Burden Of Pertussis Research Articles

PIN25 - PROJECTED BURDEN OF VACCINE-PREVENTABLE DISEASES IN OLDER ADULTS IN THE UNITED STATES: IMPACT OF POPULATION AGING

Burden of vaccine-preventable diseases in the United States (US) remains high among older adults, despite longstanding immunization recommendations. Accelerated population aging may add to the already significant disease burden in the absence of increased vaccination rates. This study aimed to quantify the impact of aging on future burden of influenza, herpes zoster (HZ), and pertussis in US adults aged 50+ years. A population-based, age-structured economic model was developed to project burden of influenza, HZ, and pertussis using disease-specific decision trees that account for case severity and resource use. The model started with the 2017 US adult population aged 50+ years stratified by 1-year age groups. In each subsequent year, corresponding US Census Bureau population projections were used to calculate undiscounted cases and direct medical costs (2017 US$), keeping current estimates of age-specific disease incidence, vaccine coverage, and efficacy constant over time. Results were calculated over multiple time horizons and for multiple diseases and scenario analyses were conducted. In 2017, influenza burden was estimated at ∼7.57 million cases, with corresponding direct medical costs of $6.6 billion. Over a 10-year horizon, the model projected an additional ∼4.98 million cumulative influenza cases solely due to population aging, with nearly $7.0 billion in additional costs. In each year, most costs were attributed to adults aged 65+ years (range: 67.5-74.2%) and unvaccinated individuals (range: 53.7-55.0%). Excess cases and costs due to population aging were further augmented when projecting over longer time periods. Results for HZ and pertussis also showed increases in disease burden due to population aging. Holding current incidence and vaccination levels constant over the next decade, the model projects notable increases in influenza, HZ, and pertussis burden due to population aging, with a corresponding impact on healthcare resource use and medical costs. Efforts to further increase vaccination rates in older adults are warranted.

Pharmacists' Attitudes and Practices Regarding Tetanus, Diphtheria and Pertussis (Tdap) Vaccination in Pregnancy and Surrounding Newborns.

Background: Bordetella pertussis or whooping cough is a serious and vaccine-preventable illness. Despite widespread vaccination in the pediatric population, pertussis still infects approximately 100,000 infants each year in the United States. The purpose of this study was to determine gaps in pharmacists’ understanding, attitudes, practices, and barriers surrounding the tetanus, diphtheria, and pertussis (Tdap) vaccination recommendation for patients who are pregnant or planning to come in close contact with infants. Methods: This study was a descriptive, exploratory electronic survey. The survey assessed three major areas; the role of the pharmacist in Tdap vaccination, perceived barriers to vaccination, and understanding the recommendations. Results: A total of 225 pharmacists responded to the survey. Pharmacists who responded to this survey agreed that pharmacists should have a role vaccinating the public and individuals expecting to come into contact with a newborn, (88.5% and 86.9%) respectively, but fewer agreed that pharmacists should have a role vaccinating pregnant women against tetanus, diphtheria, and pertussis (77%, p < 0.001). Based on the responses to case scenarios, only 22.5% and 30.6% of respondents understood the recommendations. Numerous barriers to vaccinating pregnant women were identified. Conclusion: While most pharmacists surveyed felt they should have a role in vaccinating pregnant women and those expecting to come in contact with a newborn, there are barriers to implementing this practice. Future efforts should focus on further evaluating identified gaps and developing programs for pharmacists that emphasize the significance of vaccinating these patients to reduce the burden of pertussis in infants.

Assessment of Tdap Vaccination Effectiveness in Adolescents in Integrated Health-Care Systems

