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2.
Theor Biol Med Model ; 16(1): 14, 2019 09 10.
Artículo en Inglés | MEDLINE | ID: mdl-31500635

RESUMEN

BACKGROUND: Group A streptococcus (GAS) is the most frequent cause of bacterial pharyngitis in school-aged children. The postinfection sequel as acute rheumatic fever (ARF) and rheumatic heart disease that cause morbidity and mortality among young people is public health concerns in several developing countries. Asymptomatic carriage state of GAS is not fully understood in terms of host and bacterial factors. Although the ability of transmitting GAS of the asymptomatic carriers is relatively low, they may present the reservoir of the epidemic. A fraction of GAS carriers is difficult to estimate in practice and may greatly vary between populations. Understanding the role of carriage on the transmission dynamic of GAS is important for assessing the public health impact of the ARF. METHOD: This study investigates the effect of GAS carriers on both the transmission and dynamic of ARF cases by using a mathematical model. RESULT: We derive the sufficient conditions for which the GAS can spread or extinct from the naive population under the variation of the fraction of symptomatic cases over the incidence of GAS. The threshold is possible to occur in general, but the last condition which is rather restrictive and involves parameter uncertainty. The increasing of carriers in the endemic state leads to the reduction in magnitude of the reproduction number and the number of ARF patients. We demonstrate that the adjustment of parameters can be carried out by the use of endemic state and some specific data. CONCLUSION: We show theoretically that the presence of asymptomatic carriers may induce the epidemic threshold and reduce the virulence of GAS and the prevalence of ARF.


Asunto(s)
Portador Sano/epidemiología , Portador Sano/microbiología , Fiebre Reumática/epidemiología , Fiebre Reumática/microbiología , Streptococcus pyogenes/fisiología , Número Básico de Reproducción , Calibración , Epidemias , Humanos , Modelos Biológicos
3.
Microbiol Spectr ; 7(4)2019 07.
Artículo en Inglés | MEDLINE | ID: mdl-31373269

RESUMEN

The group A streptococci are associated with a group of diseases affecting the heart, brain, and joints that are collectively referred to as acute rheumatic fever. The streptococcal immune-mediated sequelae, including acute rheumatic fever, are due to antibody and cellular immune responses that target antigens in the heart and brain as well as the group A streptococcal cross-reactive antigens as reviewed in this article. The pathogenesis of acute rheumatic fever, rheumatic heart disease, Sydenham chorea, and other autoimmune sequelae is related to autoantibodies that are characteristic of autoimmune diseases and result from the immune responses against group A streptococcal infection by the host. The sharing of host and streptococcal epitopes leads to molecular mimicry between the streptococcal and host antigens that are recognized by the autoantibodies during the host response. This article elaborates on the discoveries that led to a better understanding of the pathogenesis of disease and provides an overview of the history and the most current thought about the immune responses against the host and streptococcal cross-reactive antigens in group A streptococcal sequelae.


Asunto(s)
Antígenos Bacterianos/inmunología , Autoanticuerpos/inmunología , Autoinmunidad , Fiebre Reumática/inmunología , Streptococcus pyogenes/inmunología , Animales , Antígenos Bacterianos/química , Antígenos Bacterianos/genética , Reacciones Cruzadas , Humanos , Imitación Molecular , Fiebre Reumática/microbiología , Streptococcus pyogenes/química , Streptococcus pyogenes/genética
4.
Pak J Pharm Sci ; 32(3): 1107-1110, 2019 May.
Artículo en Inglés | MEDLINE | ID: mdl-31278727

RESUMEN

One of the most common endocrinological disorder affecting women in adolescence is Polycystic Ovarian Syndrome (PCOS). Women suffering from PCOS diagnosed with follicles in ovaries show enlarged reproductive organs with small filled follicles. Unusual bleeding, prolonged menstruation, unwanted hair growth, accumulation of fat and acne are the most common problems experienced by adolescents with PCOS. Nowadays, PCOS is treated successfully with the oral antidiabetic drug, metformin and hormone replacement therapy. Its off-label use is still controversial with unknown mechanisms due to patient risk versus benefit hypothesis by practitioners as they successfully treat PCOS in adolescents with metformin. But in few reported cases metformin has potential to induce back pain and swollen joints less frequently with rare cases of behavior alteration. Penicillin belongs to the beta-lactam antibiotics and is most commonly used to treat rheumatic fever although it has potential to cause allergic reactions affecting 10% of patients who exhibit IgE-mediated immunological reactions. Here, we present a case of a female diagnosed with PCOS who after treatment with metformin for more than two years, reported with hyperuricemia, migraine, neurological pain, severe joint and knee pains on shoulders and legs, and rheumatic fever. After treatment with benzathine benzyl penicillin for rheumatic fever, the patient also exhibited Type IV delayed hypersensitivity reaction.


