Does this coughing adolescent or adult patient have pertussis?

Real-Life Insights into Pertussis Diagnosis: High Yield of PCR Testing and Clinical Outcomes-An Emerging Old Enemy or Just a Sign of PCR Times?

Background/Objectives: Pertussis remains a significant public health concern despite effective vaccines due to diagnostic challenges and symptom overlap with other respiratory infections. This study assesses the prevalence of Bordetella pertussis using advanced polymerase chain reaction (PCR) testing and examines the clinical outcomes over a one-month follow-up. Methods: We conducted a cross-sectional study at the University Hospital of Larissa, Greece, from April to June 2024, collecting 532 nasopharyngeal swabs from patients with respiratory symptoms. Diagnostic testing utilized the BioFire® Respiratory 2.1 Plus Panel. Demographics, clinical presentations, vaccination histories, and clinical outcomes were systematically recorded and analyzed. Results: Of 532 patients, 47 (8.8%) were diagnosed with pertussis. The mean age was 61.87 ± 13.4 years; 57.4% were female. Only 12.8% had contact with known pertussis patients. Regarding vaccination history, 36.2% had received diphtheria, tetanus, and pertussis vaccines, with the last dose administered an average of 46 years prior to this study. The primary symptom was cough (100%), with additional symptoms including fever (36.2%) and paroxysmal cough (34%). Six patients (12.8%) required hospitalization due to pneumonia and severe respiratory failure. All patients received successful treatment; however, 23.4% reported persistent post-infectious cough at the one-month follow-up. Conclusions: PCR testing significantly improved the diagnosis of pertussis among adults presenting with respiratory symptoms. The findings highlight the need for updated vaccination strategies and improved diagnostic protocols to effectively manage pertussis and reduce its public health impact.

Burden of whooping cough in China (PertussisChina): study protocol of a prospective, population-based case-control study

INTRODUCTION

Pertussis is one of the top 10 diseases of children under 10 years of age, and the few vaccine-preventable diseases who is on a rise in China in recent years; however, the true burden of pertussis, including age-stratified incidence and risk factors of severe sequelae, are under-recognised. We aim to estimate the health burden of laboratory-confirmed pertussis by age groups, considering the setting of illness onset (ie, in community, outpatient and inpatient), in a Chinese population (~2.23 million in total) at two sites.

METHODS AND ANALYSIS

This paper describes the study design of a 1-year, prospective, age-stratified and population-based case-control study, including site selection, study population, case registry, ascertainment and enrolment, control recruitment, follow-up of case, microbiological methods, data collection, quality control activities and statistical methods used to generate incidence estimates. During June 2021 through May 2022, registry of suspected pertussis cases (namely chronic/persistent cough) will be conducted in several participating hospitals (SHs) at the two sites, which are selected based on Healthcare Utilisation and Attitudes Surveys (HUAS) carried out before study initiation. A case-control study will be conducted in the SHs and we aim to enrol a total of 1000 suspected pertussis cases (ie, all hospital admissions and the first 1-3 outpatient visits each week each hospital) and 2000 frequency matched healthy controls in community. Our primary study outcome, the laboratory-confirmed Bordetella pertussis infection, will be determined by a comprehensive laboratory methods and procedures (ie, culture, PCR and serological tests) in both cases and controls at enrolment and during 60-day's follow-up visits. Finally, data from HUAS (ie, population size), case registry (ie, the total number of suspected pertussis cases) and case-control study (ie, the prevalence or population attributable fraction of Bordetella pertussis) will be combined to calculate incidence and its 95% CI through bootstrap method. Epidemiological analyses will be conducted to determine the risk factors associated with severe sequelae of pertussis.

ETHICS AND DISSEMINATION

This study has been approved by Chinese Centre for Disease Control and Prevention's Institutional Review Board (no. ICDC-202110). Results will be disseminated via academic presentations and publication in peer-reviewed journals, and will provide valuable scientific data and some new insights into the incidence, aetiology and risk factors for severe sequelae of pertussis to academic societies and the public health authorities who is currently struggling and fighting against this burdensome disease worldwide.

A Symptom-Directed Paradigm for the Evaluation and Management of Upper Respiratory Tract Infections

Upper respiratory tract infections are one of the most common challenges in ambulatory medicine. Effective evaluation involves identification, primarily through the history, of the dominant set of patient symptoms leading to accurate diagnosis. Certain more morbid illnesses that mimic common upper respiratory symptoms can also be excluded with this approach. Treatment should address patient preferences through an understanding of the limited utility of antibiotics and through tailored advisement of the numerous pharmacologic options for symptom relief.

