Last data update: Sep 23, 2024. (Total: 47723 publications since 2009)
Records 1-24 (of 24 Records) |
Query Trace: Ballard RC [original query] |
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Antibody responses to two recombinant treponemal antigens (rp17 and TmpA) before and after azithromycin treatment for yaws in Ghana and Papua New Guinea
Parameswaran N , Mitjà O , Bottomley C , Kwakye C , Houinei W , Pillay A , Danavall D , Chi KH , Ballard RC , Solomon AW , Chen CY , Bieb SV , Adu-Sarkodie Y , Mabey DC , Asiedu K , Marks M , Martin D . J Clin Microbiol 2021 59 (5) WHO and its partners aim to interrupt yaws transmission in endemic countries and to certify others as being yaws-free. Transmission can be assessed using rapid plasma reagin (RPR) tests, reflecting current or recent infection, but RPR is operationally impractical.We evaluated changes in antibody levels against two recombinant treponemal antigens, rp17 (also known as Tp17) and TmpA, after antibiotic treatment given as part of a randomized controlled trial for yaws in Ghana and Papua New Guinea. Paired serum samples from children aged 6-15 years with confirmed yaws, collected before and after treatment, were tested for antibodies to rp17 and TmpA using a semi-quantitative bead-based immunoassay.Of 344 baseline samples, 342 tested positive for anti-rp17 antibodies and 337 tested positive for anti-TmpA antibodies. Six months after treatment, the median decrease in anti-rp17 signal was 3.2%, whereas the median decrease in anti-TmpA was 53.8%. The magnitude of change in the anti-TmpA response increased with increasing RPR titer fold-change. These data demonstrate that responses to TmpA decrease markedly within 6 months of treatment whereas (as expected) those to rp17 do not.Incorporating responses to TmpA as a marker of recent infection within an integrated sero-surveillance platform could provide a way to prioritize areas for yaws mapping. |
Increased discrimination of Treponema pallidum strains by subtyping with a four-component system incorporating a mononucleotide tandem repeat in rspA.
Pillay A , Lee MK , Slezak T , Katz SS , Sun Y , Chi KH , Morshed M , Philip S , Ballard RC , Chen CY . Sex Transm Dis 2019 46 (4) e42-e45 A guanine mononucleotide repeat in the rpsA (tp0279) gene was evaluated for improved strain discrimination using 72 Treponema pallidum-positive specimens. The tandem repeat combined with the enhanced Centers for Disease Control and Prevention typing system resulted in increased discrimination and should be useful for molecular epidemiologic studies on syphilis especially in outbreaks and among men who have sex with men. |
Molecular strain typing of the yaws pathogen, Treponema pallidum subspecies pertenue.
Katz SS , Chi KH , Nachamkin E , Danavall D , Taleo F , Kool JL , Addo KK , Ampofo W , Simpson SV , Ye T , Asiedu KB , Ballard RC , Chen CY , Pillay A . PLoS One 2018 13 (9) e0203632 Yaws is a neglected tropical disease caused by the bacterium Treponema pallidum subspecies pertenue. The disease primarily affects children under 15 years of age living in low socioeconomic conditions in tropical areas. As a result of a renewed focus on the disease owing to a recent eradication effort initiated by the World Health Organization, we have evaluated a typing method, adapted from and based on the enhanced Centers for Disease Control and Prevention typing method for T. pallidum subsp. pallidum, for possible use in epidemiological studies. Thirty DNA samples from yaws cases in Vanuatu and Ghana, 11 DNA samples extracted from laboratory strains, and 3 published genomic sequences were fully typed by PCR/RFLP analysis of the tpr E, G, and J genes and by determining the number of 60-bp repeats within the arp