Pertussis in infants: an underestimated disease

Bronchiolitis guidelines: what about the Italian situation in a primary care setting?

Acute viral bronchiolitis is the most common cause of hospitalization in children under 12 months of age. The variable clinical presentation and the potential for sudden deterioration of the clinical conditions require a close monitoring by healthcare professionals.In Italy, first access care for children is provided by primary care physicians (PCPs) who often must face to a heterogeneous disease presentation that, in some cases, make the management of patient with bronchiolitis challenging. Consequently, Italian studies report poor adherence to national and international guidelines processed to guide the clinicians in decision making in acute viral bronchiolitis.This paper aims to identify the potential factors contributing to the lack of adherence to the suggested guidelines derived by clear and evidence-based recommendations among primary care physicians operating in an outpatient setting, with a specific focus on the context of Italy. Particularly, we focus on the prescription of medications such as β2-agonists, systemic steroids, and antibiotics which are commonly prescribed by PCPs to address conditions that can mimic bronchiolitis.

Sero-Epidemiological Study of Bordetella pertussis Infection in the Italian General Population

A multicenter study was conducted to estimate the prevalence of pertussis IgG antibodies (anti-PTx) in the Italian population. Serum samples (4154) collected in the years 2019−2020 from subjects aged 6 to 90 years were tested. The anti-PTx IgG levels were determined by ELISA test. The limit of detection was 5 IU/mL (International Units per milliliter); values ≥ 40 IU/mL and ≥100 IU/mL indicate an infection that has occurred in recent years and a recent infection (occurred during the last year), respectively. The mean concentration of anti-PTx IgG antibodies in the tested samples was 13 IU/mL; 1.0% of subjects had a titer ≥ 100 IU/mL, 5.3% a titer between 40 and 100 IU/mL, and 38.9% a titer < 5 IU/mL. The mean antibody concentration was significantly higher in males than in females. The age group 25−39 years had the lowest percentage of negative subjects (36.9%) and the highest prevalence of subjects with antibody titers ≥ 100 IU/mL (1.3%). In the age group ≥ 65 years, the prevalence of subjects with titers between 40 and 100 IU/mL (6.7%) and the percentage of negative subjects (44.8%) was higher than in the other age groups. The results highlight the possible role of adolescents and adults in the transmission of B. pertussis.

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.

Incidence and severity of pertussis hospitalisations in infants aged less than 1 year in 37 hospitals of six EU/EEA countries, results of PERTINENT sentinel pilot surveillance system, December 2015 to December 2018

Introduction

PERTINENT is a pilot active surveillance system of infants hospitalised with pertussis in six European Union/European Economic Area countries (37 hospitals, seven sites).

Aim

This observational study aimed to estimate annual pertussis incidence per site from 2016 to 2018 and respective trends between 2017 and 2018. Pertussis cases were described, including their severity.

Methods

We developed a generic protocol and laboratory guidelines to harmonise practices across sites. Cases were hospitalised infants testing positive for Bordetella pertussis by PCR or culture. Sites collected demographic, clinical, laboratory data, vaccination status, and risk/protective factors. We estimated sites’ annual incidences by dividing case numbers by the catchment populations.

Results

From December 2015 to December 2018, we identified 469 cases (247 males; 53%). The median age, birthweight and gestational age were 2.5 months (range: 0–11.6; interquartile range (IQR): 2.5), 3,280 g (range: 700–4,925; IQR: 720) and 39 weeks (range: 25–42; IQR: 2), respectively. Thirty cases (6%) had atypical presentation either with cough or cyanosis only or with absence of pertussis-like symptoms. Of 330 cases with information, 83 (25%) were admitted to intensive care units including five deceased infants too young to be vaccinated. Incidence rate ratios between 2018 and 2017 were 1.43 in Czech Republic (p = 0.468), 0.25 in Catalonia (p = 0.002), 0.71 in France (p = 0.034), 0.14 in Ireland (p = 0.002), 0.63 in Italy (p = 0.053), 0.21 in Navarra (p = 0.148) and zero in Norway.

Conclusions

Incidence appeared to decrease between 2017 and 2018 in all but one site. Enhanced surveillance of hospitalised pertussis in Europe is essential to monitor pertussis epidemiology and disease burden.

Pertussis in early life: underdiagnosed, severe, and risky disease. A seven-year experience in a pediatric tertiary-care hospital

AIM

Pertussis continues to be a common worldwide infection in pediatric and adult populations.We aimed to study epidemiological and clinical characteristics of infants and children admitted for pertussis to a tertiary-care hospital and to investigate the risk factors for pediatric intensive care unit (PICU) admission.

