Hospitalizations for pertussis in Italy, 1999-2009: analysis of the hospital discharge database

Impact of national recommendations for routine pertussis vaccination during pregnancy on infant pertussis in Ontario, Canada: a population-based time-series study

BACKGROUND

In February 2018, Canada's National Advisory Committee on Immunization (NACI) recommended antenatal tetanus-diphtheria-acellular pertussis (Tdap) immunization in every pregnancy regardless of previous Tdap immunization history. We examined the impact of the NACI recommendation on rates of infant pertussis in Ontario, Canada.

METHODS

We conducted a population-based time-series study of all live births in Ontario between August 1, 2011 and February 28, 2020. We used interventional autoregressive integrated moving average models to examine the impact of the NACI recommendation on monthly rates of pertussis among infants ≤ 3 months of age.

RESULTS

We observed 675 incident cases of pertussis among 1,368,024 infants 3 months of age or less between August 2011 and February 2020. The average monthly percent change in infant pertussis during the period up to and including publication of the NACI guidance and the period following publication were 0.0% (95% CI: -0.4-0.3%) and - 0.8% (95% CI -2.3% to -0.1%), respectively. Following interventional ARIMA modelling, publication of the NACI guidance was not associated with a statistically significant decrease in the monthly pertussis incidence trend (-0.67 cases per 100,000 infants; p = 0.73).

CONCLUSION

Publication of national recommendations for antenatal Tdap immunization in every pregnancy did not significantly reduce infant pertussis rates. This may reflect the persistently low rate of antenatal vaccination following publication of the recommendations. Expanding the scope of practice of allied health care providers to include antenatal Tdap immunization and patient education regarding antenatal pertussis immunization should be considered to further optimize uptake of vaccination.

Assessment of Pertussis Underreporting in Italy

A study was conducted to assess the degree of pertussis underreporting in Italy. An analysis was performed to compare the frequency of pertussis infections estimated using seroprevalence data with the pertussis incidence based on reported cases among the Italian population. For this purpose, the proportion of subjects who had an anti-PT ≥ 100 IU/mL (indicative of B. pertussis infection within the last 12 months) was compared with the reported incidence rate among the Italian population ≥5 years old, divided into two age groups (6-14 and ≥15 years old), obtained from the European Centre for Disease Prevention and Control (ECDC) database. The pertussis incidence rate in the Italian population ≥5 years old reported by the ECDC in 2018 was 6.75/100,000 in the 5-14 age group and 0.28/100,000 in the ≥15 age group. The proportion of subjects recruited in the present study with an anti-PT ≥ 100 IU/mL was 0.95% in the 6-14 age group and 0.97% in the ≥15 age group. The estimated rate of pertussis infections based on seroprevalence was approximately 141-fold and 3452-fold higher than the reported incidence in the 6-14 age group and in the ≥15 age group, respectively. Quantification of underreporting can allow for the burden of pertussis, as well as the impact of ongoing vaccination, to be better evaluated.

Vaccinating Front-Line Healthcare Workers: Results of a Pre-Pandemic Cross-Sectional Study from North-Eastern Italy on First Responders

