AAUS guidelines 2021 revision sexually transmitted infection (STIs) diagnostic strategy for STI

Abstract

World Health Organization (WHO) declared STI as “one of five types of disease for which adults around the world most commonly seek medical help.” According to WHO report, there were several key facts in Sexually Transmitted infection (STI) More than one million STI occur every day, an estimated 376 million chlamydia, gonorrhea, syphilis and trichomoniasis infections occur each year. In 2016, the total incidence of STI was 376 million per year, including 127 million chlamydia cases, 87 million gonorrhea cases, 156 million trichomoniasis cases and 6 million syphilis cases, showing an increase compared to that reported by Rowley et al. [[1]Rowley J. Vander Hoorn S. Korenromp E. Low N. Unemo M. Abu-Raddad L. et al.Global and regional estimates of the prevalence and incidence of four curable sexually transmitted infections in.2016Google Scholar,[2]Organization W.H. Report on global sexually transmitted infection surveillance.2018Google Scholar]More than 500 million people have genital infection with herpes simplex virus (HSV1 or HSV2) [[3]Looker K.J. Magaret A.S. Turner K.M. Vickerman P. Gottlieb S.L. Newman L.M. Global estimates of prevalent and incident herpes simplex virus type 2 infections in 2012.PloS One. 2015; 10e114989https://doi.org/10.1371/journal.pone.0114989Crossref PubMed Scopus (322) Google Scholar]. Approximately 300 million women have a human papilloma virus (HPV) infection and this number is likely similar in men [[4]de Sanjosé S. Diaz M. Castellsagué X. Clifford G. Bruni L. Muñoz N. et al.Worldwide prevalence and genotype distribution of cervical human papillomavirus DNA in women with normal cytology: a meta-analysis.Lancet Infect Dis. 2007; 7: 453-459https://doi.org/10.1016/s1473-3099(07)70158-5Abstract Full Text Full Text PDF PubMed Scopus (0) Google Scholar]. The majority of STIs occur without symptoms. Some STIs can increase the risk of HIV acquisition three-fold or more. STIs can have serious consequences beyond the immediate infection itself, through mother-to-child transmission of infections or conditions such as infertility and cervical cancer. Drug resistance for gonorrhea is a major threat to control this STI worldwide [[5]Unemo M. Golparian D. Eyre D.W. Antimicrobial resistance in Neisseria gonorrhoeae and treatment of gonorrhea.Methods Mol Biol. 2019; 1997: 37-58https://doi.org/10.1007/978-1-4939-9496-0_3Crossref PubMed Scopus (45) Google Scholar]. STIs are caused by different pathogen such as virus, bacteria, parasites and the symptoms and lesions appear in various parts of the human body. Most STIs have typical symptoms, signs and lesions by disease. However, symptomatic STI as well as asymptomatic carriers and asymptomatic carriers are important because they can be transmit the infection to other people [[6]Levy S.B. Gunta J. Edemekong P. Screening for sexually transmitted diseases.Prim Care. 2019; 46: 157-173https://doi.org/10.1016/j.pop.2018.10.013Abstract Full Text Full Text PDF PubMed Scopus (10) Google Scholar]. So in the case of STI, it can be said that the specific screening test is important. The strategies for diagnosis of STIs in Asian countries are very important for the following reasons: curable STIs are frequently found in Asians; STIs can result in serious physical complications in some patients; and deplete a middle- or low-income countries' economic reservoir for controlling the infections [[7]Organization W.H. Prevalence and incidence of selected sexually transmitted infections, Chlamydia trachomatis, Neisseria gonorrhoeae, syphilis and Trichomonas vaginalis: methods and results used by WHO to generate 2005 estimates.in: Book Prevalence and incidence of selected sexually transmitted infections, Chlamydia trachomatis, Neisseria gonorrhoeae, syphilis and Trichomonas vaginalis: methods and results used by WHO to generate 2005 estimates. World Health Organization, 2011Google Scholar]. Practically, untreated early syphilis will result in a stillbirth rate of 25% and be responsible for 14% of neonatal deaths. Untreated gonococcal and chlamydia infections in women will result in pelvic inflammatory disease in up to 40% of cases. One in four of these cases will result in infertility [[8]Aral S.O. Holmes K.K. Social and behavioral determinants of the epidemiology of STDs: industrialized and developing countries.1999: 39-76Google Scholar]. STIs are not only medical problems, but also social, political, behavioral and economic problems [9Unemo M. Bradshaw C.S. Hocking J.S. de Vries H.J.C. Francis S.C. Mabey D. et al.Sexually transmitted infections: challenges ahead.Lancet Infect Dis. 2017; 17: e235-e279https://doi.org/10.1016/s1473-3099(17)30310-9Abstract Full Text Full Text PDF PubMed Scopus (0) Google Scholar, 10Korenromp E.L. Wi T. Resch S. Stover J. Broutet N. Costing of national STI program implementation for the global STI control strategy for the health sector, 2016-2021.PloS One. 2017; 12e0170773https://doi.org/10.1371/journal.pone.0170773Crossref PubMed Scopus (35) Google Scholar, 11Zajac K. Kennedy C.E. Fonner V.A. Armstrong K.S. O'Reilly K.R. Sweat M.D. A systematic review of the effects of behavioral counseling on sexual risk behaviors and HIV/STI prevalence in low- and middle-income countries.AIDS Behav. 