gene. Subtyping was performed by sequencing a homonucleotide "G" tandem repeat immediately upstream of the rpsA gene and an 84-bp region of tp0548. A total of 22 complete strain types were identified; two strain types in clinical samples from Vanuatu (5q11/ak and 5q12/ak), nine strain types in clinical samples from Ghana (3q12/ah, 4r12/ah, 4q10/j, 4q11/ah, 4q12/ah, 4q12/v, 4q13/ah, 6q10/aj, and 9q10/ai), and twelve strain types in laboratory strains and published genomes (2q11/ae, 3r12/ad, 4q11/ad, 4q12/ad, 4q12/ag, 4q12/v, 5r12/ad, 6r12/x, 6q11/af, 10q9/r, 10q12/r, and 12r12/w). The tpr RFLP patterns and arp repeat sizes were subsequently verified by sequencing analysis of the respective PCR amplicons. This study demonstrates that the typing method for subsp. pallidum can be applied to subsp. pertenue strains and should prove useful for molecular epidemiological studies on yaws. |
Community-based mass treatment with azithromycin for the elimination of yaws in Ghana - Results of a pilot study
Abdulai AA , Agana-Nsiire P , Biney F , Kwakye-Maclean C , Kyei-Faried S , Amponsa-Achiano K , Simpson SV , Bonsu G , Ohene SA , Ampofo WK , Adu-Sarkodie Y , Addo KK , Chi KH , Danavall D , Chen CY , Pillay A , Sanz S , Tun Y , Mitja O , Asiedu KB , Ballard RC . PLoS Negl Trop Dis 2018 12 (3) e0006303 INTRODUCTION: The WHO yaws eradication strategy consists of one round of total community treatment (TCT) of single-dose azithromycin with coverage of > 90%.The efficacy of the strategy to reduce the levels on infection has been demonstrated previously in isolated island communities in the Pacific region. We aimed to determine the efficacy of a single round of TCT with azithromycin to achieve a decrease in yaws prevalence in communities that are endemic for yaws and surrounded by other yaws-endemic areas. METHODS: Surveys for yaws seroprevalence and prevalence of skin lesions were conducted among schoolchildren aged 5-15 years before and one year after the TCT intervention in the Abamkrom sub-district of Ghana. We used a cluster design with the schools as the primary sampling unit. Among 20 eligible primary schools in the sub district, 10 were assigned to the baseline survey and 10 to the post-TCT survey. The field teams conducted a physical examination for skin lesions and a dual point-of-care immunoassay for non-treponemal and treponemal antibodies of all children present at the time of the visit. We also undertook surveys with non-probabilistic sampling to collect lesion swabs for etiology and macrolide resistance assessment. RESULTS: At baseline 14,548 (89%) of 16,287 population in the sub-district received treatment during TCT. Following one round of TCT, the prevalence of dual seropositivity among all children decreased from 10.9% (103/943) pre-TCT to 2.2% (27/1211) post-TCT (OR 0.19; 95%CI 0.09-0.37). The prevalence of serologically confirmed skin lesions consistent with active yaws was reduced from 5.7% (54/943) pre-TCT to 0.6% (7/1211) post-TCT (OR 0.10; 95% CI 0.25-0.35). No evidence of resistance to macrolides against Treponema pallidum subsp. pertenue was seen. DISCUSSION: A single round of high coverage TCT with azithromycin in a yaws affected sub-district adjoining other endemic areas is effective in reducing the prevalence of seropositive children and the prevalence of early skin lesions consistent with yaws one year following the intervention. These results suggest that national yaws eradication programmes may plan the gradual expansion of mass treatment interventions without high short-term risk of reintroduction of infection from contiguous untreated endemic areas. |
Complete Genome Sequences of 11 Haemophilus ducreyi Isolates from Children with Cutaneous Lesions in Vanuatu and Ghana.
