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1.
Lancet ; 402(10398): 336-346, 2023 07 22.
Artículo en Inglés | MEDLINE | ID: mdl-37481272

RESUMEN

Syphilis is a sexually and vertically transmitted bacterial infection caused by the bacterium Treponema pallidum. Its prevalence is high in low-income and middle-income countries, and its incidence has increased in high-income countries in the last few decades among men who have sex with men. Syphilis is a major cause of adverse pregnancy outcomes in low-income and middle-income countries. Clinical features include a primary chancre at the point of inoculation, followed weeks later by the rash of secondary syphilis, a latent period, and in some cases, involvement of the eyes, CNS, and cardiovascular systems. It is diagnosed serologically. A single intramuscular dose of long-acting benzathine penicillin is recommended for people who have had syphilis for less than 1 year and longer courses for people with late latent syphilis. Control strategies include screening and treatment of all pregnant women, and targeted interventions for groups at high risk. Vaccine development, research on antibiotic prophylaxis, and digital messaging as prevention strategies are ongoing.


Asunto(s)
Chancro , Minorías Sexuales y de Género , Sífilis , Embarazo , Masculino , Femenino , Humanos , Sífilis/diagnóstico , Sífilis/tratamiento farmacológico , Sífilis/epidemiología , Homosexualidad Masculina , Treponema pallidum , Penicilinas
2.
Clin Infect Dis ; 73(9): e2773-e2780, 2021 11 02.
Artículo en Inglés | MEDLINE | ID: mdl-32776137

RESUMEN

BACKGROUND: In the Solomon Islands and Vanuatu, the sign trachomatous inflammation-follicular (TF) is common, but ocular infection with Chlamydia trachomatis is not. It is therefore debatable whether azithromycin mass drug administration (MDA), the recommended antibiotic treatment strategy for trachoma's elimination as a public health problem, is necessary in this setting. We set out to estimate what proportion of adolescents were at risk of progression of trachomatous scarring. METHODS: A cross-sectional survey was undertaken of all children aged 10-14 years resident in communities identified as high-TF clusters during previous population-based mapping. Graders examined children for clinical evidence of trachomatous scarring, pannus, and Herbert's pits (HPs) or limbal follicles in both eyes. A dried blood spot was collected from each child and tested for antibodies to C. trachomatis. RESULTS: A total of 492 children in 24 villages of the Solomon Islands and Vanuatu were examined. In total, 35/492 (7%) of children had limbal signs (pannus and/or HPs) plus any conjunctival scarring. And 9/492 (2%) had limbal signs and moderate or severe conjunctival scarring; 22% of children were anti-Pgp3 seropositive. CONCLUSIONS: Few adolescents here are at risk of future complications from trachoma, supporting the conclusion that further antibiotic MDA is not currently required for trachoma elimination purposes in these settings.


Asunto(s)
Tracoma , Adolescente , Niño , Cicatriz/epidemiología , Estudios Transversales , Humanos , Melanesia/epidemiología , Pannus , Tracoma/tratamiento farmacológico , Tracoma/epidemiología , Vanuatu
3.
J Clin Microbiol ; 59(5)2021 04 20.
Artículo en Inglés | MEDLINE | ID: mdl-33568467

RESUMEN

WHO and its partners aim to interrupt yaws transmission in countries of endemicity 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 to 15 years with confirmed yaws, collected before and after treatment, were tested for antibodies to rp17 and TmpA using a semiquantitative 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.


Asunto(s)
Azitromicina , Buba , Formación de Anticuerpos , Azitromicina/uso terapéutico , Niño , Ghana , Humanos , Papúa Nueva Guinea , Treponema pallidum , Buba/tratamiento farmacológico
4.
Sex Transm Infect ; 97(1): 51-55, 2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-32345631

RESUMEN

OBJECTIVES: Complications from sexually transmitted infections (STIs) can result in severe morbidity and mortality. To date, no STI population studies have been conducted on the Bijagos Islands, Guinea Bissau. Our objective was to estimate the prevalence of and identify risk factors for Chlamydia trachomatis (Ct), Neisseria gonorrhoea (Ng), Mycoplasma genitalium (Mg), Trichomonas vaginalis (Tv) and Treponema pallidum (Tp) on Bubaque, the most populated island. METHODS: A cross-sectional survey was conducted on the island of Bubaque among people aged 16-49 years. Participants were asked to answer a questionnaire on STI risk factors, to provide urine samples (men and women) and vaginal swabs (women) for PCR testing for Ct, Ng, Mg and Tv, and to provide dry blood spots for Tp particle agglutination assays. Data were analysed to estimate the prevalence of STIs and logistic regression was used to identify risk factors. RESULTS: In total, 14.9% of participants were found to have a curable STI, with the highest prevalence being observed for Tv (5.9%) followed by Ct (3.8%), Ng (3.8%), Mg (1.9%) and Tp (0.8%). Significant risk factors for having any STI included being female, younger age and concurrent partnership. Having had a previous STI that was optimally treated was a protective factor. CONCLUSIONS: This study demonstrates that there is a considerable burden of STI on the Bijagos Islands, stressing the need for diagnostic testing to facilitate early detection and treatment of these pathogens to stop ongoing transmission. Moreover, these results indicate the need to conduct further research into the STI burden on the Bijagos Islands to help inform and develop a national STI control strategy.