Asunto(s)
Artralgia/inducido químicamente , Metformina/efectos adversos , Penicilina G Benzatina/efectos adversos , Síndrome del Ovario Poliquístico/tratamiento farmacológico , Fiebre Reumática/tratamiento farmacológico , Analgésicos/uso terapéutico , Artralgia/tratamiento farmacológico , Artralgia/etiología , Hipersensibilidad a las Drogas/etiología , Femenino , Humanos , Hiperuricemia/inducido químicamente , Metformina/uso terapéutico , Trastornos Migrañosos/inducido químicamente , Penicilina G Benzatina/uso terapéutico , Síndrome del Ovario Poliquístico/diagnóstico por imagen , Fiebre Reumática/inducido químicamente , Fiebre Reumática/microbiología , Infecciones Estreptocócicas/tratamiento farmacológico , Infecciones Estreptocócicas/etiología , Streptococcus pyogenes/patogenicidad , Adulto Joven
5.
BMC Infect Dis ; 19(1): 633, 2019 Jul 17.
Artículo en Inglés | MEDLINE | ID: mdl-31315580

RESUMEN

BACKGROUND: Group A Streptococcal (GAS) infections cause the autoimmune disease acute rheumatic fever (ARF), which can progress to chronic rheumatic heart disease (RHD). Treating pharyngitis caused by GAS with antibiotics is important in preventing ARF. However, it is difficult to distinguish these infections from GAS carriers. There is growing evidence for GAS skin infections as a cause of ARF. This study will identify the incidence of true GAS pharyngitis and serological responses to GAS skin infections. The effectiveness of antibiotics for these conditions will be explored, and modifiable risk factors. Serum antibody titres indicating the upper limits of normal (ULN for ASO/ADB antibodies) will be established alongside carriage rates in asymptomatic children. METHODS: This is a prospective disease incidence study, with an associated case-control study. The study population includes 1000 children (5-14 years) from Auckland, New Zealand, 800 of whom have visited their healthcare professional, resulting in a throat or skin swab for GAS, and 200 who are asymptomatic. The conditions of interest are GAS throat swab positive pharyngitis (n = 200); GAS carriage (n = 200); GAS negative throat swab (n = 200); GAS skin infections (n = 200); and asymptomatic controls (n = 200). All participants, except asymptomatic controls, will have acute and convalescent serological testing for ASO/ADB titres (collected < 9 days, and 2-4 weeks following symptom onset, respectively), alongside viral PCR from throat swabs. Asymptomatic controls will have ASO/ADB titres measured in one blood specimen and a throat swab for microbial culture. Caregivers of children will be interviewed using a questionnaire and any GAS isolates identified will be emm typed. The persistence of GAS antibodies will also be investigated. DISCUSSION: Findings from this study will fill critical gaps in scientific knowledge to better understand the pathophysiology of ARF, improve clinical management of GAS infections, and design more effective ARF prevention programmes. In particular it will measure the incidence of true, serologically confirmed GAS pharyngitis; assess the immune response to GAS skin infections and its role as a cause of ARF; examine the effectiveness of oral antibiotics for treating GAS pharyngitis and carriage; and identify whether risk factors for GAS infections might provide intervention points for reducing ARF.