2015; 19: 1178-1202https://doi.org/10.1007/s10461-014-0893-xCrossref PubMed Scopus (12) Google Scholar]. Tests with high accuracy are widely used in high-income countries, and are also very useful in detecting asymptomatic infections. However, in the low-income and middle-income countries, many parts of the examination are impractical because they are expensive or geographically inaccessible. Therefore, proper treatment through accurate diagnosis may take time and money in such countries. For a number of reasons, there are many efforts to reduce the cost of tests and increase their convenience to perform these screening or confirmatory tests. For example, tests such as rapid dual HIV/syphilis blood test and single rapid test for syphilis are accurate through 15–20 min to confirm the results and the examiner does not require high proficiency. To solve these complicated and entangled problems, we must explore more comprehensive approaches as follows; international cooperation, national supports or international supports, and governmental or community supports. Furthermore, the strategies for detection of STIs should be designed within one's national ability or budget [[8]Aral S.O. Holmes K.K. Social and behavioral determinants of the epidemiology of STDs: industrialized and developing countries.1999: 39-76Google Scholar]. Clinical guidelines must be based on evidence and be of value to medical practitioners. From the review of previous guidelines, we can find that the ideal guidelines are not often practice [12Lugtenberg M. Burgers J.S. Zegers-van Schaick J.M. Westert G.P. Guidelines on uncomplicated urinary tract infections are difficult to follow: perceived barriers and suggested interventions.BMC Fam Pract. 2010; 11: 51https://doi.org/10.1186/1471-2296-11-51Crossref PubMed Scopus (34) Google Scholar, 13Cabana M.D. Rand C.S. Powe N.R. Wu A.W. Wilson M.H. Abboud P.A. et al.Why don't physicians follow clinical practice guidelines? A framework for improvement.Jama. 1999; 282: 1458-1465https://doi.org/10.1001/jama.282.15.1458Crossref PubMed Scopus (5193) Google Scholar, 14Keith Radcliffe UE-i-C Martí Vall-Mayans S. Andy Winter U. Deniz Gökengin T. Marco Cusini I. Mikhail Gomberg R. et al.STI treatment pocket European guidelines.2019https://iusti.org/wp-content/uploads/2020/07/PocketGuideline2019.pdfGoogle Scholar, 15Unemo M. Ross J. Serwin A.B. Gomberg M. Cusini M. Jensen J.S. European guideline for the diagnosis and treatment of gonorrhoea in adults.Int J STD AIDS. 2020; 2020956462420949126https://doi.org/10.1177/0956462420949126Crossref Scopus (66) Google Scholar, 16Unemo M. Ross J. Serwin A. Gomberg M. Cusini M. Jensen J.J. et al.Background review for the ‘2020 European guideline for the diagnosis and treatment of gonorrhoea in adults’.. 2021; 32: 108-126Google Scholar, 17Unemo M. Clarke E. Boiko I. Patel C. Patel R. ECGJIjo S.T.D. et al.Adherence to the 2012 European gonorrhoea guideline in the WHO European region according to the 2018–19 international union against sexually transmitted infections.in: European collaborative clinical group gonorrhoea survey. 31. 2020: 69-76Google Scholar, 18Organization WH WHO guideline on syphilis screening and treatment for pregnant women. World Health Organization, 2017Google Scholar, 19Organization WH WHO guidelines for the treatment of genital herpes simplex virus. World Health Organization, 2016Google Scholar, 20Organization WH WHO guidelines for the treatment of Treponema pallidum (syphilis).2016Google Scholar, 21Organization WH WHO guidelines for the treatment of Chlamydia trachomatis.2016Google Scholar, 22WHO Who guidelines for the treatment of Neisseria gonorrhoeae.2016Google Scholar]. Additionally, while there are very good STI guidelines around the world, STIs still thrive today. The basic concept of a guideline is one rule for one fact with limited exceptions. However, a universal or multi-national guideline must capture the diversity of people across the Asian countries. To get an ideal STI guideline for Asian people, we must review some discrepant parts. Accurate diagnostic tests for STIs are widely used in high-income countries but in low- and middle-income countries, the diagnostic tests