Pillay A , Katz SS , Abrams AJ , Ballard RC , Simpson SV , Taleo F , Lahra MM , Batra D , Rowe L , Trees DL , Asiedu K , Chen CY . Genome Announc 2016 4 (4) Haemophilus ducreyi causes chancroid and has recently been shown to be a significant cause of cutaneous lesions in tropical or subtropical regions where yaws is endemic. Here, we report the draft genome assemblies for 11 cutaneous strains of Haemophilus ducreyi, isolated from children in Vanuatu and Ghana. |
Meta-analysis of the performance of a combined treponemal and non-treponemal rapid diagnostic test for syphilis and yaws
Marks M , Yin YP , Chen XS , Castro A , Causer L , Guy R , Wangnapi R , Mitja O , Aziz A , Castro R , da Luz Martins Pereira F , Taleo F , Guinard J , Belec L , Tun Y , Bottomley C , Ballard RC , Mabey DC . Clin Infect Dis 2016 63 (5) 627-633 BACKGROUND: The human treponematoses are important causes of disease. Mother-to-child transmission of syphilis remains a major cause of stillbirth and neonatal death. There are also almost 100,000 cases of endemic treponemal disease reported annually, predominantly yaws. Rapid diagnostic tests would improve access to screening for these diseases. Most RDTs cannot distinguish current and previous infection. The Dual Path Platform Syphilis Screen and Confirm test includes both a treponemal (T1) and non-treponemal (T2) component and may improve the accuracy of diagnosis. METHODS: We conducted a meta-analysis of published and unpublished evaluations of the DPP Rapid Diagnostic Test (RDT) for the diagnosis of syphilis and yaws. We calculated the sensitivity, specificity and overall agreement of the test compared to reference laboratory tests. RESULTS: Nine evaluations including a total of 7,267 tests were included. Sensitivity was higher in patients with higher titre RPR (≥1:16) for both the T1 (98.2% vs 90.1%, p<0.0001) and the T2 component (98.2% vs 80.6%, p<0.0001). Overall agreement between the DPP test and reference serology was 85.2% (84.4-86.1%). Agreement was highest for high titre active infection and lowest for past infection CONCLUSIONS: The RDT has good sensitivity and specificity of the treponemal and non-treponemal components both in cases of suspected syphilis and yaws, although the sensitivity is decreased at lower antibody titres. |
Challenges and key research questions for yaws eradication
Marks M , Mitja O , Vestergaard LS , Pillay A , Knauf S , Chen CY , Bassat Q , Martin DL , Fegan D , Taleo F , Kool J , Lukehart S , Emerson PM , Solomon AW , Ye T , Ballard RC , Mabey DC , Asiedu KB . Lancet Infect Dis 2015 15 (10) 1220-1225 Yaws is endemic in west Africa, southeast Asia, and the Pacific region. To eradicate yaws by 2020, WHO has launched a campaign of mass treatment with azithromycin. Progress has been made towards achievement of this ambitious goal, including the validation of point-of-care and molecular diagnostic tests and piloting of the strategy in several countries, including Ghana, Vanuatu, and Papua New Guinea. Gaps in knowledge need to be addressed to allow refinement of the eradication strategy. Studies exploring determinants of the spatial distribution of yaws are needed to help with the completion of baseline mapping. The finding that Haemophilus ducreyi causes lesions similar to yaws is particularly important and further work is needed to assess the effect of azithromycin on these lesions. The integration of diagnostic tests into different stages of the eradication campaign needs investigation. Finally, studies must be done to inform the optimum mass-treatment strategy for sustainable interruption of transmission. |
Molecular differentiation of Treponema pallidum subspecies in skin ulceration clinically suspected as yaws in Vanuatu using real-time multiplex PCR and serological methods.
