Epidemiological investigation of an outbreak of pertussis in a primary school in Rizhao / 中国学校卫生

Objective@#To investigate the epidemiological characteristics of a pertussis outbreak in a primary school in Rizhao City, so as to provide reference for the prevention and control strategy of pertussis.@*Methods@#The method of field epidemiological investigation was used to determine case definition for case search and case investigation,and the characteristics of the outbreak were comprehensively analyzed through descriptive epidemiological method.@*Results@#The outbreak lasted for 29 days from April 19 to May 17, 2022, with a total of 14 cases detected. All the cases were students aged 6-7 years from Class 2, Grade 1 in this primary school,including 6 boys and 8 girls. The attack rates of boys and girls were 30.00% and 34.78%, respectively. The time interval from onset to diagnosis of 14 cases ranged from 2 to 22 days, with a median of 10 days. All of them had received 4 doses of Diphtheria and Tetanus and acellular Pertussis(DTaP) combined vaccine, and the interval between the last vaccination and the onset of disease was 5-6 years. After isolated treatment, all the 14 sick students recovered, without severe or death cases.@*Conclusion@#The outbreak of pertussis in a primary school may be related to the decline in the effectiveness of pertussis vaccine protection over time, the lax implementation of a school registration and reporting system for sick absenteeism, and the poor sensitivity of existing pertussis surveillance systems.

Estandarización de un ELISA para la cuantificación de anticuerpos IgG humanos contra células enteras de Bordetella pertussis / Standardization of an ELISA for the quantification of human IgG antibodies against whole cells of Bordetella pertussis

Bordetella pertussis es un patógeno exclusivo de humanos que causa la tos ferina, enfermedad respiratoria aguda que afecta principalmente a la población pediátrica. Existen dos tipos de vacunas comercializadas contra este patógeno: celulares y acelulares. Las vacunas celulares han sido extensamente utilizadas y siguen teniendo gran relevancia. El presente trabajo tuvo como objetivo la estandarización de un ELISA para la cuantificación de anticuerpos IgG contra células enteras de Bordetella pertussis. Para ello se determinó la concentración de recubrimiento, el rango lineal de la curva, los parámetros de precisión intra e interensayo, la especificidad, el valor de corte y el límite de detección. Se determinó como concentración de recubrimiento 0,5 UO/mL de células enteras. La curva estándar utilizando un suero de referencia internacional presentó un buen ajuste a una función polinómica en un intervalo entre las diluciones 1/100 y 1/24.300 con un coeficiente de correlación R2≥0,98. Los coeficientes de variación en los ensayos de precisión intra e interensayo estuvieron en los intervalos establecidos para cada uno (≤10 por ciento, ≤20 por ciento respectivamente). Los resultados obtenidos avalan el empleo de este ELISA cuantitativo para la evaluación de la respuesta a células enteras de Bordetella pertussis en ensayos clínicos(AU)

Bordetella pertussis is a pathogen exclusive to humans that causes pertussis, an acute respiratory disease that mainly affects the pediatric population. There are two types of vaccines commercially available against this pathogen: cellular and acellular. Cellular vaccines have been widely used and continue to be of great relevance. The aim of the present work was to standardize an ELISA for the quantification of IgG antibodies against whole cells of Bordetella pertussis. For this purpose, the coating concentration, the linear range of the curve, the intra- and inter-assay precision parameters, the specificity, the cut-off value and the detection limit were determined. The coating concentration was determined as 0.5 UO/mL of whole cells. The standard curve using an international reference serum presented a good fit to a polynomial function in a range between dilutions 1/100 and 1/24,300 with a correlation coefficient R2≥0.98. The coefficients of variation in the intra- and inter-assay precision tests were in the intervals established for each (≤10percent, ≤20percent respectively). The results obtained support the use of this quantitative ELISA for the evaluation of whole-cell response to Bordetella pertussis in clinical trials(AU)

Amplificación directa de ADN de Bordetella pertussis purificado de hisopados nasofaríngeos por un método de bajo costo, rápido (60-segundos) y libre de equipos / Direct amplification of Bordetella pertussis DNA purified from nasopharyngeal swabs by a low-cost, fast (60-second), and equipment-free method

RESUMEN Objetivo. Desarrollar y evaluar un método de bajo costo basado en celulosa para la purificación rápida y amplificación directa de ADN de Bordetella pertussis de hisopados nasofaríngeos. Materiales y métodos. Se prepararon discos de celulosa y se evaluaron diferentes parámetros (buffers de lisis/lavado, número de discos y elución de ADN). El método se acopló a una amplificación directa por PCR en tiempo real (qPCR) y se estimó el rendimiento utilizando hisopados nasofaríngeos que fueron positivos (n=100) y negativos (n=50) para ADN B. pertussis por qPCR, comparado con el método basado en columnas de sílice. Se calculó el grado de concordancia, sensibilidad, especificidad, valor predictivo positivo (VPP) y valor predictivo negativo (VPN). Se evaluó la factibilidad del método rápido para ser acoplado a un ensayo colorimétrico de amplificación isotérmica mediada por lazo (LAMP). Resultados. El método rápido con un disco de celulosa y buffer de lisis y lavado conteniendo PVP-40 y Tween 20, respectivamente, mostró una mayor capacidad para purificar ADN amplificable de B. pertussis. El método tuvo una sensibilidad de 89,0% (IC95%, 80,2%-94,9%) y una especificidad de 98,5% (IC95%, 92,1%-100,0%), con un buen grado de concordancia (Kappa=0,867; IC95% 0,788 - 0,946), respecto al método referencial. Los VPP y VPN fueron 98,6% (IC95%, 92,7,2%-100,0%) y 88,2% (IC95%, 78,7%-94,4%), respectivamente. Se evidenció una amplificación exitosa por LAMP, y se obtuvieron resultados comparables con el método por columnas de sílice. Conclusión. El método desarrollado es simple, de bajo costo y libre de equipos para la obtención rápida (60 segundos) de ADN en el punto de atención, y puede ser implementado en diversas técnicas moleculares orientados al diagnóstico oportuno y al estudio epidemiológico de tos ferina.

ABSTRACT Objective. To develop and evaluate a low-cost cellulose-based method for rapid purification and direct amplification of Bordetella pertussis DNA from nasopharyngeal swabs. Materials and methods. We prepared cellulose discs and evaluated different parameters (lysis/wash buffers, number of discs and DNA elution). The method was coupled to a direct real-time PCR (qPCR) amplification and the performance was estimated using nasopharyngeal swabs that were positive (n=100) and negative (n=50) for B. pertussis DNA by qPCR, compared to the silica column-based method. We calculated sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) and the degree of agreement. The feasibility of the rapid method to be coupled to a loop-mediated isothermal amplification colorimetric assay (LAMP) was evaluated. Results. The rapid method, with a cellulose disk and lysis and wash buffer containing PVP-40 and Tween 20, respectively, showed a greater capacity to purify amplifiable DNA from B. pertussis. The method had a sensitivity of 89.0% (95%CI: 80.2%-94.9%) and a specificity of 98.5% (95%CI: 92.1%-100.0%), with a good degree of agreement (Kappa=0.867; 95%CI: 0.788 - 0.946), compared to the reference method. The PPV and NPV were 98.6% (95%CI: 92.7.2%-100.0%) and 88.2% (95%CI: 78.7%-94.4%), respectively. Successful amplification by LAMP was evident, and comparable results were obtained with the silica column method. Conclusion. The developed method is simple, low-cost and equipment-free for rapid (60 seconds) DNA collection at the point of care, and can be implemented in various molecular techniques aimed at the timely diagnosis and epidemiological study of pertussis.

