Pertussis Infection In Infants Research Articles

The association between vaccine hesitancy and pertussis: a systematic review and meta-analysis

BackgroundRobust routine immunization schedules for pertussis-containing vaccines have been applied for years, but pertussis outbreaks remain a worldwide problem. This study aimed to investigate the association between vaccine hesitancy and pertussis in infants and children.MethodsWe searched PubMed, Cochrane, Web of Science, Embase, and China National Knowledge Internet for studies published between January 2012 and June 2022. This study included case–control and cohort studies that assessed the association between childhood/maternal vaccine hesitancy and odds ratios (ORs), risk ratios (RRs), and vaccine effectiveness (VE) related to pertussis in infants and children le 9 years old. ORs/VEs with a 95% confidence interval (CI) were calculated. Random-effects meta-analysis models were used for appropriate pooled estimates, and heterogeneity was assessed using {I}^{2}. Cumulative meta-analysis and subgroup analyses stratified by study characteristics were performed.ResultsTwenty-two studies were included, with a mean quality score of 7.0 (range 6.0–9.0). Infants and children with pertussis were associated with higher vaccine hesitancy to all doses (OR = 4.12 [95% CI: 3.09–5.50]). The highest OR was between children who were unvaccinated over four doses and children who were fully vaccinated (OR = 14.26 [95%CI: 7.62–26.70]); childhood vaccine delay was not statistically significantly associated with pertussis risk (OR = 1.18 [95% CI: 0.74–1.89]). Maternal vaccine hesitancy was associated with significantly higher pertussis risk in infants aged 2 and 3 months old, with higher pertussis ORs in infants le 2 months old (OR = 6.02 [95%CI: 4.31–8.50], OR = 5.14 [95%CI: 1.95–13.52] for infants le 2 and le 3 months old, respectively). Maternal and childhood VEs were high in reducing pertussis infection in infants and children. The administration time of maternal vaccination had little effect on VE.ConclusionVaccine hesitancy increased pertussis risks in infants and children. Ensuring that children receive up-to-date pertussis vaccines is essential; short delays in receiving childhood vaccinations may be unimportant. Maternal vaccinations for pertussis should be encouraged.

Influenza and pertussis vaccine coverage in pregnancy in Australia, 2016-2021.

Vaccination in pregnancy is the best strategy to reduce complications from influenza or pertussis infection in infants who are too young to be protected directly from vaccination. Pregnant women are also at risk of influenza complications preventable through antenatal vaccination. Both vaccines are funded under the National Immunisation Program for pregnant women in Australia, but coverage is not routinely reported nationally. We reviewed all reported Australian maternal influenza and pertussis vaccine coverage data for the period 2016-2021, to identify gaps and information needs. Maternal influenza vaccine coverage was suboptimal at < 58% for 2016-2018, with higher coverage of 62-75% reported in two states (Victoria and Western Australia) for 2019-2021. Maternal pertussis vaccine coverage from 2016 was generally higher than for influenza at > 70%, with the highest jurisdictional coverage of 89% reported in Western Australia in 2020. Vaccination rates were often suboptimal among First Nations pregnant women and up to 20% lower than among non-First Nations Australian women; while data were limited, coverage was low among culturally and linguistically diverse women and among women of lower socio-economic status. Jurisdictional perinatal data collections were the best source of information on antenatal vaccine coverage but were only available for a minority of the population; a nationally consistent systematic approach is lacking. Timely and comprehensive data are needed to provide feedback to improve maternal vaccination coverage, particularly among groups with higher risk and/or low uptake, and as new vaccines are recommended, including COVID-19 vaccination.

Invasive Bordetella pertussis Infection in Infants: A Case Report.

Infants are more likely to develop severe pertussis. We report a malignant pertussis case in a 2-month-old boy with respiratory failure, severe pneumonia, septic shock, and encephalopathy. Bordetella pertussis was detected from nasopharyngeal secretions by polymerase chain reaction, as well as both blood and cerebrospinal fluid samples via metagenomics next-generation sequencing.

Etiologies of Hospitalized Acute Bronchiolitis in Children 2 Years of Age and Younger: A 3 Years' Study During a Pertussis Epidemic.

