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Few data exist on asymptomatic carriage of Bordetella species among populations receiving acellular pertussis vaccine. We conducted a cross-sectional study among acellular-vaccinated children presenting to an emergency department (ED). Bordetella pertussis carriage prevalence was <1% in this population, a lower prevalence than that found in recent studies among whole-cell pertussis-vaccinated participants. [ABSTRACT FROM AUTHOR]

What is Known and Objective: Live‐attenuated bacterial veterinary vaccines can constitute an infection risk for individuals with any defect in their phagocytic function, including chronic granulomatous disease, leukocyte adhesion deficiency, myeloperoxidase deficiency, as well as Chediak‐Higashi syndrome, from accidental acquisition of licenced attenuated live bacterial vaccine, at vaccination or from their vaccinated pet. Ownership of small companion animals, including cats and dogs, is popular within the cystic fibrosis (CF) community. These animals require vaccines as part of their routine care, which may involve live viral and bacterial vaccines, with potential for infection in the CF owner. This report examines the scope of current canine and feline vaccines, with particular emphasis on veterinary vaccination strategies against the Gram‐negative pathogen, Bordetella bronchiseptica and describes new vaccine innovations offering protection to both pet and CF owner. Comment: The Gram‐negative bacterium, Bordetella bronchoseptica, may cause respiratory disease in small companion animals, as well as in certain human vulnerable groups, including those with CF. Live licenced veterinary bacterial vaccines for Bordetella bronchiseptica (Kennel Cough) are available for cats and dogs, which are an infection concern for humans with CF who may come into contact with vaccinated animals. Live licenced veterinary bacterial vaccines for Bordetella bronchiseptica (Kennel Cough) are available for intranasal administration to cats and dogs. These vaccines require a withdrawal period of vaccinated animal from vulnerable owner, ranging from 35 days – 11 weeks. Recently, a new dead IM vaccine is now available not requiring exclusion of the vaccinated pet from CF owner. What is new & conclusion: CF pharmacists, hospital pharmacists and community pharmacists are important custodians of vaccine‐related advice to people with CF, who are frequently consulted for such advice. Pharmacists should be aware of the recent innovations in veterinary medicines, so that they can give appropriate advice to people with CF when asked. Immunocompromised patients, that is those with CF or those with any defect in their phagocytic function (chronic granulomatous disease, leukocyte adhesion deficiency, myeloperoxidase deficiency, Chediak‐Higashi syndrome) should avoid exposure to live veterinary bacterial vaccines and seek animal vaccination utilising non‐live vaccines. Most importantly, this manuscript highlights the development of a new veterinary vaccine for dogs, which we want to make the CF healthcare community aware of, which is an acellular dead vaccine, so that those patients with dogs needing annual vaccination can select this vaccine pathway, thereby minimising risk of infection from the vaccine strains and avoiding the social exclusion between CF patient and their pet. CF patients should understand the potential infection implications of live‐attenuated viral and bacterial strains as vaccines, whether these are small companion animals, exotic animals or large farm animals. Patients should make their veterinarian aware of their CF status, so that a safe and efficacious vaccine strategy is used, both mitigating the potential infection risks from live vaccine components with the CF patient, but simultaneously offering maximum immunological protection to the animal. [ABSTRACT FROM AUTHOR]

What is known and objective: The Gram‐negative bacterium, Bordetella bronchiseptica, causes lower airway respiratory disease in people with cystic fibrosis (CF), as well as in companion animals, especially dogs. Presently, there are several acellular vaccines available for B. pertussis but no vaccine available for B. bronchiseptica. However given the shared protein homology between these two closely related species, we wished to explore whether pertussis vaccines may offer some cross‐protection against B. bronchiseptica. Comment: Bordetella pertussis and B. bronchiseptica are closely related phylogenetically, as well as sharing protein homology in several pertussis vaccine components, including (i) pertussis toxin (PT), (ii) filamentous haemagglutinin (FHA), (iii) pertactin and (iv) fimbriae (types 2 and 3). Given that pertussis vaccine contains cross‐reactive antigens with B. bronchiseptica, licensed pertussis vaccines may therefore offer cross‐protection against B. bronchiseptica. What is new and conclusion: Cystic fibrosis pet owners should ensure that they have an up‐to‐date vaccination record relating to their pertussis vaccine. Although no monovalent human pertussis vaccines are currently available, licensed non‐live booster vaccines for B. pertussis are available for individuals in the age range >10 years old. People with CF should ensure that they are adequately and currently protected against pertussis, to avoid whooping cough, which may also offer some cross‐protection against B. bronchiseptica and therefore help further mitigate the risk of zoonotic infection of this organism from pets to their owners. [ABSTRACT FROM AUTHOR]

From 2015 to 2017, 3197 interpretable Bordetella polymerase chain reaction (PCR) tests were performed for 2760 children presenting to our tertiary university hospital. Requests mainly came from the emergency department (62%) and for children older than 1 year (68%). Only 32 PCR (1%) results were positive, mainly in children younger than 1 year (n = 29/32, 90.6%; p <0.001). When focusing on the PCR indications in 2017, we found the requests were mainly based on nonspecific respiratory symptoms and were clinically unjustified in 383 cases (39%). Pediatricians overused Bordetella PCR in clinical practice. They should reserve their requests for cases of young children with symptoms suggestive of respiratory illness and/or incomplete pertussis immunization. [ABSTRACT FROM AUTHOR]

Background: In an effort to improve the pertussis diagnosis, the Global Pertussis Initiative (GPI) proposed an algorithm of the signs/symptoms of pertussis for three age groups: 0–3 months, 4 months to 9 years, and ≥10 years of age. Methods: We evaluated the accuracy of the clinical case definitions for pertussis proposed by the GPI using laboratory-confirmed pertussis as a reference standard for four groups: clinically suspected pertussis without comorbidity; asthma exacerbation; allergic constitution, and other diagnoses (bronchitis, bronchiolitis, laryngitis, and tracheitis). We included only patients who fulfilled one or more criteria of clinical case definitions for the age groups (0–3 months, 4 months–9 years, and ≥10 years of age). The data for this prospective epidemiological study were collected between 1st January 2013–31st December 2016 at the outpatients and inpatients health care settings in the South Bačka District of Autonomous Province of Vojvodina, Serbia. We evaluated accuracy of the certain sign and symptom combinations of GPI case definitions based on their sensitivity, specificity, and likelihood ratios. Results: A total of 1043 participants were included, with 306 (29.3%) laboratory-confirmed pertussis cases. In patients aged 0–3 months, whoop and apnoea associated with laboratory confirmation of pertussis. In patients aged 4 months-9 years with a pertussis suspicion infection or with one of the other diagnoses, the highest accuracy was found for whoop combined with apnoea or post-tussive emesis. In patients aged 10 years and older, several different sign and symptom combinations were associated with an increased risk of pertussis among all enrolment diagnoses. There were fewer hospitalizations among the fully vaccinated children than in partly or unvaccinated children aged 4 months to 6 years (20.7% vs. 60.0%, p = 0.017). Conclusions: The numerous sign and symptom combinations in the observed case definitions were good predictors for laboratory-confirmed pertussis among all enrolment diagnoses, therefore suggesting the necessity for increased awareness of possibility for pertussis in patients with certain pertussis-like medical conditions. [ABSTRACT FROM AUTHOR]