Asunto(s)
Enfermedades de Transmisión Sexual/epidemiología , Adolescente , Adulto , Infecciones por Chlamydia/epidemiología , Chlamydia trachomatis , Estudios Transversales , ADN/orina , Femenino , Gonorrea/epidemiología , Guinea Bissau/epidemiología , Humanos , Masculino , Persona de Mediana Edad , Infecciones por Mycoplasma/epidemiología , Mycoplasma genitalium , Neisseria gonorrhoeae , Prevalencia , Factores de Riesgo , Sífilis/epidemiología , Treponema pallidum , Vaginitis por Trichomonas/epidemiología , Trichomonas vaginalis , Adulto Joven
5.
Infect Immun ; 88(4)2020 03 23.
Artículo en Inglés | MEDLINE | ID: mdl-31964744

RESUMEN

Trachoma is initiated during childhood following repeated conjunctival infection with Chlamydia trachomatis, which causes a chronic inflammatory response in some individuals that leads to scarring and in-turning of the eyelids in later life. There is currently no treatment to halt the progression of scarring trachoma due to an incomplete understanding of disease pathogenesis. A cohort study was performed in northern Tanzania in 616 children aged 6 to 10 years at enrollment. Every 3 months for 4 years, children were examined for clinical signs of trachoma, and conjunctival swabs were collected for C. trachomatis detection and to analyze the expression of 46 immunofibrogenic genes. Data were analyzed in relation to progressive scarring status between baseline and the final time point. Genes that were significantly associated with scarring progression included those encoding proinflammatory chemokines (CXCL5, CCL20, CXCL13, and CCL18), cytokines (IL23A, IL19, and IL1B), matrix modifiers (MMP12 and SPARCL1), immune regulators (IDO1, SOCS3, and IL10), and a proinflammatory antimicrobial peptide (S100A7). In response to C. trachomatis infection, IL23A and PDGF were significantly upregulated in scarring progressors relative to in nonprogressors. Our findings highlight the importance of innate proinflammatory signals from the epithelium and implicate interleukin 23A (IL-23A)-responsive cells in driving trachomatous scarring, with potential key mechanistic roles for PDGFB, MMP12, and SPARCL1 in orchestrating fibrosis.


Asunto(s)
Cicatriz/patología , Cicatriz/fisiopatología , Conjuntiva/patología , Inmunidad Innata , Factores Inmunológicos/biosíntesis , Tracoma/patología , Tracoma/fisiopatología , Niño , Chlamydia trachomatis/crecimiento & desarrollo , Femenino , Perfilación de la Expresión Génica , Humanos , Factores Inmunológicos/genética , Estudios Longitudinales , Masculino , Tanzanía
6.
Clin Infect Dis ; 71(12): 3226-3228, 2020 12 15.
Artículo en Inglés | MEDLINE | ID: mdl-32421762

RESUMEN

The prevalence of antibodies to Strongyloides stercoralis was measured in 0-12-year-olds using a bead-based immunoassay before and after ivermectin mass drug administration (MDA) for scabies in the Solomon Islands. Seroprevalence was 9.3% before and 5.1% after MDA (P = .019), demonstrating collateral benefits of ivermectin MDA in this setting.


