Clinical and epidemiological features of pertussis in Salvador, Brazil, 2011-2016.

Pertussis, a severe respiratory infection caused by Bordetella pertussis, is distributed globally. Vaccination has been crucial to annual reductions in the number of cases. However, disease reemergence has occurred over the last decade in several countries, including Brazil. Here we describe the clinical and epidemiological aspects of suspected pertussis cases in Salvador, Brazil, and evaluate factors associated with case confirmation. This descriptive and retrospective study was conducted in the five hospitals in Salvador that reported the highest number of pertussis cases between 2011-2016. Demographic and clinical data were recorded for each patient. Bivariate analysis was performed to evaluate differences between groups (confirmed vs. unconfirmed cases) using Pearson's Chi-square test or Fisher's exact test. Results: Of 529 suspected pertussis cases, 29.7% (157/529) were confirmed by clinical, clinical-epidemiological or laboratory criteria, with clinical criteria most frequently applied (63.7%; 100/157). Unvaccinated individuals (43.3%; 68/157) were the most affected, followed by age groups 2-3 months (37.6%; 59/157) and <2 months (31.2%; 49/157). Overall, ≤50% of the confirmed cases presented a complete vaccination schedule. All investigated cases presented cough in association with one or more symptoms, especially paroxysmal cough (66.9%; 105/529) (p = 0.001) or cyanosis (66.2%; 104/529) (p<0.001). Our results indicate that pertussis occurred mainly in infants and unvaccinated individuals in Salvador, Brazil. The predominance of clinical criteria used to confirm suspected cases highlights the need for improvement in the laboratory tools used to perform rapid diagnosis. Fluctuations in infection prevalence demonstrate the importance of vaccination strategies in improving the control and prevention of pertussis.

Neurologic alterations in an HIV adult patient with pertussis: a case report.

BACKGROUND: Pertussis is a highly contagious disease of public health interest caused by the bacterium Bordetella pertussis. Although its incidence has decreased substantially after the introduction of a vaccination, the burden of the disease remains high. Although the paroxysmal phase is highly disabling, complications are uncommon and more prevalent in children than in adults. The most frequent neurological complication is encephalopathy, but seizures, paresis, paraplegia, ataxias, aphasias, and decerebration postures have also been described. The complication of decerebration postures has not been previously reported in adults. CASE PRESENTATION: We present a video case of an adult HIV patient with severe coughing paroxysms, post-tussive emesis and syncope, whose workup confirmed the diagnosis of a B. pertussis respiratory infection. During hospitalization, he had fluctuant encephalopathy and post-tussive decerebration postures following paroxysms. He was treated with antibiotic therapy and finally sent home without residual neurological deficits. CONCLUSION: This case illustrates the biological plausibility of neurologic complications of pertussis in adults, which, albeit rare, can cause important morbidities. Future research should explore whether there are differences in the clinical presentation, risk factors and pathophysiology of the disease among adults or interventions aimed at preventing or treating pertussis encephalopathy.

Seroprevalencia de Bordetella pertussis en el personal de enfermería y médicos residentes del Hospital Infantil de México Federico Gómez / Seroprevalence of Bordetella pertussis in pediatric healthcare workers at the Hospital Infantil de México Federico Gómez

Resumen Introducción Bordetella pertussis es el agente causal de la tosferina, una enfermedad de alta letalidad, especialmente en menores de 6 meses, pero prevenible mediante la vacunación. Los reportes en hospitales de brotes de tosferina muestran que el caso índice suelen ser personas adultas. En adultos, la enfermedad se manifiesta principalmente con tos persistente. El propósito de este estudio fue conocer la seroprevalencia de B. pertussis en el personal de salud de un hospital pediátrico en un país donde aún no se considera la vacunación obligatoria para los empleados. Métodos Participaron personal de enfermería y médicos residentes en trato directo con pacientes hospitalizados. A cada participante se le realizó detección de anticuerpos inmunoglobulina G, antitoxina de pertussis (anti-TP) y se le aplicó un cuestionario para datos clínicos y demográficos. Resultados Se incluyeron 93 individuos, el 85% de personal de enfermería con mediana de edad de 35 años (rango intercuartil: 29-42.5). El 21.5% de los participantes laboraban en el Servicio de Urgencias, el 8.6%, en la Unidad de Terapia Intensiva Pediátrica, el 6.5%, en la Unidad de Cuidados Intensivos Neonatales. Se encontraron títulos detectables de anticuerpos anti-TP en el 18.3%, de los cuales, el 53% presentaron títulos de infección reciente y solamente el 23.5%, historia de tos de más de dos semanas de evolución. Conclusiones El personal de salud está en riesgo de sufrir la enfermedad y de transmitirla a los lactantes, quienes pueden fallecer por esta causa. Este estudio sugiere que las políticas actuales de vacunación en personal de salud se deben de modificar para determinar obligatoriedad de la vacuna, especialmente en quienes atienden a la población pediátrica.