Despite the importance of Bordetella avium (BA) as a respiratory pathogen of young turkeys, no infection model for the evaluation of BA-vaccine efficacy is available. The objective of this study was to evaluate the influence of route and dose of infection on the establishment of a BA-challenge model. In our first experiment, 28-day-old turkeys were either inoculated oculonasally with 105, 107 or 109 colony forming units (CFU) of BA per bird or exposed to BA by aerosol with 105-108 CFU/m3. The respiratory tract of all inoculated birds was BA-colonized, which was confirmed by choanal swabs and samples of trachea and lung, showing the highest prevalence in the aerosol-inoculated group. BA-specific humoral immune response was detected in the form of IgG in serum from five days post infection (dpi) and IgA in lacrimal fluid from seven dpi. In the second experiment, the model was tested in a vaccination trial. Twenty-one-day-old turkeys were vaccinated with a formalin-inactivated BA vaccine intramuscularly and challenged 21 days post vaccination with 107 CFU per bird oculonasally. BA-specific IgG antibodies were detected in serum and in lacrimal fluid 14 days post vaccination. As in the first experiment, secretory BA-specific antibodies of the IgA isotype were only detected in the inoculated groups from seven dpi. Despite the lack of clinical signs or pathological alterations in both experiments, vaccine efficacy was demonstrated by significant reduction in BA colonization of the trachea (P ≤ 0.05). In our study, a reliable model for BA infection has been established and has been demonstrated to be suitable for evaluation of vaccine efficacy. [ABSTRACT FROM AUTHOR]

Context • Pertussis cough (whooping cough) is distressing due to the intensity and chronicity of its cough. No specific drugs are available that can alleviate the cough’s intensity or significantly shorten its duration. Homeopathic medicines are used for a wide variety of medical conditions, including cough. Objective • The study investigated the benefits of homeopathic medicines for whooping cough, to alleviate the cough’s intensity and to shorten its duration. Design • The current study was a case series of patients with whooping cough. Setting • The study took place at one of the suburban hospital clinics of the Ann & Robert H. Lurie Children’s Hospital of Chicago (Chicago, IL, USA). Participants • Participants were 20 patients aged 21 mo to 20 y, of whom 11 were female and 18 were male, who visited the hospital clinic for treatment of the chronic cough that is characteristic of whooping cough. The details of the cases of 3 representative participants are highlighted in the text. Intervention • The 3 representative patients all received 1 dose weekly of a 30c dilution of homeopathic pertussinum and a 6c dilution of homeopathic Drosera 3 times daily. The homeopathic medicines most often used for the other participants were the same doses of pertussinum and Drosera. Outcome Measures • Verbal feedback from patient or family were obtained at the follow-up visits. Results • The intensity and duration of participant’s coughs were alleviated within days to 1 wk in most cases. Conclusions • Homeopathic medicines can alleviate the intensity or reduce the duration of whooping cough, with no adverse effects. [ABSTRACT FROM AUTHOR]

Objective To collect data of all patients admitted to hospital with a positive test to Bordetella bronchiseptica between 2001 and 2015. Methods We performed a retrospective monocentric study of all hospitalized patients over the past 15 years with a positive test to B . bronchiseptica . Results Nine patients were included between 2001 and 2015; two presented with infectious relapses, i.e. a total of 14 positive test samples were observed. Age, induced immunodeficiency, and preexisting respiratory illnesses are risk factors. All patients showed symptoms at sample collection and the infection was exclusively respiratory. The diagnosis was obtained through a cytobacteriological test of sputum, bronchial aspiration, or bronchial fibroscopy with a bronchoalveolar lavage. The drug susceptibility test revealed a natural resistance to cephalosporins including ceftazidime, monobactam, and fosfomycin. There were cases of resistance to penicillin A and to the trimethoprim/sulfamethoxazole association. The classically used antibiotic treatment for community-acquired pneumonia is based on probability and may thus fail. Four patients died. The duration and nature of the antibiotics to use have not been codified. Conclusion B . bronchiseptica infection mainly affects the elderly. All patients should be treated, regardless of the importance of the inoculum, and all infected animals should be treated. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Background and Objectives: Bordetella holmesii is associated with a pertussis-like respiratory syndrome in healthy individuals and also a rare cause of septicaemia, endocarditis, pneumonia, and septic arthritis, mostly in immunocompromised patients. Culture technique and real-time PCR are 2 methods used to detect Bordetella spp. Materials and Methods: In this study, 435 nasopharyngeal specimens of patients with suspected whooping cough were checked for the presence of B. holmesii using 2 methods of culture technique and real-time PCR. Results: In this study, we detected hIS1001 and IS481 of B. holmesii in 2 infants suspected of having pertussis-like syndrome. Conclusion: Our observations demonstrate that accurate diagnosis is needed to discriminate between B. holmesii and B. pertussis infections among pertussis cases; otherwise, it could lead to misestimating pertussis rate and vaccine efficacy. [ABSTRACT FROM AUTHOR]

Background: We describe the epidemiology of pertussis in Alberta, Canada by person, place, and time between 2004 and 2015, identify outbreak years, and examine vaccination coverage and vaccination timeliness.Methods: We used health data from Alberta's Communicable Disease Registry System for the period of January 1, 2004 through August 31, 2015 to identify unique cases of pertussis. Unique cases were deterministically linked to data in Alberta's immunization repository and health care insurance plan registry. Population estimates and vaccination coverage were extracted from Alberta's online Interactive Health Data Application. We estimated pertussis incidence rates per 100,000 persons by year, age group, gender, and health zone. Outbreak years were identified using a one-sided cumulative sum (CUSUM) analysis by comparing annual incidence rates to baseline rates.Results: Over the period, 3510 cases of pertussis were confirmed by laboratory testing or epidemiological linkage. Incidence rates per 100,000 persons were highest in 2004 (20.5), 2005 (13.6), and 2015 (10.4) for all age groups. Incidence rates were highest among the youngest age groups and decreased as age groups increased. Based on CUSUM analysis, 2008 and 2012 met the criteria for outbreak years. Vaccination coverage was over 90% among the general population, however only 61% of cases received at least one dose. About 60% of cases were diagnosed 5+ years after receiving the vaccine. Approximately 87-91% of vaccinated cases did not receive the first three vaccine doses in a timely manner.Conclusion: Pertussis incidence rates fluctuated over the period across all age groups. The majority of cases had no record of vaccination or were delayed in receiving vaccines. CUSUM analysis was an effective method for identifying outbreaks. [ABSTRACT FROM AUTHOR]