First responders are front-line healthcare workers who are potentially exposed to different infectious agents. Characterizing their knowledge, attitudes, and practices (KAP) towards immunization, therefore, has the potential to significantly improve occupational health and safety. A cross-sectional study was performed in October 2018 using a sample of 161 first responders from the Parma Province (mean age 45.1 ± 14.1 years; seniority 10.8 ± 8.6 years). The participants were questioned on three recommended vaccinations (i.e., the seasonal influenza, measles, and pertussis vaccines) and on meningococcal vaccines (not officially recommended for first responders). The participant’s knowledge status and risk perception were assessed as percentage values through a specifically designed questionnaire. Adjusted odds ratios (aOR) for factors associated with vaccination status were calculated by means of a binary logistic regression analysis. The internal consistency result, calculated using a general knowledge test, was good (Cronbach’s alpha = 0.894), but the corresponding score was unsatisfying (46.5% ± 32.4), evidencing uncertainties surrounding the recommendations for measles and meningococcal vaccines (39.1% and 34.2% incorrect answers, respectively). While the large majority of respondents were favorable towards the meningococcal (89.4%), measles (87.5%), and pertussis vaccines (83.0%), 55.3% exhibited a favorable attitude toward the seasonal influenza vaccine, the uptake of which in 2018, was reported by 28.0% of respondents, compared to the self-reported lifetime status for meningitis (26.1%), measles (42.2%), and pertussis (34.8%). Not coincidentally, all assessed infections were associated with a low-risk perception score, particularly influenza (33.9% ± 18.4). Interestingly enough, neither knowledge status nor risk perception were associated with vaccination rates. More precisely, the main predictor for being vaccinated against seasonal influenza in 2018 was a seniority of ≥10 years (aOR 3.26, 95% confidence interval [95% CI] 1.35–7.91), while both pertussis and measles were positively associated with higher educational achievement (aOR 3.27, 95%CI 1.29–8.30; and aOR 2.69, 95%CI 1.09–6.65, respectively). The reasons for vaccination gaps among the sampled first responders, apparently, did not find their roots in inappropriate knowledge status and risk perception alone. However, the very low rates of sampled immunization lead us to recommend stronger and more appropriate information campaigns.

Experts' Opinion for Improving Pertussis Vaccination Rates in Adolescents and Adults: A Call to Action

This article highlights the importance of diphtheria-tetanus-acellular pertussis (with reduced antigen content, dTap) vaccination in preventing pertussis, a respiratory infection that is still widespread and easily transmitted. In particular, it highlights the need to receive a booster vaccination throughout life to maintain high antibody levels, which decrease through time. This document collects the opinions that emerged from the comparison between major Italian experts in the field of vaccination. This working group was created to promote a "call to action", aimed at raising awareness among all institutions, public health authorities, and health workers involved in the vaccination process, about the importance of dTap vaccine administration and with the mindset of implementing the strategic vaccination plan provided by the National Vaccine Plan (NVP). In fact, despite this vaccine being included in the NVP, there are some issues attributable to the practice of vaccination (local health authorities, vaccination centers, occupational health services, gynecology centers, societies of work). Therefore, it is necessary that the Ministry defines the vaccination coverage objectives, identifies the groups of subjects who should receive the booster vaccine (subjects exposed to greater risk of infection, subjects over 60, pregnant women), and applies all the necessary measures to encourage the implementation of this practice.

Hexavalent vaccines: What can we learn from head-to-head studies?

BACKGROUND

Three hexavalent vaccines against diphtheria, tetanus, pertussis, poliomyelitis, hepatitis B virus (HBV), and Haemophilus influenzae type b (Hib) are licensed in Europe: Infanrix hexa (DT3aP-HBV-IPV/Hib), Hexyon (DT2aP-HBV-IPV-Hib) and Vaxelis (DT5aP-HBV-IPV-Hib).

METHODS

A systematic literature search was performed in various electronic databases to identify published peer-reviewed head-to-head studies comparing any licensed hexavalent vaccine to another.

RESULTS

Predefined inclusion criteria were met by 12 articles. Individual studies concluded that the 3 hexavalent vaccines have acceptable safety profiles although some significant differences were observed in their reactogenicity profiles. The immunogenicity of DT2aP-HBV-IPV-Hib and DT5aP-HBV-IPV-Hib was non-inferior versus DT3aP-HBV-IPV/Hib. Some differences in immune responses to common antigens were observed, but their clinical relevance was not established. Anti-filamentous hemagglutinin (FHA) from pertussis and anti-polyribosylribitol phosphate (PRP) from Hib antibody concentrations tended to be higher, and anti-HBV and anti-pertussis toxin (PT) from pertussis antibody concentrations lower in DT2aP-HBV-IPV-Hib versus DT3aP-HBV-IPV/Hib vaccinees. Anti-PT and post-primary anti-PRP antibody concentrations tended to be higher, and anti-HBV, anti-FHA, anti-pertactin from pertussis and post-booster anti-PRP antibody concentrations lower in DT5aP-HBV-IPV-Hib versus DT3aP-HBV-IPV/Hib recipients. Slightly lower immune responses towards most vaccine antigens were observed with 2 + 1 versus 3 + 1 schedules post-primary vaccination, suggesting that 2 + 1 schedules should only be considered in countries with very high vaccination coverage.