Asunto(s)
Faringitis/microbiología , Fiebre Reumática/microbiología , Enfermedades Cutáneas Bacterianas/microbiología , Adolescente , Antibacterianos/uso terapéutico , Estudios de Casos y Controles , Niño , Preescolar , Femenino , Humanos , Incidencia , Masculino , Nueva Zelanda/epidemiología , Faringitis/tratamiento farmacológico , Faringitis/epidemiología , Reacción en Cadena de la Polimerasa , Estudios Prospectivos , Fiebre Reumática/tratamiento farmacológico , Fiebre Reumática/epidemiología , Enfermedades Cutáneas Bacterianas/tratamiento farmacológico , Enfermedades Cutáneas Bacterianas/epidemiología , Streptococcus pyogenes/genética , Streptococcus pyogenes/aislamiento & purificación , Streptococcus pyogenes/patogenicidad
6.
Indian Pediatr ; 56(4): 311-313, 2019 04 15.
Artículo en Inglés | MEDLINE | ID: mdl-31064901

RESUMEN

OBJECTIVE: To determine the diagnostic accuracy of polymerase chain reaction-based detection of sof gene compared to throat swab culture for S. pyogenes infection in patients with acute rheumatic fever and those with recurrence of rheumatic activity. METHODS: 40 patients between 3 to 18 years of age, with clinical diagnosis of acute rheumatic fever or new activity in established rheumatic heart disease were included. The amplicon of 228bp of sof gene was detected using a polymerase chain reaction-based technique and the results were compared with throat swab culture for Streptococcus pyogenes. RESULTS: 10 patients had a positive throat swab culture and 11 had sof gene detected. The sensitivity and specificity of the test was 100% and 96.7%, respectively compared to throat swab culture (P=0.001). The positive predictive value and the negative predictive value was 90.9% and 100% respectively. CONCLUSION: Polymerase chain reaction-based detection of sof gene provides an alternative to throat swab culture in diagnosing activity in Acute Rheumatic Fever or established Rheumatic heart disease.


Asunto(s)
Técnicas de Tipificación Bacteriana/métodos , Péptido Hidrolasas/genética , Fiebre Reumática/diagnóstico , Infecciones Estreptocócicas/diagnóstico , Streptococcus pyogenes , Adolescente , Niño , Preescolar , Estudios Transversales , ADN Bacteriano/análisis , ADN Bacteriano/genética , Humanos , India , Faringe/microbiología , Reacción en Cadena de la Polimerasa , Fiebre Reumática/microbiología , Sensibilidad y Especificidad , Infecciones Estreptocócicas/microbiología , Streptococcus pyogenes/genética , Streptococcus pyogenes/aislamiento & purificación
7.
Am J Trop Med Hyg ; 100(5): 1118-1120, 2019 05.
Artículo en Inglés | MEDLINE | ID: mdl-30915960

RESUMEN

This study aimed to identify recurrent acute rheumatic fever (ARF) episodes which occurred despite adherence to prophylactic benzathine penicillin G (BPG). Data from Australia's Northern Territory were analyzed; ARF recurrences between 2012 and 2017 diagnosed while the person was prescribed BPG were identified. Days at risk (DAR)-median and interquartile range-preceding ARF onset were calculated. The timing of BPG doses was examined for individuals with no DAR. One hundred sixty-nine ARF recurrences were analyzed; median DAR in the previous 8 weeks before ARF onset was 29. Most recurrences occurred following > 7 DAR (87%). Eight recurrences (5%) occurred despite no DAR; all were aged less than 16 years at the time of their recurrence/s. Recurrent ARF most commonly occurs after delayed BPG doses, but in some cases, receiving every prescribed BPG dose on time did not prevent recurrent ARF. A method to identify high-risk individuals before recurrent ARF is needed.


Asunto(s)
Antibacterianos/administración & dosificación , Penicilina G Benzatina/administración & dosificación , Fiebre Reumática/prevención & control , Adolescente , Adulto , Niño , Preescolar , Esquema de Medicación , Femenino , Humanos , Masculino , Persona de Mediana Edad , Northern Territory , Recurrencia , Fiebre Reumática/microbiología , Infecciones Estreptocócicas/prevención & control , Insuficiencia del Tratamiento , Adulto Joven
9.
Pediatr Infect Dis J ; 38(1): e1-e6, 2019 01.
Artículo en Inglés | MEDLINE | ID: mdl-30256313