PurposeDespite high national vaccination coverage with tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccines among U.S. adolescents, rates of adolescent pertussis disease are increasing. We estimated the duration of protection after Tdap vaccination and the possible effects of the change from whole-cell to acellular childhood pertussis vaccines in the United States during the 1990s. MethodsWe conducted a retrospective cohort analysis among 11- to 18-year-olds enrolled in two integrated health-care delivery systems during 2005–2012. Cases met the Council of State and Territorial Epidemiologists' confirmed or probable definition or a polymerase chain reaction-positive suspect definition. We estimated vaccine effectiveness (VE) overall and by time since Tdap receipt. We stratified VE estimates by primary series pertussis vaccine received (based on birth year): mixed-vaccine cohort (1987–1997) and acellular vaccine cohort (1998–2001). ResultsThe overall Tdap VE was 57% (95% confidence interval [CI]: 42%–68%); the VE in the mixed-vaccine and acellular cohorts was 65% (95% CI: 44%–78%) and 52% (95% CI: 30%–68%), respectively. Tdap VE within <2 years post vaccination (69%, 95% CI: 54%–79%) was significantly different from VE ≥2 years post vaccination (34%, 95% CI: 1%–55%, p value < .01). VE was significantly higher <2 years post vaccination compared with ≥2 years post vaccination in both mixed-vaccine (87%, 95% CI: 58%–96%, and 52%, 95% CI: 13%–73%; p value = .04) and acellular cohorts (62%, 95% CI: 41%–76%, and 21%, 95% CI: −30% to 52%; p value = .01). ConclusionsAlthough Tdap vaccination remains the best pertussis prevention method for adolescents, protection wanes within 2 years regardless of the type of childhood primary vaccine. Vaccines with longer duration of protection could decrease pertussis burden.

Marked Underreporting of Pertussis Requiring Hospitalization in Infants as Estimated by Capture-Recapture Methodology, Germany, 2013-2015.

In Germany, pertussis became notifiable in eastern federal states in 2002 and nationwide in March 2013. Infants are at greatest risk for severe disease, with a high proportion requiring hospitalization. We implemented enhanced hospital-based surveillance to estimate the incidence of pertussis requiring hospitalization among infants in Germany and to determine the proportion of infants hospitalized with pertussis too young to have been vaccinated. Enhanced surveillance was implemented within a nationwide hospital surveillance network (ESPED). We defined cases as children less than 1 year of age hospitalized due to laboratory-confirmed pertussis with disease onset from 01/07/2013-30/06/2015. We matched cases to those ascertained in the national statutory notification system, and estimated incidence using capture-recapture methodology. The estimated annual incidence of pertussis requiring hospitalization in infants was 52/100,000 infants (95% confidence interval [CI] 48-57/100,000), with 39% under-reporting to the national notification system. During the two epidemiologic years under-reporting decreased from 46% to 32% and was lower in eastern than western federal states (21% vs. 40%). Within ESPED, 154 of 240 infants (64%) were younger than or still at the age recommended for the first vaccine dose; 55 (23%) could have received one or more vaccine doses. Median length of hospitalization was 9 days (IQR 5-13 days) and 18% required intensive care treatment. Our study revealed a high burden of pertussis in infants with marked under-reporting, especially in western federal states where notification was only recently established. Strategies for the prevention of severe pertussis.

An update of the global burden of pertussis in children younger than 5 years: a modelling study

Since the publication in 2003 of a model to estimate the disease burden of pertussis, new evidence of the protective effect of incomplete pertussis vaccination against severe pertussis has been reported. We revised the model to provide new estimates of regional and global pertussis cases and deaths for children younger than 5 years. We developed a revised model with data from 2014 to estimate pertussis cases and deaths. Pertussis cases were defined according to the WHO clinical case definition, as a coughing illness lasting at least 2 weeks with paroxysms of coughing, inspiratory whooping, or post-tussive vomiting. We used UN population estimates and WHO and UNICEF data on national pertussis immunisation coverage. Estimates were made for vaccine effectiveness against pertussis cases and deaths for one, two, and three doses of vaccination, probability of infection in low and high coverage countries, and case fatality ratios in low and high mortality countries in two age groups: infants younger than 1 year and children aged 1-4 years. We did sensitivity analyses with a range of input parameters to assess the effect of uncertainty of the input parameters on the model outputs. We estimated that there were 24·1 million pertussis cases and 160 700 deaths from pertussis in children younger than 5 years in 2014, with the African region contributing the largest proportions (7·8 million [33%] cases and 92 500 [58%] deaths). 5·1 million (21%) estimated pertussis cases and 85 900 (53%) estimated deaths were in infants younger than 1 year. In the sensitivity analyses, the estimated number of cases ranged from 7 million to 40 million and deaths from 38 000 to 670 000. Our estimates suggest that, compared with the 1999 estimates published in 2003 (30·6 million pertussis cases and 390 000 deaths from pertussis in children younger than 5 years), the numbers of cases and deaths of pertussis have fallen substantially. Model sensitivity emphasised the importance of better surveillance to improve country-level decision making and pertussis control. None.