CONCLUSION

Although the licensed hexavalent vaccines are generally considered similar, analyses of immunogenicity data from head-to-head trials highlighted differences that could be related to differences in composition and formulation. In addition, the demonstrated non-inferiority of the immunogenicity of the more recent vaccines versus DT3aP-HBV-IPV/Hib does not allow a full bridging to similar efficacy, effectiveness and safety. The availability of DT3aP-HBV-IPV/Hib over > 20 years allowed to collect a wealth of data on its long-term immunogenicity, safety and effectiveness in clinical and post-marketing studies, and makes it a key pillar of pediatric immunization.

Trends in Hospital Admissions for Pertussis Infection: A Nationwide Retrospective Observational Study in Italy, 2002-2016

Background: Pertussis is a highly contagious infectious disease which continues to be an important public-health issue despite the high immunization coverage rates achieved. However, evidence of increased circulation of pertussis among adolescents and adults due to waning immunity and atypical clinical manifestations seem to be the main reasons for its resurgence. The aim of this study was the analysis of the epidemiological trend for pertussis-related hospitalizations in Italy, in relation with vaccination coverage and information from laboratory confirmed cases of pertussis. Methods: A retrospective observational study investigating hospitalizations for pertussis from 2002 to 2016 in Italy was conducted. Frequencies and rates of hospitalization were analyzed and hospitalization data were compared with a series of already published laboratory confirmed data. Results: This study highlighted a rising trend for pertussis hospitalizations in Italy since 2008. Infants aged <1 year showed the highest frequencies (63.39%) and average rates (74.60 × 100000 infants) of hospitalization despite an extremely high vaccination coverage (95.89%). An increasing trend of hospitalization frequency emerged for the age group with levels of IgG antibodies to pertussis toxin compatible with pertussis infection within the last year (20–29 years old age group). Conclusions: The rising trend for pertussis hospitalizations and the greater involvement of infants aged <1 year require an integrated approach, including the implementation of booster doses administration in adolescence and adulthood, the vaccination of pregnant women and the cocoon strategy.

Insights and expectations for Tdap vaccination of pregnant women in Italy

BACKGROUND

Pertussis is a widespread vaccine-preventable disease, associated with an increasing trend to hospitalization among newborns. Pertussis in newborns can be fatal, and the most effective way to prevent it is maternal immunization (MI) with a reduced antigen content tetanus, diphtheria, and acellular pertussis vaccine (Tdap). In Italy, the National Immunization Plan (NIP) 2017-2019 introduced de novo Tdap vaccination during each pregnancy at no cost for the recipient. Despite this, vaccination coverage is suboptimal. This survey of pregnant women across Italy was conducted to investigate their knowledge and expectations of Tdap.

METHODS

A cross-sectional survey was conducted. Pregnant women up to 28th gestational weeks were interviewed by Telephone using a questionnaire with 16 questions. Statistics were descriptive.

RESULTS

The final sample recruited 600 respondents evenly distributed across Italy. The average duration of pregnancy at the time of the interview was 20.8 weeks (standard deviation [SD] 6.0). Most women (60.7%) were between 30 and 40 years of age. About half were aware of the risks of pertussis for newborns (54.5%) and the increased risk of hospitalization (59.8%); 47.2% were aware that Tdap MI was offered free of charge under the NIP. Safety information regarding the mother and newborn was considered the most important information in deciding whether to be vaccinated (47.4%), followed by safety information related only to the newborn (29.5%). About half (52.2%) stated that they would "certainly" accept MI, and 25.3% would like to receive more information. Gynecologists were the preferred healthcare providers (HCPs) for the provision of MI information (34.3%), followed by pediatricians (25.5%). Two-thirds of the respondents would prefer to be informed about MI before getting pregnant (66.0%). Vaccines investigated specifically for use in pregnancy were preferred by respondents. Overall, no relevant differences were observed between women pregnant for the first time and those with more than one pregnancy, nor between geographical regions.