Asunto(s)
Escabiosis , Strongyloides stercoralis , Estrongiloidiasis , Animales , Niño , Humanos , Ivermectina/uso terapéutico , Melanesia/epidemiología , Prevalencia , Escabiosis/tratamiento farmacológico , Escabiosis/epidemiología , Estudios Seroepidemiológicos , Estrongiloidiasis/tratamiento farmacológico , Estrongiloidiasis/epidemiología
7.
Emerg Infect Dis ; 26(11): 2685-2693, 2020 11.
Artículo en Inglés | MEDLINE | ID: mdl-33079046

RESUMEN

Yaws is a neglected tropical disease targeted for eradication by 2030. To achieve eradication, finding and treating asymptomatic infections as well as clinical cases is crucial. The proposed plan, the Morges strategy, involves rounds of total community treatment (i.e., treating the whole population) and total targeted treatment (TTT) (i.e., treating clinical cases and contacts). However, modeling and empirical work suggests asymptomatic infections often are not found in the same households as clinical cases, reducing the utility of household-based contact tracing for a TTT strategy. We use a model fitted to data from the Solomon Islands to predict the likelihood of elimination of transmission under different intervention schemes and levels of systematic nontreatment resulting from the intervention. Our results indicate that implementing additional treatment rounds through total community treatment is more effective than conducting additional rounds of treatment of at-risk persons through TTT.


Asunto(s)
Erradicación de la Enfermedad , Buba , Trazado de Contacto , Humanos , Melanesia , Modelos Teóricos , Enfermedades Desatendidas/tratamiento farmacológico , Enfermedades Desatendidas/epidemiología , Enfermedades Desatendidas/prevención & control , Treponema pallidum , Buba/tratamiento farmacológico , Buba/epidemiología , Buba/prevención & control
8.
PLoS Med ; 17(9): e1003364, 2020 09.
Artículo en Inglés | MEDLINE | ID: mdl-32931499

RESUMEN

In this Perspective, David Mabey and colleagues discuss a recent PLOS Medicine article on azithromycin as an intervention for reducing child mortality.


Asunto(s)
Azitromicina , Mortalidad del Niño , Niño , Humanos , Niger
9.
Genome Res ; 27(7): 1220-1229, 2017 07.
Artículo en Inglés | MEDLINE | ID: mdl-28588068

RESUMEN

Chlamydia trachomatis is the world's most prevalent bacterial sexually transmitted infection and leading infectious cause of blindness, yet it is one of the least understood human pathogens, in part due to the difficulties of in vitro culturing and the lack of available tools for genetic manipulation. Genome sequencing has reinvigorated this field, shedding light on the contemporary history of this pathogen. Here, we analyze 563 full genomes, 455 of which are novel, to show that the history of the species comprises two phases, and conclude that the currently circulating lineages are the result of evolution in different genomic ecotypes. Temporal analysis indicates these lineages have recently expanded in the space of thousands of years, rather than the millions of years as previously thought, a finding that dramatically changes our understanding of this pathogen's history. Finally, at a time when almost every pathogen is becoming increasingly resistant to antimicrobials, we show that there is no evidence of circulating genomic resistance in C. trachomatis.


Asunto(s)
Chlamydia trachomatis/genética , Farmacorresistencia Bacteriana/genética , Ecotipo , Evolución Molecular , Genoma Bacteriano , Chlamydia trachomatis/aislamiento & purificación , Femenino , Humanos , Masculino
10.
Malar J ; 19(1): 412, 2020 Nov 17.
Artículo en Inglés | MEDLINE | ID: mdl-33203419

RESUMEN

BACKGROUND: Malaria remains a significant public health problem in Guinea-Bissau, West Africa. Government control measures include bed net distribution campaigns, however, local knowledge, attitudes and practices towards bed nets and malaria are uncharacterized on the remote Bijagos Archipelago. METHODS: Knowledge, attitude and practice questionnaires were conducted with household heads, aiming to explore the understanding of malaria and factors influencing bed net uptake and usage. Nets were observed in situ to appraise net quality and behaviour. All 14 villages and one semi-urban neighbourhood on Bubaque Island were included. One in 5 households containing school-aged children were randomly selected. RESULTS: Of 100 participants, 94 were aware of malaria and 66 of those considered it a significant or severe problem, primarily because of its impact on health and income. Transmission, symptoms and risk factors were well known, however, 28.0% of participants felt under-informed. Some 80.0% reported contact with distribution campaigns, with inter-village variability. Campaign contact was associated with feeling well informed (OR 3.44; P = 0.024) and inversely with perceiving malaria a household (OR 0.18; P = 0.002) or regional problem (OR 0.25; P = 0.018). Every household contained nets; every identifiable example was a long-lasting insecticide-treated net (LLIN), however, 23.0% of households contained at least one expired net. Replacements were in demand; 89.0% of households reported that all residents used nets, and average occupancy was 2.07 people per net; 65.2% stated that the repurposing of bed nets was common. Correctly using bed nets, defined by age, integrity and demonstration, was 35.0% and strongly associated with completing intermittent preventative treatment in pregnancy (RR 3.63; P = 0.014). CONCLUSIONS: Knowledge of malaria is good in these communities. Bed nets are used widely and are valued for their role in preventing malaria. However, their use is frequently sub-optimal and offers a target for improving malaria control by adapting popular distribution campaigns to provide more education alongside fresh LLINs. The impact of this could be significant as LLINs represent the mainstay of malaria prevention in Guinea-Bissau; however, the persistence of malaria despite the high uptake of LLINs seen in this study suggests that novel supplementary approaches must also be considered.


