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In a recent article, Sriram and collaborators ([8][1]) described a comparative study designed to detect Chlamydia pneumoniae DNA in the cerebrospinal fluid (CSF) of patients with multiple sclerosis (MS) or other neurological diseases (OND). Two PCR assays were performed on a common set of CSF

To evaluate the expected change in the prevalence of male circumcision (MC)-reduced infections and resulting health care costs associated with continued decreases in MC rates. During the past 20 years, MC rates have declined from 79% to 55%, alongside reduced insurance coverage.We used Markov-based Monte Carlo simulations to track men and women throughout their lifetimes as they experienced MC procedure-related events and MC-reduced infections and accumulated associated costs. One-way and probabilistic sensitivity analyses were used to evaluate the impact of uncertainty.United States.Birth cohort of men and women.Decreased MC rates (10% reflects the MC rate in Europe, where insurance coverage is limited).Lifetime direct medical cost (2011 US$) and prevalence of MC-reduced infections.Reducing the MC rate to 10% will increase lifetime health care costs by $407 per male and $43 per female. Net expenditure per annual birth cohort (including procedure and complication costs) is expected to increase by $505 million, reflecting an increase of $313 per forgone MC. Over 10 annual cohorts, net present value of additional costs would exceed $4.4 billion. Lifetime prevalence of human immunodeficiency virus infection among males is expected to increase by 12.2% (4843 cases), high- and low-risk human papillomavirus by 29.1% (57 124 cases), herpes simplex virus type 2 by 19.8% (124 767 cases), and infant urinary tract infections by 211.8% (26 876 cases). Among females, lifetime prevalence of bacterial vaginosis is expected to increase by 51.2% (538 865 cases), trichomoniasis by 51.2% (64 585 cases), high-risk human papillomavirus by 18.3% (33 148 cases), and low-risk human papillomavirus by 12.9% (25 837 cases). Increased prevalence of human immunodeficiency virus infection among males represents 78.9% of increased expenses.Continued decreases in MC rates are associated with increased infection prevalence, thereby increasing medical expenditures for men and women.

To assess the utility of PCR-enzyme immunoassay (EIA) for diagnosis of acute infection with Chlamydia pneumoniae, we compared tissue culture, PCR-EIA, direct fluorescent-antibody (DFA) stain, and serology in studies with 56 patients with respiratory symptoms and 80 asymptomatic persons. Thirty-five patients were positive by either culture or PCR-EIA, and 101 were negative by both assays. Thirty specimens from symptomatic patients and one from an asymptomatic patient were culture positive; 23 of these were also PCR-EIA positive. Of the eight culture-positive, PCR-EIA-negative specimens, five were DFA negative and three were DFA positive. Four additional specimens were culture negative and PCR-EIA positive; of these, three were DFA positive and one was DFA negative. When we used culture- and/or DFA-positive results as a reference or "gold standard," the sensitivity and specificity of PCR were 76.5 and 99.0%, respectively. When we used PCR- and/or DFA-positive results as the reference, the sensitivity of culture was 87.5%. On the basis of single acute serum specimens, only 8 of these 35 patients had diagnostic antibody titers. Of the asymptomatic patients, 75% had immunoglobulin G or immunoglobulin M antibody to C. pneumoniae; 15 (18.8%) of these had antibody levels considered to be diagnostic of acute infection. This multicenter study indicates that culture and/or PCR-EIA is more reliable for prompt diagnosis of C. pneumoniae infection than single-point serology alone.

Trachoma, the result of repeated infection with Chlamydia trachomatis, is the leading infectious cause of blindness.1 The World Health Organization (WHO) strategy for trachoma control consists of surgery for trichiasis, antibiotics for reduction of the infectious pool in the community, and facial and environmental hygiene to interrupt transmission. In endemic communities the community load of active trachoma, and infection, resides in preschool children.2,3 Simple assessment of the clinical signs of follicular trachoma is deemed sufficient to determine the communities and districts that require trachoma control interventions. Mass drug administration (MDA) of endemic districts and communities with azithromycin is recommended for at least 3 years if the prevalence of trachoma is 10% or greater in children ages 1 to younger than 10 years, followed by resurvey to determine whether further MDA is warranted. A recent change in guidelines suggests that when the prevalence is high at baseline, such as 30%, there is no advantage to a resurvey before 5 years of MDA. Antibiotics target the infectious agent, C. trachomatis, not the clinical signs of trachoma. Prevalence surveys have repeatedly shown that the rates of clinical signs of trachoma, follicular trachoma (TF), and inflammatory trachoma (TI) in children are higher than the actual rates of infection.4–9 These findings are expected, as shown in animal models and longitudinal studies in which follicles in the conjunctiva take a long time to resolve after infection has disappeared.10–13 Using the WHO simplified grading scheme for trachoma assessment, approximately 50% to 90% of those with TI and 30% to 50% of those with TF have concomitant infection,14 with even lower rates after MDA.8,11,15,16 Even if free of infection, communities with TF prevalence ≥10% will continue another series of rounds of MDA in compliance with WHO guidelines. However, the other sign of active trachoma, TI, appears to be more sensitive to antibiotic treatment.15 If a combination of more or less severe signs of trachoma would better capture the infection status, then the use of such a combination might be useful to identify communities in which infection is either absent or persists. Although studies have examined the relationship between clinical signs of trachoma and infection in individual children, there has not been a systematic evaluation of the use of clinical signs, and especially an expanded array of clinical signs, at the community level to help determine whether infection persists after MDA. As part of a larger survey of trachoma and infection in Tanzanian communities that had at least three annual rounds of mass treatment, we expanded the WHO simplified grading scheme to include additional levels of TF and TI that could be graded reliably. The aim of this study was to determine whether a combination of these clinical signs could predict the presence, or absence, of infection at the community level and could have programmatic utility.