Immunological Distinctions between Acellular and Whole-Cell Pertussis Immunizations of Baboons Persist for at Least One Year after Acellular Vaccine Boosting

While both whole-cell (wP) and acellular pertussis (aP) vaccines have been highly effective at reducing the global pertussis disease burden, there are concerns that compared to wP vaccination, the immune responses to aP vaccination may wane more rapidly. To gain insights into the vaccine elicited immune responses, pre-adult baboons were immunized with either aP or wP vaccines, boosted with an aP vaccine, and observed over a nearly two-year period. Priming with a wP vaccine elicited a more Th17-biased response than priming with aP, whereas priming with an aP vaccine led to a more Th2-biased response than priming with wP. These differences were maintained after aP vaccine boost immunizations. Compared to aP, animals primed with a wP vaccine exhibited greater numbers of pertussis specific memory B cells. While aP and wP vaccine priming initially elicited similar levels of anti-pertussis toxin antibody, titers declined more rapidly in aP vaccine primed animals leading to a 4-fold difference. Both wP and aP vaccine immunization could induce serum bactericidal activity (SBA); however, only one wP vaccine immunization was required to elicit SBA while multiple aP vaccine immunizations were required to elicit lower, less durable SBA titers. In conclusion, when compared to aP vaccine, priming with wP vaccine elicits distinct cellular and humoral immune responses that persist after aP vaccine boosting.

A profile of the Simplexa™ Bordetella Direct assay for the detection and differentiation of Bordetella pertussis and Bordetella parapertussis in nasopharyngeal swabs

INTRODUCTION

Pertussis is a highly contagious respiratory infection caused by Bordetella pertussis and to minor extent B. parapertussis. Despite high vaccination coverage, epidemics persist worldwide. Laboratory testing with the capacity to support increasing demand and generate fast and accurate results is needed to promptly provide treatment to mitigate symptoms, prevent transmission, and thus impact infection control and disease surveillance.

AREAS COVERED

This review will describe the features of the Simplexa™ Bordetella Direct Assay and compare this technology with other existing assays. Unmet needs and future directions will be discussed.

EXPERT COMMENTARY

Resurgence of pertussis highlights the importance of reliable and accurate diagnosis. The Simplexa™ Bordetella Direct Assay provides an easy workflow, reduced hand-on time, less risk of contamination, and rapid turnaround time. The use of efficient molecular assays in routine clinical laboratory is valuable for increasing demand, improvement of infection control, and surveillance.

Diagnostic limitations of clinical case definitions of pertussis in infants and children with severe lower respiratory tract infection

INTRODUCTION

Diagnosis of pertussis is challenging especially in infants. Most low and middle-income countries (LMIC) lack resources for laboratory confirmation, relying largely on clinical diagnosis alone for both case management and surveillance. This necessitates robust clinical case definitions.

OBJECTIVES

This study assesses the accuracy of clinical case definitions with and without lymphocytosis in diagnosing pertussis in children with severe lower respiratory tract infection (LRTI) in a LMIC setting.

METHODS

Children hospitalized with severe LRTI in a South African hospital were prospectively enrolled and evaluated for pertussis using PCR on respiratory samples. Clinical signs and differential white cell counts were recorded. Sensitivity and specificity of pertussis clinical diagnosis using WHO and Global Pertussis Initiative (GPI) criteria; and with addition of lymphocytosis were assessed with PCR as the reference standard.

RESULTS

458 children <10 years were enrolled. Bordetella pertussis infection was confirmed in 32 (7.0%). For WHO criteria, sensitivity was 78.1% (95% CI 60.7-89.2%) and specificity 15.5% (95% CI 12.4-19.3%); for GPI sensitivity was 34.4% (95% CI 20.1-52.1) and specificity 64.8% (95% CI 60.1-69.2%). Area under the curve (AUC) on receiver operating character (ROC) analysis was 0.58 (95% CI 0.46-0.70 for WHO criteria, and 0.72 (95% CI 0.56-0.88) for GPI with highest likelihood ratios of 5.33 and 4.42 respectively. Diagnostic accuracy was highest between five and seven days of symptoms for both criteria. Lymphocytosis had sensitivity of 31.3% (95% CI 17.5-49.3%) and specificity of 70.7% (95% CI 66.1-74.8%) and showed a marginal impact on improving clinical criteria.

CONCLUSION

Clinical criteria lack accuracy for diagnosis and surveillance of pertussis. Non-outbreak settings should consider shorter durations in clinical criteria. New recommendations still fall short of what is required for a viable clinical screening test which means the need to improve access to laboratory diagnostic support remains crucial.

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.

Clinical Findings and Management of Pertussis

Pertussis is an endemic highly infectious vaccine-preventable disease. The disease is a major cause of childhood morbidity and mortality. In the most recent years, the re-emergence of pertussis occurred, and many efforts were done to identify the possible causes. Certainly, more effective laboratory methods have a role in making the diagnosis easier. However, sub-optimal efficacy of available vaccines as well as their limited duration of protection could explain the resurgence of the disease. Many forms and clinical features of the disease, ranging from the most classical to atypical and very nuanced forms, have been reported. There are many aspects that influence the clinical features of the pathology, such as a previous immunization or infection, patient's age, gender and antibiotic treatment. A prompt suspect and a rapid diagnosis of pertussis is fundamental for an appropriate clinical management and for preventing pertussis complications, especially in children. However, under a clinical point of view, pertussis is often difficult to be diagnosed. A prompt treatment may decrease the duration and severity of cough; the cornerstone drugs are the macrolides. Although prompt diagnosis and effective therapy are important for pertussis control, only with a broad vaccination coverage will be possible to reduce circulation of Bordetella pertussis.

Acute Illness in the Athlete

Athletes are susceptible to many acute illnesses that can interfere with their ability to train and compete as well as potentially affecting teammates and coaching staff. A solid understanding of the preventive measures, diagnosis, and management of such diseases is paramount in the care of an athletic population.