are largely unavailable. So inexpensive and rapid result for STI is needed and especially in resource-limiting environment. Several rapid tests for STIs are under development which can be potentially efficient tests for STI diagnosis and treatment, especially in resource-limited settings [[23]WHO OJFS Sexually transmitted infections (STIs).2019Google Scholar]. In STI, sexually trasmitred infections include asymptomatic and symptomatic infections. In general, in the case of symptomatic infections, treatment can be carried out through a confirmatory test, but in the case of asymptomatic cases, the actual causative agent exists in the human body and there is a risk of transmission, but there are no symptoms, so diagnosis and treatment are difficult. Therefore, it is important to evaluate the risk and block transmittion through screening tests in high-risk groups. However, there are many limitations in screening and testing these asymptomatic STI patients, such as cost, facilities, and trained personnel. The medical or social costs are very expensive because we would require highly sensitive laboratory or screening tests to detect non-symptomatic pathogens by qualified personnel after adequate training for performing technically demanding procedures. Therefore, diagnostic tests for STI differ in suitability according to the socioeconomic status of each country. The high-income country can use various tests but the low-to-mid income country has limitations on the tests. There are many methods for etiological diagnosis of STIs. While the standard bacterial culture method for Neisseria gonorhoeae(NG) or Trichomonas vaginalis(TV) are well established around the world, the culture method for cryptic organisms such as Chlamydia trachomatis (CT) or Mycoplasma genitalium are difficult to set up, time-consuming, and demanding highly qualified cell culture techniques. Many health care facilities in Asian countries may lack the cell culturing equipment and trained personnel for STI approaching. The screening tests on the base of pathogens, nucleic acid amplification technique (NAAT), can be alternative method for etiological detection of STIs. Though it is customized and the whole procedures can be automatically performed, the cost is expensive to cover all person who wants to check for STIs. Practically, wide use of NAAT is not acceptable in less developed Asian countries. However, we cannot overlook serious complications of asymptomatic STIs in Asian countries. Screening test was strongly recommended that the STIs core group or people with potentially serious risks after STIs infection should be tested with STIs screening tests regardless of symptoms. We should provide the NAAT for all symptomatic patients whatever the risk for STIs [24Swartz S.L. Kraus S.J. Herrmann K.L. Stargel M.D. Brown W.J. Allen S.D. Diagnosis and etiology of nongonococcal urethritis.. 1978; 138: 445-454Google Scholar, 25Workowski K.A. Centers for Disease Control and Prevention sexually transmitted diseases treatment guidelines.. 2015; 61: S759-S762Google Scholar, 26Choi J.Y. Cho I.-C. Lee G.I. Min S.K. Prevalence and associated factors for four sexually transmissible microorganisms in middle-aged men receiving general prostate health checkups: a polymerase chain reaction-based study in Korea.. 2013; 54: 53Google Scholar]. To successfully implement this concept, we must decide “Who should be tested for screening tests in each country?” and “Who are the STI core groups in each country?” There is no single or independent test to diagnose the causative agent that causes STI. However, there are some considerations for each country and region in selecting various tests. Various considerations exist, including the cost of the examination and the prevalence of STIs in specific region. Table 1 shows considerations for each test [[27]Unemo M. Ballard R. Ison C. Lewis D. Ndowa F. Peeling R. et al.Laboratory diagnosis of sexually transmitted infections, including human immunodeficiency virus.2013Google Scholar].Table 1Potential factors influencing choice of tests for STIs.Purpose of testingTest-specific considerations•Surveillance•Quality assurance•Evaluation of syndromic diagnosis•Diagnosis•Screening•Antimicrobial susceptibility testing•Performance (sensitivity, specificity, predictive value)•Specimen collection and transportation requirements•Prevalence•Associated morbidity•Resources•Financial•Personnel•Infrastructure (utilities, etc.)