Chi KH , Danavall D , Taleo F , Pillay A , Ye T , Nachamkin E , Kool JL , Fegan D , Asiedu K , Vestergaard LS , Ballard RC , Chen CY . Am J Trop Med Hyg 2014 92 (1) 134-8 We developed a TaqMan-based real-time quadriplex polymerase chain reaction (PCR) to simultaneously detect Treponema pallidum subspecies pallidum, T. pallidum subsp. pertenue, and T. pallidum subsp. endemicum, the causative agents of venereal syphilis, yaws, and bejel, respectively. The PCR assay was applied to samples from skin ulcerations of clinically presumptive yaws cases among children on Tanna Island, Vanuatu. Another real-time triplex PCR was used to screen for the point mutations in the 23S rRNA genes that have previously been associated with azithromycin resistance in T. pallidum subsp. pallidum strains. Seropositivity by the classical syphilis serological tests was 35.5% among children with skin ulcerations clinically suspected with yaws, whereas the presence of T. pallidum subsp. pertenue DNA was only found in lesions from 15.5% of children. No evidence of T. pallidum subsp. pertenue infection, by either PCR or serology was found in approximately 59% of cases indicating alternative causes of yaws-like lesions in this endemic area. |
Introducing new diagnostics into STI control programmes: the importance of programme science
Peeling RW , Mabey D , Ballard RC . Sex Transm Infect 2013 89 (2) 115-9 Many innovative diagnostic technologies will become commercially available over the next 5-10 years. These tests can potentially transform the diagnosis of sexually transmitted infections but their introduction into control programmes can be hampered by health system constraints, and political, cultural, socioeconomic and behavioural factors. We used the introduction of syphilis rapid tests to illustrate the importance of programme science to address the gap between accruing evidence of acceptable test performance and the complexity of programme design, implementation and evaluation of test deployment to address public health needs and improve patient-important outcomes. |
Detection of the A2058G and A2059G 23S rRNA gene point mutations associated with azithromycin resistance in Treponema pallidum by use of a TaqMan real-time multiplex PCR assay.
Chen CY , Chi KH , Pillay A , Nachamkin E , Su JR , Ballard RC . J Clin Microbiol 2013 51 (3) 908-13 Macrolide treatment failure in syphilis patients is associated with a single point mutation (either A2058G or A2059G) in both copies of the 23S rRNA gene in Treponema pallidum strains. The conventional method for the detection of both point mutations uses nested PCR combined with restriction enzyme digestions, which is laborious and time-consuming. We initially developed a TaqMan-based real-time duplex PCR assay for detection of the A2058G mutation, and upon discovery of the A2059G mutation, we modified the assay into a triplex format to simultaneously detect both mutations. The point mutations detected by the real-time triplex PCR were confirmed by pyrosequencing. A total of 129 specimens PCR positive for T. pallidum that were obtained from an azithromycin resistance