The role of respiratory virus infection in suspected pertussis: A prospective study.

BACKGROUND: Infections caused by Bordetella pertussis are frequent and responsible for cases of huge severity in unvaccinated young infants. However, clinical manifestations vary and mimic other respiratory diseases as respiratory viruses. METHODS: A prospective cohort study was performed with infants under 1 old, hospitalized with suspected pertussis. All infants were submitted to etiological research to identify Bordetella pertussis (nasopharynx swab for culture and/or PCR) and respiratory viruses (nasopharyngeal aspirate for indirect immunofluorescence). Clinical and demographic data were collected. RESULTS: Among 59 infants, an etiological agent was identified in 37 (62.8%). Respiratory virus was identified in 19 (32%) and Bordetella pertussis in 14 (23.7%) as sole agent. Codetection was found in 4 (7%). Younger age, absence of fever, lack of BP immunization, leukocytosis > 20,000/mm3, lymphocytosis >10,000/mm3 were associated to a greater chance of pertussis. Wheezing and living with siblings were associated with viral infection. After adjustment for confounders, the most important predictors were presence of wheezing for respiratory virus and leukocytosis for pertussis. The severity of infections by RV and BP were similar. CONCLUSION: Respiratory virus infections are frequent in cases of clinical suspicion of pertussis and may actually exceed the prevalence of BP. Clinical/laboratory characteristics may suggest the etiology, but they are not pathognomonic, which stresses the need for respiratory virus and Bordetella pertussis research in this clinical situation.

Pathogen analysis of pertussis-like syndrome in children.

BACKGROUND: The aim of the study was to identify the pathogens, in addition to bordetella pertussis (B. pertussis), which cause pertussis-like syndrome in children and to compare clinical presentation between those with B. pertussis and pertussis-like syndrome. METHODS: A cross-sectional analysis was conducted from March 2016 to September 2018. In total, 281 children with suspected pertussis infections were enrolled in this study. Multi-pathogen detection was performed. RESULTS: In total, 281 children were enrolled including 139 males and 142 females. Among them, 149 (53.0%) were B. pertussis positive, and 72 (15.6%) children tested positive for other pathogens. Mycoplasma pneumoniae (MP, 27 cases) was the most common causative pathogen in pertussis-like syndrome, followed by human rhinovirus (HRV, 23 cases), Streptococcus pneumoniae (SP, 13 cases), Haemophilus influenzae (HI, 12 cases) and parainfluenza virus 3 (Pinf-3, 9 cases). Children in the B. pertussis group had a higher rate of vaccination and longer hospital stay (P < 0.05). B. pertussis was more likely to be detected in winter than other pathogens, but this difference was not significant (P = 0.074). The number of white blood cells, neutrophils and blood platelets was significantly higher in children in the B. pertussis than in the pertussis-like group (P < 0.05). In addition, the percentage of CD3-CD19+ cells was significantly higher in the B. pertussis group (P = 0.018). CONCLUSION: About half of the children with pertussis-like syndrome were B. pertussis positive. MP was the second most common causative pathogen followed by HRV, SP, HI and Pinf-3. Children infected with B. pertussis had longer hospital stay and higher numbers of white blood cells, neutrophil and blood platelets compared with other pathogens.

Transcriptional profiling of human macrophages during infection with Bordetella pertussis.

Bordetella pertussis, a strictly human re-emerging pathogen and the causative agent of whooping cough, exploits a broad variety of virulence factors to establish efficient infection. Here, we used RNA sequencing to analyse the changes in gene expression profiles of human THP-1 macrophages resulting from B. pertussis infection. In parallel, we attempted to determine the changes in intracellular B. pertussis-specific transcriptomic profiles resulting from interaction with macrophages. Our analysis revealed that global gene expression profiles in THP-1 macrophages are extensively rewired 6 h post-infection. Among the highly expressed genes, we identified those encoding cytokines, chemokines, and transcription regulators involved in the induction of the M1 and M2 macrophage polarization programmes. Notably, several host genes involved in the control of apoptosis and inflammation which are known to be hijacked by intracellular bacterial pathogens were overexpressed upon infection. Furthermore, in silico analyses identified large temporal changes in expression of specific gene subsets involved in signalling and metabolic pathways. Despite limited numbers of the bacterial reads, we observed reduced expression of majority of virulence factors and upregulation of several transcriptional regulators during infection suggesting that intracellular B. pertussis cells switch from virulent to avirulent phase and actively adapt to intracellular environment, respectively.