Background: Although Epstein-Barr virus (EBV), a common gamma herpesvirus known to contribute to several cancers (e.g., Burkitt's lymphoma), has been detected in prostate tissue, results from the few epidemiologic studies of EBV infection and prostate cancer have been null. One possible reason for these null findings may be that not all EBV infections contribute to prostate cancer risk. For instance, for other proposed EBV-associated conditions, such as multiple sclerosis, infections acquired later in life (e.g., in adolescence or early adulthood) when EBV infection tends to manifest as infectious mononucleosis (IM) have been found to be more important for risk than those acquired earlier in life when EBV infection is typically asymptomatic. To begin to explore the importance of later-onset EBV infections for prostate carcinogenesis, we investigated the extent of prostate pathogenesis during adult-onset IM by measuring prostate specific antigen (PSA) concentration as a marker of prostate infection, inflammation, and cell damage in adult-onset IM cases and controls with stored serum in the Department of Defense Serum repository (DoDSR). Methods: IM cases were men diagnosed with IM in 1998–2003 (n=55) and controls were a sample of men with no IM diagnoses from 1995–2006 (n=255). For each IM case, we selected two archived serum specimens from the DoDSR, one collected after their diagnosis (acute specimen, range: 1 day-3 years after diagnosis) and the first specimen collected immediately before their acute specimen (pre-acute specimen, range: 46 days-4 years before diagnosis). We also selected two specimens for each control, one collected from 1998–2003 (“acute”) and the first specimen collected immediately before their “acute” specimen (“pre-acute”). All specimens were anonymized before release from the DoDSR. We measured PSA in each of these stored specimens by the Access Hybritech PSA assay. We compared the absolute and relative change in PSA between the pre-acute and acute specimens for cases and controls using logistic regression and adjusting for age, race, and time between specimens. Results: IM cases were significantly more likely to have a large increase in PSA between their pre-acute and acute specimens than controls. This finding was observed both when PSA increase was defined as a large absolute (≥0.4 ng/mL; 9.9% versus 2.7%, p=0.033) or relative rise (≥40%; 25.2% versus 8.9%, p=0.0021). Similar results were observed when men with any infectious disease or genitourinary diagnoses between their pre-acute and acute specimens were excluded. Conclusions: Our findings suggest that EBV may infect the prostate and contribute to prostate inflammation and/or cell damage in some men with adult-onset IM. However, another interpretation of our findings that also warrants further investigation is the possibility of systemic inflammation-mediated PSA elevation. This alternate interpretation might have implications not only for a role of later-onset EBV infection in prostate carcinogenesis, but also for the specificity of PSA as a screening test for prostate cancer when used below the currently proposed age for screening initiation of 40 years. Funding: This study was funded by the Patrick C. Walsh Prostate Cancer Research Fund. Citation Information: Cancer Prev Res 2011;4(10 Suppl):A96.

Trachoma, a chronic conjunctivitis caused by repeated reinfection with C. trachomatis, remains the leading infectious cause of blindness worldwide.1 The World Health Organization (WHO) has endorsed SAFE (Surgery for trichiasis, Antibiotics for active trachoma, Facial hygiene and Environmental improvement to reduce transmission), a multi-faceted strategy for trachoma control in endemic areas. Where the prevalence of follicular trachoma (TF) is greater than 10% in children aged 1 to 9 years, WHO recommends mass drug administration (MDA) for everyone, preferably with azithromycin, a single dose antibiotic given annually and currently donated to countries in need by the manufacturer. However, the use of azithromycin in children aged

Background Diagnosis of syphilis is problematic and an accurate rapid point of care (POC) test could be useful in busy STD clinics. There are no FDA Cleared POC tests for Syphilis serology in the USA. Objective To determine the performance of a new, rapid point of care (POC) test, Syph-Check, which is not yet FDA cleared, for the serological diagnosis of Treponema pallidum in female and male STD patients. Methods Men and women >18 yr visiting the Baltimore City Health Department STD clinic were consented to enrol in a trial to determine the accuracy of a new, innovative POC test for syphilis (Veda, manufactured in France) that used a cassette format to test syphilis serology. The Syph-Check One-Step Syphilis test is a point of care, rapid immunoassay screening test for qualitative detection of IgG and IgM antibodies to Treponema pallidum in finger stick blood, plasma, and serum. This product can be used as an initial screening test or as a confirmatory diagnostic test, but is not FDA cleared for use in screening blood or plasma donors. The assay was performed in the STD clinic, required only 20 min to perform, and required no instrumentation. RPR and TPPA tests were performed to determine the sensitivity and specificity of the Syph-Check POC test. Results 194 men and 205 women were enrolled. Of the 399 samples tested, 33 were positive and 366 were negative by the Syph-Check. There were 14 positives and 385 negatives by RPR confirmatory testing. Overall sensitivity compared to RPR testing was 85.7% (95% CI 60.3% to 97.5%) and specificity was 94.5% (95% CI 91.9% to 96.5%). There were 32 positives and 367 negatives by TPPA confirmatory testing. Overall sensitivity compared to TPPA was 43.8% (95% CI 27.5% to 61.1%) and specificity was 94.8% (95% CI 92.2% to 96.8%). Conclusions The Syph-Check POC test was moderately accurate compared to the RPR test, but not as sensitive compared to TPPA. A more accurate POC test for syphilis could be useful for clinicians to test clinic patients and provide immediate screening results for syphilis to patients during an office or clinic visit.

Chlamydia trachomatis (CT) is the most prevalent bacterial sexually transmitted infection (STIs) reported to the Centers for Disease Control and Prevention (CDC). There were 1.2 million cases of chlamydia reported to the CDC in 2008. Neisseria gonorrhoeae (GC) is also one of the most prevalent sexually transmitted infections in men and women. In 2009, there were 301 174, cases reported to the CDC, a rate of 99.1 per 100 000 populations. The CDC estimates that STIs cost the healthcare system $1.5 billion annually. Subsequently, there is an urgent need to develop a low cost sensitive and specific rapid diagnostic test to detect bacterial sexually transmitted infections. To this end, an exciting, novel and rapid technology, which integrates power lysis” and MAMEF (Microwave-Accelerated Metal-Enhanced Fluorescence), to both lyse CT and GC and detect the DNA released from CT and GC and combined CT and GC samples, within 40 s, is demonstrated. In a microwave cavity, 2.45 GHz microwave energy is highly focused into a lysing chamber, using 100 nm thick gold films with “bow-tie” structures, to lyse the bacteria within 10 s. The ultrafast detection of the released DNA from