CONCLUSIONS

The results show room for improving the awareness and understanding of the risks of pertussis for infants and the protective role of MI. The pregnant women preferred to receive advice on MI from an HCP, primarily their gynecologist. They were most interested in information on the safety profile of Tdap during pregnancy, on the mother, fetus, and newborn. The potential impact of this study to support clinical practice of Healthcare Providers is highlighted in the Focus on the Patient section. [Formula: see text].

Pertussis vaccination in pregnancy: how many pediatric hospitalizations could be prevented?

Pertussis is a severe disease in children, especially in neonates and it is preventable by vaccination during pregnancy. After the observation of a 2-month-old toddler who needed extracorporeal membrane oxygenation for severe RSV plus Bordetella pertussis infection, we performed a review of all cases of pertussis admitted at the Istituto Giannina Gaslini, Genoa, Italy, from 2012 to 2018. We retrieved 72 cases of admission for pertussis, 46% aging less than 3 months, 42% with at least one comorbidity. Two patients needed ICU admission. Pertussis vaccination during pregnancy could contribute to reduce this burden of hospitalizations in youngest subjects.

Trends in Canadian infant pertussis hospitalizations in the pre- and post-acellular vaccine era, 1981-2016

OBJECTIVE

The acellular pertussis vaccine was introduced into the routine childhood immunization schedule across Canada in 1997-98 and adolescent booster doses were added between 1999 and 2005. We sought to assess the impact of these changes on infant pertussis hospitalizations and admissions to intensive care units (ICU) in Canada.

METHODS

Hospitalizations with a primary diagnosis of pertussis were extracted from the Canadian Discharge Abstract Database (DAD) for cases with hospital discharge dates between 1981 and 2016 using relevant ICD-9 and ICD-10 codes. Only cases with age less than one year at time of admission were included. Disease severity was assessed by admission to ICU. Cases were categorized into two periods: pre-program implementation period (1981-1995) and the post-program implementation period (2006-2016). Incidence rates, risk ratios, and rate differences were calculated for each period and comparisons for the two periods were done using chi-squared and t-tests. Quasi Poisson analysis was used to investigate trends.

RESULTS

When comparing the pre- and post-implementation periods, the average annual hospitalization rates for infants less than 1 year declined from 165.1 (95% CI 161.3, 168.9) to 33.6 (95% CI 31.6, 35.6) pertussis-related admissions per 100,000 population, with a corresponding reduction in the risk ratio of 4.9 (95% CI 4.6, 5.2). The risk of admission into an ICU was 1.58 times higher in the pre- versus post-implementation period while the highest reduction in average annual hospitalizations was 263.3 admissions per 100,000 population in infants 2 months of age. In the post-implementation period, infants less than 1 month of age had the highest average annual hospitalization rate at 126.6 (95% CI 113.1, 140.1) hospitalizations per 100,000 infants.

CONCLUSION

Infant pertussis hospitalizations have reduced greatly over time. Infants under 2 months of age remain the most at-risk age group for hospitalization and admission to ICU.

Resurgence of Pertussis and Emergence of the Ptxp3 Toxin Promoter Allele in South Italy

BACKGROUND

Despite universal immunization programs, pertussis remains a major public health concern. This study aimed to describe the pertussis epidemiology in the Puglia region in 2006-2015 and to identify recent polymorphisms in Bordetella pertussis virulence-associated genes.

METHODS

The pertussis cases in 2006-2015 were identified from the National Hospital Discharge Database and the Information System of Infectious Diseases. Samples of pertussis cases in 2014-2016 that were confirmed by the Regional Reference Laboratory were subjected to ptxA, ptxP and prn gene sequencing and, in 10 cases, multiple-locus variable-number tandem repeat analysis.