Changes in environmental temperature represent one of the major stresses faced by microorganisms as they affect the function of the cytoplasmic membrane. In this study, we have analyzed the thermal adaptation in two closely related respiratory pathogens Bordetella pertussis and Bordetella bronchiseptica. Although B. pertussis represents a pathogen strictly adapted to the human body temperature, B. bronchiseptica causes infection in a broad range of animals and survives also outside of the host. We applied GC-MS to determine the fatty acids of both Bordetella species grown at different temperatures and analyzed the membrane fluidity by fluorescence anisotropy measurement. In parallel, we also monitored the effect of growth temperature changes on the expression and production of several virulence factors. In response to low temperatures, B. pertussis adapted its fatty acid composition and membrane fluidity to a considerably lesser extent when compared with B. bronchiseptica. Remarkably, B. pertussis maintained the production of virulence factors at 24 °C, whereas B. bronchiseptica cells resumed the production only upon temperature upshift to 37 °C. This growth temperature-associated differential modulation of virulence factor production was linked to the phosphorylation state of transcriptional regulator BvgA. The observed differences in low-temperature adaptation between B. pertussis and B. bronchiseptica may result from selective adaptation of B. pertussis to the human host. We propose that the reduced plasticity of the B. pertussis membranes ensures sustained production of virulence factors at suboptimal temperatures and may play an important role in the transmission of the disease. [ABSTRACT FROM AUTHOR]

Bordetella holmesii can cause invasive infections but can also be isolated from the respiratory tract of patients with whooping-cough like symptoms. For the first time, we describe the lipid A structure of B. holmesii reference strain ATCC 51541 (alias NCTC12912 or CIP104394) and those of three French B. holmesii clinical isolates originating from blood (Bho1) or from respiratory samples (FR4020 and FR4101). They were investigated using chemical analyses, gas chromatography–mass spectrometry (GC–MS), and matrix-assisted laser desorption ionization–mass spectrometry (MALDI–MS). The analyses revealed a common bisphosphorylated β-(1→6)-linked d-glucosamine disaccharide with hydroxytetradecanoic acid in amide linkages. Similar to B. avium, B. hinzii and B. trematum lipids A, the hydroxytetradecanoic acid at the C-2′ position are carrying in secondary linkage a 2-hydroxytetradecanoic acid residue resulting of post-traductional biosynthesis modifications. The three clinical isolates displayed characteristic structural traits compared to the ATCC 51541 reference strain: the lipid A phosphate groups are more or less modified with glucosamine in the isolates and reference strain, but the presence of 10:0(3-OH) is only observed in the isolates. This trait was only described in B. pertussis and B. parapertussis strains, as well as in B. petrii isolates by the past. The genetic bases for most of the key structural elements of lipid A were analyzed and supported the structural data. [ABSTRACT FROM AUTHOR]

B. parapertussis is a whooping cough etiological agent with the ability to evade the immune response induced by pertussis vaccines. We previously demonstrated that in the absence of opsonic antibodies B. parapertussis hampers phagocytosis by neutrophils and macrophages and, when phagocytosed, blocks intracellular killing by interfering with phagolysosomal fusion. But neutrophils can kill and/or immobilize extracellular bacteria through non-phagocytic mechanisms such as degranulation and neutrophil extracellular traps (NETs). In this study we demonstrated that B. parapertussis also has the ability to circumvent these two neutrophil extracellular bactericidal activities. The lack of neutrophil degranulation was found dependent on the O antigen that targets the bacteria to cell lipid rafts, eventually avoiding the fusion of nascent phagosomes with specific and azurophilic granules. IgG opsonization overcame this inhibition of neutrophil degranulation. We further observed that B. parapertussis did not induce NETs release in resting neutrophils and inhibited NETs formation in response to phorbol myristate acetate (PMA) stimulation by a mechanism dependent on adenylate cyclase toxin (CyaA)-mediated inhibition of reactive oxygen species (ROS) generation. Thus, B. parapertussis modulates neutrophil bactericidal activity through two different mechanisms, one related to the lack of proper NETs-inducer stimuli and the other one related to an active inhibitory mechanism. Together with previous results these data suggest that B. parapertussis has the ability to subvert the main neutrophil bactericidal functions, inhibiting efficient clearance in non-immune hosts. [ABSTRACT FROM AUTHOR]

Bordetella bronchiseptica (B. bronchiseptica) is the most important pathogen associated with kennel cough in dogs. The presence of B. bronchiseptica in pet dogs and shelter dogs with clinical respiratory disease was investigated in present study. The genetic relatedness among the strains was determined to evaluate the role of stray dogs in spread of B. bronchiseptica to pet dogs by detection of virulence genes such as filamentous hemagglutinin (fha), pertactin (prn) and dermonecrotic toxin (dnt). We also performed the random amplified polymorphic DNA (RAPD) assay. A total of 96 B. bronchiseptica were isolated from stray and pet dogs. The fha, prn and dnt virulence genes were detected in 86, 83.3 and 61.4% strains, respectively by polymerase chain reaction (PCR) techniques. The most common genotype from stray and pet dogs was fha+prn+dnt+ as detected in 37.5% and 11.4% of all the strains, respectively. The RAPD assay showed that 3 different patterns were obtained from 96 B. bronchiseptica strains. Sixty one (63.5%) of them were clustered in one main group and then further placed in another 2 sub-groups by RAPD assay. Genetic association was seen between the B. bronchiseptica strains from stray and pet dogs. In conclusion, this study revealed that B. bronchiseptica is present at a higher rate in stray dogs than pet dogs. Stray dogs might have a significant role in the transmission of B. bronchiseptica to pet dogs. [ABSTRACT FROM AUTHOR]