surveillance study conducted in the United States were analyzed. Sixty-six (51.2%) of the 129 samples with the A2058G mutation were identified by both real-time PCR assays. Of the remaining 63 samples that were identified as having a macrolide-susceptible genotype by the duplex PCR assay, 17 (27%) were found to contain the A2059G mutation by the triplex PCR. The proportions of macrolide-susceptible versus -resistant genotypes harboring either the A2058G or the A2059G mutation among the T. pallidum strains were 35.6, 51.2, and 13.2%, respectively. None of the T. pallidum strains examined had both point mutations. The TaqMan-based real-time triplex PCR assay offers an alternative to conventional nested PCR and restriction fragment length polymorphism analyses for the rapid detection of both point mutations associated with macrolide resistance in T. pallidum. |
Prevalence and associations of genital ulcer and urethral pathogens in men presenting with genital ulcer syndrome to primary health care clinics in South Africa
Lewis DA , Muller E , Steele L , Sternberg M , Radebe F , Lyall M , Ballard RC , Paz-Bailey G . Sex Transm Dis 2012 39 (11) 880-885 BACKGROUND: This study aimed to determine the prevalence of genital ulcer and urethral pathogens, as well as their association with clinical features, in men with genital ulcer disease (GUD) enrolled in a clinical trial. METHODS: Clinical data were collected by questionnaire. Ulcer swabs were tested for herpes simplex viruses (HSV-1/2), Treponema pallidum, Haemophilus ducreyi, and Chlamydia trachomatis L1-L3. First-pass urine was tested for urethral pathogens, namely Neisseria gonorrhoeae, C. trachomatis, Trichomonas vaginalis, and Mycoplasma genitalium. Pathogens were detected by real-time molecular assays. Blood was tested for HIV, HSV-2, and syphilis-associated antibodies. Pathogens and clinical associations were investigated using the chi test. RESULTS: A total of 615 men with GUD were recruited. Herpes simplex virus (HSV-1, 4.2%; HSV-2, 98.2%) and bacterial pathogens were detected in 451 (73.6%) and 48 (7.8%) of genital ulcers, respectively. Human immunodeficiency virus, HSV-2, and treponemal antibodies were detected in 387 (62.9%), 434 (70.6%), and 141 (23.0%) men, respectively, whereas 54 men (8.8%) were rapid plasmin reagin (RPR) seropositive. A total of 223 urethral infections were diagnosed in 188 men (30.6%), including 69 (11.2%) M. genitalium, 64 (10.4%) T. vaginalis, 60 (9.8%) C. trachomatis, and 30 (4.9%) N. gonorrhoeae infections. Dysuria was reported by 170 men (27.6%), and 69 men (11.5%) had urethral discharge on examination. Urethral pathogens were detected in 102/409 (24.9%) men without these clinical features. CONCLUSIONS: Herpes accounted for most GUD cases and urethral pathogen coinfections were common. Erythromycin, dispensed to treat infrequent chancroid and lymphogranuloma venereum cases, provided additional treatment of some asymptomatic urethral pathogens. Additional antibiotics would be required to treat asymptomatic trichomoniasis and gonorrhea. |
The molecular diagnosis of sexually transmitted genital ulcer disease.