RESUMEN

BACKGROUND: Globally, there is wide variation in streptococcal titer upper limits of normal (ULN) for antistreptolysin O (ASO) and anti-deoxyribonuclease B (ADB) used as an evidence of recent group A streptococcal infection to diagnose acute rheumatic fever (ARF). METHODS: We audited ASO and ADB titers among individuals with ARF in New Zealand (NZ) and in Australia's Northern Territory. We summarized streptococcal titers by different ARF clinical manifestations, assessed application of locally recommended serology guidelines where NZ uses high ULN cut-offs and calculated the proportion of cases fulfilling alternative serologic diagnostic criteria. RESULTS: From January 2013 to December 2015, group A streptococcal serology results were available for 350 patients diagnosed with ARF in NZ and 182 patients in Northern Territory. Median peak streptococcal titers were similar in both settings. Among NZ cases, 267/350 (76.3%) met NZ serologic diagnostic criteria, whereas 329/350 (94.0%) met Australian criteria. By applying Australian ULN titer cut-off criteria to NZ cases, excluding chorea, ARF definite cases would increase by 17.6% representing 47 cases. CONCLUSIONS: ASO and ADB values were similar in these settings. Use of high ULN cut-offs potentially undercounts definite and probable ARF diagnoses. We recommend NZ and other high-burden settings to use globally accepted, age-specific, lower serologic cut-offs to avoid misclassification of ARF.


Asunto(s)
Anticuerpos Antibacterianos/sangre , Costo de Enfermedad , Fiebre Reumática/epidemiología , Factores Socioeconómicos , Infecciones Estreptocócicas/epidemiología , Adolescente , Antiestreptolisina/sangre , Niño , Desoxirribonucleasas/inmunología , Femenino , Humanos , Masculino , Nueva Zelanda/epidemiología , Northern Territory/epidemiología , Estudios Retrospectivos , Fiebre Reumática/microbiología , Pruebas Serológicas , Infecciones Estreptocócicas/inmunología , Streptococcus pyogenes
10.
J Am Heart Assoc ; 7(24): e010223, 2018 12 18.
Artículo en Inglés | MEDLINE | ID: mdl-30561268

RESUMEN

Background Acute rheumatic fever ( ARF ) and rheumatic heart disease cause substantial burdens worldwide. Long-term antibiotic secondary prophylaxis is used to prevent disease progression, but evidence for benefits of different adherence levels is limited. Using data from northern Australia, we identified factors associated with adherence, and the association between adherence and ARF recurrence, progression to rheumatic heart disease, worsening or improvement of rheumatic heart disease, and mortality. Methods and Results Factors associated with adherence (percent of doses administered) were analyzed using logistic regression. Nested case-control and case-crossover designs were used to investigate associations with clinical outcomes; conditional logistic regression was used to estimate odds ratios ( OR ) with 95% CIs Adherence estimates (7728) were analyzed. Being female, younger, having more-severe disease, and living remotely were associated with higher adherence. Alcohol misuse was associated with lower adherence. The risk of ARF recurrence did not decrease until ≈40% of doses had been administered. Receiving <80% was associated with a 4-fold increase in the odds of ARF recurrence (case-control OR : 4.00 [95% CI : 1.7-9.29], case-crossover OR : 3.31 [95% CI : 1.09-10.07]) and appeared to be associated with increased all-cause mortality (case-control OR : 1.90 [95% CI : 0.89-4.06]; case-crossover OR 1.91 [95% CI : 0.51-7.12]). Conclusions We show for the first time that increased adherence to penicillin prophylaxis is associated with reduced ARF recurrence, and a likely reduction in mortality, in our setting. These findings can motivate patients to receive doses since even relatively low adherence can be beneficial, and additional doses further reduce adverse clinical outcomes.


Asunto(s)
Antibacterianos/administración & dosificación , Cumplimiento de la Medicación , Penicilinas/administración & dosificación , Fiebre Reumática/prevención & control , Cardiopatía Reumática/prevención & control , Prevención Secundaria/métodos , Adolescente , Adulto , Anciano , Niño , Preescolar , Esquema de Medicación , Femenino , Conocimientos, Actitudes y Práctica en Salud , Humanos , Masculino , Cumplimiento de la Medicación/etnología , Persona de Mediana Edad , Northern Territory/epidemiología , Grupo de Ascendencia Oceánica/psicología , Factores Protectores , Recurrencia , Estudios Retrospectivos , Fiebre Reumática/etnología , Fiebre Reumática/microbiología , Fiebre Reumática/mortalidad , Cardiopatía Reumática/etnología , Cardiopatía Reumática/microbiología , Cardiopatía Reumática/mortalidad , Factores de Riesgo , Factores de Tiempo , Resultado del Tratamiento , Adulto Joven
11.
J Infect Chemother ; 24(7): 531-537, 2018 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-29606414