•Relative importance among other priorities Open table in a new tab There are many things to consider about STI. It is necessary to distinguish whether it is a treatable STI or a preventable STI. Depending on each, an appropriate selection should be made between screening and confirm diagnosis. In addition, it is necessary to distinguish whether it is high risk or low risk through risk management, and for complications of STI itself, priority should be given to diagnosis by considering no complication, mild complication, severe or irreversible complication. Education for disease prevention, diagnosis, treatment, etc. also has many points to be considered depending on how and what is delivered to whom. Education that considers all aspects such as national characteristics, demographic characteristics, and economic and social characteristics is necessary. In addition, in establishing a strategy based on these considerations, it is important to establish a strategy for each country or administrative unit, but international, regional and global strategy must be considered and established (Fig. 1). Screening for STI in a specific population can be very helpful [[6]Levy S.B. Gunta J. Edemekong P. Screening for sexually transmitted diseases.Prim Care. 2019; 46: 157-173https://doi.org/10.1016/j.pop.2018.10.013Abstract Full Text Full Text PDF PubMed Scopus (10) Google Scholar,[28]Frati E.R. Fasoli E. Martinelli M. Colzani D. Bianchi S. Carnelli L. et al.Sexually transmitted infections: a novel screening strategy for improving women's health in vulnerable populations.. 2017; 18: 1311Google Scholar]. A large number of untreated STIs cause complications such as genitourinary infection, infertility, pelvic inflammatory disease, cervical cancer, and chronic infection, and may also cause transmission to others. Symptomatic STI can be tested for diagnosis according to the symptoms, but in the case of asymptomatic STI, it is difficult to confirm if screening is not performed, and asymptomatic infection leads to complications and disease spread. Ideally, screening should be performed on all people at risk for developing STIs. However, these screening tests inevitably incur costs, and some tests may incur costs and may have location limitations. In the case of high-income countries, capital and administrative measures such as these screening tests are sufficiently implemented, and medical access is excellent, so there will be few restrictions on testing. However, in middle-income or low-income countries, sufficient national medical expenses may not be invested or policy measures may not be taken, there is a limit to available medical resources, and not everyone has easy access to medical care. It is necessary to designate a high-risk group such as a specific age and a specific occupation, and to conduct a screening test on a minimum number of subjects. The screening of curable STI is summarized by the CDC US Preventive Service Task Force (USPSTF) in 2019. The CDC and USPSTF classify risk groups for Chlamydia, Neisseria gonorrhea, Syphilis, and HIV, respectively, and divide risk groups by sex and specific situation, and recommend screening in each (Table 2). The screening recommendations for each disease are summarized as follows for each disease [[6]Levy S.B. Gunta J. Edemekong P. Screening for sexually transmitted diseases.Prim Care. 2019; 46: 157-173https://doi.org/10.1016/j.pop.2018.10.013Abstract Full Text Full Text PDF PubMed Scopus (10) Google Scholar] (See Table 3, Table 4, Table 5).Table 2Risk factors for gonorrhea, chlamydia, and syphilis by population.PopulationRisk FactorsWomenPrior CT or GC infection, particularly in the past 24 mo>1 sex partner in the past yearPartner with concurrent partnersNew partner in the past 3 moPartner with STITransactional sex (eg, drugs, money, housing)Inconsistent condom use and not in mutually monogamous relationshipIntravenous (IV) drug users and/or partners who are IV drug usersHigh-prevalence population, such as incarcerated, military recruit, public STI clinicMSMMultiple or anonymous partnersIV drugs useSex in conjunction with illicit drug use, including methamphetamineReceptive or insertive anal sexOral sex with partners who have syphilis sores or lesionsPartners who engage in the above activitiesMen who have sex with womenPrior infection (in past 24 mo)IV drug useHigh-risk setting such as Adolescent clinicsCorrectional facilitiesSTD clinicsNational job training programs Open table in a new tab Table 3Screening for chlamydia and gonorrhea: summary of recommendations.GenderPopulationRecommendationScreening FrequencyCommentsWomenSexually active <25 yScreen for chlamydia and gonorrheaAnnuallyScreen more frequently for those at increased riskSexually active ≥25 yNo routine screeningTargeted CT/NG screening for women with risk factorsHIV positiveScreen all HIV positive women up to 64 y of ageAnnuallyRepeat according to level of riskPregnantScreen all pregnant women (vaginal, cervical, or urine)First trimesterRepeat screening in third trimester if at increased riskMenHeterosexual