Chen CY , Ballard RC . Methods Mol Biol 2012 903 103-12 Highly sensitive and specific nucleic acid amplification tests (NAATs) have emerged as the gold standard diagnostic tests for many infectious diseases. Real-time PCR has further refined the technology of nucleic acid amplification with detection in a closed system and enabled multiplexing to simultaneously detect multiple pathogens. It is a versatile, fast, and high-throughput system for pathogen detection that has reduced the risk of PCR contamination, eliminated post-PCR manipulations, and improved the cost-effectiveness of testing. In addition, real-time PCR can be applied to self-collected noninvasive specimens. Here, we describe an in-house developed TaqMan-based real-time multiplex PCR (M-PCR) assay for the diagnosis of sexually transmitted genital ulcer disease (GUD) and discuss briefly on issues associated with validation of assay performance. |
Genital herpes and HIV infection: can we still exploit the intimate relationship?
Ballard RC . South Afr J Epidemiol Infect 2011 26 (4) 210-214 South Africa is suffering the most severe HIV epidemic on earth. Prior to emergence of HIV/AIDS, conventional sexually transmitted infections (STIs) were endemic in many underprivileged communities as a result of many social factors. Since conventional STIs may act as co-factors in both acquisition and transmission of HIV, it was initially thought that improved treatment of these infections would result in a reduction of HIV transmission. As the HIV epidemic matured, the aetiological agents causing genital ulcer disease changed, with genital herpes emerging as the most potent STI co-factor in HIV spread. Despite learning more about herpes simplex virus/HIV interactions, attempts to utilise this knowledge to design HIV prevention strategies proved disappointing. However, the lessons learned may prove to be valuable in the future. |
Cost-effectiveness of a dual non-treponemal/treponemal syphilis point-of-care test to prevent adverse pregnancy outcomes in Sub-Saharan Africa
Owusu-Edusei K Jr , Gift TL , Ballard RC . Sex Transm Dis 2011 38 (11) 997-1003 BACKGROUND: A dual nontreponemal/treponemal point-of-care test (Dual-POC) that simultaneously detects both nontreponemal and treponemal antibodies has been developed and evaluated. In this study, we compare the health and economic outcomes of the new test with existing syphilis tests/testing algorithms in a high prevalence setting. METHODS: We used a cohort decision analysis model to examine 4 testing/screening algorithms; the Dual-POC test, the laboratory-based rapid plasma reagin and Treponema pallidum haemagglutination assay (RPR+TPHA) algorithm, an onsite RPR testing, and point-of-care treponemal immunochromatographic strip (ICS) testing. Outcomes included miscarriage, stillbirth, congenital syphilis, low birth weight, and neonatal death. Disability-adjusted life-years were estimated for all health outcomes. The analytic horizon was the life expectancy for the mother and child. RESULTS: For a cohort of 1000 pregnant women in a historically high syphilis prevalence population (10% infected and 15% previously infected), the model predicted a total of 39 adverse pregnancy outcomes if no serologic screening were performed; 13 for the laboratory-based RPR+TPHA; 11 for the on-site RPR strategy; 5 for the Dual-POC strategy; and 2 for the ICS strategy. On the basis of assumption that the cost of ICS and the Dual-POC tests were the same, the ICS strategy was the most cost saving (saved $30,000) followed by the Dual-POC strategy (saved $27,000). CONCLUSIONS: The dual-POC test may help save cost in resource-poor settings where disease prevalence (and loss to follow-up) is high, while substantially reducing overtreatment. |
Laboratory confirmed case of yaws in a 10 year-old boy from the Republic of the Congo
Pillay A , Chen CY , Reynolds MG , Mombouli JV , Castro AC , Louvouezo D , Steiner B , Ballard RC . J Clin Microbiol 2011 49 (11) 4013-5 We report a case of yaws in a patient with puritic cutaneous eruption who was initially suspected of infection with monkeypox. The diagnosis was established by real-time PCR and sequencing of specific treponemal DNA sequences. This is the first report describing the use of DNA sequencing to identify T. pallidum subsp. pertenue-specific sequences in a patient with active yaws. |
Gonococcal resistance: are cephalosporins next?
Kirkcaldy RD , Ballard RC , Dowell D . Curr Infect Dis Rep 2011 13 (2) 196-204 The development of resistance to multiple antibiotics has limited treatment options for gonorrhea in many countries. Currently, the Centers for Disease Control and Prevention only recommend cephalosporin antibiotics for treatment of uncomplicated gonorrhea. Although the cephalosporins remain effective, the demonstrated ability of Neisseria gonorrhoeae to develop resistance has raised concerns about the possibility of multidrug-resistant N. gonorrhoeae strains, which include cephalosporin resistance. This article provides a review of global trends in cephalosporin susceptibility among gonococcal isolates, recent findings that deepen our understanding of genetic mechanisms of resistance, and the public health and clinical implications of the potential emergence of cephalosporin-resistant gonorrhea. |
Laboratory diagnosis of sexually transmitted infections in Belarus
Pankratov O , Shimanskaya I , Pankratov V , Navrotsky A , Ballard RC , Unemo M , Domeika M . Acta Derm Venereol 2011 91 (1) 64-5 Following the collapse of the Soviet Union, the manage-ment of sexually transmitted infections (STIs) became fragmented, with a consequent increase in STI morbidity. In Belarus, reliable data are generally lacking as a result of poor access to effective diagnostic facilities, while the quality of laboratory testing for STIs in recognised centres is questionable. As part of the Belarusian-Swedish project “Optimization of the prevention and control of STI/HIV in Belarus” (1) we surveyed STI diagnostic facilities for the methods they used (including their range, availability and quality) and their adherence to international evidence-based guidelines |
The tale of two serologic tests to screen for syphilis-treponemal and nontreponemal: does the order matter?
