A survey of the domestic epidemiological characteristics and clinical manifestations of pertussis

PURPOSE: This report describes the results of a survey of the characteristics of pertussis in children from a single institution and compares it to data from the Korea Centers of Disease Control (KCDC). METHODS: We retrospectively evaluated the medical records of 17 and 6 patients diagnosed with pertussis and parapertussis, respectively, at Soonchunhyang University Bucheon Hospital from January 2005 to January 2017. RESULTS: Of the 17 patients with pertussis, 9 were under 1 year of age (52.9%), 3 were aged between 1 and 10 years (17.6%), and 5 were over 10 years of age (29.4%). Seven patients (41.2%) had never received diphtheria-tetanus-acellular pertussis vaccines, of which 5 were infants below 2 months of age and 2 were 10 years old and lived in China. Four patients showed the initial symptoms of cough in China. The sources of infection were the parents (2 cases) and the siblings (8 cases). All patients showed prolonged severe cough and the average duration of cough was 26 days. Severe symptoms, including dyspnea, cyanosis, apnea, and seizures, were observed in the children under 2 months of age. According to the recent 10-year KCDC data, the highest rate of pertussis diagnosis was noted in infants (47.8%), followed by adolescents (18.7%). Six patients with parapertussis also presented with prolonged severe cough without any other severe symptoms. Lymphocytosis was not found, unlike the patients with pertussis. CONCLUSION: The possibility of pertussis and parapertussis should be considered among patients with prolonged severe cough, especially in infants and adolescents.

Infección por Bordetella pertussis y bordetella parapertussis en casos con sospecha de coqueluche (2011-2015). Mar del Plata, Argentina / Infection by Bordetella pertussis and bordetella parapertussis in cases of suspected whooping cough (2011-2015) in Mar del Plata, Argentina

RESUMEN Objetivos Caracterizar la población en estudio en el marco del Sistema Nacional de Vigilancia de Salud de la Argentina, determinar la proporción de infección por Bordetella pertussis y Bordetella parapertussis e identificar factores asociados de los casos con sospecha de coqueluche atendidos en la ciudad de Mar del Plata y alrededores durante el período 2011- 2015. Materiales y Métodos Se realizó un estudio observacional y descriptivo. Se diagnosticaron por laboratorio casos clínicos con sospecha de coqueluche. Los estudios de laboratorio consistieron en cultivo, PCR y serología por técnica de ELISA. Resultados Se evaluaron 572 casos. El sexo femenino fue el más frecuente con 51,9% (296/570), el rango etario más frecuente fue de 2 a 17 meses con 51,1% (290/568) que fue además el grupo con más casos confirmados. Solo el 47,8% (155/324) de la población estudiada tenía vacunación completa para su edad. Se confirmó coqueluche por Bordetella pertussis en el 15,5 % y un solo caso con Bordetella parapertussis. Hubo asociación entre tener un contacto familiar tosedor por más de dos semanas con la confirmación de Bordetella spp. (odds ratio [OR]: 3,3; [intervalo de confianza al 95%] IC 95%: 1,9 - 5,4). Conclusiones Existe la necesidad de realizar una evaluación oportuna de los casos sospechosos de coqueluche tanto en niños como en adolescentes y adultos para lograr un mejor control de la enfermedad. Asimismo, continuar con las medidas de prevención y de contención resulta fundamental para disminuir la circulación del agente causal.

ABSTRACT Objectives . To classify the study population in the Argentinian National Health Surveillance System framework, determine the proportion of infection by Bordetella pertussis and Bordetella parapertussis, and identify factors associated with the cases of suspected whooping cough attended to in the city of Mar del Plata and its outskirts during the period 2011- 2015. Materials and Methods An observational and descriptive study was carried out. Clinical cases with suspicion of whooping cough were diagnosed by laboratory. The laboratory studies consisted of culture, PCR, and serology using the ELISA technique. Results A total of 572 cases were evaluated. The female sex was the most frequent (51.9%). The most frequent age range was 2 to 17 moths (51.1%; 290/568), which was also the group with the most confirmed cases. Only 47.8% (155/324) of the population studied had complete vaccination for their age. Whooping cough due to B. pertussis was confirmed in 15.5% (89/572) of cases and one case with B. parapertussis. Those cases that had contact with a coughing relative were significantly associated with the confirmation of Bordetella spp. by the laboratory (odds ratio: 3.3; 95% confidence interval: 1.9-5.4). Conclusions The results show the need to suspect whooping cough and diagnose it early in children, adolescents, and adults in order to better control the disease. Likewise, continuing prevention and containment measures are fundamental in decreasing the circulation of the causal agent.