RESUMEN

Reactive arthritis after Group A streptococcal infection (poststreptococcal reactive arthritis: PSRA) that does not meet the Jones criteria for acute rheumatic fever (ARF) has been reported as a new entity for over a decade. In Japan there are few reports of PSRA. We encountered four children with arthritis accompanied with Group A streptococcal infection in our department. We investigated our cases and the recent Japanese literature. Japanese cases of PSRA are frequently accompanied with uveitis and erythema nodosum, and tonsillectomy resolved their symptoms in some cases. There were overlap cases between ARF, juvenile idiopathic arthritis, and PSRA.


Asunto(s)
Artritis Juvenil/diagnóstico por imagen , Artritis Reactiva/diagnóstico por imagen , Artritis Reactiva/microbiología , Infecciones Estreptocócicas/complicaciones , Adolescente , Antibacterianos/uso terapéutico , Artritis Juvenil/microbiología , Artritis Reactiva/tratamiento farmacológico , Biomarcadores/sangre , Niño , Preescolar , Quimioterapia Combinada , Eritema Nudoso , Femenino , Humanos , Japón , Masculino , Fiebre Reumática/diagnóstico por imagen , Fiebre Reumática/microbiología , Infecciones Estreptocócicas/tratamiento farmacológico , Tonsilectomía , Uveítis
12.
Infect Genet Evol ; 61: 160-175, 2018 07.
Artículo en Inglés | MEDLINE | ID: mdl-29530660

RESUMEN

Streptococcus pyogenes is a human-specific and globally prominent bacterial pathogen that despite causing numerous human infections, this bacterium is normally found in an asymptomatic carrier state. This review provides an overview of both bacterial and human factors that likely play an important role in nasopharyngeal colonization and pharyngitis, as well as the development of acute rheumatic fever and rheumatic heart disease. Here we highlight a recently described role for bacterial superantigens in promoting acute nasopharyngeal infection, and discuss how these immune system activating toxins could be crucial to initiate the autoimmune process in rheumatic heart disease.


Asunto(s)
Faringitis/microbiología , Fiebre Reumática/microbiología , Streptococcus pyogenes , Superantígenos , Portador Sano/microbiología , Humanos , Nasofaringe/microbiología , Infecciones Estreptocócicas/microbiología
13.
J Infect ; 76(4): 361-368, 2018 04.
Artículo en Inglés | MEDLINE | ID: mdl-29269013

RESUMEN

OBJECTIVES: Streptococcal serology provides evidence of prior Group A Streptococcus (GAS) exposure, crucial to the diagnosis of acute rheumatic fever (ARF) and post-streptococcal glomerulonephritis. However, current tests, which measure anti-streptolysin-O and anti-DNaseB antibodies, are limited by false positives in GAS endemic settings, and incompatible methodology requiring the two tests to be run in parallel. The objective was to improve streptococcal serology by combining the novel GAS antigen, SpnA, with streptolysin-O and DNaseB in a contemporary, bead-based immunoassay. METHODS: Recombinant streptolysin-O, DNAseB and SpnA were conjugated to polystyrene beads with unique fluorescence positions so antibody binding to all three antigens could be detected simultaneously by cytometric bead array. Multiplex assays were run on sera collected in three groups: ARF; ethnically matched healthy children; and healthy adults. RESULTS: The ability of the antigens to detect a previous GAS exposure in ARF was assessed using the 80th centile of the healthy children group as cut-off (upper limit of normal). SpnA had the highest sensitivity at 88%, compared with 75% for streptolysin-O and 56% for DNaseB. CONCLUSIONS: SpnA has favorable immunokinetics for streptococcal serology, and can be combined with anti-streptolysin-O and anti-DNaseB in a multiplex format to improve efficiency and accuracy.