MATERIALS AND METHODS

With a retrospective study, we analyzed all medical reports of patients admitted to Bambino Gesù Children's Hospital in Rome from January 2011 to December 2018 with a diagnosis of pertussis.

RESULTS

We examined 195 patients. The majority of hospitalized children (66.15%) were <3 months of age. No mother had received pertussis containing vaccine during pregnancy. Ten cases required admission in PICU. The age at admission was lower in PICU patients with respect to ward patients (42.8 vs 240 days; p < .0007), length of hospital stay was longer in PICU group (24.7 vs 7.52 days; p < .003). Patients who needed PICU admission had greater white blood cell count at hospital admission compared with those hospitalized in the pediatric ward. One infant died and one had encephalitis.

CONCLUSIONS

Pertussis is a remerging disease. In infants, it is associated with significant morbidity and mortality. In recent years, many countries have implemented different vaccination strategies and public health measures to prevent the increase in pertussis cases. Maternal vaccination has been shown to be highly protective for infants <3 months of age before they can develop their own immunity via vaccination.

Analysis of antibiotic sensitivity and resistance genes of Bordetella pertussis in Chinese children

OBJECTIVE

To understood the pathogen detection status and clinical characteristics of suspected pertussis in children and to observe the drug sensitivity and drug resistance genes of Bordetella pertussis (B. pertussis).

METHODS

Three hundred fifty-one cases were collected and their nasopharyngeal swab samples were analyzed by culture and fluorescent quantitative polymerase chain reaction. The susceptibility to erythromycin, clindamycin, ampicillin, levofloxacin, and sulfamethoxazole-trimethoprim were tested by E-test for the positive strains, and the susceptibility to erythromycin was also tested for the KB disk diffusion method. The 23S rRNA gene of the positive strains was amplified and sequenced, and statistical analysis was performed in conjunction with clinical data.

RESULTS

The positive rate of bacterial culture was 16.8% (59/351), and the positive rate of PCR was 62.4% (219/351). Two cases were positive about bacterial culture and negative for PCR. There were 221 confirmed cases of pertussis. The E-test results showed that the rate of the sensitivity of the 55 strains of pertussis to erythromycin and clindamycin was 50.9% (28/55), the minimum antibiotic concentration50 (MIC50) and MIC90 values were 0.094/>256 and 0.75/>256 mg/L, respectively, and the MIC50/MIC90 to ampicillin, levofloxacin, and sulfamethoxazole were 0.125/0.19, 0.38/0.5, and 0.125/0.25 mg/L, respectively. The KB disk diffusion method showed 27 of the 55 strains 49.1% (27/55) was resistant to erythromycin; all of the resistant strains had the 23S rRNA gene A2047G mutation, and their MIC of erythromycin was >256 mg/L.

CONCLUSION

The diagnosis of pertussis by a fluorescent quantitative polymerase chain reaction method is more sensitive than that of bacterial culture. The resistance of B. pertussis to erythromycin was prominent. All of the strains of B. pertussis resistant to erythromycin in our center had the A2047G mutation of the 23S rRNA gene.

Pertussis in Italy: how to protect the "unprotectable"?

Whooping cough continues to be an important public health issue despite high levels of vaccination coverage with acellular pertussis vaccine. Young unimmunized infants represent the most vulnerable group with the highest rates of complications and death. As infant-specific pertussis epidemiologic data, especially among neonates, in Italy were limited, a retrospective observational study of hospitalizations for whooping cough in Italian infants aged <12 months between 2007 and 2018 was conducted to address this knowledge gap. The temporal trend of rates, also stratified for age classes according to the expected age for the administration of vaccine doses, were analyzed by the slope of the regression line. The mean age at the time of admission was 92 d (±64). A clear seasonal pattern in the occurrence of pertussis hospitalizations with a summer peak was observed. Infants younger than 3 months old had the highest hospitalization rates (169 x 100000 infants on average), with a significant rising trend of 9 x 100000 infants on average per year. Limiting the analysis to Bordetella pertussis-related hospitalizations such trend was even more evident. In the other age classes, hospitalization rates were considerably lower and gradually decreased with increasing age. This study demonstrated that pediatric populations, too young to be protected by vaccination, had a greater risk of contracting pertussis. Thus, it is necessary to promote additional immunization strategies besides one booster dose in adolescents, including vaccination during pregnancy.