Abstract Background Bordetella pertussis is the causative agent of pertussis, a disease that is preventable by vaccination but has a high mortality, particularly in children < 6 months. Reports of pertussis outbreaks in hospitals show that the index case is usually an adult. In adults, the disease manifests mainly with persistent cough. The purpose of this study was to determine the seroprevalence of B. pertussis in the health personnel of a pediatric hospital in a country where vaccination of this staff is not considered mandatory. Methods Nursing staff and resident doctors who were involved in direct treatment with hospitalized patients participated in the study. Each participant was screened for immunoglobulin G anti-pertussis toxin antibodies (anti-PT), and a questionnaire was applied for clinical and demographic data. Results Ninety-three individuals were included, of which 85% were nurses, median age 35 years (interquartile range: 29-42.5). The participants worked in the emergency department (21.5%), in the Pediatric Intensive Care Unit (8.6%), and in the Neonatal Intensive Care Unit (6.5%). Detectable titers of anti-TP antibodies were found in 18.3%, of which 53% presented titles suggestive of recent infection and only 23.5% cough > 2 weeks of duration. Conclusions Health personnel are at risk of suffering from the disease and be potential transmitters to infants, who may die from this cause. This study suggests that the current vaccination policies in health personnel should be modified to determine the compulsory nature of the vaccination, especially in those individuals in charge of the care of the pediatric population.

Seroprevalence of Bordetella pertussis in pediatric healthcare workers at the Hospital Infantil de México Federico Gómez.

Background: Bordetella pertussis is the causative agent of pertussis, a disease that is preventable by vaccination but has a high mortality, particularly in children < 6 months. Reports of pertussis outbreaks in hospitals show that the index case is usually an adult. In adults, the disease manifests mainly with persistent cough. The purpose of this study was to determine the seroprevalence of B. pertussis in the health personnel of a pediatric hospital in a country where vaccination of this staff is not considered mandatory. Methods: Nursing staff and resident doctors who were involved in direct treatment with hospitalized patients participated in the study. Each participant was screened for immunoglobulin G anti-pertussis toxin antibodies (anti-PT), and a questionnaire was applied for clinical and demographic data. Results: Ninety-three individuals were included, of which 85% were nurses, median age 35 years (interquartile range: 29-42.5). The participants worked in the emergency department (21.5%), in the Pediatric Intensive Care Unit (8.6%), and in the Neonatal Intensive Care Unit (6.5%). Detectable titers of anti-TP antibodies were found in 18.3%, of which 53% presented titles suggestive of recent infection and only 23.5% cough > 2 weeks of duration. Conclusions: Health personnel are at risk of suffering from the disease and be potential transmitters to infants, who may die from this cause. This study suggests that the current vaccination policies in health personnel should be modified to determine the compulsory nature of the vaccination, especially in those individuals in charge of the care of the pediatric population.

Introducción: Bordetella pertussis es el agente causal de la tosferina, una enfermedad de alta letalidad, especialmente en menores de 6 meses, pero prevenible mediante la vacunación. Los reportes en hospitales de brotes de tosferina muestran que el caso índice suelen ser personas adultas. En adultos, la enfermedad se manifiesta principalmente con tos persistente. El propósito de este estudio fue conocer la seroprevalencia de B. pertussis en el personal de salud de un hospital pediátrico en un país donde aún no se considera la vacunación obligatoria para los empleados. Métodos: Participaron personal de enfermería y médicos residentes en trato directo con pacientes hospitalizados. A cada participante se le realizó detección de anticuerpos inmunoglobulina G, antitoxina de pertussis (anti-TP) y se le aplicó un cuestionario para datos clínicos y demográficos. Resultados: Se incluyeron 93 individuos, el 85% de personal de enfermería con mediana de edad de 35 años (rango intercuartil: 29-42.5). El 21.5% de los participantes laboraban en el Servicio de Urgencias, el 8.6%, en la Unidad de Terapia Intensiva Pediátrica, el 6.5%, en la Unidad de Cuidados Intensivos Neonatales. Se encontraron títulos detectables de anticuerpos anti-TP en el 18.3%, de los cuales, el 53% presentaron títulos de infección reciente y solamente el 23.5%, historia de tos de más de dos semanas de evolución. Conclusiones: El personal de salud está en riesgo de sufrir la enfermedad y de transmitirla a los lactantes, quienes pueden fallecer por esta causa. Este estudio sugiere que las políticas actuales de vacunación en personal de salud se deben de modificar para determinar obligatoriedad de la vacuna, especialmente en quienes atienden a la población pediátrica.