Asunto(s)
Conocimientos, Actitudes y Práctica en Salud , Malaria/psicología , Control de Mosquitos/estadística & datos numéricos , Mosquiteros/estadística & datos numéricos , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Guinea Bissau , Humanos , Islas , Masculino , Persona de Mediana Edad , Adulto Joven
11.
Malar J ; 19(1): 27, 2020 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-31941507

RESUMEN

BACKGROUND: Bubaque is the most populous island of the Bijagos archipelago, a group of malaria-endemic islands situated off the coast of Guinea-Bissau, West Africa. Malaria vector control on Bubaque relies almost exclusively on the use of long-lasting insecticidal nets (LLINs). However, there is little information on local vector bionomics and insecticide resistance. METHODS: A survey of mosquito species composition was performed at the onset of the wet season (June/July) and the beginning of the dry season (November/December). Sampling was performed using indoor adult light-traps and larval dipping. Anopheles mosquitoes were identified to species level and assessed for kdr allele frequency by TaqMan PCR. Females were analysed for sporozoite positivity by CSP-ELISA. Resistance to permethrin and α-cypermethrin was measured using the CDC-bottle bioassay incorporating the synergist piperonyl-butoxide. RESULTS: Several Anopheles species were found on the island, all belonging to the Anopheles gambiae sensu lato (s.l.) complex, including An. gambiae sensu stricto, Anopheles coluzzii, Anopheles melas, and An. gambiae/An. coluzzii hybrids. Endophagic Anopheles species composition and abundance showed strong seasonal variation, with a majority of An. gambiae (50% of adults collected) caught in June/July, while An. melas was dominant in November/December (83.9% of adults collected). Anopheles gambiae had the highest sporozoite rate in both seasons, with infection rates of 13.9% and 20% in June/July and November/December, respectively. Moderate frequencies of the West African kdr allele were found in An. gambiae (36%), An. coluzzii (35%), An. gambiae/An. coluzzii hybrids (42%). Bioassays suggest moderate resistance to α-cypermethrin, but full susceptibility to permethrin. CONCLUSIONS: The island of Bubaque maintained an An. gambiae s.l. population in both June/July and November/December. Anopheles gambiae was the primary vector at the onset of the wet season, while An. melas is likely to be responsible for most dry season transmission. There was moderate kdr allele frequency and synergist assays suggest likely metabolic resistance, which could reduce the efficacy of LLINs. Future control of malaria on the islands should consider the seasonal shift in mosquito species, and should employ continuous monitoring for insecticide resistance.


Asunto(s)
Anopheles/clasificación , Resistencia a los Insecticidas , Malaria/transmisión , Mosquitos Vectores/clasificación , Animales , Anopheles/enzimología , Anopheles/genética , Bioensayo/métodos , ADN/aislamiento & purificación , Femenino , Técnicas de Genotipaje , Guinea Bissau , Resistencia a los Insecticidas/genética , Islas , Malaria/prevención & control , Mosquitos Vectores/enzimología , Mosquitos Vectores/genética , Proyectos Piloto , Estaciones del Año , Encuestas y Cuestionarios , Receptor 2 de Factores de Crecimiento Endotelial Vascular/genética
12.
Am J Phys Anthropol ; 171 Suppl 70: 5-41, 2020 05.
Artículo en Inglés | MEDLINE | ID: mdl-31956996

RESUMEN

Syphilis was perceived to be a new disease in Europe in the late 15th century, igniting a debate about its origin that continues today in anthropological, historical, and medical circles. We move beyond this age-old debate using an interdisciplinary approach that tackles broader questions to advance the understanding of treponemal infection (syphilis, yaws, bejel, and pinta). How did the causative organism(s) and humans co-evolve? How did the related diseases caused by Treponema pallidum emerge in different parts of the world and affect people across both time and space? How are T. pallidum subspecies related to the treponeme causing pinta? The current state of scholarship in specific areas is reviewed with recommendations made to stimulate future work. Understanding treponemal biology, genetic relationships, epidemiology, and clinical manifestations is crucial for vaccine development today and for investigating the distribution of infection in both modern and past populations. Paleopathologists must improve diagnostic criteria and use a standard approach for recording skeletal lesions on archaeological human remains. Adequate contextualization of cultural and environmental conditions is necessary, including site dating and justification for any corrections made for marine or freshwater reservoir effects. Biogeochemical analyses may assess aquatic contributions to diet, physiological changes arising from treponemal disease and its treatments (e.g., mercury), or residential mobility of those affected. Shifting the focus from point of origin to investigating who is affected (e.g., by age/sex or socioeconomic status) and disease distribution (e.g., coastal/ inland, rural/urban) will advance our understanding of the treponemal disease and its impact on people through time.