The effectiveness and safety of pertussis booster vaccination for adolescents and adults: A systematic review and meta-analysis

BACKGROUND

Due to the resurgence of pertussis, many countries have revised the pertussis immunization schedules and recommended booster doses of pertussis component vaccine for adolescents and adults. Here we aim to investigate the effectiveness and safety of pertussis component vaccines in adolescents and adults.

METHODS

Based on a prospectively registered protocol, we reviewed the literature and selected trials in adolescents and adults using pertussis component vaccine. We followed Cochrane and GRADE (Grading of Recommendations, Assessment, Development and Evaluation) guidance to assess risk of bias, quality of evidence and to perform meta-analyses.

RESULTS

A total of 17 clinical trials were included. At post-vaccination with pertussis component vaccine, the vaccine protective rate of pertussis reached 88.89%, the vaccine response rate of pertussis antibodies in most trials were above 85%, and the antibody titers at post-vaccination were higher than at pre-vaccination. Reduced-antigen-content diphtheria-tetanus-acellular pertussis vaccine was associated with significantly higher incidences of nausea [RR = 1.26, 95%CI:1.01, 1.57] and vomiting [RR = 2.08, 95%CI:1.21, 3.58] in acellular pertussis vaccines combined with tetanus and diphtheria (Tdap) group than diphtheria tetanus-toxoid vaccines (Td) group. Higher dose of diphtheria toxoid and adjuvant in dTap might cause higher incidence of fever.

CONCLUSIONS

Except for significant difference in gastrointestinal reaction (nausea, vomiting), acellular pertussis component vaccines are quite safe and has short-term effectiveness for the adolescents and adults. The adverse event of acellular pertussis component vaccine is similar to or safer than that of placebo or other vaccines without pertussis component.

Acute exacerbation of idiopathic pulmonary fibrosis induced by pertussis: the first case report

BACKGROUND

Acute exacerbation of idiopathic pulmonary fibrosis (AE-IPF) is a severe condition with limited treatment strategies. Although respiratory infection is a major cause of AE-IPF, no reports have indicated pertussis infection as a cause. Here we report two cases of pertussis infection-induced AE-IPF.

CASE PRESENTATION

Both patients presented with a chief complaint of acute respiratory distress and were previously diagnosed with idiopathic pulmonary fibrosis (IPF). Neither patient had received any pertussis vaccination since adolescence. Both patients were diagnosed with AE-IPF accompanying acute pertussis infection based on chest computed tomography and serum pertussis toxin antibody > 100 EU/mL. Both patients were treated with macrolide antibiotics and systemic corticosteroids. Both patients were able to be discharged and return home.

CONCLUSIONS

The presence of pertussis infection in AE-IPF can present a diagnostic challenge, as coughing accompanying pertussis may be difficult to distinguish from IPF-associated coughing. Pertussis infection should be assayed in AE-IPF patients. Since pertussis can be prevented with vaccination and is expected to be affected by antibiotics, consideration of pertussis infection as a causative virulent factor of AE-IPF may be important for management of subjects with IPF.

Prevention of pertussis: An unresolved problem

Pertussis is a highly contagious respiratory disease caused by Bordetella pertussis. However, after the introduction of the whole-cell pertussis vaccine (wP), the annual incidence rates of the disease progressively declined. Despite this result, the inclusion of wP in the national immunization schedule of infants and young children was debated regarding its safety. Several efforts to produce vaccines based on B. pertussis components capable of evoking protective immunity with no or limited adverse events were made. Of these others, five pertussis antigens were considered possible components of acellular vaccines (aPs): pertussis toxin (PT), filamentous haemagglutinin (FHA), pertactin (PRN) and fimbria proteins 2 and 3. However, the introduction of aPs was followed by a slight but progressive increase in the incidence of pertussis. This paper discusses the potential reasons for reduced aPs efficacy. Moreover, it attempts to evaluate the real effectiveness of aPs and the potential differences between available preparations. Data analysis showed that several boosters are needed to maintain protection against pertussis and additional studies are needed to confirm the antigens that should be included in aPs to improve the prevention of pertussis.

Clinical Characteristics of Pertussis-Associated Cough in Adults and Children: A Diagnostic Systematic Review and Meta-Analysis

BACKGROUND

Pertussis (whooping cough) is a highly infective cause of cough that causes significant morbidity and mortality. Existing case definitions include paroxysmal cough, whooping, and posttussive vomiting, but diagnosis can be difficult. We determined the diagnostic accuracy of clinical characteristics of pertussis-associated cough.

METHODS

We systematically searched CINAHL, Embase, Medline, and SCI-EXPANDED/CPCI-S up to June 2016. Eligible studies compared clinical characteristics in those positive and negative for Bordetella pertussis infection, confirmed by laboratory investigations. Two authors independently completed screening, data extraction, and quality and bias assessments. For each characteristic, RevMan was used to produce descriptive forest plots. The bivariate meta-analysis method was used to generate pooled estimates of sensitivity and specificity.