menNo recommended routine screeningTargeted screening for CT in high-risk settingsMSMCT and GC(Urine)CT and GC (rectal)GC (pharyngeal)AnnuallyAnnually (if exposed)Annually (if exposed)Repeat screening every 3–6 mo, as indicated by riskHIV positiveCT and GC(Urine)CT and GC (rectal)GC (pharyngeal)AnnuallyAnnually (if exposed)Annually (if exposed)Repeat screening every 3–6 mo, as indicated by risk*For women, in addition to vaginal, cevical swab and urine, which were previously performed, pharyngeal and rectal swab must be performed as screening tests. Open table in a new tab *For women, in addition to vaginal, cevical swab and urine, which were previously performed, pharyngeal and rectal swab must be performed as screening tests. Table 4Screening for syphilis: summary of recommendations.GenderPopulationRecommendationScreening FrequencyCommentsWomenPregnant womenScreen at first prenatal visitEvery PregnancyUse RPRRetest early in the third trimester and at delivery if at high riskSexually ActiveNo routine screeningTargeted screening for women with risk factorsHIV positiveScreen all women up to age 64AnnuallyMay screen more often depending on risk factorsMenHeterosexual menNo routine screeningTargeted screening in high-risk settings or risk factorsMSMScreen if sexually activeAnnuallyRepeat screening every 3 mo, as indicated by riskHIV positiveScreenAnnuallyRepeat screening every 3 mo, as indicated by risk Open table in a new tab Table 5Screening for human immunodeficiency virus: summary of recommendations.GenderPopulationRecommendationScreening FrequencyCommentsWomenNonpregnant sexually active13–65 years oldOne-time screeningOnceConsider screening more frequently if at increased RiskPregnant womenScreen at first prenatal visitEvery pregnancyRepeat testing in the third trimester if increased risk of HIVMenSexually active heterosexual men 13–65 years oldOne-time screenOnceConsider screening more frequently if at increased RiskMSMScreenAnnually (if sexually active)Screen more often if more than one partner since most recent HIV testing Open table in a new tab There are many defined STIs in the literatures. The common pathogens or diseases are bacterial vaginosis, Chlamydia trachomatis (CT), genital herpes, Neisseria gonorrhoeae (NG), hepatitis B and C viral infections, human papillomavirus, HIV/AIDS, pubic lice, syphilis, and Trichomonas vaginalis (TV) [[29]Markle W. Conti T. Kad M. Sexually transmitted diseases.Prim Care. 2013; 40: 557-587https://doi.org/10.1016/j.pop.2013.05.001Abstract Full Text Full Text PDF PubMed Scopus (23) Google Scholar]. The three pathogens (CT, NG, TV) are very well known organisms for male urethritis. Today, we can definitively add on Mycoplasma genitalium as a urethritis pathogen as in the USA CDC classification as one of the definitive pathogens of male urethritis, while there are many disputes that the Ureaplsma pavum or Ureaplasma urealyticum can be pathogens for urethritis [30Choi J.Y. Cho I.C. Lee G.I. Min S.K. Prevalence and associated factors for four sexually transmissible microorganisms in middle-aged men receiving general prostate health checkups: a polymerase chain reaction-based study in Korea.Korean J Urol. 2013; 54: 53-58https://doi.org/10.4111/kju.2013.54.1.53Crossref Scopus (4) Google Scholar, 31Daley G.M. Russell D.B. Tabrizi S.N. McBride J. Mycoplasma genitalium: a review.Int J STD AIDS. 2014; 25: 475-487https://doi.org/10.1177/0956462413515196Crossref PubMed Scopus (55) Google Scholar, 32Cazanave C. Manhart L.E. Bébéar C. Mycoplasma genitalium, an emerging sexually transmitted pathogen.Med Maladies Infect. 2012; 42: 381-392https://doi.org/10.1016/j.medmal.2012.05.006Crossref PubMed Scopus (49) Google Scholar, 33Hamasuna R. Mycoplasma genitalium in male urethritis: diagnosis and treatment in Japan.Int J Urol. 2013; 20: 676-684https://doi.org/10.1111/iju.12152Crossref PubMed Scopus (13) Google Scholar]. In a review article recently published in the Europe STI guideline Editorial Board [[34]Horner P. Donders G. Cusini M. Gomberg M. Jensen J. MJJotEAoD Unemo et al.Should we be testing for urogenital Mycoplasma hominis, Ureaplasma parvum and Ureaplasma urealyticum in men and women?–a position statement from the European.in: STI Guidelines Editorial Board. 32. 