Identfication of viral and bacterial etiologic agents of the pertussis-like syndrome in children under 5 years old hospitalized.

BACKGROUND: Acute respiratory infections (ARIs) represent an important cause of morbidity and mortality in children, remaining a major public health concern, especially affecting children under 5 years old from low-income countries. Unfortunately, information regarding their epidemiology is still limited in Peru. METHODS: A secondary data analysis was performed from a previous cross-sectional study conducted in children with a probable diagnosis of Pertussis from January 2010 to July 2012. All samples were analyzed via Polymerase Chain Reaction (PCR) for the following etiologies: Influenza-A, Influenza-B, RSV-A, RSV-B, Adenovirus, Parainfluenza 1 virus, Parainfluenza 2 virus, Parainfluenza 3 virus, Mycoplasma pneumoniae and Chlamydia pneumoniae. RESULTS: A total of 288 patients were included. The most common pathogen isolated was Adenovirus (49%), followed by Bordetella pertussis (41%) from our previous investigation, the most prevelant microorganisms were Mycoplasma pneumonia (26%) and Influenza-B (19.8%). Coinfections were reported in 58% of samples and the most common association was found between B. pertussis and Adenovirus (12.2%). CONCLUSIONS: There was a high prevalence of Adenovirus, Mycoplasma pneumoniae and other etiologies in patients with a probable diagnosis of pertussis. Despite the presence of persistent cough lasting at least two weeks and other clinical characteristics highly suspicious of pertussis, secondary etiologies should be considered in children under 5 years-old in order to give a proper treatment.

Emerging of ptxP3 lineage in Bordetella pertussis strains circulating in a population in northeastern Mexico.

We determined the molecular epidemiology of Bordetella pertussis isolates to evaluate its potential impact on pertussis reemergence in a population of Mexico. Symptomatic and asymptomatic cases were included. Pertussis infection was confirmed by culture and real-time polymerase chain reaction (PCR). Selected B. pertussis isolates were further analysed; i.e. clonality was analysed by pulsed-field gel electrophoresis (PFGE) and ptxP-ptxA, prn, fim2 and fim3 typing was performed by PCR and sequencing. Out of 11 864 analysed samples, 687 (5.8%) were positive for pertussis, with 244 (36%) confirmed by both culture and PCR whereas 115 (17%) were positive only by culture and 328 (48%) were positive only by PCR. One predominant clone (clone A, n = 62/113; 55%) and three major subtypes (A1, A2 and A3) were identified by PFGE. All 113 selected isolates had the allelic combination ptxP3-ptxA1. The predominant clone A and the three major subtypes (A1, A2 and A3) corresponded to the emerging genotypes ptxP3-ptxA1-prn2-fim2-1-fim3-2 and ptxP3-ptxA1-prn2-fim2-1-fim3-1. In conclusion, the presence of an endemic clone and three predominant subtypes belonging to the genotypes ptxP3-ptxA1-prn2-fim2-1-fim3-2 and ptxP3-ptxA1-prn2-fim2-1-fim3-1 were detected. This finding supports the global spread/expansion reported for these outbreaks associated genotypes.

Bordetella pertussis in children hospitalized with a respiratory infection: clinical characteristics and pathogen detection in household contacts.

OBJECTIVE: Describe the prevalence of Bordetella pertussis via PCR in children under 5 years old hospitalized as probable cases of pertussis and report the most common clinical features among them. RESULTS: A positive PCR result for B. pertussis was observed in 20.5% of our samples (18/88), one-third of them were from infants between 2 and 3 months old. The most common symptoms were paroxysms of coughing (88.9%), difficulty breathing (72.2%), cyanosis (77.8%) and fever (50%). The mother was the most common symptomatic carrier (27.8%), followed by uncles/aunts (22.2%) among children with pertussis.

Challenges of interpreting epidemiologic surveillance pertussis data with changing diagnostic and immunization practices: the case of the state of São Paulo, Brazil.