RESULTS

Of 1,969 identified papers, 53 were included. Forty-one clinical characteristics were assessed for diagnostic accuracy. In adult patients, paroxysmal cough and absence of fever have a high sensitivity (93.2% [CI, 83.2-97.4] and 81.8% [CI, 72.2-88.7], respectively) and low specificity (20.6% [CI, 14.7-28.1] and 18.8% [CI, 8.1-37.9]), whereas posttussive vomiting and whooping have low sensitivity (32.5% [CI, 24.5-41.6] and 29.8% [CI, 8.0-45.2]) and high specificity (77.7% [CI, 73.1-81.7] and 79.5% [CI, 69.4-86.9]). Posttussive vomiting in children is moderately sensitive (60.0% [CI, 40.3-77.0]) and specific (66.0% [CI, 52.5-77.3]).

CONCLUSIONS

In adult patients, the presence of whooping or posttussive vomiting should rule in a possible diagnosis of pertussis, whereas the lack of a paroxysmal cough or the presence of fever should rule it out. In children, posttussive vomiting is much less helpful as a clinical diagnostic test.

Use of a 40-day rolling incidence to monitor pertussis in Nova Scotia, 2015

Background

Pertussis can cause a serious respiratory bacterial infection, especially in infants. Between January 1 and December 31, 2015, there was an increase in the number of reported pertussis cases in Nova Scotia (NS). Surveillance practices for pertussis in NS were challenging because immunization coverage data are not available and rate information was neither timely nor precise with respect to geography. Public health officials in NS decided to adopt a new surveillance technique to inform public health actions across the Province.

Objective

To assess the use of a 40-day rolling incidence rate to monitor pertussis activity in Nova Scotia.

Intervention

A 40-day rolling incidence rate was calculated for pertussis by age groups and various levels of geography. Public health authorities continued to anticipate new cases of pertussis if the contacts of known cases were still within the incubation period (range between six and 20 days). The 40-day incubation period was chosen to reflect twice the incubation period's upper range. Rates were calculated using Statistics Canada population projections for 2014 and then compared with traditional case counts and cumulative incidences. The usefulness of the statistics was assessed by public health decision makers.

Outcomes

Increased pertussis activity was noted across NS, most notably in the South West region. The use of a 40-day rolling incidence rate as a surveillance tool provided more timely and geographically precise descriptions of ongoing trends in pertussis activity and helped to inform appropriate public health action. Health officials valued the information provided from the rolling incidence because it allowed them to manage activities based on weekly estimates at various levels of geography.

Conclusion

Rolling incidence proved to be a useful tool to monitor a cyclical increase in pertussis cases in Nova Scotia and to inform related public health actions. The rolling incidence provided geographically precise and timely information that was useful to estimate new cases in the absence of reliable immunization coverage information. This method could supplement traditional epidemiological surveillance of future communicable disease events, especially those characterized by long incubation periods and low case counts.

Prevalence of Atypical Pathogens in Patients With Cough and Community-Acquired Pneumonia: A Meta-Analysis

PURPOSE

Community-acquired pneumonia (CAP), acute cough, bronchitis, and lower respiratory tract infections (LRTI) are often caused by infections with viruses or Streptococcus pneumoniae. The prevalence of atypical pathogens Mycoplasma pneumoniae, Chlamydophila pneumoniae, Legionella pneumophila, and Bordetella pertussis among patients with these illnesses in the ambulatory setting has not been previously summarized. We set out to derive prevalence information from the existing literature.

METHODS

We performed a systematic review of MEDLINE for prospective, consecutive-series studies reporting the prevalence of M pneumoniae, C pneumoniae, L pneumophila and/or B pertussis in outpatients with cough, acute bronchitis, LRTI, or CAP. Articles were independently reviewed by 2 authors for inclusion and abstraction of data; discrepancies were resolved by consensus discussion. A meta-analysis was performed on each pathogen to calculate the pooled prevalence estimates using a random effects model of raw proportions.

RESULTS

Fifty studies met our inclusion criteria. While calculated heterogeneity was high, most studies reported prevalence for each pathogen within a fairly narrow range. In patients with CAP, the overall prevalences of M pneumoniae and C pneumoniae were 10.1% (95% CI, 7.1%-13.1%) and 3.5% (95% CI, 2.2%-4.9%), respectively. Consistent with previous reports, M pneumoniae prevalence peaked in roughly 6-year intervals. Overall prevalence of L pneumophila was 2.7% (95% CI, 2.0%-3.4%), but the organism was rare in children, with only 1 case in 1,765. In patients with prolonged cough in primary care, the prevalence of B pertussis was 12.4% (95% CI, 4.9%-19.8%), although it was higher in studies that included only children (17.6%; 95% CI, 3.4%-31.8%).

CONCLUSIONS

Atypical bacterial pathogens are relatively common causes of lower respiratory diseases, including cough, bronchitis, and CAP. Where surveillance data were available, we found higher prevalences in studies where all patients are tested for these pathogens. It is likely that these conditions are underreported, underdiagnosed, and undertreated in current clinical practice.

Underdetection and underreporting of pertussis in children attended in primary health care centers: Do surveillance systems require improvement?

BACKGROUND

Pertussis is an underestimated disease. Several European countries have developed models to account for underreporting of pertussis. The aim of this study was to estimate pertussis underdetection and underreporting in pediatric patients attending primary health care centers (PHCCs).