Owusu-Edusei K Jr , Koski KA , Ballard RC . Sex Transm Dis 2010 38 (5) 448-56 BACKGROUND: Standard syphilis screening involves an initial screening with a nontreponemal test and confirmation of positives with a treponemal test. However, some laboratories have reversed the order. There is no detailed quantitative and qualitative evaluation for the order of testing. In this study, we analyzed the health and economic outcomes of the order of testing for the 2 serologic tests used in syphilis screening under pure screening settings. METHODS: We used a cohort decision analysis to examine the health and economic outcomes of the screening algorithms for low and high prevalence settings. The 2-step algorithms were nontreponemal followed by treponemal (Nontrep-First) and treponemal followed by nontreponemal (Trep-First). We included the 1-step algorithms (treponemal only [Trep-Only] and an on-site nontreponemal only [Nontrep-Only]) for comparison. We estimated overtreatment rates and the number of confirmatory tests required for each algorithm. RESULTS: For a cohort of 10,000 individuals, our results indicated that the overtreatment rates were substantially higher (more than 3 times) for the 1-step algorithms, although they treated a higher number of cases (over 15%). The 2-step algorithms detected and treated the same number of individuals. Among the 2-step algorithms, the Nontrep-First was more cost-effective in the low prevalence setting ($1400 vs. $1500 per adverse outcome prevented) and more cost-saving ($102,000 vs. $84,000) in the high prevalence setting. CONCLUSIONS: The difference in cost was largely due to the substantially higher number of confirmatory tests required for the Trep-First algorithm, although the number of cases detected and treated was the same. |
Novel point-of-care test for simultaneous detection of nontreponemal and treponemal antibodies in patients with syphilis
Castro AR , Esfandiari J , Kumar S , Ashton M , Kikkert SE , Park MM , Ballard RC . J Clin Microbiol 2010 48 (12) 4615-9 We describe a point-of-care immunochromatographic test for the simultaneous detection of both nontreponemal and treponemal antibodies in the sera of patients with syphilis that acts as both a screening and a confirmatory test. A total of 1,601 banked serum samples were examined by the dual test, and the results were compared to those obtained using a quantitative rapid plasma reagin (RPR) test and the Treponema pallidum passive particle agglutination (TP-PA) assay. Compared to the RPR test, the reactive concordance of the dual test nontreponemal line was 98.4% when the RPR titers of sera were ≥1:2 and the nonreactive concordance was 98.6%. Compared to the TP-PA assay, the reactive and nonreactive concordances of the treponemal line were 96.5% and 95.5%, respectively. These results indicate that the dual test could be used for the serological diagnosis of syphilis in primary health care clinics or resource-poor settings and therefore improve rates of treatment where patients may fail to return for their laboratory results. |
Guidelines for the laboratory diagnosis of mycoplasma genitalium infections in East European countries
Shipitsyna E , Savicheva A , Solokovskiy E , Ballard RC , Domeika M , Unemo M , Jensen JS . Acta Derm Venereol 2010 90 (5) 461-7 The present guidelines aim to provide comprehensive information regarding laboratory diagnosis of Mycoplasma genitalium infections in East European countries. These guidelines are intended primarily for laboratory professionals testing specimens from patients at sexual health care clinics, but may also be useful for community-based screening programmes. Diagnosis of M. genitalium infection is performed exclusively using nucleic acid amplification tests (NAATs), owing to the poor and slow growth of the bacterium in culture. Because no internationally validated and approved commercial NAAT for M. genitalium detection is presently available, it is necessary that laboratories performing M. genitalium diagnostics not only carefully evaluate and validate their in-house PCRs before using them routinely, but also use comprehensive internal controls and take part in external quality assessment programmes. The guidelines were elaborated as a consensus document of the Eastern European Sexual and Reproductive Health (EE SRH) Network, and comprise one element of a series of guidelines aimed at optimizing, standardizing, and providing guidance on quality laboratory testing for reproductive tract infections. |
Guidelines for the laboratory diagnosis of trichomoniasis in East European countries