Objective: In recent years, the incidence of Bordetella pertussis infection in infants and young children has been increasing. Multiple studies have suggested that B. pertussis may be one of the pathogens of bronchiolitis in infants and young children. However, the prevalence and clinic characteristic of B. pertussis in bronchiolitis is controversial. This prospective descriptive study evaluated the prevalence and clinical manifestations of infants and young children hospitalized for bronchiolitis with B. pertussis.Methods: Children hospitalized with bronchiolitis were eligible for a prospective study for 36 months from January 1, 2017, to December 31, 2019. Besides B. pertussis, 10 common respiratory viruses and Mycoplasma pneumoniae (MP) were confirmed by laboratory tests. Medical records of patients were reviewed for demographic, clinical characteristics, and laboratory examination.Results: A total of 1,092 patients with bronchiolitis were admitted. B. pertussis was detected in 78/1,092 (7.1%) patients. Of the 78 patients with B. pertussis bronchiolitis, coinfections occurred in 45 (57.7%) patients, most frequently with human rhinovirus (28/78, 35.9%), followed by MP (9/78, 11.4%), and human bocavirus (6/78, 7.7%). The peak incidence of B. pertussis infection was in May. A high leukocyte count could help distinguish B. pertussis–associated acute bronchiolitis from other acute bronchiolitis etiologies. After excluding coinfections, children with B. pertussis–only bronchiolitis exhibited a milder clinical presentation than those with RSV-only infection; also, children with MP-only and other pathogen infections revealed similar severity. The morbidity of B. pertussis was common (31/78, 39.7%) in infants with bronchiolitis under 3 months.Conclusion: In summary, B. pertussis is one of the pathogens in children with bronchiolitis, and coinfection of B. pertussis with other viruses is common in bronchiolitis. B. pertussis should be considered when patients hospitalized with bronchiolitis present a longer course and have an elevated leukocyte count. Patients with B. pertussis–associated bronchiolitis present a milder clinical presentation.

Risk factors for pertussis among children hospitalized for pertussis during 2016–2017, in Guizhou Province of China: a case-control study

AimPertussis is a respiratory tract infection, the vaccine for which was introduced in the Expanded Programme on Immunization (EPI) in Guizhou Province of China (hereafter referred as Guizhou) in the 1980s. This vaccine rapidly decreased incidence rates of pertussis in the province, however, despite the wide high coverage of the diphtheria, tetanus and acellular pertussis (DTaP) combined vaccine, there has been a resurgence of pertussis since 2014. Even with this recent increase in disease transmission, risk factors for pertussis infection have not been evaluated in Guizhou. We aimed to provide information on pertussis risk factors and insight on designing targeted pertussis control policies and measures through this study. MethodsA 1∶2 matched retrospective case-control study was conducted between 2016 and 2017, involving infants and children younger than 6 years old and parents of the participants. The enrolled cases included clinical and laboratory confirmed pertussis cases according to the WHO-recommended pertussis definition. Controls were selected from children in the same neighborhood who were not diagnosed with pertussis prior to our investigation and did not exhibit any clinical manifestations of pertussis. ResultsThe household size [Matched odds ratio (ORm) = 1.4, 95% confidence interval (CI): 1.1–1.7] and household members with antecedent cough (ORm = 3.6, 95% CI: 1.8–7.2) were significantly associated with their child’s pertussis onset. The parents’ occupations were significantly associated with their child’s pertussis onset (ORm = 9.4, 95% CI: 1.6–54.8, for mother side; ORm = 4.5, 95% CI: 1.2–16.5, for father side), when they worked in the business and/or service industry. Having family members with a history of cough was an independent risk factor for pertussis [Adjusted odds ratio (AOR) = 43.6, 95% CI: 2.7–694.0]. Besides, the parents' demographic characteristics and DTaP doses were not found to be independent factors. ConclusionHousehold exposure is an important risk factor for pertussis infection in infants and young children and should therefore be considered as a major factor during formulation of pertussis control policies and measures.

Bordetella pertussis Infection in Infants and Young Children in Shanghai, China, 2016-2017: Clinical Features, Genotype Variations of Antigenic Genes and Macrolides Resistance.