RESULTS

In Puglia in 2006-2015, the pertussis incidence rose from an average of 1.39/100,000 inhabitants in 2006-2013 to 2.56-2.54/100,000 in 2014-2015. In infants <1 year of age, the incidence rose from an average of 60.4/100,000 infants in 2006-2013 to 149.9/100,000 in 2015. Of the 661 cases recorded in 2006-2015, 80.3% required hospitalization; of these, 45.4% were <1 year of age. Of the 80 sequenced samples, the allelic profile ptxA1-ptxP3-prn2 was detected in 74. This variant was detected in both vaccinated and unvaccinated people. Six Bordetella pertussis samples were prn deficient. The multiple-locus variable-number tandem repeat analysis cases exhibited multiple-locus variable-number tandem repeat analysis-type 27.

CONCLUSIONS

The pertussis incidence in Puglia has risen. The hypervirulent strain was also found in vaccinated people. This suggests bacterial adaptation to the vaccine and raises questions about acellular vaccine effectiveness. Prevention of infant pertussis cases is best achieved by immunizing the pregnant mother. Enhanced surveillance and systematic laboratory confirmation of pertussis should be improved in Italy.

Trends and costs of pertussis hospitalizations in Portugal, 2000 to 2015: from 0 to 95 years old

BACKGROUND

Pertussis has caused several outbreaks and concern worldwide. Despite high vaccination coverage, people of all ages are still affected with significant morbidity and mortality. We aimed to analyse all pertussis hospitalizations in Portugal to help to delineate preventive policies.

METHODS

Data were collected from a Portuguese administrative database, which contains all registered hospitalizations in mainland Portugal. Cases were identified using the ICD-9-CM code 033.x (whooping cough) as principal or secondary diagnosis, with hospital discharges between 2000 and 2015. Data were analysed by age groups.

RESULTS

Of 2281 hospitalizations, 94% occurred in infants (<1 year). The mean and median ages were 20 and 2 months, respectively. A seasonal pattern was observed, with higher number of hospitalizations during the winter for infants, and during the summer for other age groups. Higher hospitalization rates were registered in the Southern regions. The mean and median lengths of hospital stay were 8 and 6 days, respectively. The main complications were acute respiratory failure and pneumonia. Invasive or non-invasive ventilation, or both, was required in 2.4, 1.8 and 0.6% of hospitalized cases, respectively. The overall inpatient case fatality rate was 0.7%; 0.8, 11.5 and 17.4% for the age groups 0-1 months, 18-64 years and ≥65 years, respectively. Total hospitalization costs were estimated to be 2,698,995€.

CONCLUSION

Our study emphasizes the need to adopt new preventive strategies mainly focused on infants, to reduce morbidity and costs of hospitalizations related to pertussis.

Burden of varicella in Italy, 2001-2010: analysis of data from multiple sources and assessment of universal vaccination impact in three pilot regions

Varicella represents the most widespread vaccine-preventable childhood infectious disease in Italy. The purpose of this retrospective study was to assess the burden of varicella in Italy and in three regions that first implemented universal varicella vaccination. Four data sources were analysed: statutory notification data, the National Hospital Discharge Database, mortality data, and the vaccination coverage reached in Sicilia, Veneto and Apulia. The incidence rates per 100,000 population were calculated using the Italian resident population provided by the Italian Institute of Statistics in 2001-2010. In 2001-2010, the mean annual incidence of notifications of varicella was 150.7 cases per 100,000 population, reaching 948.6 cases per 100,000 population in the paediatric age group. The annual incidence declined to 102.6 per 100,000 population in 2010. During the period considered, 20,295 hospitalizations for varicella were observed. The mean annual incidence was 3.4 per 100,000 population, reaching a minimum of 2.5 per 100,000 in 2009 and 2010. Of the hospitalizations, 68.4% occurred in the paediatric age group. The median length of hospital stay was 4 days. During 2001-2003 and 2006-2010, 33 deaths were reported. In the three regions considered, vaccination coverage increased steadily, reaching 81.5% in Sicily, 79.4% in Veneto and 75.6% in Apulia in 2010. During the same period, hospitalization and notification rates decreased significantly. This study demonstrated that varicella continues to represent a relevant health problem in Italy, especially in the paediatric age group. Data obtained from the three Italian regions that first introduced universal vaccination demonstrated that vaccination reduces the incidence of varicella and hospitalization rates.