Domeika M , Zhurauskaya L , Savicheva A , Frigo N , Sokolovskiy E , Hallen A , Unemo M , Ballard RC . J Eur Acad Dermatol Venereol 2010 24 (10) 1125-1134 The laboratory diagnosis of sexually transmitted infections in many Eastern European countries remains suboptimal. The main objective of the present evidence-based guidelines is to provide comprehensive information regarding the laboratory diagnosis of infections caused by Trichomonas vaginalis in East European countries. In particular, the present guidelines recommend: (i) to encourage examination of the wet mounts of vaginal exudates, instead of stained smears, at all clinical settings; (ii) nucleic acid amplification tests (NAATs) or culture could be employed if no trichomonads are detected on microscopic examination of the wet preparation and there is a strong indication of infection and (iii) the use of NAATs is encouraged in screening, using non-invasive specimens, or high volume testing situations. In the absence of internationally recognized commercial NAAT systems, tests developed in-house should be validated using obtainable international standards and quality assured strictly. Individual East European countries may be required to make minor national adjustments to these guidelines as a result of lack of accessibility to some reagents or equipment, or laws in a specific country. |
Serologic testing for syphilis in the United States: a cost-effectiveness analysis of two screening algorithms
Owusu-Edusei Jr K , Peterman TA , Ballard RC . Sex Transm Dis 2010 38 (1) 1-7 BACKGROUND: The introduction of automated treponemal enzyme immunoassays and chemiluminescence assays (EIA/CA) tests has led some laboratories in the United States to use new syphilis screening algorithms that start with a treponemal test. We compared the economic and health outcomes of this new algorithm with the standard algorithm from the perspective of the United States health system. METHODS: We used a cohort decision analysis to estimate the expected costs and effects (including follow-ups and overtreatment) of the 2 algorithms from a health-care system perspective. In the standard algorithm, rapid plasma reagin (RPR) is followed (if reactive) by EIA/CA (Nontreponemal-First). In the new algorithm, EIA/CA is followed (if reactive) by RPR. If the RPR is negative, Treponema pallidum passive particle agglutination assay (TP-PA) test is used (Treponemal-First). RESULTS: For a cohort of 200,000 individuals (1000 current infections and 10,000 previous infections), the net costs were $1.6 m (Treponemal-First) and $1.4 m (Nontreponemal-First). The Treponemal-First option treated 118 more cases (986 vs. 868) but resulted in a substantially higher number of follow-ups (11,450 vs. 3756) and overtreatment (964 vs. 38). Treating the additional 118 cases might prevent 1 case of tertiary syphilis. The estimated cost-effectiveness ratios were $1671 (Treponemal-First) and $1621 (Nontreponemal-First) per case treated. The overtreatment was a function of the specificity of the EIA/CA and the lack of independence of EIA/CA and TP-PA. CONCLUSION: The Treponemal-First option costs slightly more and results in more unnecessary treatment. The use of an independent confirmatory treponemal test, rather than TP-PA, might reduce this overtreatment. |
An immunofiltration device for the simultaneous detection of non-treponemal and treponemal antibodies in patients with syphilis
Castro AR , Mody HC , Parab SY , Patel MT , Kikkert SE , Park MM , Ballard RC . Sex Transm Infect 2010 86 (7) 532-6 OBJECTIVE: The development of a rapid immunofiltration (flow-through) test for the simultaneous detection of non-treponemal and treponemal antibodies in the serum of patients with syphilis. METHODS: The assay is rapid, inexpensive, and requires limited expertise in interpreting the results. The test is based on the principle of immunofiltration, with two antigens and control material spotted on the membrane of a through-flow device. A positive test is characterised by the appearance of three red/magenta spots within 2-10 min. RESULTS: A total of 376 banked serum samples obtained from the Georgia Public Health Laboratory was examined by the flow-through test, the rapid plasma reagin (RPR) test and the Treponema pallidum passive particle agglutination assay (TPPA). The sensitivity and specificity of the non-treponemal spot were 96.5% and 97.7%, respectively, when compared with the RPR test, and the sensitivity and specificity of the treponemal test spot were 97.3% and 99.1% when compared with the TPPA test. In addition, the test yielded equivalent results to those obtained in comparator tests when 104 sera from cases of syphilis of known stage, 49 sera from diseases other than syphilis and 23 sera known to exhibit biological false-positive reactions were tested in parallel. CONCLUSIONS: These results indicate that the dual treponemal and non-treponemal assay could be used as a screen and confirmatory test for the serological diagnosis of syphilis in remote or resource-poor settings where there is a need to provide counselling and treatment at the initial consultation. |
Molecular epidemiology of syphilis-San Francisco, 2004-2007
Katz KA , Pillay A , Ahrens K , Kohn RP , Hermanstyne K , Bernstein KT , Ballard RC , Klausner JD . Sex Transm Dis 2010 37 (10) 660-3 We describe the molecular epidemiology of syphilis in San Francisco (SF) using Treponema pallidum specimens obtained from patients examined at the SF municipal sexually transmitted diseases clinic during 2004-2007. Of 69 specimens, 52 (75%) were subtype 14d9. Single subtype predominance might reflect a closely linked sexual network in SF. |
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