The global resurgence of pertussis in countries with high vaccination coverage has been a concern of public health. Nasopharyngeal swabs were collected for Bordetella pertussis culture from children with suspected pertussis. Clinical and vaccination information were reviewed through electronic medical chart and immunization record. Antibiotics susceptibility was evaluated using E-test for erythromycin, azithromycin, clarithromycin and sulfamethoxazole/trimethoprim. The MLST genotypes and 7 antigenic genes (ptxP, ptxA, ptxC, Prn, fim3, fim2 and tcfA) of Bordetella pertussis were identified by polymerase chain reaction amplification and sequencing. During January 2016 to September 2017, a total of 141 children 1-48 months of age were culture-confirmed with pertussis, of whom 98 (69.5%) were younger than 6 months, 25 (17.7%) had completed at least 3 doses of DTaP and 75 (53.2%) had a clear exposure to household members with persistent cough. Fully vaccinated cases manifested milder disease than unvaccinated and not-fully vaccinated cases. All strains were MLST2. High-virulent strains characteristic of ptxP3/prn2/ptxC2 constituted 41.1% (58/141) and were all susceptible to macrolides while low-virulent strains characteristic of ptxP1/prn1/ptxC1 constituted 58.9% (83/141) and 97.6% (81/83), respectively, were highly resistant to macrolides. Pertussis is resurging among infants and young children in Shanghai, and household transmission is the main exposure pathway. The high-virulent strains harboring ptxP3/prn2/ptxC2 and the macrolide-resistant Bordetella pertussis strains are quite prevalent. These issues impose a public health concern in Shanghai. Our findings are important to modify the DTaP vaccination strategy and the management guideline of pertussis in China.

The under appreciated need for maternal and newborn immunization: call to action

In spite of clear evidence regarding the safety and efficacy of maternal and neonatal immunization, the accetance of maternal influenza and pertussis immunization and neonatal Hepatitis B vaccination has been disappointingly slow to reach optimal levels in the United States. Maternal influenza disease is associated with increased birth defects, premature delivery, and the delivery of small for gestational age infants. Influenza immunization has been recommended for all women who are or will be pregnant, regardless of trimester, during influenza season (October through May), but only about half receive them. Concerns about influenza immunization clearly overlook the solid data regarding the overall association between influenza immunization and decreased mortality and morbidity for both mothers and infants. Pertissis disease in infants under 2 months of age is associated with significantly increased morbidity and mortality. Pertussis incidence in the US has seen a significant increase in the past two decades in most age groups including that of parents and siblings. Recommended attempts to decrease infant pertussis infection include both maternal immunization and immunization of individuals who are expected to come in contact with these newborn infants (cocooning). Transmission of maternal Hepatitis B infection to their infants is associated with a significant incidence of chronic disease with subsequent cirrhosis and death. The administration of both Hepatitis B immune globulin and a “birth dose” of Hepatitis B vaccine have been demonstrated to be very safe and effective in preventing infant acquisition of Hepatitis B infection from infected mothers. A birth dose of Hepatitis B vaccine should be administered to every newborn.

Effectiveness of parental cocooning as a vaccination strategy to prevent pertussis infection in infants: A case-control study

BackgroundDuring a pertussis epidemic in 2009, the Department of Health, Victoria, Australia, implemented a cocoon program offering parents of new babies a funded-dose of pertussis-containing vaccine. We assessed vaccine effectiveness (VE) of the program in reducing pertussis infection in infants. MethodsUsing a matched case-control design, infants aged <12 months that were notified with pertussis between 1 January 2010 and 31 December 2011, and born during the time that the cocoon program was in place, were identified. Controls were matched by area of residence and date of birth. Telephone interviews we conducted to ascertain parents’ vaccination status, and if vaccinated, timing of vaccination receipt relative to the birth of their baby. Odds ratios (ORs) were calculated for the association between vaccination and pertussis infection, with VE calculated as (1 – OR) × 100%. ResultsThe study recruited 215 cases and 240 controls (response rates 67% and 25% of eligible participants, respectively). Vaccination of both parents after delivery of the infant and ≥28 days prior to illness onset reduced pertussis infection by 77% (Vaccine Effectiveness [VE] = 77% (confidence interval [95% CI], 18–93%). After adjusting for maternal education, presence of a sibling within the household, and the infants’ primary course vaccination status, the adjusted VE was 64% (95% CI, −58–92%). ConclusionsAlthough not reaching statistical significance, our results demonstrated that cocoon immunisation – where both parents are vaccinated in the post-partum period – may offer some protection again infant pertussis infection. Cocoon immunisation could be considered in circumstances where antenatal vaccination of the mother has not occurred.

Evaluation of a Cocooning Program on Infant Pertussis Infection in the Northern Territory

AbstractSince 2008, the Northern Territory (NT) Guidelines recommended delivering dTpa vaccine to postnatal women and all other household and close infant contacts. We aim to determine whether this pertussis cocooning strategy reduced infections in young infants in the NT. Infants &lt; 12 months of age notified with pertussis and born at times when the cocooning strategy was in place (2009–2014) were compared with infants born preintervention (2002–2007). The proportion of cases of pertussis occurring in infants &lt; 12 months of age was significantly higher in the preintervention period (6.7%) compared with the cocooning period (3.3%, p = 0.0067).