Background Lymphogranuloma venereum is a clinical condition caused by infection with one of the Chlamydia trachomatis (CT) L serovars. Proper diagnosis of LGV is critical as the treatment varies significantly from antibiotic therapy utilised for other CT infections. LGV has re-emerged in Europe as an important sexually transmitted infection (STI), particularly in men who have sex with men (MSM), due to an outbreak in the Netherlands. LGV surveillance data for the USA is lacking as LGV screening is not routinely performed, even in high risk populations. This study presents LGV surveillance data from multiple sites in the USA. Methods 1671 rectal samples from African-American MSM participating in a study of the HIV Prevention Trials Network (HPTN 061) BROTHERS Project, were collected from six different cities: Los Angeles and San Francisco CA, Atlanta, GA, Boston MA, Washington D.C., New York, NY; and tested for CT by Aptima Combo 2 (Gen-Probe). Additionally, 127 samples from men from Baltimore, MD who reported anal sex or were symptomatic for CT, and had rectal swabs positive for CT by Combo 2 were also included. All samples were screened for LGV utilising a previously verified LGV specific real-time PCR to determine if the samples were positive for any one of the CT L serovars. Results Of the 1671 HPTN 061 samples, 112 (6.75%) were positive for CT and 102 of these have been screened thus far for LGV; none were LGV+. Of 127 CT+ samples from Baltimore, two were LGV+. Thus, of 229 CT+ rectal samples, only 2 (0.87%), tested positive for LGV by real-time PCR. Conclusions Less than 1% of the CT positive samples obtained from rectal swabs from MSM in the US tested positive for LGV. The samples utilised for this study were from a population presumably at high risk for acquisition of LGV, as all samples tested were from men who had either tested positive for CT, reported anal sex, or were symptomatic for CT infection. The prevalence for LGV in this study was quite low, while the non LGV CT prevalence was high in African American MSM from the six cities. Concomitant STDs are thought to drive the disproportionate HIV epidemic among African American MSM and the low prevalence of LGV in this study is of interest. LGV has re-emerged as an important STI in Europe, however this data suggests that it has either not re-emerged in the U.S. or has re-emerged in a population that is not being screened.

Background The Abbott m2000 RealTime CT assay was evaluated as a new option for the detection of Chlamydia trachomatis in specimens obtained from Tanzania, and its performance was compared to the performance of the Roche Amplicor CT Assay. Methods Duplicate swab specimens were collected from villages throughout Tanzania. 304 duplicate samples were shipped to the Johns Hopkins STD laboratory at 2–8°C for the detection of C trachomatis . All swab specimens were shipped in a dry state, expressed in 1 ml of sterile molecular grade DEPC water upon arrival, and analysed using the Roche Amplicor CT assay. Prior to Roche Amplicor amplification and detection, DNA extraction was performed using the Roche Magna Pure LC robot. The duplicate swab specimens were shipped to Indiana University for Abbott m2000 RealTime CT assay analysis. The bacterial load was measured by the DC value of the m2000 RealTime CT. Results Of 304 specimens, 44 (14.5%) were positive for CT via Roche Amplicor CT assay, and 53 (17.4%) were positive for CT via Abbott m2000 RealTime CT assay. The relative quantitation for the m2000 assay ranged from DC 0.62 to DC 22.16. If the Roche PCR assay was considered to be the reference standard, the Abbott m2000 RealTime CT assay sensitivity was 44/44 (100%), specificity was 251/260 (96.53%), positive predictive value was 251/251(100%), and negative predictive value was 44/53 (83.01%). The κ score was 0.890. Discordant specimens, which were determined to be negative by Roche Amplicor and positive by Abbott m2000 RealTime, were tested by Gen-Probe TMA. Of nine discordant tests, two were positive, five were negative, and two were of insufficient volume for retesting. After discordant testing, there appeared to be five samples that were graded to be false positives by m2000. The Abbott m2000 RealTime CT assay sensitivity remained 100%, while specificity increased to 256/258 (99.2%). The negative predictive value increased to 46/48 (95.83%). The κ score was 0.9748 after discordant results were further analysed. Conclusions Abbott m2000 RealTime CT assay demonstrates excellent sensitivity and specificity compared to the Roche Amplicor CT Assay for the detection of C trachomatis . It may be advantageous to be able to measure the relative concentration for CT in some epidemiologic studies.

Background We are developing a highly sensitive, ultra-rapid, multiplex PCR method with fully-integrated DNA preparation and ambient-stable reagents. The assay was used in conjunction with a novel electrochemical detection method to demonstrate low copy number amplification and detection in Chlamydia trachomatis (CT). Methods The method employs custom PCR cards, utilising a thin-film laminate construction to achieve rapid heat transfer, in conjunction with an ultra-rapid thermocycler. All reagents necessary to perform the extraction, amplification and detection are deposited into the cards and air dried at the point of manufacture. Novel, ambient-stable reagent formulations with an 18 month shelf life have been developed. A sample is added to the card and DNA extracted from the sample. The resulting eluate reconstitutes dried PCR reagents and a 40-cycle multiplex PCR is performed using rapid thermocycling. Amplified target is detected using electrochemically-labelled target-specific probes and a double-stranded DNA-specific exonuclease to release the electrochemical label. Released label is read by applying a voltage to a screen printed carbon electrode and at a known oxidation potential the label is oxidised producing a measurable current. The unique rapid performance of this device has been demonstrated in terms of analytical sensitivity and reagent stability under ambient storage conditions. Multiplex capability is demonstrated in this test with the presence of internal control (IC) DNA. Results Analytical sensitivity of the device was evaluated by testing dilutions of CT in the presence of IC DNA. The results show CT detection down to 50 copies when co-extracted, amplified in duplex and detected electrochemically with the IC DNA (see graph). Tests on the reagents dried into the device showed stability for 18 months when stored at ambient temperature (20–25°C). Reagent performance after 18 months9 storage was shown to be equivalent to performance at time zero see Abstract P4-S1.03 figure 1. Conclusions The results show that this device could be used to perform ultra-rapid multiplex PCR with no user intervention after sample addition, allowing minimally-trained staff to carry out the assay in

Background: To investigate the possible effects of different levels of attributes of a point-of-care test (POCT) on sexually transmitted infection (STI) professionals’ decisions regarding an ideal POCT for STI(s). Methods: An online survey was designed based on a large-scale in-depth focus discussion study among STI experts and professionals. The last section of the survey ‘‘build your own POCT’’ was designed by employing the discrete choice experiment approach. Practicing clinicians from two venues, STI-related international conference attendees and U.S. STD clinic clinicians were invited to participate in the survey. Conditional logistical regression modeling was used for data analysis. Results: Overall, 256 subjects took the online survey with 218 (85%) completing it. Most of the participants were STD clinic clinicians who already used some POCTs in their practice. ‘‘The time frame required’’ was identified as a major barrier that currently made it difficult to use STI POCTs. Chlamydia trachomatis was the organism chosen as the top priority for a new POCT, followed by a test that would diagnose early seroconversion for HIV, and a syphilis POCT. Without regard to organism type selected, sensitivity of 90–99% was always the most important attribute to be considered, followed by a cost of $20. However, when the test platform was prioritized for early HIV seroconversion or syphilis, sensitivity was still ranked as most important, but specificity was rated second most important. Conclusions: STI professionals preferred C. trachomatis as the top priority for a new POCT with sensitivity over 90%, low cost, and a very short completion time.