Analysis of the time series of pertussis in Brazil from 2010 to 2019 / Análise da série temporal da coqueluche no Brasil no período de 2010 a 2019

Abstract Objectives: to analyze a decade of spatio-temporal behavior of pertussis in Brazil and its epidemiological characteristics. Methods: ecological time series study of pertussis cases and deaths from the Notifable Diseases Information System in Brazil (2010-2019). The method of generalized linear analysis of Prais-Winsten and the Kernel analysis were used. Results: 32,849 cases were reported, of which 466 (1.42%) evolved to death, with a prevalence of 1.63/100,000 inhabitants and a mortality rate of 0.023/100,000 inhabitants. In the temporal analysis, the cyclical behavior of pertussis was evidenced, with trend variations in the period in 2014. Most cases occurred in children under 1 year of age (60.16%, p<0.01), sex female (55.28%, p=0.066) and white (48.42%, p=0.14). The largest share of deaths was in children aged <1 year (98.07, p<0.01), females (56.01%, p=0.066) and whites (43.78%, p=0.14). In the Kernel of prevalence, the South, Southeast and Northeast regions stood out with high density; while for mortality, the Southeast and Northeast stood out. Conclusions: the cyclical behavior of pertussis was observed, with a decreasing trend in recent years and the concentration of cases in children. This reinforces the importance of strengthening the population's immunization process.

Resumo Objetivos: analisar uma década do comportamento espaço-temporal da coqueluche no Brasil e as suas características epidemiológicas. Métodos: estudo ecológico de série temporal dos casos e óbitos por coqueluche do Sistema de Informação de Agravos de Notificação no Brasil (2010-2019). Utilizou-se o método de análise linear generalizada de Prais-Winsten e a análise de Kernel. Resultados: notificaram-se 32.849 casos, desses 466 (1,42%) evoluíram para óbito, com prevalência de 1,63/100.000 habitantes e coeficiente de mortalidade de 0,023/100.000 habitantes. Na análise temporal, evidenciou-se o comportamento cíclico da coqueluche com variações de tendência no período em 2014. A maioria dos casos ocorreu em menores de 1 ano (60,16%, p<0,01), sexo feminino (55,28%, p=0,066) e brancos (48,42%, p=0,14). A maior parcela dos óbitos foi em crianças <1 ano (98,07, p<0,01), sexo feminino (56,01%, p=0,066) e brancos (43,78%, p=0,14). No Kernel da prevalência, destacaram-se as regiões Sul, Sudeste e Nordeste com alta densidade; enquanto para mortalidade, sobressaíram-se Sudeste e Nordeste. Conclusão: observou-se o comportamento cíclico da coqueluche, com tendência de decréscimo nos últimos anos e a concentração de casos no público infantil. O que reforça a importância de fortalecer o processo de imunização da população.

Opinión de un panel de expertos sobre la protección contra la tos ferina en México: el papel de las vacunas acelulares y de células enteras / An expert panel opinion on protection against pertussis in Mexico: The role of acellular and whole-cell vaccines

Resumen La tos ferina es una enfermedad causada por Bordetella pertussis. Aunque es altamente contagiosa, puede ser prevenible por vacunación. Existen dos tipos de vacunas: las de células enteras y las acelulares. La tos ferina ha resurgido en algunos países debido a que su control a escala mundial es heterogéneo. Esta reemergencia se ha relacionado con diversos factores: mayor sensibilidad hacia la infección, mejor detección de la enfermedad, problemas para obtener adecuadas coberturas de vacunación, incremento en los sujetos susceptibles (especialmente menores de 6 meses), pérdida de la inmunidad en los adolescentes y adultos jóvenes, y probables cambios genéticos y adaptativos de B. pertussis. En este documento se analizan las características, las ventajas y las desventajas de las vacunas de células enteras y de las vacunas acelulares. Se presentan las recomendaciones internacionales y se ofrece el posicionamiento de los participantes con respecto a la influencia del uso de vacunas acelulares y las desventajas potenciales de volver a utilizar vacunas de células enteras, en especial por su reactogenicidad. Por último, se analizan las estrategias para lograr un mejor control de la tos ferina en México.

Abstract Pertussis is a highly contagious disease caused by Bordetella pertussis, which may be preventable by vaccination. There are two types of vaccines: whole-cell vaccines and acellular vaccines. Since pertussis control worldwide is heterogeneous, re-emergence of whooping cough has been observed in some countries. This re-emergence has been related to several factors: increased susceptibility to infection, better detection of disease, problems in obtaining adequate vaccination coverage, increase in susceptible subjects (mainly under 6 months of age), loss of immunity in adolescents and young adults, and likely genetic and adaptive B. pertussis changes. This paper discusses whole-cell and acellular vaccines' characteristics, advantages, and disadvantages. International recommendations are presented, and the participants' position is offered regarding the influence of the use of acellular vaccines and the potential disadvantages of reintroducing whole-cell vaccines, mainly due to their reactogenicity. Finally, strategies to achieve better control of pertussis in Mexico are discussed.

Síndrome coqueluchoide y tosferina

RESUMEN Introducción: El síndrome coqueluchoide es una causa frecuente de ingreso y no siempre se descarta a la Bordetella pertussis como su origen. Objetivo: Identificar la etiología infecciosa en niños ingresados con síndrome coqueluchoide/coqueluche y su relación con el estado de la vacunación. Métodos: Estudio descriptivo, transversal, en 120 niños hasta 10 años de edad con diagnóstico de síndrome coqueluchoide ingresados en el Servicio de Neumología del Hospital Pediátrico "Juan Manuel Márquez", entre enero 2010 y septiembre 2012. Se evaluó la edad, sexo, evolución, resultados de reacción en cadena de la polimerasa y cultivo para virus, bacterias y micoplasmas en muestras obtenidas al ingreso, procesadas en el Instituto de Medicina Tropical, además, cumplimiento de vacunación antipertussis. Las variables cualitativas se describieron mediante frecuencias absolutas y porcentajes; para evaluar la relación tos ferina e incumplimiento de la vacunación se empleó la prueba Ji cuadrada con un nivel de significación de p≤ 0,05. Resultados: Predominaron los menores de un año (69,2 %) y el sexo femenino (55%). Bordetella pertussis se aisló en 71 casos (59,2 %); más frecuente en menores de 6 meses (59,7 %) y en niños con vacunación incompleta (80 %), pero no fue significativa la diferencia con los casos no pertussis (p=0,214).Existió coinfección con virus y micoplasmas (54-76 %). La etiología viral predominó en los restantes 49; rinovirus fue el más representado en general. Falleció una recién nacida con neumonía por B pertussis. Conclusiones: Ante un síndrome coqueluchoide debemos siempre tener presente la posibilidad de tos ferina, sobre todo en niños pequeños con vacunación incompleta.