Asunto(s)
Antígenos Bacterianos/inmunología , Inmunoensayo/métodos , Fiebre Reumática/diagnóstico , Infecciones Estreptocócicas/diagnóstico , Enfermedad Aguda , Adulto , Anticuerpos Antibacterianos/sangre , Antígenos Bacterianos/sangre , Proteínas Bacterianas , Niño , Femenino , Humanos , Masculino , Fiebre Reumática/microbiología , Streptococcus pyogenes/inmunología , Estreptolisinas , Adulto Joven
14.
Indian J Med Res ; 145(6): 758-766, 2017 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-29067978

RESUMEN

BACKGROUND & OBJECTIVES: Rheumatic fever (RF) and rheumatic heart disease (RHD) are the autoimmune sequelae caused by Group A Streptococcus. RHD still remains a major concern in the developing countries due to its poor diagnosis, lack of vaccines and social awareness among population. This study was aimed to identify the plausible early- and late-stage disease markers associated with RF/RHD. METHODS: A total of 84 patients with confirmed pharyngitis (n=18), RF (n=23) and RHD (n=43) were included in the comparative analysis of different factors involved in host-pathogen interaction during RF/RHD pathogenesis. RESULTS: This study revealed high titre of serum antistreptolysin O (ASO) antibody in pharyngitis compared to RF and RHD patients, whereas procollagen type 1 C-peptide (PICP) level was elevated in RHD which showed an inverse correlation with serum ASO titre. The significant elevation of serum anti-peptide associated with RF (PARF) antibody in RF patients was correlated as a probable stage-specific determinant. In addition, pro-inflammatory cytokine profile revealed high levels of interleukin-12 (IL-12)/IL-23p40, IL-17A in RF, whereas IL-6 concentration was higher in RHD compared to healthy controls. INTERPRETATION & CONCLUSIONS: The overall assessment of the factors/ disease markers involved in host-pathogen interaction in RF/RHD may be suggestive of plausible disease marker in different groups of patients. Further studies with larger sample need to be done to better understand RF/RHD pathogenesis.


Asunto(s)
Biomarcadores/sangre , Faringitis/sangre , Fiebre Reumática/sangre , Cardiopatía Reumática/sangre , Adolescente , Adulto , Anciano , Anticuerpos/sangre , Antiestreptolisina/sangre , Niño , Preescolar , Citocinas/sangre , Femenino , Interacciones Huésped-Patógeno/genética , Humanos , India , Masculino , Lectina de Unión a Manosa/sangre , Persona de Mediana Edad , Fragmentos de Péptidos/sangre , Faringitis/genética , Faringitis/microbiología , Faringitis/patología , Procolágeno/sangre , Fiebre Reumática/genética , Fiebre Reumática/microbiología , Fiebre Reumática/patología , Cardiopatía Reumática/genética , Cardiopatía Reumática/microbiología , Cardiopatía Reumática/patología , Streptococcus pyogenes/patogenicidad
15.
N Z Med J ; 130(1460): 13-20, 2017 Aug 11.
Artículo en Inglés | MEDLINE | ID: mdl-28796768

RESUMEN

AIM: To assess the circulating emm types of pharyngeal isolates of group A streptococcus (GAS) among school children living in Northland, the Gisborne region and Palmerston North, New Zealand. METHODS: GAS were isolated from throat swabs sent to laboratories in Northland (197 in 2013) and Gisborne (115 in 2014-15) and from children enrolled in the Palmerston North Solar Ventilation Project (70 in 2013-14). The incidences of acute rheumatic fever (ARF) cases in the three regions in 2014 were 9, 19.1 and 0 cases per 100,000 for Northland, the Gisborne region and Palmerston North respectively. DNA sequencing of the N-terminal portion of the emm gene was performed at the Institute of Environmental Science and Research Limited (ESR) laboratory (Porirua, New Zealand). RESULTS: A total of 36 emm types were found among pharyngeal GAS isolates from Northland children with emm1 predominating (24%), 28 emm types from the Gisborne region with emm12 predominating (25%) and 20 emm types from Palmerston North, again with emm12 predominating (36%). Of these GAS isolates, 38% were emm pattern A-C, usually associated with throat infections, 23% were pattern D, usually associated with skin infections, and 39% pattern E or generalists. The most common of the 13 emm clusters detected were A-C4 (emm12; 18% isolates), A-C3 (emm1, emm227, emm238; 17% isolates), D4 (9 emm types; 16% isolates), E4 and E3 (8 emm types each; 15% and 10% isolates respectively). A total of 301 of the 376 (80%) isolates were serotypes previously associated with ARF in New Zealand. CONCLUSION: The only significant differences in distribution between the regions with high (Northland and Gisborne area) and low (Palmerston North) incidences of ARF were the presence of emm3 and absence of emm41 among GAS isolates from Palmerston North school children.