Background: The genus Bordetella consists of nine species that include important respiratory pathogens such as the 'classical' species B. bronchiseptica, B. pertussis and B. parapertussis and six more distantly related and less extensively studied species. Here we analyze sequence diversity and gene content of 128 genome sequences from all nine species with focus on the evolution of virulence-associated factors. Results: Both genome-wide sequence-based and gene content-based phylogenetic trees divide the genus into three species clades. The phylogenies are congruent between species suggesting genus-wide co-evolution of sequence diversity and gene content, but less correlated within species, mainly because of strain-specific presence of many different prophages. We compared the genomes with focus on virulence-associated genes and identified multiple clade-specific, species-specific and strain-specific events of gene acquisition and gene loss, including genes encoding O-antigens, protein secretion systems and bacterial toxins. Gene loss was more frequent than gene gain throughout the evolution, and loss of hundreds of genes was associated with the origin of several species, including the recently evolved human-restricted B. pertussis and B. holmesii, B. parapertussis and the avian pathogen B. avium. Conclusions: Acquisition and loss of multiple genes drive the evolution and speciation in the genus Bordetella, including large scale gene loss associated with the origin of several species. Recent loss and functional inactivation of genes, including those encoding pertussis vaccine components and bacterial toxins, in individual strains emphasize ongoing evolution. [ABSTRACT FROM AUTHOR]

Bordetella holmesii causes both invasive and respiratory diseases in humans. Although the number of cases of pertussis-like respiratory illnesses due to B. holmesii infection has increased in the last decade worldwide, little is known about the virulence factors of the organism. Here, we analyzed a B. holmesii isolate that forms large aggregates and precipitates in suspension, and subsequently demonstrated that the autoagglutinating isolate is deficient in Bordetella intermediate protein A (BipA) and that this deletion is caused by a frame-shift mutation in the bipA gene. A BipA-deficient mutant generated by homologous recombination also exhibited the autoagglutination phenotype. Moreover, the BipA mutant adhered poorly to an abiotic surface and failed to form biofilms, as did two other B. holmesii autoagglutinating strains, ATCC 51541 and ATCC 700053, which exhibit transcriptional down-regulation of bipA gene expression, indicating that autoagglutination indirectly inhibits biofilm formation. In a mouse intranasal infection model, the BipA mutant showed significantly lower levels of initial lung colonization than did the parental strain (P < 0.01), suggesting that BipA might be a critical virulence factor in B. holmesii respiratory infection. Together, our findings suggest that BipA production plays an essential role in preventing autoagglutination and indirectly promoting biofilm formation by B. holmesii. [ABSTRACT FROM AUTHOR]

Background The use of quantitative PCR ( qPCR) for detection of Bordetella bronchiseptica in bronchoalveolar lavage fluid ( BALF) and demonstration of bacteria adhering to ciliated epithelial cells in BALF or bronchial brushing fluid ( BBF) has not been assessed in a series of affected dogs. Coinfections can worsen the clinical severity in bordetellosis, but the specific association with Mycoplasma cynos has not been evaluated. Objectives To assess the utility of culture, qPCR and cytologic examination of cytospin preparations in the diagnosis of bordetellosis in dogs and the influence of coinfection by M. cynos on disease severity. Animals Twenty-four referred dogs with B. bronchiseptica infection and 10 healthy dogs. Methods Retrospective case series. qPCR ( B. bronchiseptica and M. cynos) and culture results from BALF were recorded. Cytospin preparations from BALF and BBF were reviewed. qPCR on BALF from 10 healthy dogs were used as negative control. Results The BALF culture and qPCR detected B. bronchiseptica in 14/24 and 18/18 dogs, respectively. Coccobacilli were found adhering to ciliated epithelial cells in 20 of the 21 BALF cytologic preparations where epithelial cells were found, and 2/3 BBF cytologic preparations. Quantitative PCR detected a low level of B. bronchiseptica in one healthy dog. The frequency of detection of M. cynos was not significantly different in B. bronchiseptica (9/17 dogs) compared with healthy dogs (2/10 dogs) ( P = .09). Conclusion and Clinical Importance Quantitative PCR detection of B. bronchiseptica in BALF appears to be a useful diagnostic tool. Cytologic examination of BALF or BBF, when positive, allows a rapid and reliable diagnosis. [ABSTRACT FROM AUTHOR]

We investigated the seasonality of pertussis in Queensland, Australia, between 2008 and 2011 using notification and laboratory data. Polymerase chain reaction and serology testing data demonstrate that in the vaccine era, pertussis remains a seasonal illness, with annual peaks in summer months, and that the seasonality of notification data is masked by testing trends. [ABSTRACT FROM AUTHOR]

Conventional pertussis animal models deliver hundreds of thousands of Bordetella pertussis bacteria deep into the lungs, rapidly inducing severe pneumonic pathology and a robust immune response. However, human infections usually begin with colonization and growth in the upper respiratory tract. We inoculated only the nasopharynx of mice to explore the course of infection in a more natural exposure model. Nasopharyngeal colonization resulted in robust growth in the upper respiratory tract but elicited little immune response, enabling prolonged and persistent infection. Immunization with human acellular pertussis vaccine, which prevents severe lung infections in the conventional pneumonic infection model, had little effect on nasopharyngeal colonization. Our infection model revealed that B. pertussis can efficiently colonize the mouse nasopharynx, grow and spread within and between respiratory organs, evade robust host immunity, and persist for months. This experimental approach can measure aspects of the infection processes not observed in the conventional pneumonic infection model. [ABSTRACT FROM AUTHOR]

Pertussis specific antibodies were studied with respect to quality and quantity in a cohort of apparently healthy Egyptian children and adolescents, with their age range between 1 and 18 years, in an attempt to get a close and clear insight into the current humoral immunization status in this specified group and to try find a relation between the antibody levels and their avidities in eradication of this devastating infectious disease. Our results showed that avidity increase was most marked in young school children (6–8 years) where it seemed to reach a plateau in older children and adolescents. Antibody titer was highest in toddlers (1–2 years) and young school children (6–8 years) groups, most probably following vaccination and/or booster doses. Among children aged 1–5 years, 28% had highly avid and 50% had high titer antibodies, whereas in adolescents aged 13–18 years, 70% had highly avid antibodies and only 30% had high titer antibodies. The results clearly demonstrated that while levels of anti- Bordetella pertussis ( B. pertussis ) antibodies wane with growing age, the avidity seems to increase, to a plateau, irrespective of further antigen exposure in a pattern showing complete independence of avidity on concentration. The present study draws attention to the importance of avidity measurements, together with conventional ELISAs, for evaluating immunity against pertussis. Being based on a limited sample size, it could open doors for larger-scale surveys to be possible indicators for the need and timing of booster vaccination doses among Egyptians. [ABSTRACT FROM AUTHOR]

We report 2 cases of pulmonary Bordetella hinzii infection in immunodeficient patients. One of these rare cases demonstrated the potential transmission of the bacteria from an avian reservoir through occupational exposure and its persistence in humans. We establish bacteriologic management of these infections and suggest therapeutic options if needed. [ABSTRACT FROM AUTHOR]