Identification of Etiologic Agents of the Pertussis-like Syndrome in Children by Real-time PCR Method.

The aim of this study was to recognize the identity and frequency of etiologic agents of the pertussis-like syndrome in children < 2 years of age. A cross-sectional hospital-based study conducted from August 2014 to August 2015. All children < 2 years of age (n=100) who were suspected as pertussis infected were enrolled in this study and tested for Bordetella pertussis, adenovirus (Adv), respiratory syncytial virus (RSV), human metapneumovirus (hMPV), and influenza virus A (INF-A) by real-time PCR technique. RSV was the most detected pathogen (20%), followed by B. pertussis (18%), Adv (16%), INF-A (11%), and hMPV (10%). Co-infection was observed in 8 patients (11%) and the combinations of RSV/INF-A (n=3, 4%), and AdV/B. pertussis (n=3, 4%) were more frequent. RSV, B. pertussis, and hMPV were more frequent pathogens among infants < 4 months of age. However, Adv and INF-A were more frequent pathogens among children > 6 months of age. In this study, RSV was the most frequent identified pathogen (n=20, 20%), followed by B. pertussis (n=18, 18%) and AdV (n=16, 16%). Pertussis was more frequent in spring (8%) and summer (6%). In addition, clinical symptoms of pertussis were the same as some viral pathogens, which can lead to misdiagnosis of infection. Therefore, diagnosis of pertussis should be established on the bases of both the clinical symptoms and the laboratory methods.

Surveillance of Circulating Bordetella pertussis Strains in Europe during 1998 to 2015.

One reason for increased pertussis incidence is the adaptation of Bordetella pertussis to vaccine-induced immunity by modulating its genomic structure. This study, EUpert IV, includes 265 isolates collected from nine European countries during 2012 to 2015 (n = 265) and compares the results to previous EUpert I to III studies (1998 to 2009). The analyses included genotyping, serotyping, pulsed-field gel electrophoresis (PFGE), and multilocus variable-number tandem-repeat analysis (MLVA). Genotyping results showed only small variations among the common virulence genes of B. pertussis The frequencies of serotypes Fim2 and Fim3 varied among the four collections. Genomic analyses showed that MLVA type 27 increased to 80% between the periods of 1998 to 2001 and 2012 to 2015. Two PFGE profiles, BpSR3 (29.4%) and BpSR10 (27.2%), constituted more than 50% of the circulating isolates in the present collection. Our study indicates that the European B. pertussis population is changing and became more homogenous after the introduction of acellular pertussis vaccines.

Emergence of Bordetella holmesii as a Causative Agent of Whooping Cough, Barcelona, Spain.

We describe the detection of Bordetella holmesii as a cause of whooping cough in Spain. Prevalence was 3.9% in 2015, doubling to 8.8% in 2016. This emergence raises concern regarding the contribution of B. holmesii to the reemergence of whooping cough and the effectiveness of the pertussis vaccine.

[Features of Bordetella pertussis, Bordetella spp. infection and whopping cough in Córdoba province, Argentina]. / Caracterización de la infección por Bordetella pertussis, Bordetella spp. y coqueluche en la provincia de Córdoba, Argentina.

INTRODUCTION: Whooping cough is a re-emerging infection in the world and Latin America. OBJECTIVE: It was considered relevant to investigate the clinical and epidemiological profile of Bordetella spp. and Bordetella pertussis infection in Córdoba province, Argentina; evaluating, at the same time, the co-infection with virus producing respiratory infections that may be confused with whooping cough. MATERIAL AND METHODS: All whooping cough suspected cases were studied by Polimerase Chain Reaction, amplifying the repeated insertion sequence (IS) 481 and the promoter gene encoding pertussis toxin, between 2011 and 2013. The data were obtained from the clinical and epidemiological records. RESULTS: From 2,588 whooping cough suspected cases, 11.59% was infected by Bordetella spp. and 9.16% was confirmed as Bordetella pertussis infection. The rate of infection was 7.22 and 1.84 per 100,000 for 2011 and 2012, respectively. The infection presented a seasonal tendency and it was mainly found on the group of children between 13 and 24 months old. The co-infection with virus producing respiratory infections, were uncommon. Paroxysmal cough, cyanosis and/or vomiting were predictors of the infection for Bordetella pertussis. DISCUSSION AND CONCLUSIONS: To deal with the re-emergence of whooping cough is important the knowledge of the regional epidemiological situation. This paper shows the situation of these infections in the regional clinical and epidemiological context, and makes the information available for health decision-making.