BACKGROUND: A significant increase in pertussis incidence occurred in Brazil, from 2011 to 2014, despite high coverage of childhood immunization with whole-cell-pertussis (wP) containing vaccines. This study presents pertussis surveillance data from São Paulo state and discusses the challenges to interpret them considering pertussis cyclic epidemic behavior, the introduction of new diagnostic techniques and new vaccination strategies, and enhanced disease awareness during epidemics. METHODS: Observational study including pertussis cases reported to the Surveillance System in São Paulo state, from January 2001 to December 2015. Pertussis cases data were retrieved from the National Notifiable Diseases Information System (SINAN) website and from São Paulo state Epidemiological Surveillance Center (CVE/SP) database. Vaccination coverage and homogeneity data were collected from the Unified Health System Department of Informatics (DATASUS). We presented cases distribution by year, age group and diagnostic criteria and calculated pertussis incidence rates. The proportions of cases among different age groups were compared using chi-square test for trend. RESULTS: Infants less than 1 year of age were the most affected during the whole period, but the proportions of cases in this age group had a significant decreasing trend, with significant increase in the proportions of cases reported among older age groups (1-4, 5-10 and ≥20 years). Cases among infants aged less than 6 months represented ≥90% of all cases in children less than 1 year of age in all but 2 years (2012 and 2015). A non-significant decrease in the proportion of cases among infants aged < 2 months was observed in parallel to a significant increase in the proportion of cases in infants aged 6-11 months. CONCLUSIONS: A pertussis outbreak has occurred in a state with universal use of wP vaccine. The disease cyclic behavior has probably had a major role in the increased incidence rates registered in São Paulo state, from 2011 to 2014, as well as in the decreased incidence in 2015. Maternal vaccination cannot explain the drop in the number of cases among all age groups, in 2015, as herd protection is not expected, but may have had an impact on the number of cases in infants aged < 2 months.

Identificação laboratorial da coqueluche na região do oeste do Estado de São Paulo / Laboratory identification of pertussis in the western region of São Paulo State, Brazil

O objetivo deste estudo foi de confirmar laboratorialmente os casos suspeitos de coqueluche na região oeste do Estado de São Paulo, ocorridos entre 2010 a 2015. A cultura foi realizada no Centro de Laboratório Regional - Instituto Adolfo Lutz de Presidente Prudente e a PCR em tempo real (qPCR) foi realizada no Centro de Referência Nacional para Pertussis – Instituto Adolfo Lutz em São Paulo, SP. Foram recebidas 189 amostras, sendo 29 (15,3%) confirmadas segundo os critérios laboratoriais (cultura e/ou qPCR). A faixa etária mais acometida foi em crianças menores de seis meses de idade (82,8%), não vacinados ou com o esquema de vacinação incompleto. Provavelmente, estes resultados representam apenas uma fração do número real de casos de coqueluche que ocorrem no Brasil. O contínuo monitoramento da doença e informações da prevalência por faixa etária são importantes ferramentas para melhorar as estratégias de imunização como forma de controlar esta doença reemergente.

The aim of this study was to confirm the suspected cases of pertussis in the Western region of the Sao Paulo State from 2010 to 2015. The samples were cultured in the Instituto Adolfo Lutz - Regional Laboratory of Presidente Prudente-SP, and the qPCR was performed at the National Reference Laboratory for Pertussis – Central Instituto Adolfo Lutz, São Paulo-SP. In this period, 189 samples were received, being 29 (15.3%) confirmed by the laboratory criteria (culture and/or qPCR). The most affected group was the children less than six months old (82.8%), not vaccinated or with the incomplete vaccination. Most likely, these results only represent a fraction of the actual number of pertussis cases occurring in Brazil. The continuous disease monitoring and the prevalence data by age group are fundamental to improve the immunization strategies as a way to control this important re-emerging disease.

Identificação laboratorial da coqueluche na região do oeste do Estado de São Paulo / Laboratory identification of pertussis in the western region of São Paulo State, Brazil

O objetivo deste estudo foi de confirmar laboratorialmente os casos suspeitos de coqueluche na região oeste do Estado de São Paulo, ocorridos entre 2010 a 2015. A cultura foi realizada no Centro de Laboratório Regional - Instituto Adolfo Lutz de Presidente Prudente e a PCR em tempo real (qPCR) foi realizada no Centro de Referência Nacional para Pertussis Instituto Adolfo Lutz em São Paulo, SP. Foram recebidas 189 amostras, sendo 29 (15,3%) confirmadas segundo os critérios laboratoriais (cultura e/ou qPCR). A faixa etária mais acometida foi em crianças menores de seis meses de idade (82,8%), não vacinados ou com o esquema de vacinação incompleto. Provavelmente, estes resultados representam apenas uma fração do número real de casos de coqueluche que ocorrem no Brasil. O contínuo monitoramento da doença e informações da prevalência por faixa etária são importantes ferramentas para melhorar as estratégias de imunização como forma de controlar esta doença reemergente.(AU)