Pertussis is a potentially severe respiratory disease, which affects all age groups from young infants to older adults and is responsible for an estimated 195,000 deaths occurred globally in 2008. Active research is ongoing to better understand the pathogenesis, immunology, and diagnosis of pertussis. For diagnosis, molecular assays (e.g., polymerase chain reaction) for detection of Bordetella pertussis have become more widely available and support improved outbreak detection. In children, pertussis vaccines have been incorporated into routine immunization schedules and deployed for pertussis outbreak control. Lower levels of vaccine coverage are now being observed in communities where vaccine hesitancy is rising. Additionally, recognition that newborn babies are at risk of pertussis in the USA and UK has led to recommendations to immunize pregnant women. Among adolescents and older adults in the USA, Tetanus Toxoid, Reduced Diphtheria Toxoid and Acellular pertussis (Tdap) Vaccines are recommended, but substantial individual- and system-level barriers exist that will make achieving national Healthy People 2020 targets for immunization challenging. Current antimicrobial regimens for pertussis are focused on reducing the severity of disease, reducing rates of sequelae, and minimizing transmission of infection to susceptible individuals. Continued surveillance for pertussis will be important to identify opportunities for reducing young infants' exposure and reducing the impact of outbreaks among school-aged children. Laboratory-based surveillance for newly emerging strains of B. pertussis will be important to identify strains that may evade protection elicited by currently available vaccines. Efforts to develop new-generation pertussis vaccines should be considered now in anticipation of vaccine development programs, which may require ten or more years to deliver a licensed vaccine. [ABSTRACT FROM AUTHOR]

The Type Six Secretion System (T6SS) is required for Bordetella bronchiseptica cytotoxicity, cytokine modulation, infection, and persistence. However, one-third of recently sequenced Bordetella bronchiseptica strains of the predominantly human-associated Complex IV have lost their T6SS through gene deletion or degradation. Since most human B. bronchiseptica infections occur in immunocompromised patients, we determine here whether loss of Type Six Secretion is beneficial to B. bronchiseptica during infection of immunocompromised mice. Infection of mice lacking adaptive immunity (Rag1-/- mice) with a T6SS-deficient mutant results in a hypervirulent phenotype that is characterized by high numbers of intracellular bacteria in systemic organs. In contrast, wild-type B. bronchiseptica kill their eukaryotic cellular hosts via a T6SS-dependent mechanism that prevents survival in systemic organs. High numbers of intracellular bacteria recovered from immunodeficient mice but only low numbers from wild-type mice demonstrates that B. bronchiseptica survival in an intracellular niche is limited by B and T cell responses. Understanding the nature of intracellular survival during infection, and its effects on the generation and function of the host immune response, are important to contain and control the spread of Bordetella-caused disease. [ABSTRACT FROM AUTHOR]

Despite success in expanded program immunization for an increase in vaccination coverage in the children of world, timeliness and schedule of vaccination remains as one of the challenges in public health. This study purposed to demonstrate the related factors of delayed diphtheria-tetanus-pertussis (DTP) vaccination using life table approach. A historical cohort study conducted in the poor areas of five large Iran cities. Totally, 3610 children with 24-47 months old age who had documented vaccination card were enrolled. Time of vaccination for the third dose of DTP vaccine was calculated. Life table survival was used to calculate the proportional probability of vaccination in each time. Wilcoxon test was used for the comparison proportional probability of delayed vaccination based on studies factors. The overall median delayed time for DTP3 was 38.52 days. The Wilcoxon test showed that city, nationality, education level of parents, birth order and being in rural areas are related to the high probability of delay time for DTP3 vaccination (P < 0. 001). Moreover, child gender and parent's job were not significant factors (P > 0.05). Being away from the capital, a high concentration of immigrants in the city borders with a low socioeconomic class leads to prolonged delay in DTP vaccination time. Special attention to these areas is needed to increase the levels of parental knowledge and to facilitate access to the health services care. [ABSTRACT FROM AUTHOR]

Introduction: Cough is a common indication of respiratory illness and is one of the more common symptoms of children seeking medical attention. Material and Method: We conducted a clinic-based retrospective surveillance witch analyzed the cases managed at "The National Institute for Infectious Diseases "Prof. Dr Matei Bals" - Pediatric Department, Bucharest during the period of January 2010 up to December 2014 who presented accusing cough episodes from over a week and who associated one of the following symptoms: paroxysms of coughing, inspiratory "whoop," posttussive vomiting or apnea. We selected 790 suitable cases for whom we analyzed: age, sex, vaccinal status, severity of the disease and the complications. The etiological diagnosis was made by serologic testing for Bordetella, Mycoplasma, Chlamydia, Adenovirus and by rapid testing for Sincitial Respiratory Virus (RSV). Results and findings. Based on the etiological stratification 108 patients (13,8%) were diagnosed with Bordetella Spp infections, 62,4% of them being completely unvaccinated against Pertusis, representing 11% of the national reported cases of Whooping Cough during the 5 years of survey. With decresing frequencies the rest of the cases (682) were caused by: RSV (39,7%), Adenovirus (21,5%), Mycoplasma (18,3%), Chlamydia (6,7%). The majority of the cases evolved favorable, no fatal cases were registered but 279 presented with initial altered status and required, on average, 3 days of Intensive Care Unit management. The average hospitalization period registered is 6,9 days. All the severe complications were registered in the < 6 months age group. Conclusion: Whooping cough remains endemic in Romania and Bordetells Spp. infection is associated with substantial morbidity and mortality rates among children. [ABSTRACT FROM AUTHOR]

Bordetella bronchiseptica (B. bronchiseptica) is an obligately aerobic, oxidase- and catalase-positive, nonfermentative Gram-negative coccobacillus. This study is aimed at examining the immune effects of Rg1, Rg1 plus oil, and other common adjuvants on inactivated B. bronchiseptica vaccine in rabbits. The mechanism underlying the adjuvant effect of Rg1 plus oil on the vaccine was also explored. Rg1 (100 μg) plus oil significantly improved the immune effect of B. bronchiseptica vaccine at both the humoral and cellular levels. Rg1-oil adjuvant increased the levels of IL-2 and IL-4 in rabbits after immunization. Rg1 (100 μg) plus oil also significantly increased TLR2 expression and downregulated NF-κB in splenocytes. Rg1-oil adjuvant may increase the levels of IL-2 and IL-4 via upregulating TLR2, thereby enhancing the immune effect of B. bronchiseptica vaccine. In conclusion, Rg1 plus oil could be used as a potential vaccine adjuvant for rabbit B. bronchiseptica vaccine. [ABSTRACT FROM AUTHOR]