Evaluation of a cocooning programme on infant pertussis infection in the Northern Territory

The Australian National Immunisation Guidelines were updated in 2014 to recommend diphtheria, tetanus and pertussis (dTpa) vaccination for all pregnant women from 28 weeks gestation for each pregnancy.1 Since 2008 the Northern Territory (NT) guidelines have recommended delivering dTpa vaccine to postnatal women and all other household members and close contacts in order to provide a protective cocoon of immunity around the newborn.2 We aim to determine whether the pertussis cocooning strategy reduced pertussis infections in young infants in the NT. Infants <12 months of age diagnosed with pertussis, as per the notifiable diseases register, and born at times when the cocooning strategy was in place (2009–2014) were compared with infants born pre-intervention (2002–2007). The proportion of cases of pertussis occurring in infants <12 months of age was significantly higher in the pre-intervention period (6.7%) compared with the cocooning period (3.3%) (P = 0.0067). The infants infected were similar in gender, ethnicity, geographical location, sex, hospitalisation and outcome, but were significantly younger at diagnosis during the pre-intervention period (P = 0.01). Post-partum immunisation and cocooning strategies did reduce rates of pertussis illness in infants <12 months of age. 1 The Australian Immunisation Handbook, 10th edn. Australian Government Department of Health (updated Jan. 2014). ISBN 978-74241-861-2 2 Immunisation Schedule. Centre for Disease Control, Department of Health Northern Territory, NT, Australia; 2008.

Bordetella pertussis Infection In Infants Hospitalized for Acute Bronchiolitis

Bordetella pertussis Infection In Infants Hospitalized for Acute Bronchiolitis

Clinical Manifestations and Molecular Characterization of Pertactin-Deficient and Pertactin-Producing Bordetella pertussis in Children, Philadelphia 2007-2014.

Bordetella pertussis strains lacking expression of pertactin, a bacterial adhesin and vaccine target, are emerging. There are limited data on disease manifestations of mutant strains in children. We sought to compare clinical manifestations of pertactin-deficient and pertactin-producing B. pertussis infection in infants and describe corresponding molecular characteristics. Molecular characterization of archived B. pertussis isolates (collected January 2007 to March 2014) included Western blot analysis, pulsed-field gel electrophoresis (PFGE), polymerase chain reaction, and pertactin gene sequencing. Medical record review compared epidemiologic and clinical courses of pertactin-producing and pertactin-deficient B. pertussis infections. Sixty of 72 B. pertussis isolates were viable for analysis. Within the cohort of infants, the median age was 95 days, 90% received ≤1 dose of vaccine, and 72% were hospitalized. Pertactin deficiency was first noted in 2008, and its prevalence increased over time (68% overall prevalence). There were no statistically significant differences in presenting symptoms or signs, hospitalization, intensive care, respiratory support, or laboratory results related to pertactin expression. Illness length was shorter in pertactin-deficient group (mean difference, 3.2 days; P = .04); no difference was noted in the subgroup of infants <4 months old. Molecular analyses identified 11 PFGE profiles (Centers for Disease Control and Prevention profile No. 002 predominant, 47%). In 41 pertactin-deficient strains, sequencing identified 2 stop codon and 3 IS481 locations disrupting the prn gene. Mutations and nucleotide positions were not unique to PFGE type, nor were they clustered in time. In this cohort of predominantly unimmunized infants, clinical disease did not differ between infection with pertactin-deficient and those with pertactin-producing B. pertussis. Molecular analyses demonstrated remarkable PFGE strain diversity, with multiple mechanisms and molecular sites of pertactin inactivation.