METHODS

We reviewed clinical records of PHCCs in Barcelona in 2012. Factors associated with underdetection and underreporting were analyzed by logistic regression. Adjusted odds ratios (aORs) and 95% confidence intervals (95% CIs) were calculated.

RESULTS

We included 3,505 children aged < 7 years (mean age, 34  ±  20.7 months; range, 0-82 months) presenting with cough; 9.3% (326 out of 3,505) of patients also had ≥ 1 symptoms related to pertussis accompanied by cough for a duration ≥ 2 weeks. Of the 326 children receiving clinical criteria, only 31 (9.5%) were laboratory-confirmed and 6 (1.8%) were detected but not reported. There were 295 (90.5%) undetected suspected pertussis cases. Age ≥ 18 months (aOR, 8.51; 95% CI, 1.82-39.86), cyanosis (aOR, 6.71; 95% CI, 1.43-31.39), request for chest radiograph (aOR, 0.26; 95% CI, 0.07-0.99), and request for other laboratory tests (aOR, 5.39; 95% CI, 2.19-13.27) were associated with underdetection. Paroxysmal cough (aOR, 5.77; 95% CI, 1.05-31.76) and request for other laboratory tests (aOR, 2.91; 95% CI, 1.11-7.62) were associated with underreporting.

CONCLUSIONS

Both underdetection and underreporting complicate the understanding of pertussis epidemiology. Correct assessment of pertussis symptoms and notification of cases must be improved to control pertussis.

A Case of Pertussis: What Emergency Health Care Providers Need to Know

Pertussis is a highly contagious acute respiratory illness. Prior to the availability of the whole-cell pertussis vaccine in the late 1940s, pertussis was one of the most common infectious diseases of childhood in the United States and a major cause of infant morbidity and mortality. Although pertussis vaccination has resulted in a substantial reduction in the disease, the incidence has been steadily increasing since the 1990s. The clinical presentation of pertussis may be variable depending on the age and immunization status of the patient. The classic presentation includes a triad of symptoms: paroxysms of coughing; an inspiratory whoop following cough; and posttussive vomiting. Those most vulnerable are the ones not yet immunized and the ones most likely to transmit the illness who may not exhibit "classic" pertussis symptoms, delaying or preventing identification and treatment. Because pertussis carries known morbidity and mortality risks, prevention and early identification are paramount.

[Recent progress in clinical research on pertussis]

Pertussis is a highly contagious respiratory disease. Despite the high vaccination coverage, re-emergence of pertussis has been reported in many countries over the past two decades. With the increase in the incidence of pertussis, there has been a shift in the epidemiological features: an increased incidence of pertussis has been noted in older children and adults, who normally lack typical clinical manifestations, and who may be easily missed according to current diagnostic references for pertussis. In order to achieve better prevention and treatment of pertussis, this review article summarized the recent research progress in the epidemiology, clinical features, etiology, diagnosis, treatment, and prevention of pertussis, particularly focusing on the diagnosis of pertussis in older children and adults.

Pertussis: Microbiology, Disease, Treatment, and Prevention

Pertussis is a severe respiratory infection caused by Bordetella pertussis, and in 2008, pertussis was associated with an estimated 16 million cases and 195,000 deaths globally. Sizeable outbreaks of pertussis have been reported over the past 5 years, and disease reemergence has been the focus of international attention to develop a deeper understanding of pathogen virulence and genetic evolution of B. pertussis strains. During the past 20 years, the scientific community has recognized pertussis among adults as well as infants and children. Increased recognition that older children and adolescents are at risk for disease and may transmit B. pertussis to younger siblings has underscored the need to better understand the role of innate, humoral, and cell-mediated immunity, including the role of waning immunity. Although recognition of adult pertussis has increased in tandem with a better understanding of B. pertussis pathogenesis, pertussis in neonates and adults can manifest with atypical clinical presentations. Such disease patterns make pertussis recognition difficult and lead to delays in treatment. Ongoing research using newer tools for molecular analysis holds promise for improved understanding of pertussis epidemiology, bacterial pathogenesis, bioinformatics, and immunology. Together, these advances provide a foundation for the development of new-generation diagnostics, therapeutics, and vaccines.

Immunization against pertussis in adolescents and adults

Pertussis is a highly contagious infectious disease caused by Bordetella pertussis that can be extremely serious, particularly in young infants. For many years the efforts of health authorities throughout the world to prevent pertussis had the main goals of reducing the morbidity of infants and children under 5 years of age, maintaining protection for several years during the school-age period and developing a significant herd immunity to directly and indirectly reduce the risk of the spread of the disease among young infants and the risk of transmission of the infection from preschool children to infants. However, the increased risk of B. pertussis infection among adolescents and adults due to the waning immunity to this bacterium induced by vaccines and natural infection seems to be the main reason for the resurgence of pertussis. We discuss the reasons for the administration of pertussis vaccines to individuals for whom they were previously not recommended, the expected results of the administration of additional pertussis vaccine doses and the differences in the administration of pertussis vaccines in different countries. An analysis of the literature revealed several reports indicating the need for the modification of immunization schedules against pertussis, with booster doses among adolescents and the need for the vaccination of pregnant women. However, to monitor the true epidemiology of pertussis, effective programmes to collect pertussis cases, adequate reporting systems and vaccination coverage monitoring should be urgently implemented.