Caracterización de la infección por Bordetella pertussis, Bordetella spp. y coqueluche en la provincia de Córdoba, Argentina / Features of Bordetella pertussis, Bordetella spp. infection and whopping cough in Córdoba province, Argentina

Introduction: Whooping cough is a re-emerging infection in the world and Latin America. Objective: It was considered relevant to investigate the clinical and epidemiological profile of Bordetella spp. and Bordetella pertussis infection in Córdoba province, Argentina; evaluating, at the same time, the co-infection with virus producing respiratory infections that may be confused with whooping cough. Material and Methods: All whooping cough suspected cases were studied by Polimerase Chain Reaction, amplifying the repeated insertion sequence (IS) 481 and the promoter gene encoding pertussis toxin, between 2011 and 2013. The data were obtained from the clinical and epidemiological records. Results: From 2,588 whooping cough suspected cases, 11.59% was infected by Bordetella spp. and 9.16% was confirmed as Bordetella pertussis infection. The rate of infection was 7.22 and 1.84 per 100,000 for 2011 and 2012, respectively. The infection presented a seasonal tendency and it was mainly found on the group of children between 13 and 24 months old. The co-infection with virus producing respiratory infections, were uncommon. Paroxysmal cough, cyanosis and/or vomiting were predictors of the infection for Bordetella pertussis. Discussion and Conclusions: To deal with the re-emergence of whooping cough is important the knowledge of the regional epidemiological situation. This paper shows the situation of these infections in the regional clinical and epidemiological context, and makes the information available for health decision-making.

Introducción: Coqueluche es una enfermedad reemergente en el mundo y en Latinoamérica. Objetivo: Resultó de interés caracterizar el perfil clínico-epidemiológico de la infección por Bordetella spp. y Bordetella pertussis en Córdoba, Argentina; evaluando además, la frecuencia de infecciones de etiología viral que, por cursar con un síndrome coqueluchoide (SC), pueden ser confundidas con cuadros de coqueluche. Material y Métodos: Los casos sospechosos de coqueluche, se estudiaron por reacción de polimerasa en cadena; amplificando la secuencia repetida de inserción (IS) 481 y la región promotora del gen de la toxina pertussis; entre 2011 y 2013. Los datos de los pacientes se obtuvieron de las fichas clínicoepidemiológicas. Resultados: De 2.588 pacientes, 11,59% presentó una infección por Bordetella spp. y en 9,16% se confirmó una infección por Bordetella pertussis. La tasa de infección fue 7,22 y 1,84 por 100.000 habitantes en 2011 y 2012, respectivamente. La infección presentó una tendencia estacional y se concentró principalmente en niños entre 13 y 24 meses. La tos paroxística, cianosis y/o vómitos fueron predictores de la infección por B. pertussis. La coinfección con virus productores de infecciones respiratorias fue poco frecuente. Discusión y Conclusiones: Es fundamental el conocimiento de la situación epidemiológica regional. Este trabajo presenta la situación de Córdoba y pone a disposición de la comunidad sanitaria la información para la toma de decisiones en el contexto clínico-epidemiológico regional.

Pertussis outbreak, southeastern Minnesota, 2012.