Global burden of pertussis: signs of hope but need for accurate data

Global burden of pertussis: signs of hope but need for accurate data

Incidence and Burden of Pertussis Among Infants Less Than 1 Year of Age

Incidence and Burden of Pertussis Among Infants Less Than 1 Year of Age

Incidence and Burden of Pertussis Among Infants Less Than 1 Year of Age.

Infant-specific pertussis data, especially among neonates, are limited and variable. This study (NCT01890850) provides overall and age-specific pertussis incidence and associated health care utilization and costs among commercially insured infants in the US. Nearly 1.2 million infants born from 2005 to 2010 with commercial health plan coverage were followed during their first 12 months of life. Pertussis cases were identified from medical claims (International Classification of Diseases, 9th revision, Clinical Modification code: 033.0, 033.9, 484.3), and incidence rates were calculated. Each pertussis case was then matched to 10 comparators, so pertussis-related health care utilization and costs before and after the index date could be assessed. The overall pertussis incidence rate among infants <12 months of age was 117.7/100,000 person-years; infants 3 months of age had the highest incidence rate (247.7/100,000 person-years). Infants diagnosed with pertussis were significantly more likely to have prior diagnoses of upper respiratory infection, cough and wheezing-related illnesses than comparators (P < 0.001). Pertussis cases were more likely to be hospitalized within 14 days after the index date (31.8% vs. 0.5%; P < 0.001) and their adjusted health care costs during follow-up were 2.82 times higher than comparators (P < 0.001; 95% confidence interval: 2.08-3.81). The incremental cost of pertussis during the 12-month follow-up period averaged $8271 (P < 0.001). The average incremental cost varied substantially by age, ranging from $18,781 (P < 0.001) to $3772 (P = 0.02) among infants 1 month and 7-12 months of age, respectively. The health burden of pertussis, particularly in the youngest infants, remains substantial, highlighting the need to intensify efforts to protect this most vulnerable population.

Pertussis incidence rates in Novi Sad (Serbia) before and during improved surveillance

Introduction/Objective. The Global Pertussis Initiative (GPI) proposed clinical case definitions for pertussis diagnosis in three different age cohorts in order to improve surveillance of pertussis especially in older children, adolescents, and adults. The main goal of this research was to compare the burden of pertussis in the city of Novi Sad before and after the introduction of improved surveillance using the GPI clinical case definitions of pertussis. Methods. Baseline data on pertussis were obtained from routine (non-sentinel) reporting before improved surveillance was introduced. From September 16, 2012, clinical case definitions proposed by GPI were applied within improved (sentinel and hospital) surveillance, while surveillance clinical case definitions were not introduced within non-sentinel. To confirm the suspected diagnosis, sampling of nasopharyngeal swab and/or blood was obtained from all cases. The choice of laboratory method (PCR or ELISA) depended on the duration of coughing and the age of the patients. Data were statistically processed by SPSS Statistics, version 22. Results. During the 12-year period before the introduction of improved surveillance, only two clinical pertussis cases were registered. In contrast, during the two-year period of improved surveillance, a total of 14 (season 2012/13) and 146 (season 2013/2014) confirmed pertussis cases were reported. Significant differences were determined in distribution of pertussis according to the type of surveillance and the level of health care. Conclusion. Introduction of clinical case definitions proposed by GPI improved the quality of surveillance and enabled an insight in the distribution of pertussis in all age groups and at all levels of health care.

Morbidity and Mortality Due to Bordetella pertussis: A Significant Pathogen in West Africa?