testing. This approach could increase testingwhen a pelvic exam is not performed. However, neither pH nor sialidase has optimal sensitivity and specificity compared to standard clinical criteria. Trust in self-BV test results increased when young women had the opportunity to try the test and discuss results with the clinician. Trust in self-testing was similar for TV and BV, suggesting that trust is not impacted by perceived severity or stigma associated with either diagnosis. The pH test is already marketed for over the counter use; thus, youngwomenwill likely have access to self-testing strategies for vaginitis in the future, but may continue to rely on clinicians for testing. Sources of Support: NIH/NIAID/K23 A1063182; NIBIB/1U54 B007958.

Background: In the USA, reported cases of chlamydia (Chlamydia trachomatis) continue to rise despite substantial funding for screening. National gonorrhoea (Neisseria gonorrhoeae) rates have remained relatively stable, with clusters associated with metropolitan areas. Rural areas are no exception, as every county in Illinois reported cases of chlamydia in 2007. Morbidity associated with infection remains a public health concern, with costs of $US2.5+ billion annually. Novel screening interventions must be examined for their ability to reach those at risk who are missed by traditional methods. Methods: The website Iwantthekit.org was modified to allow residents from 25 contiguous counties in Central Illinois to request a self-collected sample kit. Returned kits were tested for chlamydia and gonorrhoea. The initial study period was 12 months. Results: During the study period, 343 kits were requested from 20 counties and 39.9% were satisfactorily returned for analysis. Positivity rates for chlamydia and gonorrhoea were 5.8% and 1.2%, respectively, for females and 1.9% and 0% for males. Males comprised 37.7% of all internet samples (compared with 23.4% for traditional screening venues) and 40.4% of all internet samples submitted by whites (compared with only 17.2% of traditional screening). Conclusions: The female positivity rate was comparable to those seen in other screening venues and the method successfully engaged at-risk males. Overall, participation was low and the costs associated with the program outweighed the averted costs associated with the few cases identified. While this methodology resulted in sample requests from a wide area, it must be utilised by more individuals to become cost-effective.

Chlamydia pneumoniae has now been associated with pneumonia, bronchitis, pharyngitis, acute chest syndrome of sickle cell disease, and asthma. Because of the difficulty of primary isolation and tissue-culture adaptation of this organism, we used a previously developed polymerase chain reaction-enzyme immunoassay (PCR-EIA) to screen 132 culture-negative bronchoalveolar lavage (BAL) specimens from 108 immunocompromised patients (34% of whom were positive for human immunodeficiency virus) and 7 healthy volunteers. Thirteen specimens (9.8%) from 12 immunocompromised patients (11.1%) gave a positive result; one patient had two positive specimens obtained 3 days apart. No healthy volunteer had a PCR-EIA-positive BAL specimen. Twelve (11.1%) of the immunocompromised patients also had diagnostic levels of antibody. Four patients had positive results in both PCR-EIA and serological tests. Thus 20 (18.5%) of the 108 patients had laboratory evidence of C. pneumoniae infection. These data indicate that diagnosis of acute infection with C. pneumoniae can be established more rapidly and reliably by PCR-EIA than by culture or serology, particularly among immunocompromised patients, in whom serological changes in response to infection are relatively undependable. With an infection rate of 11.1% according to PCR-EIA, C. pneumoniae should be considered in the evaluation and treatment of pneumonia in immunocompromised patients.

Two cases of Chlamydia psittaci pneumonia are presented. In each, a rapid diagnosis was made through the use of direct immunofluorescent antibody staining of respiratory secretions with monoclonal antibodies to chlamydial antigens. In one case the diagnosis was confirmed by the isolation of the causative organism from sputum and a pharyngeal swab. Chlamydial lipopolysaccharide was detectable in sputum from this patient in an enzyme immunoassay. Serological responses to C. psittaci, Chlamydia trachomatis, and Chlamydia pneumoniae were evaluated, and serological cross-reactivity was observed between each species. Rapid antigen detection systems for Chlamydia species that use commercially available reagents can be helpful in the evaluation of selected patient populations.

The 16S ribosomal DNA sequence of Chlamydia pneumoniae was determined and compared with the corresponding gene sequences of Chlamydia psittaci and Chlamydia trachomatis. C. pneumoniae has been reported to exhibit little chromosomal DNA homology with the other chlamydial species, and its phylogenetic relationships within the genus Chlamydia have not been described. A polymerase chain reaction was employed to determine the 16S rRNA gene sequence of C. pneumoniae. Ten primers from the C. psittaci sequences were used to amplify a C. pneumoniae template in overlapping segments of the gene. Sequence data for 1,554 bases indicated that the levels of homology of C. pneumoniae with C. psittaci and C. trachomatis were 96.19 and 94.07%, respectively. These data support the results of previous biochemical and developmental studies indicating that C. pneumoniae is more closely related to C. psittaci than to C. trachomatis.

Chlamydia pneumoniae has been proposed as a possible link to an infectious etiology of MS.1,2⇓ An article in this issue of Neurology by Yao et al. supports this hypothesis; the investigators conclude that the oligoclonal bands in CSF of patients with MS represent antibodies against Chlamydophila antigens.3 This finding could be exciting, but readers are urged to exercise caution in their interpretation of these findings. MS is a complex demyelinating disease of unknown etiology with a prevalence of up to 350,000 cases in the United States annually.4 An infectious etiology has been supported by epidemiologic studies, studies in identical twins, and studies indicating an increase in IgG levels in CSF in patients with MS.4 The possible association of chlamydia with MS, first reviewed by Perlmutter and Darvish in 1983 and more recently by …