Concordancia entre las técnicas de IFD, PCR y ELISA para determinar la frecuencia de Bordetella parapertussis y Bordetella pertussis en un brote de tos ferina en el departamento de Antioquia (Colombia) en 2013 / Correlation among the DIF, PCR and ELISA techniques for determining the frequency of Bordetella parapertussis and Bordetella pertussis in an outbreak of whoopingcough in the department of Antioquia, Colombia, 2013

Objetivo: Obtener la concordancia de técnicas diagnósticas y confirmar el diagnóstico de los casos probables de tos ferina captados por inmunofluorescencia directa (IFD) durante un brote en 2013 en el departamento de Antioquia. Materiales y métodos: Se analizaron los datos demográficos, clínicos, epidemiológicos y de resultados de laboratorio de casos probables de tos ferina confirmados por IFD en un pico de tos ferina en 2013 en el departamento de Antioquia. Las muestras de aspirado nasofaríngeo y suero fueron recolectadas y recibidas entre los periodos epidemiológicos IV - VII de 2013. Todos los pacientes confirmados por IFD fueron confirmados por PCR o ELISA. El análisis de concordancia se realizó por índice kappa. Resultados: De las 180 muestras procesadas en el LSP de Antioquia, 134 (74%) fueron positivas por la técnica de IFD, de las cuales se confirmaron por PCR 109 muestras con 24 (22%) positivas para B. parapertussis , 3 (2,8%) para B. pertussis , 17 (15,6%) para Bordetella spp. y 18 (16,5%) con infección mixta por B. pertussis y B. parapertussis . De 81 casos que se confirmaron por ELISA, 31 (38,3%) fueron positivos. En el municipio de La Estrella la edad media de los casos confirmados fue de 6,6 años y la mediana de 3 años (rango: 2-4 años). Con respecto a los casos del municipio de Medellín, la edad media fue de 28,7 años y la mediana de 25 años (rango: 12-42 años). En su mayoría, en los síntomas no hubo diferencias significativas, excepto para la tos paroxística entre los casos confirmados de B. parapertussis y B. pertussis (p = <0,04) del municipio de La Estrella. De acuerdo con el índice kappa, los resultados mostraron una fuerza de concordancia pobre y sin grado de acuerdo con los resultados de las pruebas de PCR y ELISA comparados con IFD, índice kappa: (IFD/PCR: K = 0,0944) y (IFD/ELISA: K = - 0,4533). Conclusiones: Durante este análisis, en el 2013 la población de Antioquia fue afectada por la circulación de B. parapertussis y B. pertussis en población adolescente y adulta en Medellín y en la población de 2-4 años en La Estrella. Actualmente, la PCR y la ELISA son las técnicas adecuadas para el diagnóstico de tos ferina. La IFD por su subjetividad y baja concordancia se encuentra en desuso.

Objective: To determine the correlation between diagnostic techniques and to confirm the diagnosis of probable cases of whooping cough captured by direct immunofluorescence (DIF) during an outbreak in 2013 in the department of Antioquia. Materials and methods: We analysed the demographic, clinical, and epidemiological data and the laboratory results of probable cases of whooping cough confirmed by DIF at a peak of whooping cough in 2013 in the department of Antioquia. The nasopharyngeal aspirate and serum samples were collected and received between the epidemiological periods IV - VII of 2013. All patients confirmed by DIF were confirmed by polymerase chain reaction (PCR) and/or enzyme-linked immunosorbent assay (ELISA). The analysis of agreement was performed using the kappa index. Results: Of the 180 samples processed in the public health laboratory of Antioquia, 134 (74%) were positive using the DIF technique of which 109 samples were confirmed by PCR, with 24 (22%)samples positive for B. parapertussis , 3 (2.8%) for B. pertussis , 17 (15.6%) for Bordetella spp. and18 (16.5%) for mixed infection by B. pertussis and B. parapertussis . Of the 81 cases confirmed by ELISA, 31 (38.3%) were positive. In the municipality of La Estrella, the mean age of the confirmed cases was 6.6 years, and the median was 3 years (range, 2-4 years). For the municipality of Medellin, the mean age was 28.7 years, and the median was 25 years (range, 12-42 years). For most of the symptoms, there were no significant differences, except for paroxysmal cough among the confirmed cases of B. parapertussis and B. pertussis ( p = <.04) in the municipality of La Estrella. According to the kappa index, the results showed poor correlation strength and no agreement with the results of the PCR and ELISA tests compared with DIF, kappa index: (DIF/PCR: K = 0.0944) and (DIF/ELISA: K = - 0.4533). Conclusions: During this analysis in 2013, Antioquia was affected by the circulation of B. parapertussis and B. pertussis in the adolescent and adult population in Medellin and the 2-4 year-old population in La Estrella. Currently, PCR and ELISA are the recommended techniques for diagnosing whooping cough. Due to its subjectivity and low correlation, DIF is in disuse.