The optimal gestation for pertussis vaccination during pregnancy: a prospective cohort study

There is an increasing incidence of pertussis infection in infants too young to be adequately protected via vaccination. Maternal pertussis vaccination during the third trimester of pregnancy is a new strategy to provide protection to newborn infants. This study sought to determine the optimal gestational window for vaccination in the third trimester. This prospective study recruited 3 groups of women:an early vaccination group, vaccinated between 28-32 weeks' gestation; a late vaccination group, vaccinated between 33-36 weeks' gestation; and an unvaccinated control group. Maternal venous blood wastaken prior to pertussis vaccination. At birth, infant cord blood wascollected to determine antibody levels to pertussis toxin (PT), pertactin (PRN), and filamentous hemagglutinin (FHA). In all, 154 women were recruited from April through September 2014. There was no significant difference between maternal PRN and FHA antibody levels among the 3 groups, however, PT was higher in the early compared to late vaccination group (P= .05). Cord blood antibody levels to PT, PRN, and FHA were significantly higher in those born to vaccinated women compared with unvaccinated controls (P < .001, P= .001, and P < .001, respectively). Vaccination between 28-32 weeks' gestation resulted in significantly higher cord blood PT (4.18.0 vs 3.50 IU/mL, P= .009), PRN (5.83 vs 5.31 IU/mL, P= .03), and FHA (5.56vs 5.03 IU/mL, P= .03) antibody levels than vaccination between 33-36 weeks' gestation. When adjusted for maternal prevaccination antibody levels, PT levels in early vs late vaccination approached significance (P= .06). PRN levels were significantly higher in the early vaccination group (P= .003). There was no significant difference for FHAantibody levels between the 2 groups (P= .16). Maternal vaccination during the third trimester is effective in affording higher levels of pertussis antibody protection to thenewborn infant. Vaccination early in the third trimester appears moreeffective than later in pregnancy.

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...

Sources of Infant Pertussis Infection in the United States.

Pertussis is poorly controlled, with the highest rates of morbidity and mortality among infants. Although the source of infant pertussis is often unknown, when identified, mothers have historically been the most common reservoir of transmission. Despite high vaccination coverage, disease incidence has been increasing. We examined whether infant source of infection (SOI) has changed in the United States in light of the changing epidemiology. Cases <1 year old were identified at Enhanced Pertussis Surveillance sites between January 1, 2006 to December 31, 2013. SOI was collected during patient interview and was defined as a suspected pertussis case in contact with the infant case 7 to 20 days before infant cough onset. A total of 1306 infant cases were identified; 24.2% were <2 months old. An SOI was identified for 569 cases. Infants 0 to 1 months old were more likely to have an SOI identified than 2- to 11-month-olds (54.1% vs 40.2%, respectively; P < .0001). More than 66% of SOIs were immediate family members, most commonly siblings (35.5%), mothers (20.6%), and fathers (10.0%); mothers predominated until the transition to siblings beginning in 2008. Overall, the SOI median age was 14 years (range: 0-74 years); median age for sibling SOIs was 8 years. In contrast to previous studies, our data suggest that the most common source of transmission to infants is now siblings. While continued monitoring of SOIs will optimize pertussis prevention strategies, recommendations for vaccination during pregnancy should directly increase protection of infants, regardless of SOI.

Sources of Infant Pertussis Infection in the United States

Sources of Infant Pertussis Infection in the United States

A case-control study to estimate the effectiveness of maternal pertussis vaccination in protecting newborn infants in England and Wales, 2012-2013.

Infants with pertussis infection are at risk of severe clinical illness and death. Several countries, including the United Kingdom, have introduced maternal pertussis vaccination during pregnancy to protect infants from infection following national increases in pertussis notifications. The objective of this study was to estimate the effectiveness of maternal pertussis vaccination in protecting infants against laboratory-confirmed pertussis infection. A case-control study was undertaken in England and Wales between October 2012 and July 2013. Cases were infants aged <8 weeks at onset with pertussis infection tested by real-time polymerase chain reaction or culture. Family doctors of each case were asked to identify healthy infants born consecutively after the case in each practice, to act as controls. Fifty-eight cases and 55 controls were included in this study. Odds ratios (ORs) were calculated for the association between maternal vaccination and infant pertussis infection. The vaccine effectiveness (VE) was calculated as 1 - OR. This was adjusted for sex, geographical region, and birth period. Mothers of 10 cases (17%) and 39 controls (71%) received pertussis vaccine in pregnancy. This gave an unadjusted VE of 91% (95% confidence interval [CI], 77%-97%). Adjusted VE was 93% (95% CI, 81%-97%). Maternal pertussis vaccination is effective in preventing pertussis infection in infants aged <8 weeks and may be considered in other countries experiencing high levels of pertussis notifications.