To commemorate the 100th anniversary of the Nobel prize being awarded to Jules Bordet, the discoverer of Bordetella pertussis , the 12th International Bordetella Symposium was held from 9 to 12 April 2019 at the Université Libre de Bruxelles, where Jules Bordet studied and was Professor of Microbiology. The symposium attracted more than 300 Bordetella experts from 34 countries. They discussed the latest epidemiologic data and clinical aspects of pertussis, Bordetella biology and pathogenesis, immunology and vaccine development, and genomics and evolution. Advanced technological and methodological tools provided novel insights into the genomic diversity of Bordetella and a better understanding of pertussis disease and vaccine performance. New molecular approaches revealed previously unrecognized complexity of virulence gene regulation. Innovative insights into the immune responses to infection by Bordetella resulted in the development of new vaccine candidates. Such discoveries will aid in the design of more effective approaches to control pertussis and other Bordetella -related diseases. [ABSTRACT FROM AUTHOR]

Background: Pertussis is still one of the major public health problems. The increase of the disease emerged in recent decades due to the replacement of the reactogenic whole cell vaccine with the safer acellular vaccine and the genetic diversity of the bacterium. As outer membrane vesicles (OMVs) obtained from Bordetella pertussis contains surface immunogenic antigen in its structure, it has an acceptable characteristic that could be considered as a good candidate for pertussis vaccine. Materials & Methods: Vaccinal strain BP134 strain of B. pertussis was cultured under standard conditions and OMVs were isolated by modifying the method without the use of ultracentrifuge. The isolated vesicles were examined by transmission electron microscopy and protein content was measured by the Bradford method. The expression of virulence factors was confirmed by SDS-PAGE and protein expression was confirmed by Western immunoblot. Pyrogenicity test and abnormal toxicity test were performed on extracted vesicles. Results: The morphology of the vesicles was confirmed in the range of 40 to 200 nm. The protein concentration of the extracted vesicles was determined as 600 μg. Expression analysis by SDS-PAGE and western blot confirmed the presence of virulence factors, pertussis toxin, filamentous hemagglutinin, and pertactin using monoclonal antibodies in OMVs of the vaccinal strain. Pyrogenicity test and abnormal toxicity test were negative. Conclusion: The proposed method is a simple and efficient method for isolation of the B. pertussis OMVs. The OMVs extracted from B. pertussis could be a candidate for a new generation of pertussis vaccine alone or in combination with adjuvants to design future acellular vaccines. [ABSTRACT FROM AUTHOR]

The article presents a case report of a 15-year-old with chest trauma history who complained of recurrent coughing, hemoptysis and episodes of fever. He was diagnosed with Bordetella bronchiseptica pneumonia, and started on intravenous ceftriaxone, oral azithromycin, and flexible bronchoscopy, after which his hemoptysis resolved, and cough improved. The patient was discharged on oral doxycycline. Also noted is the education of at-risk patients on the condition's acquisition from animals.

We calculated the effectiveness of pertussis vaccine in preventing parapertussis among Oregon children 2 months to 10 years of age using 2 methods. During 2011–2016, the 2 VE methods found 66% (95% CI, 59–75%) and 82% (95% CI, 69–90%) effectiveness against parapertussis. Pertussis vaccine may induce cross-immunity. [ABSTRACT FROM AUTHOR]

Bordetella holmesii is a rare cause of invasive human disease. The fastidious and unusual nature of this organism makes routine isolation and identification challenging. We report two cases of B. holmesii bacteremia that were rapidly identified by matrix-assisted laser desorption-ionization time-of-fl ight mass spectrometry (MALDI-TOF MS) when standard techniques failed to provide speciation. There are no current standards for susceptibility testing or treatment recommendations. The rare occurrence and challenges in identifying this pathogen led us to perform a comprehensive review of the epidemiology, clinical presentations, and treatment options for this potentially invasive pathogen. [ABSTRACT FROM AUTHOR]

Highlights: [•] The composition and content of monosaccharide in TPPPS were firstly analyzed. [•] TPPPS can significantly eliminate immunosuppression and can serve as immunoregulator. [•] The pathogenicity of B. avium in chicks which co-infected with ALV-B was exacerbated. [•] TPPPS can enhance the immunity and resist to diseases in chicks. [ABSTRACT FROM AUTHOR]

Summary: Bordetella holmesii, first described in 1995, is believed to cause both invasive infections (bacteraemia, meningitis, endocarditis, pericarditis, pneumonia, and arthritis) and pertussis-like symptoms. Infection with B holmesii is frequently misidentified as being with B pertussis, the cause of whooping cough, because routine diagnostic tests for pertussis are not species-specific. In this Review, we summarise knowledge about B holmesii diagnosis and treatment, and assess research needs. Although no fatal cases of B holmesii have been reported, associated invasive infections can cause substantial morbidities, even in previously healthy individuals. Antimicrobial treatment can be problematic because B holmesii's susceptibility to macrolides (used empirically to treat B pertussis) and third-generation cephalosporins (often used to treat invasive infections) is lower than would be expected. B holmesii's adaptation to human beings is continuing, and virulence might increase, causing the need for better diagnostic assays and epidemiological surveillance. [ABSTRACT FROM AUTHOR]

To analyze pathogenicity changes of new isolate of Bordetella avium LL09 from chick embryos, 120 1-day-old specific pathogen free (SPF) chickens were intranasally inoculated with broth cultures of isolate LL09. Its colonization pattern in different chicken tissues was studied by bacterial isolation and indirect immunoenzyme histochemistry. Results showed that the bacteria were isolated from tracheas and lungs at 1 h post-infection. Afterwards, they colonized livers, hearts and spleens at 120 h and then infected kidneys at 168 h. The peak infection appeared on 21 d post-infection. They persisted in these organs and caused injuries up to 42 d. With growth of chickens, Bordetella avium began to be gradually cleared away from livers, hearts and spleens, except that it could still be detected in tracheas, lungs and kidneys until 56 d post-infection. It demonstrated that lungs and kidneys would possible be colonized for a long time by B. avium in addition to the tracheas. [ABSTRACT FROM AUTHOR]

Bordetella pertussis still poses an important health threat in developing countries. In Niger, notified pertussis cases are few despite the low diphtheria–tetanus–pertussis/pentavalent vaccine coverage. We aimed to estimate the prevalence of B. pertussis in children aged <5 years consulting at a pediatric ward. A 5-month study in 2011 recruited 342 children with respiratory symptoms at the National Hospital of Niamey. Nasopharyngeal aspirates were tested by culture and real-time polymerase chain reaction. Overall, 34 (11.2%) of the 305 available nasopharyngeal aspirates tested by real-time polymerase chain reaction were positive for a Bordetella spp., with an estimated prevalence of 8.2 cases per 1000 children aged <5. None was notified to the surveillance network. A single specimen was positive on culture. This study, the first to provide laboratory-confirmed data on pertussis in Niger, highlights the need to sensitize health care personnel to actively notify clinical cases and to integrate laboratory diagnosis in the existing surveillance system. [ABSTRACT FROM PUBLISHER]