Pertussis in Lao PDR: Seroprevalence and disease

OBJECTIVES

Pertussis is a debilitating vaccine-preventable infection. The aim of this study was to determine susceptibility and exposure to pertussis in Lao PDR in different age groups and subpopulations.

METHODS

A total 3072 serum samples were obtained from different cohorts: children with documented vaccination, pre-schoolers, schoolchildren, blood donors, healthcare workers (HCWs), and pregnant women and paired cord blood. Samples were tested for anti-pertussis toxin IgG antibodies. A history of Bordetella pertussis exposure was defined according to antibody titres. Four hundred and seventy-five throat swabs and nasopharyngeal aspirates were analysed by PCR for the presence of B. pertussis in symptomatic children at the Children's Hospital in Vientiane.

RESULTS

Overall pertussis seroprevalence was 57.5%. The prevalence of titres indicating acute infection or recent vaccination or infection/vaccination within the last 12 months ranged from 7.4% (100/1356) in adults to 21.4% (25/117) in pre-schoolers (age 1-5 years). B. pertussis was detected in 1.05% (5/475) of children with respiratory symptoms in Vientiane Capital.

CONCLUSIONS

It is suggested that routine childhood vaccination, in particular outreach, as well as vaccination of HCWs should be strengthened. A childhood booster and vaccination of pregnant mothers should be considered. There is also a need to improve reporting and to introduce pertussis testing in at least one central facility.

Impact of Pertussis on the Italian population: Analysis of hospital discharge records in the period 2001-2014

OBJECTIVES

The study aimed to analyze and update the impact of pertussis on the Italian population by evaluating pertussis-related hospital admissions in the period 2001-2014.

DESIGN OR METHODS

Hospital Discharge Records (HDR) were provided by the National Archive of HDR data of the Ministry of Health. Only hospitalizations included in the primary diagnosis were evaluated. Significant trends over the considered years were assessed as average annual percent changes (AAPC) applying the Joinpoint model.

RESULTS

A total of 7,102 hospital admissions for pertussis (main diagnosis) were registered; the trend of hospitalizations progressively decreased from >1/100,000 inhabitants in the years 2001-2004 to 0.64/100,000 inhabitants in 2014. A great part of hospitalizations (63.6%) involved subjects <1 year of life; almost 20% of cases were registered in the age class 5-14 years. The Joinpoint analysis showed a statistically significant variation in some age classes.

CONCLUSIONS

Even if this study shows a decreasing trend in the number of pertussis-related hospitalizations, the impact of the disease in Italy in terms of hospital admissions continues to be relevant, especially in the <1 year age class. Pertussis therefore continues to be, in Italy as well as in other European countries, an important public health issue.

Questionnaire survey on maternal pertussis vaccination for pregnant women and mothers in Nara prefecture, Japan

Background: Infantile pertussis is a major concern and causes a significant health burden worldwide. Maternal adult tetanus, diphtheria, and acellular pertussis (Tdap) vaccination is very effective way of preventing infantile pertussis. However, Tdap has not been approved by the Japanese government or been included in Japan's national immunization program (NIP). We carried out a questionnaire survey to investigate whether Japanese women would accept the Tdap vaccination if they were provided with appropriate information.Methods: The questionnaire survey was administered to pregnant women who visited the Obstetrics and Gynecology Department and mothers who visited the Pediatrics Department of Nara Medical University, Kashihara City, Japan, between October 2018 and May 2019. The questionnaire included information about pertussis infection and maternal vaccination, followed by seven questions.Results: A total of 943 participants answered the questionnaire (481 pregnant women and 462 mothers). Before reading the information, just 4.6% of participants knew that infantile pertussis can be prevented by maternal vaccination. After reading the information, 93.0% and 92.6% of participants thought that the maternal Tdap vaccine should be approved by the Japanese government and be included in the NIP, respectively. Although only 67.6% of participants wished to have the maternal Tdap vaccine without government financial support after reading the information, 92.5% said they would have the vaccine with government support (P < .001).Conclusion: Most Japanese mothers and pregnant women would like the maternal Tdap vaccine to be approved by the government and included in the NIP, once they have been provided with appropriate information.

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].

Immunisation status of children presenting to the emergency department: Linkage of a longitudinal birth cohort with national immunisation data

AIM

To describe the relationship between emergency department (ED) diagnosis of infectious disease and immunisation status in children ≤5 years. We also aimed to demonstrate feasibility of proof-of-concept linkage between disparate databases.

METHODS

Data from a cohort of 3404 children born in Southeast Queensland/Far North New South Wales between 2006 and 2011 were linked to Australian Childhood Immunisation Registry data and Emergency Department Information System data for presentations between 2006 and 2014. Immunisation status was assigned using the 2009 National Immunisation Program schedule.