In the absence of specific surveillance platforms for pertussis and availability of suitable diagnostics at the hospital level, reliable data that describe morbidity and mortality from pertussis are difficult to obtain in any setting, as is the case in West Africa. Here, we summarize the available evidence of the burden of pertussis in the region, given historical data, and describe recent and ongoing epidemiological studies that offer opportunities for additional data collection. The available seroepidemiological data provide evidence of ongoing circulation of Bordetella pertussis in the region. Due to the lack of systematic and targeted surveillance with laboratory confirmation of B. pertussis infection, we cannot definitively conclude that pertussis disease is well controlled in West Africa. However, based on observations by clinicians and ongoing demographic surveillance systems that capture morbidity and mortality data in general terms, currently there is no evidence that pertussis causes a significant burden of disease in young children in West Africa.

Pertussis in children in Bloemfontein, South Africa: A 7-year retrospective review.

Pertussis vaccination in the 1950s was associated with a decrease in the incidence of pertussis. A resurgence of pertussis has been documented, mainly in well-resourced countries since the 1990s. The burden of pertussis has not been well described in South Africa (SA). Epidemiological data are important for rational implementation of vaccination strategies. To describe the morbidity and mortality of children with pertussis admitted to public sector hospitals in Bloemfontein, SA. A retrospective descriptive hospital-based study of children diagnosed with pertussis by polymerase chain reaction testing from April 2008 to March 2015. One hundred and eighty-three laboratory results confirmed pertussis; 105/183 children (57.4%) were &lt;18 weeks old. Clinical data, available for 154/183 cases (84.2%), showed that 141/154 children (91.6%) were admitted to hospital, of whom one-third required intensive care. Hospital admission was associated with young age (p&lt;0.001). The median hospital stay was 9.0 days (interquartile range 6 - 14.5), and hospital stay was longer for children aged &lt;18 weeks than for those aged ≥18 weeks (p=0.006; 95% confidence interval 1 - 5 days). Of the 154 children, 139 (90.3%) had a cough, which lasted ≤7 days in 110/137 cases (80.3%). The total white cell count was ≥20.0 × 109/L in 58/144 cases (40.3%). Eight children (5.2%) died. This case series highlights the importance of pertussis as a problem in children. Most children had a history of cough lasting ≤7 days. Young infants were most severely affected, requiring prolonged hospital stay, often with admission to a paediatric intensive care unit.

Estimated incidence of pertussis in people aged

ABSTRACTThe introduction of pertussis vaccination in the United States (US) in the 1940s has greatly reduced its burden. However, the incidence of pertussis is difficult to quantify, as many cases are not laboratory-confirmed or reported, particularly in adults. This study estimated pertussis incidence in a commercially insured US population aged <50 years. Data were extracted from IMS' PharMetrics Plus claims database for patients with a diagnosis of pertussis or cough illness using International Classification of Diseases (ICD-9) codes, a commercial outpatient laboratory database for patients with a pertussis laboratory test, and the Centers for Disease Control influenza surveillance database. US national pertussis incidence was projected using 3 methods: (1) diagnosed pertussis, defined as a claim for pertussis (ICD-9 033.0, 033.9, 484.3) during 2008–2013; (2) based on proxy pertussis predictive logistic regression models; (3) using the fraction of cough illness (ICD-9 033.0, 033.9, 484.3, 786.2, 466.0, 466.1, 487.1) attributed to laboratory-confirmed pertussis, estimated by time series linear regression models. Method 1 gave a projected annual incidence of diagnosed pertussis of 9/100,000, which was highest in those aged <1 year. Method 2 gave an average annual projected incidence of 21/100,000. Method 3 gave an overall regression-estimated weighted annual incidence of pertussis of 649/100,000, approximately 58–93 times higher than method 1 depending on the year. These estimations, which are consistent with considerable underreporting of pertussis in people aged <50 years and provide further evidence that the majority of cases go undetected, especially with increasing age, may aid in the development of public health programs to reduce pertussis burden.

Impact of Tetanus Toxoid, Reduced Diphtheria Toxoid, and Acellular Pertussis Vaccinations on Reported Pertussis Cases Among Those 11 to 18 Years of Age in an Era of Waning Pertussis Immunity: A Follow-up Analysis.