Although Bordetella hinzii coccobacilli is most commonly identified in respiratory tracts of birds and rodents, this organism has occasionally been isolated in human infections. We describe a case of B. hinzii spontaneous bacterial peritonitis in Missouri, USA. Whole-genome sequencing of blood and peritoneal fluid isolates confirmed B. hinzii infection. [ABSTRACT FROM AUTHOR]

Transmission of pathogens has been notoriously difficult to study under laboratory conditions leaving knowledge gaps regarding how bacterial factors and host immune components affect the spread of infections between hosts. We describe the development of a mouse model of transmission of a natural pathogen, Bordetella bronchiseptica, and its use to assess the impact of host immune functions. Although B. bronchiseptica transmits poorly between wild-type mice and mice lacking other immune components, it transmits efficiently between mice deficient in Toll-Like Receptor 4 (TLR4). TLR4-mutant mice were more susceptible to initial colonization, and poorly controlled pathogen growth and shedding. Heavy neutrophil infiltration distinguished TLR4-deficient responses, and neutrophil depletion did not affect respiratory CFU load, but decreased bacterial shedding. The effect of TLR4 response on transmission may explain the extensive variation in TLR4 agonist potency observed among closely related subspecies of Bordetella. This transmission model will enable mechanistic studies of how pathogens spread from one host to another, the defining feature of infectious disease. [ABSTRACT FROM AUTHOR]

Bordetella bronchiseptica infection causing atrophic rhinitis in pigs is reported from almost all countries. In the present study, occurrence of Bordetella infection in apparently healthy pigs was determined in 392 pigs sampled to collect 358 serum samples and 316 nasal swabs from Northern India by conventional bacterioscopy, detection of antigen with multiplex polymerase chain reaction (mPCR), and detection of antibodies with microagglutination test (MAT) and enzyme linked immune-sorbent assay (ELISA). Bordetella bronchiseptica could be isolated from six (1.92%) nasal swabs. Although isolates varied significantly in their antimicrobial sensitivity, they had similar plasmid profile. The genus specific and species specific amplicons were detected from 8.2% and 4.4% nasal swabs using mPCR with alc gene (genus specific) and fla gene and fim2 gene (species specific) primers, respectively. Observations revealed that there may be other bordetellae infecting pigs because about 50% of the samples positive using mPCR for genus specific amplicons failed to confirm presence of B. bronchiseptica. Of the pig sera tested with MAT and ELISA for Bordetella antibodies, 67.6% and 86.3% samples, respectively, were positive. For antigen detection mPCR was more sensitive than conventional bacterioscopy while for detection of antibodies neither of the two tests (MAT and ELISA) had specificity in relation to antigen detection. Study indicated high prevalence of infection in swine herds in Northern India. [ABSTRACT FROM AUTHOR]

Highlights: [•] We measured the protective capacities of OMVs derived from B. parapertussis (OMVsBpp). [•] We examined the cross protective capacities of OMVsBpp. [•] Cross protection against B. pertussis was observed. [•] Commercial aP vaccines offer little protection against B. parapertussis. [•] Vaccines containing OMVsBpp are safety. [Copyright &y& Elsevier]

Bordetella holmesii is an emerging opportunistic pathogen that causes respiratory disease in healthy individuals and invasive infections among patients lacking splenic function. We used 16S rRNA gene analysis to confirm B. holmesii as the cause of bacteremia in a child with sickle cell disease. Semiconductor-based draft genome sequencing provided insight into B. holmesii phylogeny and potential virulence mechanisms and also identified a toluene-4-monoxygenase locus unique among bordetellae. [ABSTRACT FROM AUTHOR]

Bordetella pertussis isolates that do not express pertactin (PRN) are increasing in regions where acellular pertussis vaccines have been used for >7 years. We analyzed data from France and compared clinical symptoms among infants <6 months old infected by PRN-positive or PRN-negative isolates. No major clinical differences were found between the 2 groups. [ABSTRACT FROM AUTHOR]

Clin Microbiol Infect 2012; 18: E340-E346 Abstract Bordetella pertussis and Bordetella parapertussis are closely related bacterial agents of whooping cough. Whole-cell pertussis (wP) vaccine was introduced in France in 1959. Acellular pertussis (aP) vaccine was introduced in 1998 as an adolescent booster and was rapidly generalized to the whole population, changing herd immunity by specifically targeting the virulence of the bacteria. We performed a temporal analysis of all French B. pertussis and B. parapertussis isolates collected since 2000 under aP vaccine pressure, using pulsed-field gel electrophoresis (PFGE), genotyping and detection of expression of virulence factors. Particular isolates were selected according to their different phenotype and PFGE type and their characteristics were analysed using the murine model of respiratory infection and in vitro cell cytotoxic assay. Since the introduction of the aP vaccines there has been a steady increase in the number of B. pertussis and B. parapertussis isolates collected that are lacking expression of pertactin. These isolates seem to be as virulent as those expressing all virulence factors according to animal and cellular models of infection. Whereas wP vaccine-induced immunity led to a monomorphic population of B. pertussis, aP vaccine-induced immunity enabled the number of circulating B. pertussis and B. parapertussis isolates not expressing virulence factors to increase, sustaining our previous hypothesis. [ABSTRACT FROM AUTHOR]

Background: Hemolytic uremic syndrome (HUS) has been associated with a number of infectious agents. We report here the case of an infant with severe Bordetella pertussis infection who developed HUS.Case diagnosis/treatment: A 2-month-old preterm male was admitted for severe Bordetella pertussis infection. Symptoms leading to a diagnosis of hemolytic uremic syndrome (HUS) rapidly appeared: hemolytic anemia, thrombocytopenia, and acute kidney injury. He was treated with 25 days of peritoneal dialysis and received complement-targeting therapy with eculizumab (five injections over 2 months), in addition to blood transfusions, antibiotics, and respiratory support. The outcome was favorable. The genetic workup found a complement factor H gene variant which has been associated with atypical HUS. This variant was located in the C3b-binding site and functional tests revealed that it perturbed the regulatory activity of factor H.Conclusion: This case suggests that pertussis is a strong trigger of HUS and that complement investigations are necessary to guide treatment and understand the pathophysiology. [ABSTRACT FROM AUTHOR]