OBJECTIVE: To describe clinical and laboratory findings from the 2012 southeastern Minnesota pertussis outbreak. PATIENTS AND METHODS: Patients were selected for 2 parts of the study. In the first part, nasopharyngeal swabs from a convenience sample of 265 unique patients were used for both the clinician-requested polymerase chain reaction (PCR) test and culture. B pertussis isolates were tested for macrolide susceptibility and typed using whole genome sequencing and pulsed-field gel electrophoresis. Pertactin gene sequences were analyzed to identify pertactin-deficient B pertussis. In the second part, all patients seen at Mayo Clinic in Rochester, Minnesota, who had PCR results positive for Bordetella pertussis or Bordetella parapertussis between January 1, 2012, and December 31, 2012, were analyzed for patient demographic features and vaccination records. RESULTS: One hundred sixty patients had results positive for B pertussis, and 21 patients had results positive for B parapertussis. Among the 265 swabs cultured, B pertussis was detected by both culture and PCR in 11. One swab was positive for B pertussis by culture alone, and 13 were positive by PCR alone. Polymerase chain reaction detected B pertussis more frequently than did culture (P=.001). No macrolide resistance was detected. All 12 isolates tested had an altered pertactin gene, including 9 with a signal sequence deletion, 2 with insertion sequence disruptions, and 1 with a premature stop codon. Nine and 3 isolates were pertactin types prn1 and prn2, respectively. Whole genome sequencing and pulsed-field gel electrophoresis detected the presence of multiple B pertussis strains. The mean age of patients with pertussis was younger than that of those without pertussis (15.6 and 25.5 years, respectively; P=.002). Compared with those whose test results were negative for B pertussis, fewer patients with positive results had received whole-cell pertussis vaccine (P=.02). In the subgroup who had received acellular vaccine exclusively, the time since the most recent pertussis vaccination in those with results positive for B pertussis was longer than that in those with negative results (1363 vs 1010 days; P=.004). CONCLUSION: The 2012 pertussis outbreak in southeastern Minnesota included multiple strains of B pertussis, all putatively lacking pertactin. Our findings may indicate decreased efficacy of (and waning immunity from) acellular vaccines as contributors to the outbreak.

[Experimental whooping cough of nonhuman primate].

Despite considerable success in study of Bordetella pertussis virulence factors, pathogenesis of whooping cough, duration of B. pertussis bacteria persistence, types and mechanisms of immune response are still keep underinvestigated. It can be explained by the absence ofadequate experimental animal model for pertussis study. Our study estimates clinical and laboratory parameters of whooping cough in non-human primates of the Old World in the process of intranasan infection by virulent B. pertussis bacteria. Also the duration of B. pertussis bacteria persistence in animals was investigated. 14 animal units of 4 species of non-human primates of the Old World were used for intranasal infection. The examination of infect animals included: visual exploration of nasopharynx, thermometry, clinical and biochemical blood analyses, identification ofB. pertussis, using microbiologic and molecular genetic analyses, estimation of innate and adoptive immune factors. The development of infectious process was accompanied by generation of B. pertussis bacteria, catarrhal inflammation of nasopharyngeal mucosa, leucocytosis, hypoglycemia specific for pertussis, and activation of innate and adaptive immunity for all primates regardless of specie were seen. While repeated experimental infection in primates single bacterial colonies were registered during only first week after challenge. It occurs like the absence of inflammation of nasopharyngeal mucosa and the lack of laboratory marks of whooping cough, recorded after first challenge. The evident booster effect of humoral immunity was observed. As a model for investigation of B. pertussis bacteria persistence and immune response against whooping cough we suggest the usage of rhesus macaque as more available to experiments.

Dimensionamiento del sistema de microfiltración para la producción de la Vacuna Pertussis elaborada en el Instituto Nacional de Higiene “Rafael Rangel” / Microfiltration sistem dimension for using in Pertussis Vaccine toxin production in the Instituto Nacional de Higiene "Rafael Rangel"

Se evaluó el uso de la tecnología de Flujo de Filtración Tangencial (FFT), para obtener la Vacuna Pertussis Celular a partir de cultivos de la bacteria Bordetella pertussis, usando el proceso de Microfiltración (MF) a objeto de recuperar el paquete celular. Se determinaron las características de los filtros, condiciones de trabajo y el dimensionamiento del equipo a adquirir para la nueva producción in dustrial de Vacuna Pertussis Celular. Se evaluaron el flujo y tiempo de proceso, rendimiento y las características del producto obtenido. Utilizando cultivos con Vacuna Pertus sis en un equipo de filtración de laboratorio, diseñado para producir el efecto de FFT. Se seleccionó las membranas tipo cassettes, formato Suspended Screen, porosidad 0,2 μm, como las adecuadas para el proceso de MF, ya que mostraron un 100% de recuperación del paquete celular sin transmisión de células al filtrado y con un flujo promedio de filtrado de 54.00 L/m2h. Estos resultaron permitieron dimensionar, considerando las variables a utilizar en la nueva producción industrial (Volumen 650 Litros, Tiempo de Procesos, 3 a 4 horas), el área de filtración del equipo de MF a adquirir, estimado en 20 m² .