ABSTRACT Introduction: Coqueluchoid syndrome is a frequent cause of admission and Bordetella pertussis is not always ruled out as its origin. Objective: Identify the infectious etiology in children admitted with coqueluchoid/coqueluche syndrome and its relationship with vaccination status. Methods: A descriptive, cross-sectional study was conducted in 120 children up to 10 years of age diagnosed with coqueluchoid syndrome admitted to the Pulmonology Service of "Juan Manuel Márquez" Children's Hospital between January 2010 and September 2012. Age, sex, evolution, polymerase chain reaction results and culture for viruses, bacteria and mycoplasmas were evaluated in samples obtained at admission, processed at the Institute of Tropical Medicine ; in addition to the compliance with anti-pertussis vaccination. Qualitative variables were described by absolute frequencies and percentages; to evaluate the ratio of whooping cough and non-compliance with vaccination, the Ji square test was used with a significance level of p≤ 0.05. Results: Children under one year of age (69.2%) and female sex (55%) predominated. Bordetella pertussis was isolated in 71 cases (59.2%); it was more frequent in children under 6 months (59.7%) and in children with incomplete vaccination (80%), but the difference with non-pertussis cases was not significant (p= 0.214). There was co-infection with viruses and mycoplasmas (54-76%). Viral etiology predominated in the remaining 49; rhinovirus was the most represented overall. A newborn died with B. pertussis pneumonia. Conclusions: In the face of a coqueluchoid syndrome we must always keep in mind the possibility of whooping cough, especially in young children with incomplete vaccination.

Application of bacterial culture and nucleic acid detection in the diagnosis of pertussis in children / 中华检验医学杂志

Objective:To analyze the clinical characteristics of pertussis cases diagnosed by two pathological detection methods: bacterial culture and real-time polymerase chain reaction (RT-PCR), and to explore the applicable value of two pathological detection methods in the diagnosis of pertussis.Methods:Bilateral nasopharyngeal swabs and clinical information of 165 children suspected of pertussis were collected by Hebei Children′s Hospital from April 2019 to January 2020. The bacterial culture and RT-PCR for nasopharyngeal swab specimens were performed in all cases. Chi-square test was used to analyze the cases of pertussis diagnosed by the above two methods.Results:Based on clinical diagnosis, the sensitivity of bacterial culture and RT-PCR for the diagnosis of pertussis was 61.70% (58/94) and 86.17% (81/94), and the specificity was 92.96% (66/71) and 71.83% (51/71), respectively. The positive rate of RT-PCR in children of all ages, seasons and cough courses is higher than that of bacterial culture. Children with pertussis diagnosed by bacterial culture and RT-PCR were basically similar in age, season, and cough course distribution, with the most common cases ≤3 months old, a high incidence trend in summer and autumn, and the course of coughing in children was mostly within 15-21days. The positive rate of bacterial culture in the diagnosis of pertussis in children is affected by the age of the children, and there are statistical differences between children in different age groups (χ2= 11.929, P=0.036). The positive rate of bacterial culture was the highest in children with >3 years old (51.85% [14/27]), followed by children with ≤3 months old (48.72% [19/39]), and the lowest in children with >6-12 months old (15.00% [3/20]). Moreover, the positive rate of bacterial culture in the diagnosis of pertussis in children is also affected by the cough course of the children, and there are statistical differences between children in different cough course groups (χ2=9.841, P=0.020). The positive rate of bacterial culture was the highest in children with cough course 15-21 days (49.23% [32/65]), followed by 43.59% (17/39) in children with cough course 8-14 days, and the lowest in children with cough course of less than 7 days (22.86% [8/35]). Conclusions:Compared with RT-PCR, bacterial culture has lower sensitivity and higher specificity in the detection of pertussis. These two detection methods have their own advantages and limitations. Medical institutions at all levels should comprehensively analyze different laboratory detection methods. Only by combining the two methods can the diagnostic value and level be effectively improved.

Airway humidification therapy for pertussis in infants / 中国基层医药

Objective:To investigate the effects of airway humidification therapy on pertussis in infants.Methods:Sixty children with pertussis who received treatment in Wenzhou Hospital of Integrated Traditional Chinese and Western Medicine from May 2020 to September 2021 were included in this study. They were randomly divided into study and control groups, with 30 infants per group. The control group was treated with conventional drugs. The study group was subjected to airway humidification therapy based on conventional drug treatment. Clinical efficacy was evaluated in each group. Time to an improvement in clinical symptoms and length of hospital stay were recorded. Lung function indicators and serum inflammatory factor levels were determined before and after treatment. Pertussis-related complications were recorded.Results:The overall response rate in the study group was significantly higher than that in the control group (100.00% vs. 76.7%, χ2 = 5.82, P = 0.016). Time to disappearance of spastic cough, time to resolution of cyanosis, time to disappearance of pulmonary rales, and length of hospital stay in the study group were (3.10 ± 0.67) days, (1.53 ± 0.68) days, (4.27 ± 0.58) days, and (11.57 ± 0.73) days, respectively, which were significantly shorter than (4.23 ± 1.99) days, (2.67 ± 1.77) days, (5.63 ± 2.38) days, (13.33 ± 2.40) days ( t = 2.93, 3.27, 3.04, 3.86; P = 0.005, 0.002, 0.003, P < 0.001). Respiratory rate in the study group was significantly lower than that in the control group [(21.83 ± 1.15) breaths/minute vs. (24.23 ± 3.12) breaths/minute, t = 3.94, P = 0.002]. Tidal volume/kg body weight, the ratio of time to peak expiratory flow to total expiratory time and the ratio of volume to peak expiratory flow to total expiratory volume in the study group were (10.70 ± 0.81) mL/kg, (41.60 ± 1.57)%, (42.89 ± 1.44)%, respectively, which were significantly higher than (9.78 ± 1.34) mL/kg, (39.18 ± 3.37)%, (40.20 ± 3.05)% in the control group ( t = 3.21, 3.56, 4.36; P < 0.001, P = 0.001, P < 0.001). Serum tumor necrosis alpha (TNF-α), interleukin-6 and interleukin-8 levels in the study group were (62.44 ± 2.96) ng/L, (46.59 ± 1.96) ng/L, (54.63 ± 3.27) ng/L, respectively, which were significantly lower than (79.86 ± 3.30) ng/L, (58.20 ± 2.10) ng/L, (63.31 ± 3.86) ng/L in the control group ( t =21.53, 22.13, 9.38, all P < 0.001). The overall incidence of pertussis in the study group was significantly lower than that in the control group (3.3% vs. 26.7%, χ2 = 4.71, P = 0.030). Conclusion:Airway humidification therapy can shorten the time to reduction of symptoms of spasmodic pertussis, improve clinical efficacy, strengthen pulmonary ventilation function, lower respiratory tract inflammatory responses and reduce the risk of pertussis-related complications.