Background: Pertussis has caused several outbreaks and concern worldwide. Despite high vaccination coverage, people of all ages are still affected with significant morbidity and mortality. We aimed to analyse all pertussis hospitalizations in Portugal to help to delineate preventive policies. Methods: Data were collected from a Portuguese administrative database, which contains all registered hospitalizations in mainland Portugal. Cases were identified using the ICD-9-CM code 033.x (whooping cough) as principal or secondary diagnosis, with hospital discharges between 2000 and 2015. Data were analysed by age groups. Results: Of 2281 hospitalizations, 94% occurred in infants (<1 year). The mean and median ages were 20 and 2 months, respectively. A seasonal pattern was observed, with higher number of hospitalizations during the winter for infants, and during the summer for other age groups. Higher hospitalization rates were registered in the Southern regions. The mean and median lengths of hospital stay were 8 and 6 days, respectively. The main complications were acute respiratory failure and pneumonia. Invasive or non-invasive ventilation, or both, was required in 2.4, 1.8 and 0.6% of hospitalized cases, respectively. The overall inpatient case fatality rate was 0.7%; 0.8, 11.5 and 17.4% for the age groups 0-1 months, 18-64 years and ≥65 years, respectively. Total hospitalization costs were estimated to be 2,698,995€. Conclusion: Our study emphasizes the need to adopt new preventive strategies mainly focused on infants, to reduce morbidity and costs of hospitalizations related to pertussis. [ABSTRACT FROM AUTHOR]

Despite high vaccine coverage, whooping cough caused by Bordetella pertussis remains one of the most common vaccine-preventable diseases worldwide. Introduction of whole-cell pertussis (wP) vaccines in the 1940s and acellular pertussis (aP) vaccines in 1990s reduced the mortality due to pertussis. Despite induction of both antibody and cell-mediated immune (CMI) responses by aP and wP vaccines, there has been resurgence of pertussis in many countries in recent years. Possible reasons hypothesised for resurgence have ranged from incompliance with the recommended vaccination programmes with the currently used aP vaccine to infection with a resurged clinical isolates characterised by mutations in the virulence factors, resulting in antigenic divergence with vaccine strain, and increased production of pertussis toxin, resulting in dampening of immune responses. While use of these vaccines provide varying degrees of protection against whooping cough, protection against infection and transmission appears to be less effective, warranting continuation of efforts in the development of an improved pertussis vaccine formulations capable of achieving this objective. Major approaches currently under evaluation for the development of an improved pertussis vaccine include identification of novel biofilm-associated antigens for incorporation in current aP vaccine formulations, development of live attenuated vaccines and discovery of novel non-toxic adjuvants capable of inducing both antibody and CMI. In this review, the potential roles of different accredited virulence factors, including novel biofilm-associated antigens, of B. pertussis in the evolution, formulation and delivery of improved pertussis vaccines, with potential to block the transmission of whooping cough in the community, are discussed. [ABSTRACT FROM AUTHOR]

Purpose: We aimed to determine the prevalence, symptoms and course of pertussis and parapertussis among patients at any age with a cough of unknown aetiology that had lasted for ≥ 7 days and to assess the diagnostic value of the symptoms included in the World Health Organisations’ (WHO) clinical case definition of pertussis.Methods: Patients were enrolled between the 23 April 2012 and 31 December 2014 at 25 general practitioner (GP) centres and three paediatric hospitals. Pertussis was confirmed by culture and/or polymerase chain reaction (PCR) and/or quantitative serology. Parapertussis was confirmed by culture and/or PCR.Results: Altogether, 549 patients were recruited. Of them, 22 (4.0%; 95% CI 2.5–6.0) had pertussis (predominately diagnosed by positive serology 17/22) and 7 (1.3%; 95% CI 0.5–2.6) had parapertussis. Patients with pertussis were more likely to have inspiratory whooping and posttussive emesis than those with a cough of another/unknown aetiology. However, the presence or absence of these two symptoms did not definitively confirm or exclude pertussis. The sensitivity and specificity of the WHO’s clinical definition was 0.77 and 0.38, respectively.Conclusions: The prevalence of pertussis and parapertussis among patients with a persistent cough of unknown aetiology in Estonia is low. As clinical symptoms alone cannot be used to distinguish pertussis, we recommend that laboratory testing for pertussis is performed in all patients with a persistent cough regardless of age. [ABSTRACT FROM AUTHOR]

Background. Natural infection with Bordetella pertussis is thought to result in 4-20 years of immunity against subsequent symptomatic pertussis infection. However, these estimates are based on studies in unvaccinated or whole-cell pertussis-vaccinated children. We conducted a population-based study of pertussis infection and reinfection during a 5-year period in California in an cohort vaccinated exclusively with acellular pertussis (aP) vaccine. Methods. California surveillance data were reviewed to identify all children with 2 reported incidents of pertussis with symptom onset between 1 January 2010 and 31 December 2015. Case investigation reports were reviewed, and children with ≥2 episodes of symptomatic pertussis infection that met the case definition were included. Results. Of 26 259 pertussis cases reported in children (aged <18 years), 27 children met the inclusion criteria. Recurrent cases occurred among children of all ages; 5 (19%) were <6 months of age at the time of their first illness. The time from initial infection to reinfection was <1 year in 11 (41%) cases. Twenty-one children (78%) had received ≥3 doses of diphtheria and tetanus toxoids and aP vaccine at the time of their first pertussis infection, 1 (4%) had received 1 dose, and 5 (19%) were unvaccinated. Conclusions. Recurrent cases of pertussis infection are extremely rare. Based on this surveillance data, approximately 0.1% of children who were infected with pertussis experienced a clinically significant second episode of pertussis within 4 years. More research is needed to understand the immune response to B. pertussis infection in children vaccinated with aP vaccines. [ABSTRACT FROM AUTHOR]

Background: The lack of animal models to experimentally study how infectious agents transmit between hosts limits our understanding of what makes some pathogens so contagious.Methods: We recently developed a Bordetella bronchiseptica mouse model to study transmission and have used it to assess, for the first time, which of several well-studied "virulence factors" common to classical Bordetella species contribute to transmission.Results: Among 13 mutants screened, a mutant lacking an extracellular polysaccharide (EPS) locus consistently failed to transmit. The loss of EPS had no obvious effect on in vitro characteristics of growth, adherence, cytotoxicity, or serum resistance, though it profoundly reduced the ability of the mutant to colonize the lower respiratory tract of mice. While wild-type B. bronchiseptica was shed from colonized mice and efficiently transmitted to cage-mates, the mutant colonized less efficiently, shed at lower numbers, and consequently did not transmit to naive animals.Conclusions: These results have important implications for potential roles of polysaccharides in the pathogenesis and transmission of Bordetella species as well as other respiratory pathogens. Cases of pertussis (whooping cough) caused by Bordetella pertussis are on the rise, and understanding factors that contribute to their spread is critical to its control. [ABSTRACT FROM AUTHOR]