Asunto(s)
Evolución Biológica , Treponema pallidum/fisiología , Infecciones por Treponema/historia , Arqueología , Europa (Continente) , Historia del Siglo XV , Historia del Siglo XVI , Historia Antigua , Historia Medieval , Infecciones por Treponema/epidemiología , Infecciones por Treponema/microbiología
13.
Clin Infect Dis ; 68(6): 927-933, 2019 03 05.
Artículo en Inglés | MEDLINE | ID: mdl-29985978

RESUMEN

BACKGROUND: Scabies is a public health problem in many countries, with impetigo and its complications important consequences. Ivermectin based mass drug administration (MDA) reduces the prevalence of scabies and, to a lesser extent, impetigo. We studied the impact of co-administering azithromycin on the prevalence of impetigo and antimicrobial resistance. METHODS: Six communities were randomized to receive either ivermectin-based MDA or ivermectin-based MDA co-administered with azithromycin. We measured scabies and impetigo prevalence at baseline and 12 months. We collected impetigo lesions swabs at baseline, 3 and 12 months to detect antimicrobial resistance. RESULTS: At baseline, scabies and impetigo prevalences were 11.8% and 10.1% in the ivermectin-only arm and 9.2% and 12.1% in the combined treatment arm. At 12 months, the prevalences had fallen to 1.0% and 2.5% in the ivermectin-only arm and 0.7% and 3.3% in the combined treatment arm. The proportion of impetigo lesions containing Staphylococcus aureus detected did not change (80% at baseline vs 86% at 12 months; no significant difference between arms) but the proportion containing pyogenic streptococci fell significantly (63% vs 23%, P < .01). At 3 months, 53% (8/15) of S. aureus isolates were macrolide-resistant in the combined treatment arm, but no resistant strains (0/13) were detected at 12 months. CONCLUSIONS: Co-administration of azithromycin with ivermectin led to similar decreases in scabies and impetigo prevalence compared to ivermectin alone. The proportion of impetigo lesions containing pyogenic streptococci declined following MDA. There was a transient increase in the proportion of macrolide-resistant S. aureus strains following azithromycin MDA. CLINICAL TRIALS REGISTRATION: clinicaltrials.gov (NCT02775617).


Asunto(s)
Antiparasitarios/administración & dosificación , Azitromicina/administración & dosificación , Impétigo/complicaciones , Impétigo/prevención & control , Ivermectina/administración & dosificación , Escabiosis/complicaciones , Escabiosis/prevención & control , Adolescente , Adulto , Niño , Quimioterapia Combinada , Femenino , Humanos , Impétigo/tratamiento farmacológico , Impétigo/epidemiología , Masculino , Administración Masiva de Medicamentos , Persona de Mediana Edad , Pruebas de Sensibilidad Parasitaria , Prevalencia , Escabiosis/tratamiento farmacológico , Escabiosis/epidemiología , Resultado del Tratamiento , Adulto Joven
14.
Sex Transm Infect ; 95(7): 522-528, 2019 11.
Artículo en Inglés | MEDLINE | ID: mdl-30981999