Investigation on serum pertussis toxin antibody levels in children aged 0-14 in Hangzhou / 中华实用儿科临床杂志

Objective:To investigate the serum antibody level in children with pertussis in Hangzhou city, and to evaluate the incidence of pertussis in children and the immunization effect of vaccine.Methods:A retrospective study was conducted.The pertussis toxin IgG antibody levels in 1 486 children aged 0-14 who received physical exa-mination in Hangzhou Children′s Hospital from January to December 2018 of were collected and analyzed.Serum antibody level ≥30 IU/mL was considered seropositive.The children enrolled were divided into the 0-3-year-old, 4-6-year-old, 7-9-year-old and 10-14-year-old groups; then the children under 3 years old were subdivided into groups of 0-<3 months, 3-<6 months, 6-<9 months, 9-<12 months, 12-<18 months, and 18-≤ 36 months; finally, the children were grouped according to their vaccination times, the pertussis toxin IgG antibody level and the infection rate of pertussis were compared among different groups by Mann- Whitney U, Kruskal- Wallis and χ2 tests. Results:The overall positive rate of the pertussis toxin IgG antibody was 23.62% (351/1 486), and the median antibody concentration was 6.60 IU/mL.Among children aged 0-14, the 0-3-year-old children had the highest positive rate of the pertussis toxin IgG antibody and the highest median antibody concentration, which were 24.58% (29/118) and 6.95 IU/mL, respectively.There was no significant difference in the antibody positive rate and the median antibody concentration among different age groups (all P>0.05). Among different subgroups of children aged 0-3, the pertussis toxin IgG antibody positive rate and the median antibody concentration were statistically significant (all P<0.05). It was predicted that the pertussis infection rate in children over 3 years old in Hangzhou was about 45.99%.The patients receiving more than 3 doses of vaccination accounted for 87.48% (1 300/1 486), and their antibody positive rate was 25.46% (331/1 300). After excluding unvaccinated children, the comparison results suggested that there was statistical significance in the antibody positive rate and median antibody concentration among different vaccination groups ( χ2=24.467, 67.438, all P<0.001). Conclusions:The serum pertussis toxin IgG antibody positive rate in children aged 0-14 in Hangzhou is low, but their predicted pertussis infection rate is higher.Children aged 0-14 are easy to become a main source of infection.Therefore, it is necessary to pay attention to and strengthen the vaccination plan and research, enhance the monitoring of the infection source, and prevent the " recurrence of pertussis" .

Incidência de coqueluche em crianças menores de 1 ano e relação com a vacinação materna no Brasil, 2008 a 2018 / Incidencia de tos ferina en niños menores de 1 año y relación con la vacunación materna en Brasil, 2008 a 2018 / Pertussis incidence in children under 1 year old and relation with maternal vaccination in Brazil, 2008-2018

Objetivo: Analisar o impacto da vacina adsorvida difteria, tétano e coqueluche (pertússis acelular), tipo adulto (dTpa), materna, na incidência de coqueluche em crianças menores de 1 ano no Brasil, de 2008 a 2018. Métodos: Estudo de tipo ecológico, descritivo de tendência temporal, utilizando-se de dados dos sistemas de vigilância do Departamento de Informática do Sistema Único de Saúde (Datasus). Foram calculadas taxas de incidência e razão das taxas de incidência (IRR), com respectivos intervalos de confiança de 95% (IC95%). Resultados: O número de casos de coqueluche foi de 20.650. Houve redução na incidência de coqueluche no período pós-vacinal, de 26,6% (IRR = 0,73; IC95% 0,66;0,82) nas crianças de 3 meses a 1 ano incompleto, e de 63,6% (IRR = 0,36; IC95% 0,15;0,58) nas crianças de zero a 2 meses. Conclusão: O aumento da cobertura da vacinação com dTpa materna correspondeu à redução na incidência de coqueluche, principalmente na faixa etária de zero a 2 meses.

Objetivo: Analizar la incidencia de tos ferina en menores de 1 año y su relación con la cobertura de vacunación materna por la vacuna adsorbida contra la difteria, el tétanos y la tos ferina (tos ferina acelular) tipo adulto (dTpa), de 2008 a 2018, en Brasil. Métodos: Estudio ecológico descriptivo de tendencia temporal utilizando datos de los sistemas de vigilancia del Departamento de Informática do Sistema Único de Saúde (Datasus). Se calcularon los tasas de incidencia y las razones de tasas de incidencia (RTI) con los respectivos intervalos de confianza del 95% (IC95%). Resultados: El número de casos de tos ferina en el período de estudio fue de 20,650. Hubo una reducción en la incidencia de tos ferina en el período post-vacunación. En los niños de 3 meses a 1 año incompleto, la reducción fue del 26,6% (RTI = 0,73; IC95% 0,66;0,82), mientras que en el otro grupo la diferencia relativa fue del 63,6% (RTI = 0,36; IC95% 0,15;0,58)]. Conclusión: La vacunación materna con dTpa coincide con una reducción en la incidencia de tos ferina, especialmente en el grupo de edad de cero a 2 meses.

Objetive: To analyze the impact of maternal vaccination coverage with diphtheria-tetanus-acellular pertussis (Tdap) adsorbed vaccine for adults on pertussis incidence in children under 1 year old in Brazil from 2008 to 2018. Methods: This was a descriptive ecological temporal trend study using data from surveillance systems managed by the Brazilian National Health System Information Technology Department (DATASUS). Incidence rates and incidence rate ratios (IRR) were calculated with respective 95% confidence intervals (95%CI). Results: There were 20,650 pertussis cases in the study period. In the post-vaccination period there was a 26.6% reduction (IRR = 0.73; 95%CI 0.66;0.82) in pertussis incidence among children aged from 3 months up to but not including 1 year old, and a 63.6% reduction (IRR = 0.36; 95%CI 0.15;0.58) among children from birth to 2 months old. Conclusion: The increase in maternal Tdap vaccination coverage coincided with a reduction in pertussis incidence, especially in the birth to two-month-old age group.