There is accumulating literature on waning acellular pertussis vaccine-induced immunity, confirming the results of studies assessing the duration of protection of pertussis vaccines. To evaluate the tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccine's effect over time among those 11 to 18 years old, while accounting for the transition from whole-cell to acellular pertussis vaccines for the childhood primary series. Extended, retrospective analysis of reported pertussis cases between January 1, 1990, and December 31, 2014, in the United States. The analysis included all nationally reported pertussis cases. US Tdap vaccination program and the transition from whole-cell to acellular pertussis vaccines. Rate ratios of reported pertussis incidence (defined as incidence among 11- to 18-year-old individuals divided by the combined incidence in all other age groups) modeled with segmented regression analysis and age-specific trends in reported pertussis incidence over time. Between 1990 and 2014, 356 557 pertussis cases were reported in the United States. Of those, 191 914 (53.8%) were female and 240 665 (67.5%) were white. Overall incidence increased from 1.7 in 100 000 to 4.0 in 100 000 between 1990 and 2003, while latter years were dominated by epidemic peaks. Incidence was highest among infants younger than 1 year throughout the analysis period. Pertussis rates were comparable among all other age groups until the late 2000s, when an increased burden of pertussis emerged among children 1 to 10 years old, resulting in the second highest age-specific incidence. By 2014, 11- to 18-year-old individuals once again had the second highest incidence. While slope coefficients from segmented regression analysis showed a positive impact of Tdap immediately following introduction (slope, -0.4959; P < .001), a reversal in trends was observed in 2010 when rates of disease among 11- to 18-year-old individuals increased at a faster rate than all other age groups combined (slope, 0.5727; P < .001). While the impact of Tdap among adolescents looked promising following vaccine introduction, our extended analysis found that trends in adolescent disease were abruptly reversed in 2010, corresponding directly to the aging of acellular pertussis-vaccinated cohorts. Despite the apparent limitations of Tdap, it remains the best prevention against disease in adolescents.

Immunization update: A look back at 2015

Immunization update: A look back at 2015

Infant outcomes after exposure to Tdap vaccine in pregnancy: an observational study

ObjectivePertussis vaccination during pregnancy has recently been recommended in both the USA and UK to prevent pertussis infection in infants. While there are no apparent safety concerns about the administration...

Clinical characteristics and pertussis costs in cases reported to epidemiological services and cases detected in household contacts in Catalonia (Spain).

To assess the clinical characteristics and direct health costs associated with pertussis cases reported to and confirmed by epidemiological services and cases detected among household contacts in Catalonia (Spain) in 2012-2013. All pertussis cases confirmed by the epidemiological services (n = 641) and all cases detected among the household contacts (n = 422) were included in the study. The chi-square test and odds ratios were used to compare percentages and the t-test was used to compare mean pertussis costs, with p < 0.05 being considered statistically significant. Cases reported to epidemiological services had a higher percentage of hospitalizations (OR = 32.2, p < 0.001) and severe disease (OR = 27.7, p < 0.001) than cases detected among the household contacts. The total health costs associated with pertussis cases were €871,648, €799,704 (92 %) for cases reported to epidemiological services and €71,944 (8 %) for cases detected among the household contacts. Total treatment, detection, and quimiprophylaxis costs were € 809,702, € 44,312, and € 17,635, representing 92.5 %, 5.5 %, and 2 % of total pertussis costs respectively. The mean costs were significantly higher (p < 0.001) in cases reported to epidemiological services than in cases detected among the household contacts, for all cases (€1248 vs €170), and for severe (€4546 vs €1073), moderate (€204 vs €165), and mild (€153 vs €133) disease. The burden of pertussis in Catalonia was high in terms of health costs, especially in infants aged less than 1 year. Active epidemiological surveillance activities could prevent pertussis transmisison and reduce pertussis costs.

What to do about pertussis vaccines? Linking what we know about pertussis vaccine effectiveness, immunology and disease transmission to create a better vaccine.

Pertussis (whooping cough) is a respiratory disease caused by the bacterium Bordetella pertussis. Despite the implementation of immunization programs and high vaccine coverage in most jurisdictions, pertussis is still one of the most common vaccine-preventable diseases, suggesting that the current vaccines and immunization schedules have not been sufficiently effective. Several factors are thought to contribute to this. The acellular pertussis vaccine that has been used in many jurisdictions since the 1990s is less effective than the previously used whole-cell vaccine, with immunity waning over time. Both whole-cell and acellular pertussis vaccines are effective at reducing disease severity but not transmission, resulting in outbreaks in vaccinated cohorts. In this review, we discuss various limitations of the current approaches to protection from pertussis and outline various options for reducing the burden of pertussis on a population level.