RESUMEN

BACKGROUND: Mass drug administration (MDA) of 20 mg/kg (maximum 1 g in adults) azithromycin for ocular Chlamydia trachomatis (CT) infection is a key component of the WHO trachoma elimination strategy. However, this dose may be suboptimal in Mycoplasma genitalium infection and may encourage emergence of antimicrobial resistance (AMR) to azithromycin. OBJECTIVES: To determine the effect of MDA for trachoma elimination on M. genitalium prevalence, strain type and azithromycin resistance. METHODS: A secondary analysis of CT-negative vulvovaginal swabs from three outpatient antenatal clinics (Honiara, Solomon Islands) from patients recruited either pre-MDA, or 10 months post-MDA in two cross-sectional surveys was carried out. Swabs were tested for M. genitalium infection using Fast Track Diagnostics Urethritis Plus nucleic acid amplification assay. M. genitalium-positive samples were subsequently tested for azithromycin resistance by sequencing domain V of the 23S rRNA DNA region of M. genitalium and underwent phylogenetic analysis by dual locus sequence typing. RESULTS: M. genitalium prevalence was 11.9% (28/236) in women pre-MDA and 10.9% (28/256) 10 months post-MDA (p=0.7467). Self-reported receipt of azithromycin as part of MDA was 49.2% in women recruited post-MDA and 17.9% (5/28) in those who tested M. genitalium positive. Of samples sequenced (21/28 pre-MDA, 22/28 post-MDA), all showed a macrolide susceptible genotype. Strain typing showed that sequence types diverged into two lineages, with a suggestion of strain replacement post-MDA. CONCLUSION: A single round of azithromycin MDA in an island population with high baseline M. genitalium prevalence did not appear to impact on either prevalence or azithromycin resistance, in contrast to reported decreased genital CT prevalence in the same population. This may be due to limitations such as sample size, including CT-negative samples only, and low MDA coverage. Further investigation of the impact of multiple rounds of MDA on M. genitalium azithromycin AMR in antibiotic experienced and naïve populations is warranted.


Asunto(s)
Antibacterianos/efectos adversos , Azitromicina/efectos adversos , Farmacorresistencia Bacteriana , Administración Masiva de Medicamentos/efectos adversos , Infecciones por Mycoplasma/epidemiología , Mycoplasma genitalium/efectos de los fármacos , Tracoma/tratamiento farmacológico , Adolescente , Adulto , Antibacterianos/administración & dosificación , Azitromicina/administración & dosificación , Análisis por Conglomerados , Estudios Transversales , ADN Bacteriano/química , ADN Bacteriano/genética , ADN Ribosómico/química , ADN Ribosómico/genética , Femenino , Genotipo , Humanos , Melanesia/epidemiología , Persona de Mediana Edad , Tipificación Molecular , Infecciones por Mycoplasma/microbiología , Mycoplasma genitalium/clasificación , Mycoplasma genitalium/genética , Mycoplasma genitalium/aislamiento & purificación , Filogenia , Prevalencia , ARN Ribosómico 23S/genética , Análisis de Secuencia de ADN , Tracoma/prevención & control , Adulto Joven
15.
Clin Infect Dis ; 66(6): 818-824, 2018 03 05.
Artículo en Inglés | MEDLINE | ID: mdl-29045605

RESUMEN

Background: Yaws-like chronic ulcers can be caused by Treponema pallidum subspecies pertenue, Haemophilus ducreyi, or other, still-undefined bacteria. To permit accurate evaluation of yaws elimination efforts, programmatic use of molecular diagnostics is required. The accuracy and sensitivity of current tools remain unclear because our understanding of T. pallidum diversity is limited by the low number of sequenced genomes. Methods: We tested samples from patients with suspected yaws collected in the Solomon Islands and Ghana. All samples were from patients whose lesions had previously tested negative using the Centers for Disease Control and Prevention (CDC) diagnostic assay in widespread use. However, some of these patients had positive serological assays for yaws on blood. We used direct whole-genome sequencing to identify T. pallidum subsp pertenue strains missed by the current assay. Results: From 45 Solomon Islands and 27 Ghanaian samples, 11 were positive for T. pallidum DNA using the species-wide quantitative polymerase chain reaction (PCR) assay, from which we obtained 6 previously undetected T. pallidum subsp pertenue whole-genome sequences. These show that Solomon Islands sequences represent distinct T. pallidum subsp pertenue clades. These isolates were invisible to the CDC diagnostic PCR assay, due to sequence variation in the primer binding site. Conclusions: Our data double the number of published T. pallidum subsp pertenue genomes. We show that Solomon Islands strains are undetectable by the PCR used in many studies and by health ministries. This assay is therefore not adequate for the eradication program. Next-generation genome sequence data are essential for these efforts.


Asunto(s)
Secuenciación de Nucleótidos de Alto Rendimiento , Técnicas de Diagnóstico Molecular/normas , Úlcera Cutánea/microbiología , Treponema pallidum/genética , Buba/diagnóstico , Niño , Erradicación de la Enfermedad , Femenino , Genoma Bacteriano , Ghana , Humanos , Masculino , Melanesia , Técnicas de Diagnóstico Molecular/métodos , Reacción en Cadena en Tiempo Real de la Polimerasa , Análisis de Secuencia de ADN , Treponema pallidum/aislamiento & purificación , Secuenciación Completa del Genoma
16.
Emerg Infect Dis ; 24(4): 786-789, 2018 04.
Artículo en Inglés | MEDLINE | ID: mdl-29553314

RESUMEN

Haemophilus ducreyi, which causes chancroid, has emerged as a cause of pediatric skin disease. Isolation of H. ducreyi in low-income settings is challenging, limiting phylogenetic investigation. Next-generation sequencing demonstrates that cutaneous strains arise from class I and II H. ducreyi clades and that class II may represent a distinct subspecies.