The aim of this study was to confirm the suspected cases of pertussis in the Western region of the Sao Paulo State from 2010 to 2015. The samples were cultured in the Instituto Adolfo Lutz - Regional Laboratory of Presidente Prudente-SP, and the qPCR was performed at the National Reference Laboratory for Pertussis Central Instituto Adolfo Lutz, São Paulo-SP. In this period, 189 samples were received, being 29 (15.3%) confirmed by the laboratory criteria (culture and/or qPCR). The most affected group was the children less than six months old (82.8%), not vaccinated or with the incomplete vaccination. Most likely, these results only represent a fraction of the actual number of pertussis cases occurring in Brazil. The continuous disease monitoring and the prevalence data by age group are fundamental to improve the immunization strategies as a way to control this important re-emerging disease.(AU)

Hyperbiofilm Formation by Bordetella pertussis Strains Correlates with Enhanced Virulence Traits.

Pertussis, or whooping cough, caused by the obligate human pathogen Bordetella pertussis is undergoing a worldwide resurgence. The majority of studies of this pathogen are conducted with laboratory-adapted strains which may not be representative of the species as a whole. Biofilm formation by B. pertussis plays an important role in pathogenesis. We conducted a side-by-side comparison of the biofilm-forming abilities of the prototype laboratory strains and the currently circulating isolates from two countries with different vaccination programs. Compared to the reference strain, all strains examined herein formed biofilms at high levels. Biofilm structural analyses revealed country-specific differences, with strains from the United States forming more structured biofilms. Bacterial hyperaggregation and reciprocal expression of biofilm-promoting and -inhibitory factors were observed in clinical isolates. An association of increased biofilm formation with augmented epithelial cell adhesion and higher levels of bacterial colonization in the mouse nose and trachea was detected. To our knowledge, this work links for the first time increased biofilm formation in bacteria with a colonization advantage in an animal model. We propose that the enhanced biofilm-forming capacity of currently circulating strains contributes to their persistence, transmission, and continued circulation.

Pertussis characterization in the central-west region of São Paulo state, Brazil / Caracterização da coqueluche na região centro-oeste do Estado de São Paulo, Brasil

Pertussis is a highly contagious respiratory disease caused by Bordetella pertussis. This study aimed at characterizing the B. pertussis laboratory positivity and the isolated strains in municipalities of the Central-West Region of São Paulo State, Brazil from 2010 to 2014. A total of 597 nasopharyngeal swabs samples were collected from suspected patients and contacts, and analyzed by in vitro culture and Real-Time PCR (qPCR). Culture-positive B. pertussis strains were characterized by serotyping and pulsed-field gel electrophoresis. Considering culture and/or qPCR, the positivity rate was of 19.6%. Out of 117 samples with B. pertussis, 23 were detected by both methods, 89 by qPCR only and five by culture only. Strains presenting FIM3 (40%), FIM2,3 (32%) and FIM2 (28%) serotypes were found. Five pulsotypes were detected by PFGE, 48% of which identified as BP.Xba.0039, being the predominant type in this study. Among the positive strains, 50% were isolated from <2 months old-children and 17% were isolated from three to six months old patients. Non-vaccinated children or with incomplete vaccination schedule were at the major risk of complications and death, highlighting the importance of a continuous monitoring of this infection for the future control strategies.

A coqueluche é uma doença respiratória altamente contagiosa causada por Bordetella pertussis. Este estudo caracterizou a positividade de B. pertussis e as cepas isoladas em municípios da Região Centro-Oeste do Estado de São Paulo de 2010 a 2014. Foram coletados 597 esfregaços nasofaríngeos de pacientes e contatos suspeitos de coqueluche, e analisados por cultura e Real-TimePCR (qPCR). Os isolados de B. pertussis obtidos de cultura foram caracterizados por sorotipagem e eletroforese em gel de campo pulsado. Considerando-se a cultura e/ou qPCR, verificou-se taxa de positividade de 19,6%. Das 117 amostras positivas para B. pertussis, 23 foram detectadas por ambos os métodos, 89 apenas por qPCR e cinco apenas na cultura. Foram detectadas cepas de sorotipos FIM3 (40%), FIM2,3 (32%) e FIM2 (28%). Cinco pulsotipos foram detectados pela PFGE, e 48% identificados como BP.Xba.0039, o tipo predominante neste estudo. Entre as cepas positivas, 50% foram isoladas de crianças menores de dois meses e 17% isoladas da faixa etária de três a seis meses. Crianças não vacinadas ou com esquema de vacinação incompleta têm maior risco de complicações e óbito, o que ressalta a importância do monitoramento contínuo desta infecção para futuras estratégias de controle.