Background Blinding trachoma, caused by ocular infection with Chlamydia trachomatis, is targeted for global elimination by 2020. Knowledge of risk factors can help target control interventions. Methodology/Principal Findings As part of a cluster randomised controlled trial, we assessed the baseline prevalence of, and risk factors for, active trachoma and ocular C. trachomatis infection in randomly selected children aged 0–5 years from 48 Gambian and 36 Tanzanian communities. Both children's eyes were examined according to the World Health Organization (WHO) simplified grading system, and an ocular swab was taken from each child's right eye and processed by Amplicor polymerase chain reaction to test for the presence of C. trachomatis DNA. Prevalence of active trachoma was 6.7% (335/5033) in The Gambia and 32.3% (1008/3122) in Tanzania. The countries' corresponding Amplicor positive prevalences were 0.8% and 21.9%. After adjustment, risk factors for follicular trachoma (TF) in both countries were ocular or nasal discharge, a low level of household head education, and being aged ≥1 year. Additional risk factors in Tanzania were flies on the child's face, being Amplicor positive, and crowding (the number of children per household). The risk factors for being Amplicor positive in Tanzania were similar to those for TF, with the exclusion of flies and crowding. In The Gambia, only ocular discharge was associated with being Amplicor positive. Conclusions/Significance These results indicate that although the prevalence of active trachoma and Amplicor positives were very different between the two countries, the risk factors for active trachoma were similar but those for being Amplicor positive were different. The lack of an association between being Amplicor positive and TF in The Gambia highlights the poor correlation between the presence of trachoma clinical signs and evidence of C. trachomatis infection in this setting. Only ocular discharge was associated with evidence of C. trachomatis DNA in The Gambia, suggesting that at this low endemicity, this may be the most important risk factor. Trial Registration ClinicalTrials.gov NCT00792922, Author Summary Trachoma is caused by Chlamydia trachomatis and is the leading infectious cause of blindness. The World Health Organization's (WHO) control strategy includes antibiotic treatment of all community members, facial cleanliness, and environmental improvements. By determining how prevalent trachoma is, decisions can be made whether control activities need to be put in place. Knowing what factors make people more at risk of having trachoma can help target trachoma control efforts to those most at risk. We looked at the prevalence of active trachoma and C. trachomatis infection in the eyes of children aged 0–5 years in The Gambia and Tanzania. We also measured risk factors associated with having active trachoma or infection. The prevalence of both active trachoma and infection was lower in The Gambia (6.7% and 0.8%, respectively) than in Tanzania (32.3% and 21.9%, respectively). Risk factors for active trachoma were similar in the two countries. For infection, the risk factors in Tanzania were similar to those for TF, whereas in The Gambia, only ocular discharge was associated with infection. These results show that although the prevalence of active trachoma and infection is very different between the two countries, the risk factors for active trachoma are similar but those for infection are different.

Objectives Self-testing and point-of-care (POC) tests could improve the detection of sexually transmitted infections (STIs) in adolescents. This study aimed to (1) validate a scale measuring acceptability of self-testing for trichomoniasis, (2) compare acceptability of self versus clinician testing using a POC test for trichomoniasis, (3) examine changes in acceptability after experience and review of results, and (4) examine predictors of acceptability. Methods Women (14–22 years old) performed the POC test and completed surveys assessing acceptability of self and clinician testing at baseline, after testing, and after discussion of results. Factor analysis examined scale structure; changes in mean scale scores were assessed with mixed models. Generalised linear models examined predictors of acceptability. Results Of 247 participants, 54 (22%) had a positive POC test for trichomoniasis. Factor analysis confirmed four acceptability subscales: trust of results, confidence, comfort, and effects of testing. At baseline, trust and confidence were higher, and comfort was lower, for clinician versus self testing. For self-testing, all subscale scores increased from baseline to after testing, and trust increased from after testing to after discussion. Trust of self and clinician results was not significantly different after discussion. A positive attitude towards home testing predicted higher self-test acceptability on all subscales. Tampon use was associated with increased self-test comfort at baseline. Concordance between self and clinician results predicted increased trust of self testing after discussion. Conclusions Many young women lack confidence in their ability to self-test for trichomoniasis. Allowing women to try a POC test and review the results with a clinician increases acceptability of self-testing.

DNA was amplified by polymerase chain reaction from the gene encoding the major outer membrane protein (MOMP) of Chlamydia pneumoniae in order to examine the relatedness of strains isolated from diverse geographical regions. Primers for this reaction were chosen to span a 207-bp region comparable to that of the fourth variable segment of the MOMP gene of Chlamydia trachomatis. Among C. trachomatis, sequence heterogeneity is characteristic within variable sequence domain IV (VDIV) and correlates with serovar type. In contrast, sequence analysis of polymerase chain reaction products from 13 C. pneumoniae isolates indicated that all tested strains were identical in this segment of the MOMP gene. The predicted amino acid sequences from the C. pneumoniae VDIV gene products shared only 13.3 to 30% homology with published VDIV regions from serovars of C. trachomatis. Homology of these VDIV amino acid sequences with sequences from strains of C. psittaci ranged from 45.7 to 60%. The sequence conservation of the VDIV region of the MOMP gene indicates that C. pneumoniae strains may be more genetically homogeneous than C. trachomatis or Chlamydia psittaci strains. Future investigations of antigenic diversity among C. pneumoniae strains should be aimed at the evaluation of variation in other regions of the C. pneumoniae genome.

Chlamydia pneumoniae is an important cause of respiratory disease in humans, but diagnosis of C. pneumoniae is hindered by difficulties in the in vitro growth of the organism. In order to improve detection and identification, we recently developed a polymerase chain reaction (PCR) assay which uses oligonucleotide primers specific for C. pneumoniae. The nucleic acid sequence was determined for the 16S rRNA of C. pneumoniae, and regions in which C. pneumoniae differed from both Chlamydia psittaci and Chlamydia trachomatis were identified. Oligonucleotide primers corresponding to these unique regions were then synthesized and used in a PCR for the detection of C. pneumoniae. The C. pneumoniae-specific primers permitted the identification of six isolates of C. pneumoniae, but no reaction was observed with the 15 serovars of C. trachomatis or two strains of C. psittaci. PCR should prove to be valuable in confirming the identification of C. pneumoniae and in the diagnosis of C. pneumoniae infections.