Asunto(s)
Fiebre Reumática/epidemiología , Streptococcus pyogenes/clasificación , Streptococcus pyogenes/aislamiento & purificación , Adolescente , Niño , Demografía , Femenino , Humanos , Incidencia , Masculino , Nueva Zelanda/epidemiología , Faringe/microbiología , Fiebre Reumática/microbiología , Análisis de Secuencia de ADN
16.
PLoS One ; 12(5): e0177784, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28545045

RESUMEN

The secreted cysteine proteinase SpeB is an important virulence factor of group A streptococci (GAS), whereby SpeB activity varies widely among strains. To establish the degree to which SpeB activity correlates with disease, GAS organisms were recovered from patients with pharyngitis, impetigo, invasive disease or acute rheumatic fever (ARF), and selected for analysis using rigorous sampling criteria; >300 GAS isolates were tested for SpeB activity by casein digestion assays, and each GAS isolate was scored as a SpeB-producer or non-producer. Highly significant statistical differences (p < 0.01) in SpeB production are observed between GAS recovered from patients with ARF (41.5% SpeB-non-producers) compared to pharyngitis (20.5%), invasive disease (16.7%), and impetigo (5.5%). SpeB activity differences between pharyngitis and impetigo isolates are also significant, whereas pharyngitis versus invasive isolates show no significant difference. The disproportionately greater number of SpeB-non-producers among ARF-associated isolates may indicate an altered transcriptional program for many rheumatogenic strains and/or a protective role for SpeB in GAS-triggered autoimmunity.


Asunto(s)
Proteínas Bacterianas/genética , Exotoxinas/genética , Fiebre Reumática/microbiología , Streptococcus pyogenes/aislamiento & purificación , Humanos , Impétigo/microbiología , Faringitis/microbiología , Infecciones Estreptocócicas/microbiología , Streptococcus pyogenes/enzimología , Streptococcus pyogenes/genética
17.
J Immunol Methods ; 448: 59-65, 2017 09.
Artículo en Inglés | MEDLINE | ID: mdl-28554544
18.
J Prim Health Care ; 8(1): 20-9, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-27477371

RESUMEN

AIM To examine national and international guidelines on sore throat management and subsequently, to explore the phenomenon of international medical graduates working in general and rural practice in New Zealand. METHOD Two separate systematic reviews were conducted that resulted in a contingent methodology. Contingent methodologies involve syntheses of data that are derived sequentially. The initial review for this study examined international sore throat guidelines and their key points. The results of this initial review resulted in the theory that international medical graduates may be unaware of the New Zealand specific sore throat guidelines and the problem of acute rheumatic fever in this country. The subsequent review examined the phenomenon of international medical graduates working in general or rural practice in New Zealand. Data sources were Medline, Google Scholar, Trip Database, and NHS Evidence, Embase and Scopus. Electronic databases were searched for relevant data published January 2000-December 2013. Additional hand searches found key references from articles and websites. RESULTS International guidelines for the management of sore throats differ from New Zealand guidelines. Of resource rich countries, New Zealand has the second highest number of international medical graduates: they may not use New Zealand specific sore throat guidelines. DISCUSSION Acute rheumatic fever is virtually eradicated in most resource rich countries. Rheumatic fever rates of among indigenous Maori and Pacifika people in New Zealand have failed to reduce over the last three decades. Knowledge and actions of international medical graduates in relation to sore throat management needs investigating. KEYWORDS Sore throats; acute rheumatic fever; clinical guidelines; international medical graduates; mixed methods review.