Factores que influyen en la adherencia a la vacuna contra la tosferina en mujeres embarazadas en Uruguay / Factors that influence the uptake of pertussis vaccine in pregnant women in Uruguay

Introducción: desde 2015 se ofrece la vacunación contra tosferina de modo universal y gratuito a mujeres embarazadas del Uruguay. Si bien es obligatoria, la cobertura vacunal, aún no es completa. Objetivos: conocer la prevalencia de mujeres embarazadas de dos hospitales públicos de Uruguay que recibieron vacuna dpaT en 2017 y determinar posibles factores que influyen en la adherencia a vacunarse. Métodos: estudio observacional, transversal, descriptivo, mediante encuestas a pacientes cursando puerperio inmediato. Resultados: se analizaron 884 encuestas (edad promedio 25,2 años; 16% adolescentes; la mayoría en pareja y educación secundaria incompleta). Se vacunaron 317 mujeres (36%). Dentro de los factores que se asociaron a la no vacunación se destacan: adolescencia (OR 1,88; IC 95% 1,24-2,85), no tener pareja (OR 1,40; IC 95% 1,04-1,85), no conocer la obligatoriedad de la vacuna (OR 9,44; IC 95% 6,63-13,45), no haber sido informada sobre los beneficios de la vacuna (OR 4; IC 95% 2,43-6,41) y no creer en el beneficio de las vacunas en el embarazo (OR 6,37; IC 95% 4,61-8,78). Discusión: la mayoría de las mujeres embarazadas no recibieron la vacuna dpaT ni tuvieron indicación médica. La falta de información sobre la obligatoriedad y su beneficio, y las creencias con respecto a la vacunación se asociaron a una disminución en la adherencia a la misma. Los profesionales de la salud que atienden mujeres gestantes deben recomendar e informar sobre el beneficio de la vacunación para ellas y el neonato y generar la percepción de riesgo necesaria, como una de las medidas para mejorar la cobertura vacunal.

Background: since 2015, pertussis vaccine has been offered universally and free of charge to pregnant women in Uruguay. Although it is mandatory, vaccination coverage is not yet complete. Aim: to study the pertussis vaccination coverage in 2017 in pregnant women in two state hospitals and to search for barriere for uptaking the vaccine. Methods: we conducted an observational, descriptive and transversal study, using a survey in patients undergoing immediate postpartum period. Results: 884 surveys were analyzed (mean age 25.2 years; 16% teenagers, most of them in a relationship and incomplete high school). 317 women (36%) were vaccinated. Main barriere for uptaking Tdap vaccine were: teenage and being single were associated with a greater risk for the uptake. Not being aware of the vaccine mandatoriness and not being informed about its benefits were associated with 9,44 and 4 higher risks for not uptaking the vaccine (IC 95% 6.63-13.45 and IC 95% 2.43-6.41, respectively). Not believing in the benefits of pertussis vaccine during pregnancy was associated with 6.37 higher risk (OR 6.37; IC 95% 4.61-8.78). Discussion: most pregnant women in this study during 2017 did not uptake pertussis vaccine and did not have medical indication for it. The lack of information about the obligation and benefits, and also patients' beliefs about the vaccination were identified as barriere. Health professionals who treat pregnant women should recommend and inform about the benefits of pertussis vaccine for women and the infant, and create the necessary perception of risk, in order to improve the vaccination coverage.

Factores que influyen en la adherencia a la vacuna contra la tosferina en mujeres embarazadas en Uruguay / Factors that influence the uptake of pertussis vaccine in pregnant women in Uruguay

INTRODUCCIÓN: Desde 2015 se ofrece la vacunación contra tosferina de modo universal y gratuito a mujeres embarazadas del Uruguay. Si bien es obligatoria, la cobertura vacunal, aún no es completa. OBJETIVOS: Conocer la prevalencia de mujeres embarazadas de dos hospitales públicos de Uruguay que recibieron vacuna dpaT en 2017 y determinar posibles factores que influyen en la adherencia a vacunarse. MÉTODOS: Estudio observacional, transversal, descriptivo, mediante encuestas a pacientes cursando puerperio inmediato. RESULTADOS: Se analizaron 884 encuestas (edad promedio 25,2 años; 16% adolescentes; la mayoría en pareja y educación secundaria incompleta). Se vacunaron 317 mujeres (36%). Dentro de los factores que se asociaron a la no vacunación se destacan: adolescencia (OR 1,88; IC 95% 1,24-2,85), no tener pareja (OR 1,40; IC 95% 1,04-1,85), no conocer la obligatoriedad de la vacuna (OR 9,44; IC 95% 6,63-13,45), no haber sido informada sobre los beneficios de la vacuna (OR 4; IC 95% 2,43-6,41) y no creer en el beneficio de las vacunas en el embarazo (OR 6,37; IC 95% 4,61-8,78). DISCUSIÓN: La mayoría de las mujeres embarazadas no recibieron la vacuna dpaT ni tuvieron indicación médica. La falta de información sobre la obligatoriedad y su beneficio, y las creencias con respecto a la vacunación se asociaron a una disminución en la adherencia a la misma. Los profesionales de la salud que atienden mujeres gestantes deben recomendar e informar sobre el beneficio de la vacunación para ellas y el neonato y generar la percepción de riesgo necesaria, como una de las medidas para mejorar la cobertura vacunal.

BACKGROUND: Since 2015, pertussis vaccine has been offered universally and free of charge to pregnant women in Uruguay. Although it is mandatory, vaccination coverage is not yet complete. AIM: To study the pertussis vaccination coverage in 2017 in pregnant women in two state hospitals and to search for barriere for uptaking the vaccine. METHODS: We conducted an observational, descriptive and transversal study, using a survey in patients undergoing immediate postpartum period. RESULTS: 884 surveys were analyzed (mean age 25.2 years; 16% teenagers, most of them in a relationship and incomplete high school). 317 women (36%) were vaccinated. Main barriere for uptaking Tdap vaccine were: teenage and being single were associated with a greater risk for the uptake. Not being aware of the vaccine mandatoriness and not being informed about its benefits were associated with 9,44 and 4 higher risks for not uptaking the vaccine (IC 95% 6.63-13.45 and IC 95% 2.43-6.41, respectively). Not believing in the benefits of pertussis vaccine during pregnancy was associated with 6.37 higher risk (OR 6.37; IC 95% 4.61-8.78). DISCUSSION: Most pregnant women in this study during 2017 did not uptake pertussis vaccine and did not have medical indication for it. The lack of information about the obligation and benefits, and also patients' beliefs about the vaccination were identified as barriere. Health professionals who treat pregnant women should recommend and inform about the benefits of pertussis vaccine for women and the infant, and create the necessary perception of risk, in order to improve the vaccination coverage.