Desarrollo y validación de una PCR múltiple para el diagnóstico de Bordetella spp / Development and validation of a multiplex PCR for diagnosis of Bordetella spp / Desenvolvimento e validação de uma PCR múltipla para o diagnóstico de Bordetella spp

El objetivo del trabajo consistió en diseñar y validar una PCR en formato convencional que permita confirmar la presencia o ausencia de Bordetella pertussis y detectar otras especies del género, como Bordetella parapertussis y Bordetella bronchiseptica, que pudieran estar involucradas en el cuadro clínico de coqueluche. A tal fin se diseñó una reacción en cadena de la polimerasa (PCR) múltiple que amplifica una secuencia del promotor del gen de Toxina Pertussis y otra del gen de la Toxina Adenilato Ciclasa-Hemolisina. Se validó la metodología siguiendo esquemas publicados anteriormente. Se optimizaron las condiciones de la PCR. Se validó la metodología obteniéndose un límite de detección para ambas secuencias de 0,5 bacterias por reacción. Se validó, además, la especificidad y robustez de la técnica. Se presenta una nueva herramienta diagnóstica optimizada y validada, que permite detectar la presencia de las especies de Bordetella más frecuentemente involucradas en el cuadro clínico de coqueluche. Su uso combinado con alguna de las PCR habituales en diagnóstico, como la PCR IS481, permite aumentar la sensibilidad del diagnóstico de esta en­fermedad, la especificidad del mismo discriminando los resultados falsos positivos/negativos y aumentar el conocimiento sobre los agentes etiológicos implicados en esta patología.

The aim of the present work was to design and validate a conventional PCR that enables to confirm the presence or absence of Bordetella pertussis and to detect other Bordetella species, such as Bordetella parapertussis metoand B. bronchiseptica, that may be involved in this pathology. To this aim, a multiplex PCR that amplifies a sequence of the promoter of the Pertussis Toxin gene and a sequence of the Adenylate Cyclase Toxin-Hemolysin gene were designed. The PCR was validated following previously published schemes. PCR conditions were optimized. The methodology was validated obtaining a detection limit of 0.5 bacteria per reaction, for both sequences. Specificity and robustness of the technique were also validated. A new optimized and validated tool to detect the presence of the Bordetella species most frequently responsible of pertussis was presented. The combined use with some of the usual PCR, such as IS 481, may increase the sensitivity of the diagnosis of this disease, its specificity discriminating false positive/negative results and increase awareness of the etiologic agents involved in this pathology.

O objetivo do trabalho foi desenhar e validar uma reação em cadeia da polimerase (PCR) em formato convencional que permita confirmar a presença ou ausência de Bordetella pertussis e detectar outras espécies do gênero, como Bordetella parapertussis e Bordetella bronchiseptica, que pudessem estar envolvidas no quadro clínico de coqueluche. Para tal, foi desenhada uma PCR múltipla que amplifica uma sequência do promotor do gene de Toxina Pertussis e outra do gene da Toxina Adenilato Ciclase-Hemolisina. A metodologia foi validada seguindo esquemas publicados anteriormente. Foram otimizadas as condições da PCR. Validou-se a metodologia obtendo-se um limite de detecção para ambas as sequências de 0,5 bactérias por reação. Validou-se também a especificidade e robustez da técnica. Apresenta-se uma nova ferramenta diagnóstica otimizada e validada, que permite detectar a presença das espécies de Bordetella mais frequentemente envolvidas no quadro clínico de coqueluche. Seu uso combinado com alguma das PCR habituais em diagnóstico, como a PCR IS481, permite aumentar a sensibilidade do diagnóstico desta doença, a especificidade do mesmo discriminando os resultados falsos positivos/negativos e aumentar o conhecimento sobre os agentes etiológicos envolvidos nesta patologia.