Protecting Newborns Against Pertussis: Treatment and Prevention Strategies

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.

Pertussis Prevalence in Korean Adolescents and Adults with Persistent Cough

We investigated the prevalence of pertussis in Korean adolescents and adults with persistent cough. Study population was adolescents (aged 11-20 yr) and adults (≥ 21 yr old) who showed persistent cough of 1-8 weeks' duration. Pertussis was diagnosed by culture, polymerase chain reaction (PCR), and serology. A total of 310 subjects participated in this study, and 76 cases (24.5%) met the criteria for laboratory-confirmed pertussis. The majority of the pertussis cases (66/76) were confirmed by serology, while 3 cases (1.0%) were diagnosed with culture, and 10 cases (3.2%) were detected with PCR. Of the 76 subjects diagnosed with pertussis, 20/86 cases were adolescents and 56/224 cases were adults. Neither adolescents nor adults received adolescent-adult booster against pertussis within the previous 5 yr. Pertussis can be a primary cause of persistent cough in Korean adolescents and adults.

Vaccination in the elderly: what can be recommended?

The age-associated increased susceptibility to infectious disease would suggest that vaccination should be a route to promote healthy aging and keep our seniors autonomous and independent. While vaccination represents a cost-effective and efficient strategy at community level, the ability of the immune system to mount a protective immune response is still unpredictable at the level of the individual. Thus, at a similar age, some individuals, including the elderly, might still be 'good' responders while some other, even younger, would definitely fail to mount a protective response. In this review, the current burden of vaccine-preventable diseases in the aging and aged population will be detailed with the aim to identify the ideal vaccine candidates over the age of 50 years. This article will conclude with potential strategies to reduce, as best as possible, this burden and the imperative need to overcome barriers in extending current vaccine coverage towards to a lifelong vaccine schedule.

Using the Health Belief Model to develop educational strategies to improve pertussis vaccination rates among preschool staff

The number of pertussis or "whooping cough" cases has steadily increased in the United States in the last 20 years. Many of the cases are adults who have not kept up with current vaccination recommendations. Adults are unknowingly exposing susceptible infants and unvaccinated children to this potentially deadly disease. Pertussis can spread rapidly, especially in household, daycare, and school settings. This pilot study examines how school nurses can be instrumental in improving staff immunization rates for pertussis by using the Health Belief Model as a framework for educational strategies.

Epidemiology of pertussis in adolescents and adults in Turkey

Two hundred and fourteen patients who had a cough illness lasting at least 2 weeks were studied to investigate Bordetella pertussis as a cause of prolonged cough in adolescents and adults. Medical history and nasopharyngeal swab specimens for culture and polymerase chain reaction (PCR) were obtained at presentation. Three (1·4%) patients were B. pertussis culture-positive; 15 (7%) were B. pertussis PCR-positive (including the culture-positive patients) and 11 (5·1%) were Bordetella spp. PCR-positive. Symptom combinations were significantly high both in patients with pertussis and patients with indeterminate results (P < 0·05). We conclude that B. pertussis should be considered among differential diagnoses of prolonged cough in adolescents and adults and PCR and culture should be used to detect these cases and facilitate public health response.

Evaluation of reported cases of pertussis: epidemiological study in a large city in Spain

We retrospectively analysed the incidence rate of reported cases of pertussis in Barcelona during 2009–2012 according to age, sex, type of medical centre and vaccination status. We included 748 confirmed or suspected cases, 613 (82.0 %) of which were confirmed by laboratory testing and the remaining 135 (18.0 %) by epidemiological evidence. The highest reported incidence of pertussis was amongst <1 year olds [96.1 per 100 000 person-years, 95 % confidence interval (CI): 84.3–109.1]. The majority of confirmed and suspected cases were reported in 2011 and 2012, and the total incidence (confirmed or suspected) was 6.3 (95 % CI: 5.6–6.9) and 4.2 (95 % CI: 3.6–4.7) per 100 000 person-years, respectively. Incidence increased significantly (P = 0.001) in 2011–2012 compared with 2009. Most confirmed cases occurred in children <1 year old (87.9 %). Cases were confirmed by real-time (RT)-PCR (87.5 %; 95 % CI: 81.3–87.6) and bacterial culture (13.7 %; 95 % CI: 11.0–17.1). We recommend performing RT-PCR in suspected cases with no epidemiological link to a confirmed case.

[Incidence and severity of pertussis in infants with a respiratory syncytial virus infection]

INTRODUCTION

Pertussis is a re-emerging disease that mostly affects infants. At this age, the severity can be affected by intercurrent infections such as respiratory syncytial virus (RSV).

OBJECTIVES

To estimate the incidence of RSV infection during an epidemic period in patients hospitalized due to pertussis. The impact on the severity was also observed during hospitalization.

PATIENTS AND METHOD

A descriptive study of cases diagnosed with pertussis admitted to a tertiary hospital over a 3year period, where the presence of co-infection with RSV was analyzed. The estimate of severity was estimated using the incidence of complications and the level of care required.

RESULTS

From a total of 73 infants with pertussis, 34 occurred in a bronchiolitis season epidemic. A co-infection due to RSV was detected in 17 patients. The mean age was not significantly different compared to the non co-infected. The mean stay and the need for intensive care was similar in both groups. The need for oxygen therapy care and nutritional support was higher in the coinfected patients.