Asunto(s)
Chancroide/microbiología , Genoma Bacteriano , Haemophilus ducreyi/genética , Enfermedades Cutáneas Bacterianas/microbiología , Secuenciación Completa del Genoma , Adolescente , Niño , Humanos , Filogenia , Polimorfismo de Nucleótido Simple , ARN Ribosómico 16S/genética
17.
Am J Epidemiol ; 187(4): 837-844, 2018 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-29140407

RESUMEN

Yaws is a disabling bacterial infection found primarily in warm and humid tropical areas. The World Health Organization strategy mandates an initial round of total community treatment (TCT) with single-dose azithromycin followed either by further TCT or active case-finding and treatment of cases and their contacts (the Morges strategy). We sought to investigate the effectiveness of the Morges strategy. We employed a stochastic household model to study the transmission of infection using data collected from a pre-TCT survey conducted in the Solomon Islands. We used this model to assess the proportion of asymptomatic infections that occurred in households without active cases. This analysis indicated that targeted treatment of cases and their household contacts would miss a large fraction of asymptomatic infections (65%-100%). This fraction was actually higher at lower prevalences. Even assuming that all active cases and their households were successfully treated, our analysis demonstrated that at all prevalences present in the data set, up to 90% of (active and asymptomatic) infections would not be treated under household-based contact tracing. Mapping was undertaken as part of the study "Epidemiology of Yaws in the Solomon Islands and the Impact of a Trachoma Control Programme," in September-October 2013.


Asunto(s)
Antibacterianos/uso terapéutico , Azitromicina/uso terapéutico , Trazado de Contacto/estadística & datos numéricos , Buba/tratamiento farmacológico , Buba/epidemiología , Antibacterianos/administración & dosificación , Azitromicina/administración & dosificación , Control de Enfermedades Transmisibles/métodos , Control de Enfermedades Transmisibles/estadística & datos numéricos , Femenino , Humanos , Masculino , Melanesia , Modelos Estadísticos , Buba/transmisión
18.
N Engl J Med ; 372(8): 703-10, 2015 Feb 19.
Artículo en Inglés | MEDLINE | ID: mdl-25693010

RESUMEN

BACKGROUND: Mass treatment with azithromycin is a central component of the new World Health Organization (WHO) strategy to eradicate yaws. Empirical data on the effectiveness of the strategy are required as a prerequisite for worldwide implementation of the plan. METHODS: We performed repeated clinical surveys for active yaws, serologic surveys for latent yaws, and molecular analyses to determine the cause of skin ulcers and identify macrolide-resistant mutations before and 6 and 12 months after mass treatment with azithromycin on a Papua New Guinean island on which yaws was endemic. Primary-outcome indicators were the prevalence of serologically confirmed active infectious yaws in the entire population and the prevalence of latent yaws with high-titer seroreactivity in a subgroup of children 1 to 15 years of age. RESULTS: At baseline, 13,302 of 16,092 residents (82.7%) received one oral dose of azithromycin. The prevalence of active infectious yaws was reduced from 2.4% before mass treatment to 0.3% at 12 months (difference, 2.1 percentage points; P<0.001). The prevalence of high-titer latent yaws among children was reduced from 18.3% to 6.5% (difference, 11.8 percentage points; P<0.001) with a near-absence of high-titer seroreactivity in children 1 to 5 years of age. Adverse events identified within 1 week after administration of the medication occurred in approximately 17% of the participants, included nausea, diarrhea, and vomiting, and were mild in severity. No evidence of emergence of resistance to macrolides against Treponema pallidum subspecies pertenue was seen. CONCLUSIONS: The prevalence of active and latent yaws infection fell rapidly and substantially 12 months after high-coverage mass treatment with azithromycin, with the reduction perhaps aided by subsequent activities to identify and treat new cases of yaws. Our results support the WHO strategy for the eradication of yaws. (Funded by Newcrest Mining and International SOS; YESA-13 ClinicalTrials.gov number, NCT01955252.).