Pregnant women's intention to take up a post-partum pertussis vaccine, and their willingness to take up the vaccine while pregnant: A cross sectional survey

IntroductionPost-partum vaccination of new mothers is currently recommended in Australia to reduce pertussis infection in infants. Internationally, vaccination recommendations now include pregnant women in some countries. Understanding the awareness of pertussis vaccination recommendations among pregnant women, and their willingness to have the vaccine while pregnant is important for informing vaccine program implementation. ObjectiveTo determine awareness and intentions toward current recommendations for post-partum pertussis vaccination among Australian pregnant women, and their willingness to accept pertussis vaccine during pregnancy, should it be recommended in Australia in the future. DesignQuantitative self-administered survey, using a non-random stratified sampling plan based on representative proportions by age, parity and region of residence. Participants and settingPregnant women receiving antenatal care through three large, demographically diverse referral hospitals in metropolitan, urban and rural New South Wales, Australia. ResultsThe response rate was 815/939 (87%). Most women (80%) reported willingness to have the pertussis vaccine during pregnancy, should it be recommended. Thirty four per cent of women intended to receive a pertussis vaccine post-partum, 17% had received it previously, while 45% had never heard of pertussis vaccine, had not thought about it, or were undecided about having it. Compared with those who had not received a recommendation to have the vaccine post-partum, women who had received a recommendation were 7 times more likely (95% CI 4–14) to report intention to have the vaccine. ConclusionsHealth care provider recommendation is paramount to raising awareness of pertussis vaccination recommendations among pregnant women. Women's willingness to have the vaccine while pregnant is encouraging, and indicates the potential for high pertussis vaccine coverage among pregnant women, should it be recommended in Australia.

BothCD4+andCD8+Lymphocytes Participate in the IFN-γ Response to Filamentous Hemagglutinin fromBordetella pertussisin Infants, Children, and Adults

Infant CD4+ T-cell responses to bacterial infections or vaccines have been extensively studied, whereas studies on CD8+ T-cell responses focused mainly on viral and intracellular parasite infections. Here we investigated CD8+ T-cell responses upon Bordetella pertussis infection in infants, children, and adults and pertussis vaccination in infants. Filamentous hemagglutinin-specific IFN-γ secretion by circulating lymphocytes was blocked by anti-MHC-I or -MHC-II antibodies, suggesting that CD4+ and CD8+ T lymphocytes are involved in IFN-γ production. Flow cytometry analyses confirmed that both cell types synthesized antigen-specific IFN-γ, although CD4+ lymphocytes were the major source of this cytokine. IFN-γ synthesis by CD8+ cells was CD4+ T cell dependent, as evidenced by selective depletion experiments. Furthermore, IFN-γ synthesis by CD4+ cells was sometimes inhibited by CD8+ lymphocytes, suggesting the presence of CD8+ regulatory T cells. The role of this dual IFN-γ secretion by CD4+ and CD8+ T lymphocytes in pertussis remains to be investigated.

Role of PCR in the diagnosis of pertussis infection in infants: 5 years' experience of provision of a same-day real-time PCR service in England and Wales from 2002 to 2007

As part of an enhanced surveillance programme for pertussis in England and Wales, a real-time PCR service for the detection of Bordetella pertussis was introduced for infants aged <or=6 months admitted to a paediatric intensive care unit or paediatric ward with a respiratory illness compatible with pertussis. Two real-time fluorescent resonance energy transfer hybridization probe LightCycler (Roche Diagnostics) PCR assays were used. One (designed in-house) targeted the pertussis toxin S1 promoter (ptxA-pr), and included an internal process control to test for sample inhibition and reagent performance. The other (already published) targeted the insertion element IS481. The analytical sensitivities of the assays were 100 and 10 fg per reaction for the ptxA-pr and IS481 PCRs, respectively. The ptxA-pr assay was specific for B. pertussis, whilst the IS481 PCR also showed some cross-reactivity with Bordetella holmesii and the type strain of Bordetella parapertussis. From April 2002 to March 2007, 848 samples were received from 774 patients and DNA was extracted. Of 824 samples that were suitable for testing, 183 (22.2 %) had evidence of Bordetella infection (18.9 % ptxA-pr and IS481; 3.3 % IS481 only), 621 (75.4 %) were negative and 20 (2.4 %) were inhibitory for the PCR. Within the targeted age group of <or=6 months, most patients (130/138) with evidence of Bordetella spp. by PCR were <or=3 months old. The overall percentage increase in laboratory-confirmed cases due to PCR compared with culture for the 5 year period described ranged from 9 to 26 % per year (mean 19 %). Real-time PCR is an invaluable tool both for enhanced epidemiological surveillance and for the provision of a rapid diagnosis of pertussis where results can affect patient and contact management.