Cambios epidemiológicos y actualidades sobre vacunación contra Bordetella pertussis en Latinoamérica / Epidemiologic changes and novelties on vaccination against Bordetella pertussis in Latin America

Resumen A pesar de que la tosferina (coqueluche) es una enfermedad prevenible por vacunas (EPV), la epidemiología latinoamericana muestra que hay persistencia de brotes en la región. Esta persistencia se debe, al menos en parte, a factores tales como la cobertura vacunal, la presencia de movimientos anti vacunas, la diversidad de los sistemas locales de vigilancia y la falta de una definición de caso unificada para la región. Dada la importancia de la tosferina en Latinoamérica y los cambios ocurridos en las recomendaciones para la vacunación, este manuscrito tiene como objetivo revisar los datos epidemiológicos y los cambios recientes en los calendarios de vacunación y su impacto sobre la enfermedad pediátrica por Bordetella pertussis en Latinoamérica. Los datos epidemiológicos más recientes muestran que entre regiones, países, y segmentos dentro de cada país hay heterogeneidad en la cobertura vacunal, con distintos rebrotes. Esfuerzos en la región han tratado de mejorar esta situación al introducir vacunas acelulares (aP), menos reactogénicas que las vacunas de células enteras (wP) en los calendarios vacunales. Además, algunos países han mejorado la definición de caso confirmado, al introducir la reacción de polimerasa en cadena (RPC) como criterio diagnóstico. En respuesta a las heterogeneidades de cada país y a la epidemiología actual de la región, un Comité de Expertos de la Sociedad Latinoamericana de Infectología Pediátrica (SLIPE) y la Asociación Latinoamericana de Pediatría (ALAPE) propone una definición unificada de caso y recomendaciones para mejorar la cobertura vacunal y reducir los brotes de tosferina en Latinoamérica.

Abstract Although whooping cough is a vaccine-preventable disease (VPD), its epidemiologic characteristics in Latin America shows persistence of outbreaks in the region. This persistence is due, at least in part, to the presence of antivaccine movements, the diversity of the surveillance systems, and the lack of a uniform case definition for the region. Given the importance of whooping cough in Latin America and the changes in vaccine recommendations, this manuscript aims to review epidemiologic data and recent changes in the vaccination calendars and their impact on the pediatric disease by Bordetella pertussis in Latin America. Recent epidemiological data reveal that between regions, countries, and administrative units within each country there is a marked heterogeneity of vaccine coverage, with different outbreak patterns. Efforts in the region have tried to improve this situation by introducing acellular pertussis vaccines (aP) in the vaccine calendars, which are less reactogenic than whole-cell pertussis vaccines (wP). Moreover, some countries have improved the case definition. Some countries have implemented a confirmed case definition by introducing polymerase chain reaction (PCR) as a diagnostic criterion. As a response to the heterogeneities observed within and between countries and the regional epidemiologic profiles, a Steering Committee from the Latin American Society for Pediatric Infectiology (SLIPE) and the Latin American Association of Pediatrics (ALAPE) propose a unified case definition and recommendations to improve vaccine coverage and reduce the outbreaks of whooping cough in Latin America.

Levels and influencing factors of serum pertussis toxin-IgG antibody in children with pertussis / 中华传染病杂志

Objective:To investigate the levels and influencing factors of serum pertussis toxin (PT)-IgG antibody in children with pertussis.Methods:The clinical data including age, course of disease and vaccination status of children with laboratory-confirmed pertussis and tested for PT-IgG antibody in Shenzhen Children′s Hospital from July 2015 to December 2018 were collected. Venous blood samples were obtained to detect PT-IgG antibody levels. Nasopharyngeal swabs were taken for polymerase chain reaction (PCR) test to detect Bordetella pertussis nucleic acid and culture of Bordetella pertussis. Mann-Whitney U test was used for comparison between two groups.Kruskal-Wallis test was used for comparison among multiple groups. Multiple linear regression was used to analyze the influencing factors of PT-IgG antibody levels. Results:A total of 871 children aged 4(2, 7) months were included, among whom, 592(68.0%) cases were under six months and 754 (86.6%) cases were under one year old. The course of disease was 15 (11, 20) days. Among 871 cases, 864 (99.2%) cases were PCR test and (or) culture positive, including 696 cases positive only for PCR test, 35 cases positive only for culture and 133 cases positive for both PCR test and culture. There were 452 (51.9%) children who were not vaccinated and 346 (39.7%) children vaccinated with at least one dose. In terms of age, the PT-IgG amtibody levels of children aged 0 to two months, three to five months, six months to two years and ≥three years were 0.7 (0, 8.2) IU/mL, 2.3 (0, 23.0) IU/mL, 24.6 (0, 112.3) IU/mL and 24.9 (0, 114.7) IU/mL, respectively. The PT-IgG antibody levels of children after onset of symptoms at 0 to two weeks, more than two to four weeks, more than four to eight weeks and more than eight weeks were 0(0, 7.9) IU/mL, 8.7(0, 56.0) IU/mL, 26.6(5.1, 82.9) IU/mL and 68.0(15.3, 118.8) IU/mL, respectively. The differences were both statistically significant ( H=88.346 and 94.076, respectively, both P<0.01). The PT-IgG antibody levels in children who were unvaccinated and vaccinated with at least one dose were 0.9 (0, 12.7) IU/mL and 14.6(0, 86.3) IU/mL, respectively. The difference was statistically significant ( Z=-8.520, P<0.01) PT-IgG≥80 IU/mL accounted for 16%(139/871) in the whole range of age, 34.3%(12/35) in children ≥three years old. There were 13 patients aged ≥three years old with a disease course >two weeks, among whom, six patients had PT-IgG≥80 IU/mL. Age, course of disease and vaccination status were independent influencing factors of PT-IgG levels ( β=0.108, 0.189 and 0.250, respectively, all P<0.01). Conclusions:The levels of PT-IgG antibody in children with pertussis are influenced by age, course of disease and vaccination status. The single serum PT-IgG of 80 IU/mL as cut-off value in the diagnosis of pertussis may lead to a increase of missed diagnosis. Therefore, it is necessary to further explore the standards suitable for children in China.

Perfil epidemiológico dos atendimentos dos casos suspeitos de coqueluche em um hospital particular de Maceió no período de 2013 a 2017 / Epidemiological profile of the care of the suspect cases of coqueluche in a particular hospital of Maceió in the period from 2013 to 2017 / Perfil epidemiológico de los atendimentos de los casos suspensos de coqueluche en un hospital particular de Maceió en el período de 2013 a 2017

Justificativa e Objetivos: traçar o perfil do público-alvo acometido pela doença, possibilitando o rastreamento dos casos suspeitos, realizar identificação e estratificação dos casos e elaborar um perfil epidemiológico do atendimento no hospital para se obter um plano de contingência no fluxo de atendimento. Métodos: estudo descritivo, com abordagem quantitativa no contexto de notificações. Para estudo epidemiológico foram utilizados os dados do Sistema de Informação de Agravos de Notificação, o Sistema Gerenciador de Ambiente Laboratorial, Prontuário Eletrônico e Planilha dinâmica de controle interno. Os dados coletados foram distribuídos em uma planilha idealizada usando o programa de Excel, e os seus resultados foram expressos pela estatística descritiva e quantitativa em frequência absoluta. A busca pelos dados foi definida entre os anos de 2013 a 2017 para o agravo de notificação coqueluche, a partir de então foram estratificados os casos suspeitos e confirmados, por faixa etária, gênero e ocorrência de confirmação diagnóstica. Resultados: Foram notificados de janeiro de 2013 a dezembro de 2017, 48 casos de suspeitos de coqueluche, sendo que 2 (4,2%) casos foram confirmados. O número de casos suspeitos de coqueluche apresentou um número elevado no ano de 2014 nos meses de março e junho e nos anos seguintes foi percebida uma estabilização. Conclusão: foi observado um grande número de casos suspeitos sem investigação clínica, ou seja, sem a presença de exames laboratoriais para confirmar ou descartar esta patologia.(AU)