CONCLUSIONS

Coinfection with RSV in infants hospitalized with pertussis occurred in ono in 2 patients during a RSV epidemic season, in infants of similar age. Severity in terms of stay, presence of apnea and admission to intensive care was similar, but more need for respiratory care and nutritional support was found.

Whooping cough in 2014 and beyond: an update and review

Pertussis, or whooping cough, has had a dramatic resurgence in the past several years and is the most common vaccine-preventable disease in the world. The year 2012 marked the most cases in the United States in &gt; 50 years. Large outbreaks have occurred in multiple states, and infant deaths have drawn the attention of not only health-care providers but also the media. Although the disease is theoretically preventable by vaccination, it remains a challenge to control. New vaccination strategies have been implemented across different age groups and populations of patients, but vaccine coverage remains dismally low. Acellular vaccines, although safe, do not afford the same long-lasting immunity as the previously used whole-cell vaccine. Ultimately, improvements in the development of vaccines and in vaccination coverage will be essential to decrease the burden of pertussis on society. This article provides a review of pertussis infection and discusses advances related to the epidemiology, diagnosis, treatment, and prevention of infection, as well as continued areas of uncertainty.

Diagnosis and laryngeal complications of Bordatella pertussis infection in the ambulatory adult population

Bordatella pertussis infection leads to a chronic, debilitating, and paroxysmal cough that can last for months to years. Incidence of B pertussis in the immunized adult population is rising nationwide, but many otolaryngologists are unfamiliar with the diagnosis and management of this disease. Adults often present late in the disease process when traditional diagnostic testing is ineffective and without the classic pediatric symptoms of whooping cough. As a result, B pertussis infections in adults are often overlooked or misdiagnosed as asthma exacerbations or viral bronchitis, leading to increased morbidity, unnecessary testing, and additional exposure of vulnerable populations to the pathogen. This commentary describes 3 adult cases of B pertussis confirmed with serum testing in the ambulatory population and describes varied presentations based on time from initial infection. Specific emphasis is presented on the physical manifestations of the disease in laryngeal structures, methods of diagnosis, and recommendations for treatment.

Whooping cough in school age children presenting with persistent cough in UK primary care after introduction of the preschool pertussis booster vaccination: prospective cohort study

OBJECTIVE

To estimate the prevalence and clinical severity of whooping cough (pertussis) in school age children presenting with persistent cough in primary care since the introduction and implementation of the preschool pertussis booster vaccination.

DESIGN

Prospective cohort study (November 2010 to December 2012).

SETTING

General practices in Thames Valley, UK.

PARTICIPANTS

279 children aged 5 to 15 years who presented in primary care with a persistent cough of two to eight weeks' duration. Exclusion criteria were cough likely to be caused by a serious underlying medical condition, known immunodeficiency or immunocompromise, participation in another clinical research study, and preschool pertussis booster vaccination received less than one year previously.

MAIN OUTCOME MEASURES

Evidence of recent pertussis infection based on an oral fluid anti-pertussis toxin IgG titre of at least 70 arbitrary units. Cough frequency was measured in six children with laboratory confirmed pertussis.

RESULTS

56 (20%, 95% confidence interval 16% to 25%) children had evidence of recent pertussis infection, including 39 (18%, 13% to 24%) of 215 children who had been fully vaccinated. The risk of pertussis was more than three times higher (21/53; 40%, 26% to 54%) in children who had received the preschool pertussis booster vaccination seven years or more previously than in those who had received it less than seven years previously (20/171; 12%, 7% to 17%). The risk of pertussis was similar between children who received five and three component preschool pertussis booster vaccines (risk ratio for five component vaccine 1.14, 0.64 to 2.03). Four of six children in whom cough frequency was measured coughed more than 400 times in 24 hours.

CONCLUSIONS

Pertussis can still be found in a fifth of school age children who present in primary care with persistent cough and can cause clinically significant cough in fully vaccinated children. These findings will help to inform consideration of the need for an adolescent pertussis booster vaccination in the United Kingdom.

STUDY REGISTRATION

UK Clinical Research Network portfolio ID 8361.

The diagnosis and treatment of acute cough in adults

BACKGROUND

Cough is the most common complaint for which patients visit their primary care physician, being present in about 8% of consultations. A profusion of new evidence has made it necessary to produce a comprehensively updated version of the guideline on cough of the German College of General Practitioners and Family Physicians (Deutsche Gesellschaft für Allgemeinmedizin und Familienmedizin, DEGAM), which was last issued in 2008.

METHOD

The interdisciplinary evidence and consensus based S3 guideline on cough of the DEGAM was updated on the basis of a systematic review of the relevant literature published from 2003 to July 2012 (MEDLINE, Cochrane Library, EMBASE, Web of Science). Evidence levels were assessed and consensus procedures were followed as prescribed by AWMF standards, with the participation of 7 medical societies.