Pertussis characterization in the central-west region of São Paulo state, Brazil / Caracterização da coqueluche na região centro-oeste do Estado de São Paulo, Brasil

Pertussis is a highly contagious respiratory disease caused by Bordetella pertussis. This study aimed at characterizing the B. pertussis laboratory positivity and the isolated strains in municipalities of the Central-West Region of São Paulo State, Brazil from 2010 to 2014. A total of 597 nasopharyngeal swabs samples were collected from suspected patients and contacts, and analyzed by in vitro culture and Real-Time PCR (qPCR). Culture-positive B. pertussis strains were characterized by serotyping and pulsed-field gel electrophoresis. Considering culture and/or qPCR, the positivity rate was of 19.6%. Out of 117 samples with B. pertussis, 23 were detected by both methods, 89 by qPCR only and five by culture only. Strains presenting FIM3 (40%), FIM2,3 (32%) and FIM2 (28%) serotypes were found. Five pulsotypes were detected by PFGE, 48% of which identified as BP.Xba.0039, being the predominant type in this study. Among the positive strains, 50% were isolated from <2 months old-children and 17% were isolated from three to six months old patients. Non-vaccinated children or with incomplete vaccination schedule were at the major risk of complications and death, highlighting the importance of a continuous monitoring of this infection for the future control strategies.(AU)

A coqueluche é uma doença respiratória altamente contagiosa causada por Bordetella pertussis. Este estudo caracterizou a positividade de B. pertussis e as cepas isoladas em municípios da Região Centro-Oeste do Estado de São Paulo de 2010 a 2014. Foram coletados 597 esfregaços nasofaríngeos de pacientes e contatos suspeitos de coqueluche, e analisados por cultura e Real-TimePCR (qPCR). Os isolados de B. pertussis obtidos de cultura foram caracterizados por sorotipagem e eletroforese em gel de campo pulsado. Considerando-se a cultura e/ou qPCR, verificou-se taxa de positividade de 19,6%. Das 117 amostras positivas para B. pertussis, 23 foram detectadas por ambos os métodos, 89 apenas por qPCR e cinco apenas na cultura. Foram detectadas cepas de sorotipos FIM3 (40%), FIM2,3 (32%) e FIM2 (28%). Cinco pulsotipos foram detectados pela PFGE, e 48% identificados como BP.Xba.0039, o tipo predominante neste estudo. Entre as cepas positivas, 50% foram isoladas de crianças menores de dois meses e 17% isoladas da faixa etária de três a seis meses. Crianças não vacinadas ou com esquema de vacinação incompleta têm maior risco de complicações e óbito, o que ressalta a importância do monitoramento contínuo desta infecção para futuras estratégias de controle.(AU)

Increase in pertussis cases along with high prevalence of two emerging genotypes of Bordetella pertussis in Perú, 2012.

BACKGROUND: As has occurred in many regions worldwide, in 2012 the incidence of pertussis increased in Perú. This epidemiologic situation has been associated with a waning vaccine-induced immunity and the adaptation of Bordetella pertussis to vaccine-induced immunity along with improved diagnostic methods. METHODS: The study comprised a total of 840 pertussis-suspected cases reported in Perú during 2012. We summarize here the distribution of pertussis cases according to age and immunization status along with the immunization-coverage rate. Laboratory diagnosis was performed by culture test and real-time polymerase-chain reaction (PCR). B. pertussis bacteria recovered from infected patients were characterized by pulsed-field gel electrophoresis (PFGE), and the DNA sequencing of the pertussis-toxin (promoter and subunit A), pertactin, and fimbriae (fim2 and fim3) genes. RESULTS: From the total pertussis-suspected cases, 191 (22.7 %) infections were confirmed by real-time PCR and 18 through cultivation of B. pertussis (2.1 %), while one infection of B. parapertussis (0.11 %) was also detected by culture. Pertussis was significantly higher in patients that had had 0-3 vaccine doses (pentavalent vaccine alone) than in those who had had 4-5 vaccine doses (pentavalent plus DwPT boosters) at 94.3 vs. 5.7 %, respectively (p < 0.00001). The relative risk (RR) for patients with 4-5 doses compared to those with fewer than 4 doses or no dose was 0.23 (95 % Confidence Interval: 0.11-0.44), while the vaccine effectiveness was 77 % and coverage 50.5 %. Genetic analysis of B. pertussis isolates from different Peruvian regions detected two clonal groups as identified by PFGE. Those two groups corresponded to the B. pertussis genotypes emerging worldwide ptxP3-ptxA1-prn2 or 9-fim3-1 and ptxP3-ptxA1-prn2 or 9-fim3-2. CONCLUSIONS: Two emerging B. pertussis genotypes similar to isolates involved in worldwide epidemics were detected in Perú. Low vaccine coverage (<50 %) and genetic divergence between the vaccine-producing strain and the local isolates could contribute to this pertussal epidemic.