Tangential Flow Filtration (TFF) technology was evaluated to process Whole Cell Pertussis Vaccine which is produced by Bordetella pertussis bacterium. Microfiltration (MF) is used to recovery cells to produ ce the vaccine. MF pro - cesses was evaluated to specify the filters and corresponding critical process parameters to scale-up the application. As part of the evaluation, flow rate, processing time, yield and product attributes were characterized. The cell harvest con taining the Whole Cell Pertussis was processed using a laboratory scale TFF system designed to pro duct the TFF effect. The evaluation demonstrated that a cassette in suspended screen format and membrane with 0.2μm pore is the right selection for the MF step. It showed 100% of cell recovery without cell transmission to the filtrate and average process flux of 54.00 L/m2h. These results were used to scale-up the application to process the industrial volume of 650 liters in 3 hours of processing time. Membrane area sizing of MF to be acquired is estimated in 20 m².

Bordetella pertussis infection is common in nonvaccinated infants admitted for bronchiolitis.

BACKGROUND: Preliminary evidence suggests that viral-pertussis coinfections are common in nonvaccinated infants. SUBJECTS AND METHODS: Bordetella pertussis infection was studied by polymerase chain reaction in nasopharyngeal aspirates in 142 infants <6 months of age, who were admitted for bronchiolitis. Viral etiology,documented by antigen detection or polymerase chain reaction in nasopharyngeal aspirate, was respiratory syncytial virus (RSV) in 105, rhinovirus in 8, influenza A virus in 8, and other viruses in 10 cases. Only 11 samples were negative. RESULTS: B. pertussis infection was found in 12 (8.5%) cases, being coinfection with RSV in 8 (67%) cases (7.6% of all RSV infections). In a retrospective analysis, RSV-pertussis coinfections and sole RSV infections did not differ for the presence of cough. Preliminary evidence was found that a history of coughing spells was associated with B. pertussis identification. CONCLUSIONS: Coinfection with B. pertussis was present in 8.5% of <6-month-old infants, who were hospitalized for viral bronchiolitis. To avoid underdiagnosis, pertussis should be considered in all nonvaccinated infants admitted for lower respiratory tract infection.

[Microorganisms isolated in cases of pertussis-like syndrome]. / Microorganismos aislados en casos de síndrome pertusoide.

OBJECTIVE: To describe the etiologic study of the pertussis-like syndrome, not only as far as Bordetella genus is concerned but also regarding the causative role of other microorganisms for a 11-year period (1988-1998). METHODS: In all specimens from patients suffering from pertussis-like cough the presence of Bordetella spp., other bacteria, viruses, and mycoplasma was investigated. The analysed data included microbiological findings and epidemiologic issues (age, sex, hospital admission area, yearly distribution and seasonal period). RESULTS: A total of 1,063 specimens were investigated, most of them nasopharyngeal aspirates (910), corresponding to 905 patients; a positive culture was obtained form 56.9 of these patients. B. pertussis was isolated from 10.5% of patients. As for other bacteria, Haemophilus influenzae and Streptococcus pneumoniae were also isolated, in 16.9% and 15.8% of occasions, respectively. The respiratory syncitial virus was isolated from 10.7% of patients and other viruses in 9.4%. Among mycoplasma, Ureaplasma urealyticum predominated, with a recovery rate of 2.9%. The male/female ratio was 495/410; the ages of 67.2% of patients ranged from 0 to 6 months; a total of 689 (76.1%) required hospital admission. The recovery of B. pertussis and adenoviruses predominated during spring and summer months. In contrast, H. influenzae, S. pneumoniae and respiratory syncitial virus were recovered more frequently during winter months. CONCLUSIONS: Most patients with pertussis-like syndrome are children aged less than 6 months. The recovery percentages of B. pertussis and respiratory syncitial virus are identical and therefore we think that the investigation of their presence in this syndrome is fully warranted as well as the search for other microorganisms, since clinical symptoms are commonly non-specific among infants.