Michel et al (see page 187) present documentation in this issue that a Conformitee Europeenne (CE) marked home-use test for Chlamydia trachomatis that is available over the internet performs very poorly.1 The authors demonstrated a lack of accuracy of this assay compared with Amplicor PCR with sensitivities of 12.5% and 20% in both a lower (8% prevalence) and high prevalence (22.9% prevalence) population, respectively. False-positive results were equally as problematic, since the specificities were only 93.5% and 88.1% in the two populations studied. Since this test could be used by asymptomatic women, taking advantage of easy purchasing through the internet, the demonstrated positive predictive value of 28% is also unacceptable. With …

The polymerase chain reaction was used to detect major outer membrane protein (MOMP) gene sequences from the three species of Chlamydia. Using three primer pairs and one restriction enzyme digestion, three distinct genotypes, corresponding to the three species, Chlamydia trachomatis, Chlamydia pneumoniae, and Chlamydia psittaci, were demonstrated. C. trachomatis was amplified by all three primer pairs and the amplified fragment was digested by EcoRI. C. pneumoniae was amplified by only two of the three primer pairs, and the amplified fragment was digested by EcoRI. C. psittaci was amplified by only two of the pairs and the amplified fragment was EcoRI-resistant. C. trachomatis was detected in direct patient specimens, tissue culture specimens, and fixed specimens, and all serovars of C. trachomatis were detectable. The polymerase chain reaction can detect and differentiate the three species of Chlamydia and may prove a valuable diagnostic tool.

Detection of Chlamydia trachomatis infection was evaluated by culture and a new Syva enzyme immunoassay (EIA) in 1,012 patients at two Baltimore, Md., sexually transmitted disease clinics. The overall chlamydia prevalence determined by culture was 12%. For 506 fresh cervical and urethral specimens, the sensitivity of Syva EIA was 90% and its specificity was 94% compared with culture. Discordant Syva EIA results were further evaluated by staining the sediment in centrifuged culture transport media and Syva EIA transport tubes with a fluorescent monoclonal antibody to C. trachomatis to detect elementary bodies. Reanalysis of the data after use of this technique to resolve discordant results increased sensitivity and specificity to 92 and 96%, respectively. A subsample of 307 fresh cervical specimens was also tested in a three-way comparison using Abbott Chlamydiazyme, Syva EIA, and culture. In this sample, compared with culture, the sensitivity and specificity of Syva EIA were 87 and 95%, respectively, and for Chlamydiazyme they were 77 and 98%, respectively. Syva EIA is a 4-h, easy-to-perform enzyme-linked immunosorbent assay which has a high sensitivity with fresh genital specimens and offers an excellent alternative to culture.

This work compares a rapid solid-phase EIA (Abbott TestPack Chlamydia) to tissue culture and a direct fluorescent antibody test (Syva Microtrak) for detection of C. trachomatis in 436 patients attending two inner-city sexually transmitted diseases (STD) clinics. The prevalence of C. trachomatis by culture was 12% (5% in men, 15% in women). Overall sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of TestPack compared to culture were 70%, 98%, 80%, and 96% respectively. In men, 12 specimens were positive by TestPack, while only eight specimens were positive by culture. Six TestPack-positive, culture-negative specimens were further evaluated by centrifugation of culture transport media and examination of the sediment for chlamydia elementary bodies (EBs) using fluorescent monoclonal antibodies to C. trachomatis. Using this procedure, five of six culture negative specimens contained EBs (revised sensitivity 85%, specificity 99%, PPV 92%, NPV 99%). In 285 women evaluable in culture and TestPack, 44 (15%) specimens were culture positive; TestPack was positive in 29 (sensitivity 66%) culture positive women. Of 241 culture negative patients, 238 had negative TestPack results (specificity 99%) and no EBs were detected in the culture-negative, TestPack-positive specimens. Twenty-three (8%) Microtrak specimens were unsatisfactory for testing; two of these were culture and TestPack positive. Therefore, of 263 specimens evaluable using Microtrak, 42 (16%) specimens were culture positive; Microtrak was positive in 32 (sensitivity 76%) culture-positive women. Abbott TestPack Chlamydia is a rapid (25 minute), visually read format requiring no specialized equipment for detection of chalmydia infections with a sensitivity comparable to that of Microtrak.

To serially examine the immunopathogenesis and histopathology of infection with Chlamydia pneumoniae, we inoculated two cynomolgus monkeys in the conjunctival sac, nose, and nasopharynx with C. pneumoniae TWAR. After inoculation, C. pneumoniae was isolated from the inoculation sites and the rectums of both monkeys for a period of 5 weeks. After a second inoculation, C. pneumoniae was recovered from the inoculation sites and the rectums of both monkeys for 20 weeks. A third inoculation with C. pneumoniae caused very little productive infection at any site. Prior C. pneumoniae infection did not prevent subsequent C. trachomatis serovar E (Bour strain) infection. Clinical and histopathologic ocular responses to C. pneumoniae infection were mild compared with those to infection with C. trachomatis serovar E. Rectal infection, demonstrated by culture isolation and immunohistopathology, occurred without direct experimental inoculation. Both immunofluorescent staining of mucosal smears with monoclonal antibodies and tissue culture were able to detect C. pneumoniae infection. Experimental nonhuman primate infection with C. pneumoniae appears to be clinically and histopathologically mild and can occur at extrapulmonary sites.

PURPOSE. The World Health Organization recommends mass treatment of trachoma-hyperendemic communities, but there are scant empiric data on the number of rounds of treatment that are necessary for sustainable reductions. The rates of active trachoma and infection with C. trachomatis were determined in a community 3.5 years after two rounds of mass treatment with azithromycin. METHODS. Maindi village in Tanzania received a first round of mass treatment with azithromycin after a baseline survey for trachoma and infection. All residents aged 6 months and older were offered single-dose treatment with azithromycin (excluding pregnant women with no clinical trachoma, who were offered topical tetracycline). The residents were followed over an 18-month period, and, according to similar treatment criteria, were offered retreatment at 18 months. Five years after baseline (3.5 years after the second round of mass treatment), a new census and survey of current residents for trachoma and infection was conducted. Children are the sentinel markers of infection and trachoma in communities, so data are presented specifically for ages 0 to 7 years (preschool age) and 8 to 16 years. RESULTS. Treatment coverage was above 80% for all ages in the first round, and highest (90%) in preschool-aged children. Second-round coverage was lower, 70%, and 70% in preschoolaged children. At 5 years, trachoma rates were still lower than baseline, ranging from 45% in those aged 0 to 3 years to 8% in those aged 11 to 15 years (compared with 81% and 39% at baseline, respectively). Infection rates at baseline ranged from 71% to 57%, but were 27% to 17% at 5 years after two rounds of mass treatment. At 5 years, there were no differences in trachoma or infection rates, when comparing new residents who came after the second mass treatment with those who had been resident in the village during both rounds (P 0.05). Infection rates were lower in those who had been treated twice or at 18 months than in those treated only at baseline or never treated. CONCLUSIONS. Although mass treatment appears to be associated with lower disease and infection rates in the long term, trachoma and C. trachomatis infection were not eliminated in this trachoma hyperendemic village 3.5 years after two rounds of mass treatment. Continued implementation of the SAFE strategy in this environment is needed. (Invest Ophthalmol Vis Sci. 2007;48:1492‐1497) DOI:10.1167/iovs.06-0625