Bordetella pertussis diagnosis in children under five years of age in the Regional Hospital of Cajamarca, Northern Peru.

INTRODUCTION: Bordetella pertussis is an important human pathogen that causes whooping cough (pertussis), an endemic illness responsible of significant morbidity and mortality, especially in infants and children. Worldwide, there are an estimated of 16 million cases of pertussis, resulting in about 195,000 child deaths per year. In Peru, pertussis is a major health problem that has been on the increase despite immunization efforts. The objective of this study was to determine the prevalence of B. pertussis among children under five years of age suspected to have whopping cough in Cajamarca, Peru. METHODOLOGY: Children diagnosed with whooping cough admitted to the Hospital Regional de Cajamarca from August 2010 to July 2013 were included. Nasopharyngeal samples were obtained for B. pertussis culture and polymerase chain reaction (PCR) detection. RESULTS: In 133 children, the pertussis toxin and IS481 gene were detected in 38.35% (51/133) of the cases by PCR, while only 9.02% (12/133) of the Bordetella cultures were positive. The most frequent symptoms in patients with positive B. pertussis were paroxysm of coughing 68.63% (35/51), cyanosis 56.86% (29/51), respiratory distress 43.14% (22/51), and fever 39.22% (20/51). Pneumonia and acute bronchial obstructive syndrome were present in 17.65% (9/51) and 13.72% (7/51) of the cases, respectively. CONCLUSIONS: B. pertussis is responsible for an important proportion of whooping cough in hospitalized children in Cajamarca. Epidemiologic surveillance programs for B. pertussis are essential in Peru, especially in children who could most benefit from the vaccine.

Resurgence of pertussis at the age of vaccination: clinical, epidemiological, and molecular aspects / Ressurgimento da coqueluche na era vacinal: aspectos clínicos, epidemiológicos e moleculares

OBJECTIVE: Report the incidence, epidemiology, clinical features, death, and vaccination status of patients with whooping cough and perform genotypic characterization of isolates of B. pertussis identified in the state of Paraná, during January 2007 to December 2013.METHODS: Cross-sectional study including 1,209 patients with pertussis. Data were obtained through the Notifiable Diseases Information System (Sistema de Informação de Agravos de Notificação - SINAN) and molecular epidemiology was performed by repetitive sequence-based polymerase chain reaction (rep-PCR; DiversiLab(r), bioMerieux, France).RESULTS: The incidence of pertussis in the state of Paraná increased sharply from 0.15-0.76 per 100,000 habitants between 2007-2010 to 1.7-4.28 per 100,000 between 2011-2013. Patients with less than 1 year of age were more stricken (67.5%). Fifty-nine children (5%) developed pertussis even after receiving three doses and two diphtheria-tetanus-pertussis (DTP) boosters vaccine. The most common complications were pneumonia (14.5%), otitis (0.9%), and encephalopathy (0.7%). Isolates of B. pertussis were grouped into two groups (G1 and G2) and eight distinct patterns (G1: P1-P5 and G2: P6-P8).CONCLUSION: The resurgence of pertussis should stimulate new research to develop vaccines with greater capacity of protection against current clones and also encourage implementation of new strategies for vaccination in order to reduce the risk of disease in infants.