Asunto(s)
Antibacterianos/administración & dosificación , Azitromicina/administración & dosificación , Treponema pallidum/aislamiento & purificación , Buba/tratamiento farmacológico , Adolescente , Adulto , Distribución por Edad , Antibacterianos/efectos adversos , Azitromicina/efectos adversos , Chancroide/epidemiología , Niño , Preescolar , Estudios Transversales , Farmacorresistencia Bacteriana/genética , Enfermedades Endémicas , Haemophilus ducreyi/aislamiento & purificación , Humanos , Lactante , Papúa Nueva Guinea/epidemiología , Reacción en Cadena de la Polimerasa , Prevalencia , Treponema pallidum/genética , Buba/diagnóstico , Buba/epidemiología , Adulto Joven
19.
Sex Transm Infect ; 94(8): 585-588, 2018 12.
Artículo en Inglés | MEDLINE | ID: mdl-30061192

RESUMEN

INTRODUCTION: Syphilis continues to be a major public health problem and the recent resurgence in syphilis in high-income settings has seen an accompanying increase in cases of neurosyphilis. While the introduction of PCR has had a significant impact on the diagnosis of early syphilis, cerebrospinal fluid (CSF) serological assays remain the most commonly used tests to diagnosis neurosyphilis. We reviewed data on the performance of CSF-PCR for the diagnosis of neurosyphilis. METHODS: We searched Pubmed, Medline, EMBASE and the grey literature for references on PCR in neurosyphilis. We calculated the sensitivity and specificity of PCR compared with reference testing for the diagnosis of neurosyphilis. RESULTS: We identified 66 articles of which seven met the study inclusion criteria. The sensitivity of PCR for definite neurosyphilis varied between 40% and 70% and specificity between 60% and 100% across the studies. The most commonly used PCR assay targeted Tp47 which had an overall sensitivity of 68% and a specificity of 91.9%. DISCUSSION: The sensitivity of PCR was low compared with CSF-serological assays but the challenges of evaluating a diagnostic test in the absence of a clear gold standard make definitive interpretation challenging. Most studies were small and not adequately powered highlighting the need for multicentre, multicountry trials to provide adequate statistical power in evaluations of new tests the diagnosis of neurosyphilis.


Asunto(s)
Técnicas de Diagnóstico Molecular , Neurosífilis/diagnóstico , Reacción en Cadena de la Polimerasa , Humanos , Neurosífilis/líquido cefalorraquídeo , Sensibilidad y Especificidad , Serodiagnóstico de la Sífilis/métodos , Treponema pallidum
20.
Clin Infect Dis ; 64(6): 743-750, 2017 03 15.
Artículo en Inglés | MEDLINE | ID: mdl-27956455

RESUMEN

Background: The World Health Organization recommends annual treatment of entire trachoma-endemic communities, although children typically have a higher load, longer duration, and greater likelihood of infection. Methods: Forty-eight communities in Matameye, Niger, were randomized to annual oral azithromycin treatment of the entire community or biannual treatment of children aged 0-12 years only. Both children and adults were monitored for ocular chlamydial infection by polymerase chain reaction. Results: The prevalence of childhood infection was reduced in the annually treated arm from 21.2% (95% confidence interval [CI], 15.2%-28.0%) at baseline to 5.8% (95% CI, 3.2%-9.0%) at 36 months (P < .001) and in the biannual arm from 20.2% (95% CI, 15.5%-25.3%) to 3.8% (95% CI, 2.2%-6.0%; P < .001). Adult infection in the annual arm was reduced from 1.7% (95% CI, .9%-2.7%) to 0.3% (95% CI, .0%-.7%) and in the biannual arm from 1.2% (95% CI, .5%-2.2%) to 0.0% (95% CI, .0%-.7%; P = .005). The effect of biannual treatment of children compared with annual treatment of the entire community in both children (95% CI, -.04% to .02%) and adults (95% CI, .9%-2.7%) excluded the prespecified noninferiority threshold of 6% (P = .003 and P < .001, respectively). Conclusions: Periodic distribution of antibiotics to children in trachoma-endemic communities reduces chlamydial infection in both children and untreated adults, suggesting a form of herd protection. Biannual treatment of children was comparable to (specifically, noninferior to) annual treatment of the entire community, and may offer lower antibiotic use and other logistical advantages. Clinical Trials Registration: NCT00792922.


Asunto(s)
Antibacterianos/uso terapéutico , Tracoma/tratamiento farmacológico , Adulto , Antibacterianos/administración & dosificación , Antibacterianos/efectos adversos , Azitromicina/administración & dosificación , Azitromicina/efectos adversos , Azitromicina/uso terapéutico , Preescolar , Chlamydia trachomatis/efectos de los fármacos , Femenino , Humanos , Masculino , Prevalencia , Factores de Tiempo , Tracoma/epidemiología , Tracoma/microbiología , Resultado del Tratamiento
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