2018: 1845-1851Google Scholar], Mycoplasma genitalium is a definite pathogen of male urethritis. Other Mycoplasma hominis, Ureaplasma urealyticum, and Ureplasa parvum are difficult to see as ‘true STI’, Routine testing in both symptomatic and asymptomatic men and women is not recommended. In the urology area, urethritis can be performed as a confirmation test, and in the obstetrics area, vaginitis can be mainly targeted for examination, and these diseases can be said to be curable. So, from the next paragraph, we will examine various test methods for Tricomonas/Chlamydia trachomatis/Neisseria gonorrhoea/Mycoplasma genitalium. We need valid laboratory assays to confirm STIs from the symptomatic patients, to detect infections in asymptomatic high STIs risk individuals, and to investigate the cases of resistance to empirical treatment or to monitor the changes of antibiotics resistance patterns. The ideal diagnostic methods for STIs must be simple to perform, highly sensitive and highly specific, reproducible, rapid, and inexpensive. There may be differences between tests performed for diagnosis and tests for screening. The urethral swab was not recommended to avoid pain for screening, but urethral swab is essential for diagnosis. In addition, cervical swab should be performed for women, and recently, rectal swab or pharyngeal swab is also required depending on the situation. However, there is no one rule for covering all pathogens. Medical practitioners must understand the feasibility and weakness of each test for each pathogen within their national ability or budget. In recent years, new methods have been developed, using molecular biology techniques. Even though the newly developed NAATs meet the criteria of optimal test for STIs, they also some disadvantages for general use in Asian countries. Additionally, we must understand the limitation of not validated in-house NAATs in Asian markets. Furthermore, the genetic sequence mutations in the target area are a critical issue or serious limitation for NAATs [[35]Unemo M. Clarke I.N. The Swedish new variant of Chlamydia trachomatis.Curr Opin Infect Dis. 2011; 24: 62-69https://doi.org/10.1097/QCO.0b013e32834204d5Crossref PubMed Scopus (57) Google Scholar]. Interestingly, some old fashioned tests are still valid and used as a gold standard for detecting the STIs pathogens. Direct microscopic examination by medical exporters is made from a swab or urethral discharges. One drop of a physiological saline is placed into a sample on slide and immediately examined under a light microscope (×100). A swab of secretions is taken from the urethral orifice within 6 h of sample collection to inoculate a tube of Diamond's modified medium. The culture is incubated at 35 °C for 3–4 days with daily examination by wet prep for motile trichomonas. Recently, a culture system with a two-chambered bag is available [[36]Levi M.H. Torres J. Piña C. Klein R.S. Comparison of the InPouch TV culture system and Diamond's modified medium for detection of Trichomonas vaginalis.J Clin Microbiol. 1997; 35: 3308-3310https://doi.org/10.1128/jcm.35.12.3308-3310.1997Crossref PubMed Scopus (43) Google Scholar]. Even though some assays are commercially available, the feasibility has not scientifically evaluated (Table 6).Table 6Diagnostic methods for Trichomonas vaginalis.Wet smearCultureNAATSensitivity38–82%98%UnknownSpecificity100%100%UnknownSampleUrethral dischargeUrethral dischargeUrethral discharge UrineTargetMotile TrichomonasTrichomonasDNAAdvantageRapidSensitiveViable or non-viableExtremely sensitiveVariable samplesDisadvantageVery low sensitivityTakes 3–4 daysRequire expertiseAmplification inhibitorsPerformanceEasyEasyExtensiveCostCheapCheapExpensive Open table in a new tab Chlamydia culture is labor-intensive, time-consuming and expensive. It also needs considerable technique to perform. For these reasons, culture techniques are not generally recommended for clinicians. Practically, some national research laboratories may be required for monitoring of antibiotics resistance or genetic mutations. The urethral secretion is collected with cotton swabs, and rolled on glass slides. Fixed and stained with fluorescein-labelled antibodies for major outer membrane protein of CT. The stained CT can be detected with immunofluorescence microscopy by the trained person. The common target of EIA for diagnosing the CT is chlamydial genus-specific lipopolysaccharide (LPS) antigen. Because of sharing the structure of LPS in chlamydial genus or other Gram-negative bacteria, blocking process are needed for enhancing the specificity. The basic equipments for successful performance are commercial kits by certain companies and a microwell plate reader. The main advantage for rapid test is simple and rapid in chlamydial detecting process. In addition, rapid detection and onsite treatment can be an ideal method to stop spreading the infection. However, major drawback of this test is very lower sensitivity. Furthermore, the cost for doing the test is expensive. For these reasons, we do not recommend the test for diagnosing chlamydia infection before. Recently, the shortcomings of rapid test have been improved a lot recently. In addition, the time required to check the results of the NAAT test is drastically