Background: The antigen-drive association of gastric MALT lymphoma with H. pylori is well recognized. Successful antibiotic therapy can result in lymphoma remission, and with it, lymphoma prevention. We have sought to prospectively identify possible associated infections in patients with non-bulky, advanced stage indolent lymphoma as the first step to such a lymphoma treatment/prevention strategy. These patients are often candidates for “watch and wait” and it is during this period that a window of opportunity may exist to identify and treat related infections. Methods: Patients with a new diagnosis of indolent lymphoma (FL and nFL), stages II (intra-abdominal), III and IV fulfilling GELF criteria for observation were eligible. Studies performed: Stool H. pylori, Hepatitis C and Borrelia serologies, Borrelia and Chlamydia fixed tissue PCR, peripheral blood mononuclear cell PCR for Chlamydia, and a hydrogen breath test for small bowel bacterial overgrowth. Results: 55 patients have been enrolled with IRB informed consent: 32 females, 23 males; median age, 54 years (21–77); 30 FL, 25 nFL; stage II (4 pt), III (22), and IV (29). All met GELF criteria for observation. Infections tested include: H. pylori (13 positive: 6 FL, 7 nFL); Hepatitis C (3+; 1 FL, 2 nFL); and small bowel bacterial overgrowth (10+; 4 FL, 6 nFL). Borrelia serologies and tissue PCR were negative in all 13 pts tested. Chlamydia psittaci tissue PCR positive in 1 FL (12 negative). Thus, 20 of 54 (37%) patients have had at least one positive study; and, to date we have observed lymphoma responses after successful antibiotic therapy alone in 6 of 20: H. pylori (1 FL with CRu for 20+ months; 1 nFL with transient near CR); Hepatitis C (1 FL with PR but HCV persistent; 2 nFL (1 CR for 24+ mos; 1 stable, currently on HCV therapy); SBBO (1 FL in PR for 28+ mos). Of interest, the patients with associated infections but without lymphoma response to antibiotics, appear to have required institution of lymphoma treatment sooner than those without initial associated infections (Treatment free survival 48% vs. 87.5%, p=0.08; 33 months median f/u from diagnosis), possibly suggesting a different biology. Conclusion: Infections are common in advanced stage indolent lymphoma (37% in our series). Anecdotal lymphoma responses have been seen and 2 have been durable CRs (10%) ongoing for 20+ mos following infection eradication alone. The identification and treatment of associated infections may be a first step toward developing a lymphoma prevention strategy.

Background Trichiasis recurrence following surgery is a serious problem for trachoma programs. Objective To determine if postoperative treatment with azithromycin compared with topical tetracycline reduces recurrence up to 1 year, and if azithromycin treatment of household members provides additional benefit compared with treating only the surgical patient. Design A randomized, single-masked, clinical trial was conducted in Ethiopia. A total of 1452 patients with trichiasis were randomized 1:1:1 to the following 3 arms: single-dose (1 g) oral azithromycin alone, single-dose azithromycin for household members (20 mg/kg up to 1 g) plus the patient, or topical tetracycline (twice per day for 6 weeks). Main Outcome Measures Trichiasis recurrence within 1 year following surgery. Results The combined azithromycin groups had significantly fewer recurrences, 6.9 of 100 person-years overall, compared with topical tetracycline, 10.3 of 100 person-years (P = .047). There was no additional reduction in the arm that also treated household members, 8.1 of 100 person-years, compared with treating the surgical patients alone, 5.8 of 100 person-years (P = .19). Conclusions In trachoma-endemic areas, a single dose of azithromycin reduced postoperative trichiasis recurrence rates by one third compared with topical tetracycline. Application to Clinical Practice In countries where azithromycin is part of the Trachoma Control Program, patients with trachomatous trichiasis should be treated postoperatively to prevent recurrence.

Objective: To ascertain the opinions, concerns and perceptions of sexually active women to guide the development of an internet-based chlamydia outreach and screening program using self-administered vaginal swabs as a first step to prevention. Methods: Seven focus groups were conducted by trained facilitators. Questions were designed to initially open the discussion and elicit the members’ own perceptions. Secondary, more probing questions were asked later to confirm participants’ responses and elicit truthful answers. The main discussion topics were women’s ideas about internet recruitment for chlamydia screening, preferred genital sample type, self-sampling at home using vaginal swabs and using the mail to return specimens. Participants were 42 women, aged 14–49 years. Structured discussions were facilitated using open-ended questions about access to chlamydia testing via the internet. Data were collected and reviewed for common themes and emphasis. Results: All women actively participated in the discussions, providing valuable information. The concepts of self-sampling and the overall project were viewed positively, along with draft advertisements, questionnaires and self-sampling instructions; some modifications were suggested. Common themes included offering free kits available within their community or by direct mail, as well as pre-addressed, stamped mailers for returning the kit to the laboratory for testing. Commonly perceived obstacles and potential risks included: maintenance of confidentiality; situations of embarrassment; and ensuring simplicity of packaging. Women indicated confidence in their ability to collect vaginal specimens and willingness to call for their test results. Conclusions: Focus-group surveys were a useful tool and provided valuable feedback to inform the design of a specialised website to educate and facilitate access to chlamydia screening through home sampling.