Background and Objectives: to define the profile of the target population affected by the disease, it is possible to trace the suspected cases, identify and stratify the cases and elaborate an epidemiological profile of the hospital care to obtain a contingency plan in the care flow. Methods: descriptive study, with quantitative approach in the context of notifications. For the epidemiological study, the data of the Information System of Notifiable Diseases, the Laboratory Management System, the Electronic Records System and the internal spreadsheet were used. The collected data were distributed in an idealized spreadsheet using the Excel program, and its results were expressed by the descriptive and quantitative statistics in absolute frequency. The search for the data was defined between the years of 2013 and 2017 for the pertussis report, from which the suspected and confirmed cases were stratified by age, gender, and the occurrence of diagnostic confirmation. Results: From January 2013 to December 2017, 48 suspected pertussis cases were reported, of which 2 (4.2%) cases were confirmed. The number of cases of whooping cough presented a high number in the year 2014 in the months of March and June and in the following years a stabilization was perceived. Conclusion: a large number of suspected cases were observed without clinical investigation, that is, without the presence of laboratory tests to confirm or rule out this pathology.(AU)

Justificaciones y objetivos: en el presente trabajo se analizaron los resultados obtenidos en el análisis de los resultados obtenidos en el estudio de los resultados obtenidos en el estudio. Métodos: estudio descriptivo, con abordaje cuantitativo en el contexto de notificaciones. Para el estudio epidemiológico se utilizaron los datos del Sistema de Información de Agravios de Notificación, el Sistema Gestor de Ambiente Laboratorio, Prontuario Electrónico y Planilla dinámica de control interno. Los datos recolectados fueron distribuidos en una hoja de cálculo idealizada usando el programa de Excel, y sus resultados fueron expresados por la estadística descriptiva y cuantitativa en frecuencia absoluta. La búsqueda por los datos fue definida entre los años de 2013 a 2017 para el agravio de notificación coqueluche, a partir de entonces fueron estratificados los casos sospechosos y confirmados, por grupo de edad, género y ocurrencia de confirmación diagnóstica. Resultados: Se notificaron de enero de 2013 a diciembre de 2017, 48 casos de sospechas de tos ferina, siendo que 2 (4,2%) casos fueron confirmados. El número de casos de tos ferina presentó un número elevado en el año 2014 en los meses de marzo y junio y en los años siguientes se percibió una estabilización. Conclusión: se observó un gran número de casos sospechosos sin investigación clínica, es decir, sin la presencia de exámenes de laboratorio para confirmar o descartar esta patología.(AU)

Caracterización de la infección por Bordetella pertussis en el Hospital Metropolitano de Quito / Characterization of Bordetella pertussis infection at the Metropolitan Hospital of Quito

Abstract: Introduction: Whooping cough continues to be a public health problem. The objective of the study was to characterize the hospital discharge diagnosed with pertussis confirmed by Multiplex PCR in respiratory samples with Bordetella pertussis isolation in the Hospital Metropolitano Quito, 2015-2018 period. Materials and methods: Retrospective descriptive study of confirmed cases with Bordetella pertussis by Multiplex PCR in respiratory samples, period 2015-2018. Results and discussion: During 4 years, it was suspected in 19 cases of which 10 were confirmed, by PCR in respiratory samples, 1 case had positive confirmation by culture for Bordetella pertussis in the National Health Institute of Public Health Research. 80% (8) corresponded to younger infants. 20% (2) presented respiratory failure and 50% (5) entered the ICU, 3 of them required mechanical ventilation. In 40% (4) more than one microorganism was isolated in the respiratory panel, where Rhinovirus 1, 2, 3, 4 were prevalent. 100% (10) was dependent on supplemental oxygen and 50% (5) was discharged with home oxygen. 60% (6) presented incomplete vaccination for age. The average hospitalization was 8 days. 50% (5) received antibiotic therapy prior to admission. The hospital treatment was clarithromycin. All cases had family contact with respiratory infection. No mortality was recorded. Bordetella pertussis is an important causal agent of hospital admission in infants. It is imperative to maintain adequate vaccination strategies and achieve an adequate herd effect.

Severe pertussis in childhood: update and controversy - systematic review / Coqueluche grave na infância: atualização e controvérsias - revisão sistemática

ABSTRACT Objective: Through a systematic review, this essay aimed at revising the concepts of severe pertussis, updating the epidemiology, pathophysiology, clinical presentation, antibiotic therapy and auxiliary therapeutic options for symptomatology and complications. Data sources: This review considered publications from the last 30years in the databases US National Library of Medicine (PubMed), Scientific Electronic Library Online (SciELO), Literatura Latino-americana e do Caribe em Ciências da Saúde (LILACS), Cochrane, Google Scholar, as well as protocols of the Ministry of Health and recommendations of the Centers for Disease Control and Prevention, related to childhood pertussis (whooping cough), with emphasis on its severe form. This research was based on keywords derived from the terms "pertussis", "azithromycin", "antitussives", "leukocyte reduction" in Portuguese and English. Duplicate studies and those with unavailable full-text were excluded. Data synthesis: Among 556 records found, 54 were selected for analysis. Pertussis, as a reemerging disease, has affected all age groups, evidencing the transient immunity conferred by infection and vaccination. Severe cases occur in neonates and infants, with secondary viral and bacterial complications and malignant pertussis, a longside hyperleukocytosis, respiratory failure and shock. Macrolides continue to be the chosen antibiotics, while antitussives for coughing remain without efficacy. The prompt treatment in Intensive Care Units improved the prognostic in severe cases, and transfusion was promising among procedures for leukoreduction. Conclusions: Approaching severe pertussis in childhood remains a challenge for diagnostic and therapy, as the available therapeutic options are still unsatisfactory. Strategies of prevention are expected to reduce the occurrence of severe cases, while new studies should confirm the role of auxiliary therapies.

