectal examination may be used in certain groups. [36]

Special situation	What is typically included in modern screening?
Pregnancy	Syphilis, human immunodeficiency virus, viral hepatitis B, viral hepatitis C; chlamydia and gonorrhea by age and risk
Men who have sex with men	Chlamydia, gonorrhea, syphilis, human immunodeficiency virus, including the rectum and pharynx
People with human immunodeficiency virus	Chlamydia, gonorrhea, syphilis at least once a year; in women, also trichomoniasis
People with an average-risk cervix	Cervical cancer screening using cytology and/or human papillomavirus testing
Rapidly increasing symptoms or no symptoms at all	This is no longer a screening, but a diagnostic examination.

The table is compiled based on recommendations from the US Centers for Disease Control and Prevention, the US Preventive Services Task Force, and the CDC on cervical screening. [37]

Conclusion

Modern "hidden infection testing" is not a single, universal panel or a list of 20 pathogens to be tested for on everyone. It's more accurate to talk about screening for asymptomatic sexually transmitted infections, tailored based on risk, pregnancy, anatomical contact area, and the purpose of the test. This approach is supported by both the World Health Organization and US national guidelines. [38]

If the goal is evidence-based asymptomatic screening, then the focus is usually on chlamydia, gonorrhea, syphilis, human immunodeficiency virus, hepatitis B, and hepatitis C, with trichomoniasis and human papillomavirus screening as part of cervical cancer prevention in the appropriate groups. Everything else should be prescribed only when clinically necessary, not out of inertia or the marketing term "broad panel." [39]

The most common mistake is to look for "everything at once" and ignore the location of exposure, the presence of symptoms, age, pregnancy, and risk factors. As a result, a person is either under-screened because the necessary rectal or throat swabs are not submitted, or they are over-screened with unnecessary blood tests for herpes, ureaplasma, and other potentially significant microorganisms. High-quality screening is always narrower, but more accurate. [40]

FAQ

What constitutes the modern minimum risk for asymptomatic sexual contact?
There is no universal minimum for everyone. Chlamydia, gonorrhea, syphilis, human immunodeficiency virus, hepatitis B, and hepatitis C are most commonly discussed, but the actual list depends on the type of contact, time since contact, pregnancy, and risk factors. [41]

Is a "broad panel for all latent infections" necessary for asymptomatic individuals?
Generally, no. Current guidelines support targeted screening rather than indiscriminate testing for dozens of microorganisms. [42]

Which is better for chlamydia and gonorrhea: urine or a swab?
For men, the first portion of urine is usually sufficient. For women, a vaginal swab is often preferred for urogenital screening. For anal or oral contact, swabs from the appropriate areas are also needed. [43]

Should I get a blood test for herpes if I have no symptoms?
Routinely, no. Both the US Centers for Disease Control and Prevention and the US Preventive Services Task Force do not recommend such population screening due to the test's limitations and high false-positive rate. [44]

Should people without complaints be tested for ureaplasma and Mycoplasma hominis?
Routinely, no. European guidelines do not support mass testing and treatment of asymptomatic people for these microorganisms. [45]

Should I get tested for Mycoplasma genitalium if I'm asymptomatic?
No, that's not true. This test is needed in more specific situations, such as recurrent non-gonococcal urethritis or recurrent cervicitis, but not for widespread asymptomatic screening. [46]

How soon after treatment should I retest?
The U.S. Centers for Disease Control and Prevention recommends retesting 3 months after a diagnosis of chlamydia, gonorrhea, or trichomoniasis to detect reinfection. During pregnancy, chlamydia requires an additional test to confirm cure after approximately 4 weeks. [47]

Is it possible to get tested immediately the day after exposure?
It is possible, but a negative result will not always be definitive. This is especially true for the human immunodeficiency virus, where different tests begin to detect the infection at different intervals. Sometimes an initial test and a follow-up test are needed later. [48]

What tests are required during pregnancy?
Current recommendations include syphilis, human immunodeficiency virus, and hepatitis B virus screening during every pregnancy, as well as hepatitis C virus screening for universal age-specific screening of adults, including pregnant women. Chlamydia and gonorrhea are screened for pregnant women under 25 years of age and for pregnant women over 25 years of age at increased risk. [49]

Is human papillomavirus included in the "test for hidden infections"?
Not in the sense that laboratories typically advertise it. It is primarily sought as part of cervical cancer screening in people with cervical cancer by age range, not as a universal infection in a general genital panel. [50]

Should a partner be tested if the test is positive?
Yes, for many infections, this is a mandatory part of preventing reinfection and breaking the chain of transmission. This is especially true for chlamydia and gonorrhea, where reinfections are common. [51]