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.

Pertussis

Pertussis continues to be an important public-health issue. The high immunization coverage rates achieved, mainly in industrialized countries, have certainly decreased the spread of the pathogen. However, as immunity wanes, adolescents and adults play an important role in the dynamics of the infection. The surveillance system has several limitations and the underestimation of pertussis in adolescents, young adults and adults is mainly related to the atypical clinical characteristics of cases and the lack of lab confirmation. The real epidemiological impact of pertussis is not always perceived. The unavailability of comprehensive data should not hamper the adoption of active prophylactic measures designed to avoid the impact of waning immunity against pertussis. Different immunization strategies have been suggested and/or already adopted such as immunization of newborns, pre-school and school children, adolescents, adults, healthcare workers, childcare workers, pregnant women, cocoon strategy. Prevention of pertussis requires an integrated approach and the adoption of different immunization strategies, with the objective of achieving and maintaining high coverage rates.

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.

Pertussis is still common in a highly vaccinated infant population

AIM

To provide epidemiological data on pertussis in a highly vaccinated paediatric population, focusing on the age of the infected children.

METHODS

We analysed data from the regional hospital discharge database on children hospitalised for pertussis in Tuscany, Italy, from January 2000 to December 2012.

RESULTS

A total of 279 cases were recorded. The majority of hospitalised children were infants (75.6%), who had the highest rate of complications (24.2%) of any age group and a crude mortality rate of 9.47 per 1000. The overall hospitalisation rate decreased significantly during the study period, from 4.23 to 2.82 per 100 000, but when we analysed the data by age groups, we found notable differences. Hospitalisation rates in the 1- to 4-year-old age group decreased significantly from 2.82 in the year 2000 to zero per 100 000 in 2012 and decreased significantly in the 5- to 9-year-old age group over the same period, from 6.58 to 0.63 per 100 000. Overall hospitalisation rates in the infant group remained high at 53.14 per 100 000, with three peaks due to periodic pertussis outbreaks.

CONCLUSION

Pertussis is still a relevant health concern in infants who are unvaccinated or incompletely immunised, both in terms of morbidity and mortality.

Trends of human brucellosis in Italy, 1998-2010

SUMMARY

We describe the epidemiological trends and spatial distribution of human brucellosis in Italy over 13 years (1998-2010). In the study period 8483 cases were notified in Italy, with a relevant decrease (-89%) from 1998 to 2010. Most cases were notified in southern Italy (Campania, Apulia, Calabria, Sicily). In these regions we observed relevant differences in the risk of brucellosis at province level. Cases were distributed with a seasonal pattern, male patients represented 60% of the cases and no significant differences were observed between age groups. We modelled the underreporting rate that ranged between 2 and 21 (average 12·5). According to our estimates the true number of cases would have ranged from 41 821 to 155 324 providing a far more severe picture of human brucellosis in Italy than the one provided by the surveillance system.

Incidence of whooping cough in Spain (1997-2010): an underreported disease

Whooping cough is currently the worst controlled vaccine-preventable disease in the majority of countries. In order to reduce its morbidity and mortality, it is essential to adapt vaccination programmes to data provided by epidemiological surveillance. A population-based retrospective epidemiological study to estimate the minimum annual undernotification rate of pertussis in Spain from 1997 to 2010 was performed. The incidence of pertussis cases reported to the National Notifiable Disease Surveillance System was compared with the incidence of hospital discharges for pertussis from the National Surveillance System for hospital data, Conjunto Mínimo Básico de Datos. The overall reported incidence and that of hospitalisation for whooping cough were 1.3 cases × 100,000 inhabitants in both cases. Minimum underreporting oscillated between 3.8 and 22.8 %, according to the year of the study. The greatest underreporting (50 %) was observed in children under the age of 1 year.