Asunto(s)
Antibacterianos/uso terapéutico , Médicos Graduados Extranjeros/estadística & datos numéricos , Faringitis/tratamiento farmacológico , Guías de Práctica Clínica como Asunto , Fiebre Reumática/dietoterapia , Fiebre Reumática/diagnóstico , Antibacterianos/administración & dosificación , Medicina General/normas , Adhesión a Directriz , Humanos , Nueva Zelanda , Faringitis/microbiología , Fiebre Reumática/microbiología , Servicios de Salud Rural/normas
19.
Epidemiol Infect ; 144(14): 3058-3067, 2016 10.
Artículo en Inglés | MEDLINE | ID: mdl-27311633

RESUMEN

In New Zealand, efforts to control acute rheumatic fever (ARF) and its sequelae have focused on school-age children in the poorest socioeconomic areas; however, it is unclear whether this approach is optimal given the strong association with demographic risk factors other than deprivation, especially ethnicity. The aim of this study was to estimate the stratum-specific risk of ARF by key sociodemographic characteristics. We used hospitalization and disease notification data to identify new cases of ARF between 2010 and 2013, and used population count data from the 2013 New Zealand Census as our denominator. Poisson logistic regression methods were used to estimate stratum-specific risk of ARF development. The likelihood of ARF development varied considerably by age, ethnicity and deprivation strata: while risk was greatest in Maori and Pacific children aged 10-14 years residing in the most extreme deprivation, both of these ethnic groups experienced elevated risk across a wide age range and across deprivation levels. Interventions that target populations based on deprivation will include the highest-risk strata, but they will also (a) include groups with very low risk of ARF, such as non-Maori/non-Pacific children; and (b) exclude groups with moderate risk of ARF, such as Maori and Pacific individuals living outside high deprivation areas.


Asunto(s)
Fiebre Reumática/epidemiología , Streptococcus pyogenes/fisiología , Adolescente , Adulto , Factores de Edad , Anciano , Anciano de 80 o más Años , Niño , Preescolar , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Persona de Mediana Edad , Nueva Zelanda/epidemiología , Fiebre Reumática/etnología , Fiebre Reumática/microbiología , Factores de Riesgo , Factores Socioeconómicos , Adulto Joven
20.
Heart ; 102(19): 1527-32, 2016 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-27260192

RESUMEN

Acute rheumatic fever (ARF) and the related rheumatic heart disease (RHD) are autoimmune diseases thought to be triggered by group A streptococcal (GAS) pharyngitis. RHD is a leading cause of mortality in the developing world. The strong epidemiological association between GAS throat infection and ARF is highly suggestive of causation, but does not exclude other infections as contributory. There is good evidence of both humoral and cellular autoreactivity and GAS/self cross-reactivity in established RHD. RHD pathogenesis could feasibly be triggered and driven by humoral and/or cellular molecular cross-reactivity between GAS and host cardiac tissues (molecular mimicry). However, good evidence of humoral pathogenicity is lacking and the specific triggering event for RHD remains unknown. It is likely that the critical immunological events leading to ARF/RHD occur at the point of contact between GAS and the immune system in the throat, strongly implicating the mucosal immune system in RHD pathogenesis. Additionally, there is circumstantial evidence that continued live GAS may play a role in ARF/RHD pathogenesis. We suggest that future avenues for study should include the exclusion of GAS components directly contributing to RHD pathogenesis; large genome-wide association studies of patients with RHD looking for candidate genes involved in RHD pathogenesis; genome-wide association studies of GAS from patients with ARF taken at diagnosis to look for characteristics of rheumatogenic strains; and performing case/control studies of GAS pharyngitis/ARF/patients with RHD, and controls to identify microbiological, immunological and environmental differences to elucidate RHD pathogenesis.


Asunto(s)
Autoinmunidad , Inmunidad Celular , Inmunidad Humoral , Miocardio/inmunología , Faringitis/inmunología , Fiebre Reumática/inmunología , Cardiopatía Reumática/inmunología , Streptococcus pyogenes/inmunología , Animales , Predisposición Genética a la Enfermedad , Interacciones Huésped-Patógeno , Humanos , Miocardio/metabolismo , Faringitis/microbiología , Pronóstico , Fiebre Reumática/microbiología , Cardiopatía Reumática/genética , Cardiopatía Reumática/metabolismo , Cardiopatía Reumática/fisiopatología , Factores de Riesgo , Transducción de Señal , Streptococcus pyogenes/metabolismo , Streptococcus pyogenes/patogenicidad
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