For two decades, treatment guidelines for sexually transmitted diseases (STDs) have recommended empirical co-treatment for chlamydia when patients are treated for gonorrhea. Because the epidemiology of and diagnostic testing for STDs have changed over time, co-treatment may no longer be needed as a clinical or public health strategy.To assess the prevalence of chlamydia among patients at STD clinics who are infected with and treated for Neisseria gonorrhoeae and to determine whether co-treatment recommendations are still justified.Cross-sectional analysis of data from a multisite study.Five public STD clinics (Baltimore, Maryland; Denver, Colorado; Long Beach, California; Newark, New Jersey; and San Francisco, California), July 1993 through October 1995.3885 heterosexual patients (2184 men and 1701 women) who agreed to participate in a trial of counseling interventions and had conclusive results from diagnostic tests for gonorrhea and chlamydia performed routinely as part of the trial.Infection with Chlamydia trachomatis as determined by polymerase chain reaction.Chlamydia trachomatis was detected in 20% (95% CI, 16% to 24%) of 411 men and 42% (CI, 35% to 50%) of 151 women with laboratory-confirmed N. gonorrhoeae. Chlamydia trachomatis was detected in 19% (CI, 15% to 22%) of 410 men and 35% (CI, 28% to 43%) of 154 women with treatment indications for gonorrhea who would not otherwise have been treated for chlamydia: chlamydia prevalence among these patients was significantly higher than among patients without treatment indications for either gonorrhea or chlamydia: 7% in men and 9% in women (relative risk, 2.58 [CI, 1.92 to 3.47] and 4.12 [CI, 3.05 to 5.57], respectively).The frequent presence of chlamydia among patients at STD clinics who received treatment for gonorrhea, including sex partners of gonorrhea-infected patients, supports continuing current recommendations for co-treatment.

Context Adolescents are at highest risk for infection with Chlamydia trachomatis, an important preventable cause of pelvic inflammatory disease and subsequent tubal factor infertility in US women. Current guidelines for delivery of adolescent primary care services recommend yearly chlamydia screening for those adolescent females considered to be at risk. Objectives To describe the epidemiology of prevalent and incident chlamydia infection among adolescent females to assess the appropriate interval for chlamydia screening and to define risk factors that would identify adolescent females to target for screening. Design Prospective longitudinal study. Patients A consecutive sample of 3202 sexually active females 12 through 19 years old making 5360 patient visits over a 33-month period, January 1994 through September 1996. Setting Baltimore, Md, family planning, sexually transmitted disease, and school-based clinics. Intervention Testing for C trachomatis by polymerase chain reaction. Main outcome measures Prevalence and incidence of C trachomatis infections; predictors of positive test result for C trachomatis. Results Chlamydia infection was found in 771 first visits (24.1%) and 299 repeat visits (13.9%); 933 adolescent females (29.1%) had at least 1 positive test result. Females who were 14 years old had the highest age-specific chlamydia prevalence rate (63 [27.5%] of 229 cases; P=.01). The chlamydia incidence rate was 28.0 cases per 1000 person-months (95% confidence interval, 24.9-31.5 cases). The median time was 7.2 months to a first positive chlamydia test result and 6.3 months to a repeat positive test result among those with repeat visits. Independent predictors of chlamydia infection--reason for clinic visit, clinic type, prior sexually transmitted diseases, multiple or new partners, or inconsistent condom use-failed to identify a subset of adolescent females with the majority of infections. Conclusions A high prevalence and incidence of C trachomatis infection were found among adolescent females. We, therefore, recommend screening all sexually active adolescent females for chlamydia infection every 6 months, regardless of symptoms, prior infections, condom use, or multiple partner risks.

Objective. —To determine the frequency of Chlamydia trachomatis genital infection within sexual partnerships using highly sensitive polymerase chain reaction (PCR) amplification and to identify the variables that might modify transmission. Design. —Cross-sectional study of sexual partnerships comparing in vitro culture and PCR amplification for C trachomatis . Setting. —Two outpatient sexually transmitted disease clinics. Participants. —Four hundred ninety-four people in sexual partnerships attending sexually transmitted disease clinics. Main Outcome Measure. —Genital infection with C trachomatis. Methods. —DNA sequencing was performed to examine specific genotypes within and between partnerships. Cross-sectional analysis was performed to determine characteristics associated with concordance or discordance of infection with partnerships. Results. —Cultures were positive for C trachomatis in 8.5% of males and 12.9% of females ( P =.03). Using PCR, more infections were identified both in males (14.2%) and in females (15.8%), and the difference in infection rates analyzed by sex was no longer significant. In 20.4% of 494 couples, at least 1 partner had PCR results positive for C trachomatis , with a concordant infection rate of 10.7%, significantly higher than the 5.5% concordant infection rate demonstrable by culture ( P Conclusions. —Using PCR, the frequency of chlamydia transmission by infected males and females was nearly identical. The high rate of concordant infection, high frequency of infection among asymptomatic individuals, and high frequency of transmission regardless of sex underscore the importance of routine screening for chlamydia in both males and females, along with provision of treatment to all sexual partners of chlamydia-infected individuals.

The Culturette Brand Clostridium difficile test (CDT; Marion Laboratories, Inc., Kansas City, Mo.) is a latex agglutination test for C. difficile. The recent controversy involving the identity of antigens detected by CDT has made decisions on its use difficult. We compared the test results with those of selective culture and stool cytotoxin assays in investigations of two nursing home outbreaks of C. difficile-associated disease in order to formulate usage recommendations. Selective culture for C. difficile identified 27 (19%) of 142 subjects as carriers. CDT and the stool cytotoxin assay identified only 52 and 48% of these carriers, respectively. Compared with the stool cytotoxin assay, CDT had a high sensitivity (92%) and specificity (89%) for the detection of C. difficile disease, but the positive predictive value of the test was only 17% when the prevalence of disease was 2%. We conclude that the CDT should not be used to identify carriers but that it is a sufficiently sensitive and specific screening test for diagnosing C. difficile disease. However, since the positive predictive value of the CDT is low when the prevalence of disease is low, positive test results should be confirmed by the stool cytotoxin assay.

Salmonella enterica species infections are a significant public health problem causing high morbidity rates worldwide and high mortality rates in the developing world. These infections are not always rapidly diagnosed as a cause of bloodstream infections because of the limitations of blood culture, which greatly affects clinical care as a result of treatment delays. A molecular diagnostic assay that could rapidly detect and identify S. enterica species infections as a cause of sepsis is needed. Nine typhoidal and nontyphoidal S. enterica serovars were used to establish the limit of detection (LOD) of a previously published 16S rRNA gene PCR (16S PCR) in mock whole blood specimens. In addition, 16 typhoidal and nontyphoidal S. enterica serovars were used to evaluate the serovar differentiation capability of 16S PCR coupled with high-resolution melt analysis. The overall LOD of 16S PCR for the nine typhoidal and nontyphoidal S. enterica serovars analyzed was