RESULTS

182 publications were used to update the guideline, including 45 systematic reviews (26 of which included a meta-analysis) and 17 randomized controlled trials (RCTs). 11 recommendations for acute cough were approved by consensus in a nominal group process. The history and physical examination are the basis of diagnostic evaluation. When the clinical diagnosis is that of an acute, uncomplicated bronchitis, no laboratory tests, sputum evaluation, or chest x-rays should be performed, and antibiotics should not be given. There is inadequate evidence for the efficacy of antitussive or expectorant drugs against acute cough. The state of the evidence for phytotherapeutic agents is heterogeneous. Persons with community-acquired pneumonia should receive empirical antibiotic treatment for 5 to 7 days; specific risk factors can influence the choice of drug to be used. It is recommended that laboratory tests should not be performed and neuraminidase inhibitors should not be given in the routine management of influenza.

CONCLUSION

A specifically intended effect of these recommendations is to reduce the use of antibiotics to treat colds and acute bronchitis, for which they are not indicated. Further clinical trials of treatments for cough should be performed in order to extend the evidence base, which is now fragmentary.

Role of feedback and network architecture in controlling virulence gene expression in Bordetella

Bordetella is a Gram-negative bacterium responsible for causing whooping cough in a broad range of host organisms. For successful infection, Bordetella controls expression of four distinct classes of genes (referred to as class 1, 2, 3, and 4 genes) at distinct times in the infection cycle. This control is executed by a single two-component system, BvgAS. Interestingly, the transmembrane component of the two-component system, BvgS, consists of three phospho-transfer domains leading to phosphorylation of the response regulator, BvgA. Phosphorylated BvgA then controls expression of virulence genes and also controls bvgAS transcription. In this work, we perform simulations to characterize the role of the network architecture in governing gene expression in Bordetella. Our results show that the wild-type network is locally optimal for controlling the timing of expression of the different classes of genes involved in infection. In addition, the interplay between environmental signals and positive feedback aids the bacterium identify precise conditions for and control expression of virulence genes.

Evaluation and treatment of chronic cough

Chronic cough is a frustrating and common problem, resulting in significant psychological and physical sequelae as well as enormous financial costs in terms of health care expense and time lost from work. Decreased QoL and depression are common. However, using a systematic approach, including assessing whether the patient uses ACE-I and cigarettes, excluding the presence of red flags and risk factors for life-threatening diseases, and obtaining and normal chest radiograph, more than 90% of cases of chronic cough are diagnosed as being caused by UACS, asthma, or GERD. It is recommended to address these conditions sequentially, starting with UACS. Nonasthmatic eosinophilic bronchitis and pertussis infections are unrecognized by primary care providers and should be considered after UACS, asthma, and GERD have been addressed. Finally, cough hypersensitivity syndrome is a new area of research and has been hypothesized to be the underlying factor in many cases of chronic cough, regardless of the inciting factor. More clinical research is needed to further elucidate the cough reflex pathway and the factors involved in modulating its sensitivity, which may eventually lead to new antitussive therapeutics.

Assessing the impact of a pertussis active surveillance program on provider testing behavior, Minnesota 2005-2009

OBJECTIVES

The Minnesota Department of Health, in collaboration with the Centers for Disease Control and Prevention, implemented the Pertussis Active Surveillance Project to better understand pertussis epidemiology. We evaluated the program's impact.

METHODS

Clinics in 2 counties were offered free diagnostic testing and an educational presentation covering pertussis epidemiology. Clinics were identified as either active or intermittent, with active clinics testing 33% or more of the total number of months enrolled. We used generalized estimating equations to assess changes in provider testing behavior over the project period.

RESULTS

Ninety-seven clinics enrolled, with 38% classified as active. Active clinics were more likely to use the state lab for diagnostic testing and had a larger staff. During the project period, a decline in days coughing at the time of visit occurred in both jurisdictions.

CONCLUSIONS

Providing clinics with free diagnostic testing influenced their participation levels. Among active clinics, results suggest changes in provider testing behavior over the course of the project. However, given the lack of robust participation, this resource-intensive strategy may not be a cost-effective approach to evaluating trends in pertussis epidemiology.

Prolonged Pertussis Outbreak in Ontario Originating in an Under-immunized Religious Community

Abstract.

Background

A prolonged pertussis outbreak began in Ontario in November 2011 in an under-immunized religious community and subsequently spread to the general population and a second religious community in the same region of the province.

Objective

To compare the epidemiology in the religious communities to that of the general population within the affected jurisdictions.

Methods

The analysis includes cases reported through the integrated Public Health Information System (iPHIS) between November 1, 2011 and April 15, 2013 that met the outbreak case definition. Health unit staff assessed whether cases were members of religious communities through case investigations and collected information on immunization status, treatment and outcomes.

Results

A total of 443 confirmed and probable outbreak cases were reported in 7 health units. The outbreak began in one religious community (138 cases), before spreading to the general population in the region (273 cases). A second under-immunized community within the region experienced 32 cases. Thirteen cases were hospitalized and no deaths were reported. Disease peaked earlier in the religious community; cases were significantly younger, more likely to be at high risk for pertussis and more likely to be unimmunized. Among the fully immunized general population, 51% of cases were between 10-14 years and with a median of 5.6 years since their last immunization.

Conclusion

The epidemiology of pertussis in the under-immunized community is distinct from the general population. Transmission of pertussis to the general community is not unexpected during an outbreak; however, the proportion of cases up to date with immunization warrants further investigation.