RESUMO Objetivo: Rever os conceitos de coqueluche grave, atualizar epidemiologia, fisiopatologia e apresentação clínica, verificar as recomendações de antibioticoterapia e conhecer opções terapêuticas auxiliares na sintomatologia e complicações, por meio de revisão sistemática. Fontes de dados: Foram pesquisados trabalhos publicados nos últimos 30 anos nas bases US National Library of Medicine (PubMed), Scientific Electronic Library Online (SciELO), Literatura Latino-americana e do Caribe em Ciências da Saúde (LILACS), Cochrane e Google Scholar, bem como protocolos do Ministério da Saúde e recomendações do Centers for Disease Control and Prevention, relacionados à coqueluche na infância, com ênfase na forma grave. Apesquisa baseou-se em palavras-chave derivadas dos termos "coqueluche", "azitromicina", "antitussígenos" e "redução de leucócitos", nos idiomas português e inglês. Foramexcluídos estudos em duplicata ou texto integral indisponíveis. Síntese dos dados: Dos 556 registros encontrados, foram selecionados 54 para análise. A coqueluche, como doença reemergente, tem acometido todas as faixas etárias, evidenciando a imunidade transitória conferida pela infecção e pela vacinação. Quadros graves ocorrem em neonatos e lactentes, com complicações virais e bacterianas secundárias e pertussis maligna, com hiperleucocitose, insuficiência respiratória e choque refratário. Os macrolídeos continuam como antibióticos de escolha. Os sintomáticos da tosse não demonstraram eficácia. O suporte precoce em Unidade de Terapia Intensiva melhorou o prognóstico dos casos graves e a exsanguineotransfusão se mostrou a mais promissora entre os procedimentos para leucorredução. Conclusões: A abordagem da coqueluche grave na infância segue como desafio diagnóstico e terapêutico. As opções terapêuticas disponíveis ainda são insatisfatórias. Espera-se que as estratégias de prevenção reduzam a ocorrência de casos graves e que novos estudos confirmem o papel das terapias adjuvantes.

Características clínicas y epidemiológicas de tos ferina en pacientes hospitalizados en un hospital de tercer nivel de Perú / Clinical and epidemiological characteristics of whooping cough in hospitalized patients of a tertiary care hospital in Peru

RESUMEN Objetivo: Describir las características clínicas y epidemiológicas de los pacientes menores de 2 años hospitalizados con el diagnóstico de tos ferina en un hospital pediátrico de tercer nivel de Perú. Métodos: Serie de casos de pacientes menores de 2 años hospitalizados con diagnóstico de tos ferina durante el año 2012. Resultados: Fueron hospitalizados 121 pacientes. Se realizaron pruebas para confirmar el diagnóstico (inmunofluorescencia directa, reacción en cadena de la polimerasa, cultivo) al 53,72%. El 23,15% (n = 28) fueron casos confirmados, todos menores de 10 meses, ninguno había recibido 3 dosis de la vacuna contra pertussis, el 96,43% (n = 27) de ellos fueron menores de 6 meses y 42,86% (n = 12) menores de 3 meses; un 10,71% (n = 3) ingresaron a unidad de cuidados intensivos, todos menores de 2 meses, uno de los cuales falleció. Los síntomas más frecuentes en los casos confirmados fueron tos (96,43%), rubicundez facial (96,43%), tos paroxística (92,86%) y cianosis asociada a la tos (78,57%); el contacto epidemiológico probable más frecuente fue la madre (17,86%) y la mayoría de casos se presentaron en verano (46,43%). Conclusión: La tos ferina es causa de morbimortalidad sobre todo en los menores de 6 meses de edad y en los no inmunizados o parcialmente inmunizados. Se deben mejorar las tasas de vacunación y fomentar la confirmación de casos para no contribuir al infradiagnóstico de esta enfermedad.

ABSTRACT Objective: Describe the clinical and epidemiological characteristics of patients under 2 years of age hospitalized with whooping cough in a tertiary care children's hospital in Peru. Methods: This was a case series of patients under 2 years of age who were hospitalized with a diagnosis of whooping cough in 2012. Results: A total of 121 patients were hospitalized. Diagnostic testing (direct immunofluorescence, polymerase chain reaction, culture) was carried out in 53.72% of patients. Overall, 23.15% (n = 28) were confirmed cases, all of whom were patients less than 10 months old, and none of whom had received 3 doses of whooping cough vaccine. A total of 96.43% (n = 27) of cases were under 6 months of age, 42.86% (n = 12) were younger than 3 months, and 10.71% (n = 3) were admitted to the intensive care unit. Of these cases, all were younger than 2 months old, and one patient died. The most common symptoms in the confirmed cases were coughing (96.43%), facial redness (96.43%), paroxysmal coughing (92.86%), and coughing-related cyanosis (78.57%). The most frequent probable epidemiological contact was the mother (17.86%), and the majority of cases occurred in the summer (46.43%). Conclusion: Whooping cough is a cause of morbidity and mortality, especially in those younger than 6 months of age and in those who are not immunized or only partially immunized. Vaccination rates should be improved and case confirmation encouraged to prevent the underdiagnosis of this disease.

Mecanismos efetores da resposta imune na infecção por Bordetella pertussis / Immune response effector mechanisms to Bordetella pertussis infection

A coqueluche é uma doença infecciosa aguda, transmissível, com predileção pelo trato respiratório, caracterizada por paroxismos de tosse seca e considerada uma importante causa de morbidade e mortalidade infantil. A resposta imunológica humoral e celular do hospedeiro promove a contenção da infecção, pois essas respostas se caracterizam como importantes linhas de defesa durante a infecção e colonização da bactéria. Dessa forma, esta revisão bibliográfica procurou descrever os mecanismos mais eficazes de resposta imune contra Bordetella pertussis e abordar os mecanismos de evasão utilizados pelo patógeno.

Pertussis is a transmissible infectious disease with a predilection for the respiratory tract characterized by paroxysms of dry cough. It is considered an important cause of child morbidity and mortality. The humoral and cellular immune responses of the host promote the containment of the infection, and these responses are characterized as important lines of defense during infection and colonization of the bacterium. Thus, this literature review sought to describe the most effective immune response mechanisms against Bordetella pertussis and to address the avoidance mechanisms used by the pathogen.

Enzyme-linked immunosorbent assay for detecting anti-pertussis toxin antibody in mouse

PURPOSE: Although the DTaP and Tdap vaccines used to prevent pertussis have been used for a long time, there is no standard method for measuring pertussis antigens. Therefore, this preliminary study was conducted to develop an enzyme-linked immunosorbent assay method using an animal model for measuring antibodies against pertussis toxin, the most important pertussis pathogenic antigen, in the sera of vaccinated mice. MATERIALS AND METHODS: Bordetella pertussis Tohama phase I was cultured for 24–30 hours, and then pertussis toxin was purified from the culture medium by chromatography. Purified pertussis toxin was diluted in phosphate-buffered saline-coating buffer, and 100 µL of diluted pertussis toxin was added to each well and reacted at room temperature for 4 hours. Positive serum was diluted to 1/1,250–1/80,000 and negative serum was diluted to 1/50 to determine the coating concentration with the optimal signal/noise ratio. Optimal test conditions were confirmed from the dilution factors of the secondary antibody and streptavidin horseradish peroxidase (SA-HRP). RESULTS: Optimal conditions were as follows: 4 µg/mL for coating antigen; 1/40,000 for secondary antibody; and 1/1,000 for the SA-HRP dilution factor. Comparison of the sera obtained from mice treated with a developing vaccine and commercial vaccine with National Institute for Biological Standard and Control standard serum under the established conditions showed the following results: 1,300.62, 534.94, and 34.85, respectively. CONCLUSION: The method developed in this study is suitable for measuring anti-pertussis toxin antibodies and may be applicable for clinical sample analysis or indirect diagnosis of pertussis.