reduced, showing a speed that does not deteriorate compared to the rapid point-of-care test. In particular, in the case of the Point-of-Care test, it is said that it can be used when it is necessary to quickly check the result in many literatures, etc. by supplementing the low sensitivity and dramatically shortening the time to check the test result. But As rapid NAAT tests have recently come out with improved sensitivity, NAATs such as Gene Xpert have been recommended as rapid tests. However, rapid test are still not thought to be effective for diagnosing chlamydia in men of reproductive age and nonpregnant women because of a high false-negative rates [[37]Grillo-Ardila C.F. Torres M. Gaitán H.G. Rapid point of care test for detecting urogenital Chlamydia trachomatis infection in nonpregnant women and men at reproductive age.Cochrane Database Syst Rev. 2020; 1: Cd011708https://doi.org/10.1002/14651858.CD011708.pub2Crossref Scopus (1) Google Scholar]. Today, the NAAT for CT is a newly developed gold standard for detecting the infection. While the major disadvantage of the NAAT is a complicated procedure, requiring training or expertise for successful operation; today, the drawback has been solved with a semi or full automated format. With high sensitivity for detecting the organisms, we can use various clinical samples such as urine, tampons, swabs, and direct smeared samples. With the multiple targeting ability, we can detect many STIs pathogens in one sample. However, we still consider the disadvantages of NAATs for molecular diagnosis of STIs. First of all, the cost is very expensive for routinely performing in under middle- or low-income countries. Second, we must consider the technical failure with amplification inhibitors and cross-over contamination. Finally, if genetic mutation in the targeted area happens during genetic evolution, we cannot detect the infection with NAATs system (Table 7).Table 7Diagnositc methods for Chlamydia trachomatis.DFAEIARapidNAATSensitivity80–85%60–80%52–85%UnknownSpecificity99–100%97–99%>95%UnknownSampleUrethral dischargeUrethral dischargeUrethral dischargeFVU, urethral discharge, swab (cervical, urethral, vulvovaginal, anal, conjunctival, pharyngeal).TargetChlamydia LPSChlamydia MOMPChlamydia LPSChlamydia MOMPChlamydia LPSChlamydia MOMPDNAAdvantageRapidRapidRapidViable or non-viableExtremely sensitiveVariable samplesDisadvantageRequire expertiseFluorescent microscopeRequire expertiseMicrowell plateInsensitiveExpensiveRequire expertiseAmplification inhibitorsPerformanceModerate expensiveModerateEasyExtensiveCostCheapCheapExpensiveExpensive Open table in a new tab A direct Gram staining on the urethral discharge and examining under an oil immersion (×1000) has been a traditional laboratory test for NG detection. The presence of Gram-negative diplococcic inside polymorphonuclear leukocytes is a significant diagnostic criteria for NG infection. The main advantages of Gram staining are rapid and inexpensive. This is the first recommended evaluation test for the male urethritis. Inoculating the urethral secretion on NG selective media such as Thayer-Martin or blood agar plate is the next step after a direct Gram smear. Typical colonies are tested with Gram-stain, oxidase and catalase and/or superoxal tests for presumptive identification of NG. Additionally, the minimal inhibitory concentration (MIC) of antibiotics such as cefixime, ceftriaxone, fluoroquinolone, azithromycin, spectinomycin and et al. are determined to establish the antimicrobial susceptibility of the strain. The NAATs systems are designed to combo types for detecting NG and CT. Target genes are both DNA and RNA, and the molecular techniques are polymerase chain reaction (PCR) and ligase chain reaction (LCR). However, in the case of transcription-mediated amplification (TMA) testing during NAAT, the target is pathogen RNA [[39]Munson E. Bykowski H. Munson K.L. Napierala M. Reiss P.J. Schell R.F. et al.Clinical laboratory assessment of Mycoplasma genitalium transcription-mediated amplification using primary female urogenital specimens.J Clin Microbiol. 