CONCLUSION

Spanish epidemiological surveillance system of pertussis should be improved with complementary active systems to ascertain the real incidence. Paediatricians and general practitioners should be sensibilized to the importance of notification because this would be essential for adapting the prevention and control measures of this disease.

Prospective nationwide surveillance of hospitalizations due to pertussis in children, 2006-2010

BACKGROUND

Frequency of pertussis is highly variable from country to country and it depends on multiple factors including case definitions and type of surveillance systems used. Many countries recently reported an increase of pertussis cases especially in infants and adolescents.

METHODS

From April 2006 to March 2011, 15-year-old patients hospitalized with suspected or proven pertussis were reported to the Swiss Pediatric Surveillance Unit. Patients with ≥14 days of cough plus paroxysms, whooping or post-tussive vomiting fulfilled the clinical case definition of pertussis. For laboratory confirmation, Bordetella pertussis polymerase chain reaction was offered free of charge.

RESULTS

Data were available from 159 of 173 reported cases and 130 (90% of them <12 months old) were eligible including 125 laboratory-confirmed B. pertussis infections. Rates per 100,000 population were 2.6 (<16 years) and 38.8 (<12 months), respectively. Most frequent complications were cyanosis (63%) and sleep disturbance (60%); 35 (27%) patients received intensive care and 1 patient died. Source of infection was known in 79 (61%) patients and was mainly a sibling, parent or both. Most patients were unimmunized (65%) or incompletely immunized (30%).

CONCLUSIONS

The high rate of pertussis hospitalization in young infants established in this surveillance project and the incomplete pertussis immunization status in almost all hospitalized patients require further efforts for improvement. In addition, introduction of pertussis immunizations for all adolescents (in 2013), young adults (in 2012) and pregnant women (in 2013) in Switzerland should increase indirect protection of vulnerable newborns and infants too young to be fully immunized.

Combined hexavalent diphtheria-tetanus-acellular pertussis-hepatitis B-inactivated poliovirus-Haemophilus influenzae type B vaccine; Infanrix™ hexa: twelve years of experience in Italy

Infant vaccination using 2-dose priming at 3 and 5 mo of age with a booster at 11–12 mo of age was pioneered in Italy. The 3-5-11 schedule is now used in a growing number of European countries. Infanrix™ hexa (DTPa-HBV-IPV/Hib, GlaxoSmithKline Vaccines) was first licensed for use in 2000 and has been the only pediatric hexavalent vaccine available since 2005. We reviewed available clinical trial data describing the immunogenicity of DTPa-HBV-IPV/Hib when administered at 3, 5, and 11 mo of age, and conducted an analysis of safety using global and Italian post-marketing surveillance data. In Italy, DTPa-HBV-IPV/Hib has a demonstrated safety record extending over a decade of use, it has been associated with record levels of vaccine coverage, and with sustained disease control in vaccinated cohorts. Hexavalent vaccines will continue to contribute to high vaccine coverage in Italy and across Europe.

Improving adherence rates to a cocooning program: a pilot experience in Italy

Cocoon is defined as a strategy to reduce the risk for transmission of pertussis to newborn infants by vaccinating household members including parents and siblings. Programmatic challenges make implementation of cocooning program complex. At the local health care unit “ASL Napoli 1 Centro,” a one-year pilot project to evaluate the newborn contacts adherence to a cocoon strategy was started on May, 1st 2011. Healthcare providers (HCPs) offered for free a dTpa booster dose to newborns parents (mothers were immunized after delivery) and household contacts. Until June 30th, overall only 7 dTpa booster doses out of 261 newborns (2.6%) were administered for cocooning. Then, an improvement in communication strategy to the families was introduced by preparing specific information leaflets, increasing the HCPs devoted to the cocoon, and focusing the interaction with families during the visiting time at the maternity ward. Overall, 601 out of 762 (78,8%) contacted new mothers received dTpa booster. Cocoon high acceptance rates could be reached providing that proper communication tools and enough skilled HCPs were engaged in the interaction with the families. This report is, to our knowledge, the first to document successful implementation of pertussis cocooning in an Italian setting.