Seroprevalence studies of pertussis: what have we learned from different immunized populations.

Bordetella pertussis is a pathogen-causing whooping cough (pertussis) in humans. Although vaccination against the disease is effective, the bacterium is still circulating among population and can even cause death. Especially young infants, who lack protection, are vulnerable. The laboratory diagnostic methods to detect B. pertussis are culture, PCR and ELISA serology. Reported cases of the disease vary among countries but usually the incidence rates are low, <1 to 10/100 000. However, pertussis often goes unrecognized among patients as it presents itself like the common cold, especially in adults and elders who are often the source of the infection. This makes pertussis difficult to monitor and control. Serological surveillance is an easy manner to estimate the real burden of the disease among population. Furthermore, to have reliable results, anti-PT IgG antibodies should be measured, as PT is the only specific antigen to B. pertussis. This review aims to evaluate available pertussis seroprevalence studies throughout the world, and to compare the findings from countries with different vaccination histories and strategies. Estimation of the real burden of pertussis is compared to reported numbers. In addition, future aspects in seroprevalence studies are considered.

Strategies to decrease pertussis transmission to infants.

The Global Pertussis Initiative (GPI) is an expert scientific forum addressing the worldwide burden of pertussis, which remains a serious health issue, especially in infants. This age cohort is at risk for developing pertussis by transmission from those in close proximity. Risk is increased in infants aged 0 to 6 weeks, as they are too young to be vaccinated. Older infants are at risk when their vaccination schedules are incomplete. Infants also bear the greatest disease burden owing to their high risk for pertussis-related complications and death; therefore, protecting them is a high priority. Two vaccine strategies have been proposed to protect infants. The first involves vaccinating pregnant women, which directly protects through the passive transfer of pertussis antibodies. The second strategy, cocooning, involves vaccinating parents, caregivers, and other close contacts, which indirectly protects infants from transmission by preventing disease in those in close proximity. The goal of this review was to present and discuss evidence on these 2 strategies. Based on available data, the GPI recommends vaccination during pregnancy as the primary strategy, given its efficacy, safety, and logistic advantages over a cocoon approach. If vaccination during pregnancy is not feasible, then all individuals having close contact with infants <6 months old should be immunized consistent with local health authority guidelines. These efforts are anticipated to minimize pertussis transmission to vulnerable infants, although real-world effectiveness data are limited. Countries should educate lay and medical communities on pertussis and introduce robust surveillance practices while implementing these protective strategies.

The burden of pertussis in low- and middle-income countries since the inception of the Expanded Programme on Immunization (EPI) in 1974: a systematic review protocol.

BackgroundVaccine against pertussis has been in use for several decades. Despite the widespread use of pertussis vaccine, evidence shows resurgence of pertussis in high-income countries. Pertussis surveillance data is largely missing from low- and middle-income countries (LMICs). Without data on trends of pertussis, it is difficult to review and amend pertussis control policies in any country. We propose conducting a systematic review to evaluate the burden and trends of pertussis in LMICs since 1974.Methods/designCommon and medical subject heading (MeSH) terms for pertussis and LMICs will be used to search electronic databases for the relevant literature published between 1974 and December 2014. Only studies from LMICs that fulfils World Health Organisation (WHO) or CDC pertussis case definitions will be included. The studies must have a clear numerator and denominator in a well-defined population.Risk of bias will be evaluated by assessing all qualifying full-text articles for quality and eligibility using a modified quality score assessment tool.Standardised data extraction will be carried out after which descriptions of trends in the prevalence, incidence, as well as mortality rate and case fatality rate, will be done. Where sufficient data is available, the results will be stratified by age group, geography, location, vaccination and HIV status.DiscussionThe systematic review proposed by this protocol seeks to address the knowledge gap in the epidemiology of pertussis in LMICs for the first time. It is anticipated that the background epidemiological trends of pertussis in LMICs that our study will provide could be used in the planning for the control of pertussis.Systematic review registrationPROSPERO CRD42015015159