2016; 54: 432-438https://doi.org/10.1128/jcm.02463-15Crossref PubMed Scopus (0) Google Scholar]. Please see the section of Chlamydia trachomatis for understanding advantages and disadvantages. Recently, interest in gonorrhea has been increasing worldwide. This not only increases the incidence, but also reports the appearance of ceftriaxone resistant organisms and treatment failure. Therefore, in the case of NG, the need for culture and antimicrobial susceptibility testing is increasing. It is not necessary to perform this in all countries and in allregions, but in countries where resistant strains have been reported, culture and susceptibility tests may be helpful in treatment [[15]Unemo M. Ross J. Serwin A.B. Gomberg M. Cusini M. Jensen J.S. European guideline for the diagnosis and treatment of gonorrhoea in adults.Int J STD AIDS. 2020; 2020956462420949126https://doi.org/10.1177/0956462420949126Crossref Scopus (66) Google Scholar]. In these areas, if necessary, diagnostic culture is appropriate for endocervical, urethral, rectal, oropharyngeal and conjunctival specimens but not for urine or vaginal swabs. Ideally, all gonococcus-positive individuals diagnosed by NAAT should have cultures performed before initiation of gonorrhoea treatment to permit antimicrobial resistance (AMR) testing and surveillance to be performed. Selective culture media containing antimicrobials such as vancomycin, colistin, nystatin, and trimethoprim are recommended (Table 8).Table 8Diagnostic methods for Nesisseria Gonorrhoea [[14]Keith Radcliffe UE-i-C Martí Vall-Mayans S. Andy Winter U. Deniz Gökengin T. Marco Cusini I. Mikhail Gomberg R. et al.STI treatment pocket European guidelines.2019https://iusti.org/wp-content/uploads/2020/07/PocketGuideline2019.pdfGoogle Scholar].Gram smearCultureNAATSensitivity90–95%81–100%98–100%Specificity95–100%100%98–100%SampleUrethral dischargeUrethral discharge swab as for NAATspecimen: swab urethral, cervical, vulvovaginal, anal, conjunctival, pharyngeal, FVUTargetGram-negative diplococci in PMNN. gonorrhoeaeDNARNAAdvantageRapid, inexpensiveDrug resistanceViable or non-viableExtremely sensitiveVariable samplesDisadvantageLower sensitive in asymptomatic peopleStringent handling requires up to 3 daysRequire expertiseAmplification inhibitorsPerformanceEasyModerateExtensiveCostCheapCheapExpensive*TOC: clinical/culture 3–7 days post treatment; NAAT 2 weeks post treatment.*During menstruation, intracervical swabs for culture are more reliable. Open table in a new tab *TOC: clinical/culture 3–7 days post treatment; NAAT 2 weeks post treatment. *During menstruation, intracervical swabs for culture are more reliable. Only culture and NAAT method can detect the organism for diagnosis of this infection. However, unfortunately, the culture method is very difficult, time-consuming, and expensive. In addition, while there are many NAATs methods for detecting the organism, we do not have authorized commercial kits to diagnose the infection [[27]Unemo M. Ballard R. Ison C. Lewis D. Ndowa F. Peeling R. et al.Laboratory diagnosis of sexually transmitted infections, including human immunodeficiency virus.2013Google Scholar]. Mycoplasma genitalium has ability for genetic mutation under evolutional pressure. One of frequent mutation sites is determining areas for antimicrobial resistance. For this reason, we must consider unique national laboratory research center for tracking the mutation and antimicrobial susceptibility. If it is not available due to either some technical problems or national medical budget problems, we can consider one or two Asian reference centers. All male patients with urethral discharge must examine the gonococal infection. The first step is a Gram smear that is simple and rapid test. If Gram-negative diplococci in PMN cells are detected, we should do Neisseria Gonorrhoea culture. NAATs can be available to detect STIs from various samples. If NAATs test are positive in gonococal infection, we must do Neisseria Gonorrhoea culture. Screening tests for STIs can be indicated in pregnant women, sexually active adolescents, persons in correction facility, homeless adolescents, and sex workers. While they have not shown symptoms, the risk of vertical STIs infection transmission is underestimated. In addition, the potential risk of STIs core groups for spreading the infections into bridging people must be considered. Even among the at-risk groups, syphilis screening, including rapid syphilis testing, will be necessary for all pregnant women in middle-income and low-income counties. To establish good Asian STIs guideline, we must consider the heterogeneous characteristics of Asian countries, and the draft must be reviewed by wide spectrums of national specialists to adjust their performance. In near future, we should set up regional or international central laboratories to support the diagnosis and treatment of STIs. Sex is essential component of all human. But more than 1 million sexually transmitted infections occur every day. Diagnosis of disease is important for both treatable and non-curable diseases. Whether it is a confirmation test or a screening test should be applied differently according to the socioeconomic status of each region or country, and where the focus is placed will also vary. Early diagnosis and early treatment are also important for STI. Also, STI is a simple not only national problem, but also regional and worldwide.