OBJETIVO: Relatar a incidência, os aspectos epidemiológicos, clínicos, a morte e a vacinação de pacientes com coqueluche e fazer a caracterização genotípica de isolados de Bordetella pertussisidentificados no Estado do Paraná, de janeiro de 2007 a dezembro de 2013.MÉTODOS: Estudo transversal, incluindo 1.209 pacientes com coqueluche. Os dados foram obtidos no Sistema de Informação de Agravos de Notificação (Sinan) e a epidemiologia molecular foi feita por PCR baseada em sequências repetitivas (rep-PCR; DiversiLab(r), bioMerieux, France).RESULTADOS: A incidência de coqueluche no Estado do Paraná aumentou acentuadamente de 0,15-0,76 por 100.000 habitantes entre 2007-2010 para 1,7-4,28 por 100.000 habitantes entre 2011-2013. Os pacientes com menos de um ano foram os mais afetados (67,5%); 59 crianças (5%) desenvolveram coqueluche mesmo depois de receber três doses da vacina e dois reforços com a vacina tríplice DTP. As complicações mais comuns foram pneumonia (14,5%), otite (0,9%) e encefalopatia (0,7%). Isolados de B. pertussis foram agrupados em dois grupos (G1 e G2) e oito padrões distintos (G1: P1-P5 e G2: P6-P8).CONCLUSÃO: O ressurgimento da coqueluche vem para sugerir novas pesquisas com o objetivo se desenvolverem vacinas com maior capacidade de proteção contra os clones atuais e também implantar novas estratégias de vacinação, a fim de reduzir o risco de doenças em lactentes.

Resurgence of pertussis at the age of vaccination: clinical, epidemiological, and molecular aspects.

OBJECTIVE: Report the incidence, epidemiology, clinical features, death, and vaccination status of patients with whooping cough and perform genotypic characterization of isolates of B. pertussis identified in the state of Paraná, during January 2007 to December 2013. METHODS: Cross-sectional study including 1,209 patients with pertussis. Data were obtained through the Notifiable Diseases Information System (Sistema de Informação de Agravos de Notificação - SINAN) and molecular epidemiology was performed by repetitive sequence-based polymerase chain reaction (rep-PCR; DiversiLab®, bioMerieux, France). RESULTS: The incidence of pertussis in the state of Paraná increased sharply from 0.15-0.76 per 100,000 habitants between 2007-2010 to 1.7-4.28 per 100,000 between 2011-2013. Patients with less than 1 year of age were more stricken (67.5%). Fifty-nine children (5%) developed pertussis even after receiving three doses and two diphtheria-tetanus-pertussis (DTP) boosters vaccine. The most common complications were pneumonia (14.5%), otitis (0.9%), and encephalopathy (0.7%). Isolates of B. pertussis were grouped into two groups (G1 and G2) and eight distinct patterns (G1: P1-P5 and G2: P6-P8). CONCLUSION: The resurgence of pertussis should stimulate new research to develop vaccines with greater capacity of protection against current clones and also encourage implementation of new strategies for vaccination in order to reduce the risk of disease in infants.

Sources of pertussis infection in young babies from São Paulo State, Brazil.

Household contacts are important sources of Bordetella pertussis in infants. A total of 353 household contacts of 97 index cases were evaluated for pertussis by culture and polymerase chain reaction. Twenty eight contacts were positive (8.0%). The presence of symptoms did not influence the rate of diagnosed bacteriologic pertussis in communicants. We conclude that contacts with an index case can be positive for B. pertussis independently of the presence of symptoms.

Serodiagnosis as adjunct assay for pertussis infection in São Paulo, Brazil.

Pertussis remains an important public health problem in many countries despite extensive immunization. Cultures and real-time PCR (RT-PCR) assays are the recommended pertussis diagnostic tests, but they lack sensitivity at the later stage of the disease. This study introduces the IgG anti-pertussis toxin enzyme-linked immunosorbent assay (PT ELISA) in our routine diagnosis to improve disease burden estimation. Serum samples and nasopharyngeal swabs (n = 503) were collected at the same time from patients presenting with cough illness suspected of being pertussis and tested by the PT ELISA and culture and/or RT-PCR, respectively. Patients were separated into three age groups: group 1, <1 year (n = 260; mean age, 3 months), group 2, 1 to 6 years (n = 81; mean age, 3 years), and group 3, ≥7 years (n = 162; mean age, 26 years). The times (means) from cough onset to specimen collection were 16, 24, and 26 days, respectively. In group 1, 83 (82.2%) of 101 positive cases were positive for pertussis by culture/RT-PCR, while 40 (39.6%) tested positive by PT ELISA. In group 2, 6 (19.4%) of 31 positive cases were culture/RT-PCR positive, and 29 (93.6%) were seropositive. In group 3, 13 (13.8%) of 94 positive cases were positive by culture/RT-PCR and 91 (96.8%) were positive by serology. Culture/RT-PCR detected more cases of pertussis in infants (P < 0.0001), whereas the PT ELISA detected more cases in adolescents and adults (P < 0.0001). The timing between cough onset and specimen collection or recent vaccination may have partially affected our results. Serology is a suitable, cost-effective, and complementary pertussis diagnostic tool, especially among older children, adolescents, and adults during the later disease phase.