RESULTS

Of 1490 children (79% of those consented) with data on immunisation status, 87.2 and 84.6% were fully immunised by 12 and 24 months, respectively. Adding partially immunised children increased this to 93.2 and 91.4% at 12 and 24 months, respectively. Nearly two-thirds of all children made at least one ED presentation. Children presenting to ED with an infectious disease did not differ in immunisation status compared to children with other (non-infectious disease type) presentations but were younger, more likely to live with other children and had a longer ED stay and higher admission rate. Respiratory syncytial virus (RSV) was more frequently diagnosed in unimmunised children.

CONCLUSIONS

In an existing birth cohort, immunisation rates were lower than the national average. RSV was more prevalent in unimmunised children presenting to ED, but immunisation status was not significantly associated with other infectious disease presentations. Linkage between national immunisation data and Australian ED data is feasible and has the potential to identify previously unrecognised factors related to child immunisation status and health-care utilisation.

Resurgence of pertussis in Taiwan during 2009-2015 and its impact on infants

BACKGROUND/PURPOSE

Pertussis incidence markedly decreased due to universal vaccination, but outbreaks had been noted worldwide in recent decade. This study was conducted to know the epidemiology of pertussis and its impact on infants in Taiwan.

METHODS

Epidemiologic parameters for confirmed pertussis cases were collected from the Taiwan Centers for Disease Control. The incidence of each age group over years was calculated using population data. We also did retrospective reviews of laboratory-confirmed pertussis cases in NTUH to analyze clinical characteristics and disease severity.

RESULTS

A total of 668 confirmed pertussis cases were obtained from the Taiwan CDC open database between 2003 and 2017. There was higher incidence during the period 2009-2015, with a mean incidence of 0.27 cases per 100,000 population, about 2-fold increase compared with mean incidence of 0.12 cases per 100,000 population during the period 2003-2008. Infants accounted for the highest proportion of all cases (49.8%), with mean incidence of 16.1 cases per 100,000 people per year during 2009-2015, and a trend of increase was found from 2003 to 2015. In NTUH, a total of 17 laboratory-confirmed pertussis cases were diagnosed during 2012-2016, and 14 cases were young infants. Among them, 9 infants had been admitted to intensive care unit and 2 infant needed invasive ventilator support.

CONCLUSION

There was a resurgence of pertussis during 2009-2015 and it had significant impact on infants. Young infants with pertussis may be severe and need intensive care, so preventive strategy may be advocated for them.

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.

Identification of Etiologic Agents of the Pertussis-like Syndrome in Children by Real-time PCR Method

The aim of this study was to recognize the identity and frequency of etiologic agents of the pertussis-like syndrome in children &lt; 2 years of age. A cross-sectional hospital-based study conducted from August 2014 to August 2015. All children &lt; 2 years of age (n=100) who were suspected as pertussis infected were enrolled in this study and tested for Bordetella pertussis, adenovirus (Adv), respiratory syncytial virus (RSV), human metapneumovirus (hMPV), and influenza virus A (INF-A) by real-time PCR technique. RSV was the most detected pathogen (20%), followed by B. pertussis (18%), Adv (16%), INF-A (11%), and hMPV (10%). Co-infection was observed in 8 patients (11%) and the combinations of RSV/INF-A (n=3, 4%), and AdV/B. pertussis (n=3, 4%) were more frequent. RSV, B. pertussis, and hMPV were more frequent pathogens among infants &lt; 4 months of age. However, Adv and INF-A were more frequent pathogens among children &gt; 6 months of age. In this study, RSV was the most frequent identified pathogen (n=20, 20%), followed by B. pertussis (n=18, 18%) and AdV (n=16, 16%). Pertussis was more frequent in spring (8%) and summer (6%). In addition, clinical symptoms of pertussis were the same as some viral pathogens, which can lead to misdiagnosis of infection. Therefore, diagnosis of pertussis should be established on the bases of both the clinical symptoms and the laboratory methods.

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.

Infant Hospitalizations and Mortality After Maternal Vaccination

BACKGROUND

The Advisory Committee on Immunization Practices currently recommends pregnant women receive influenza and tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccines. There are limited studies of the long-term safety in infants for vaccines administered during pregnancy. We evaluate whether maternal receipt of influenza and Tdap vaccines increases the risk of infant hospitalization or death in the first 6 months of life.

METHODS

We included singleton, live birth pregnancies in the Vaccine Safety Datalink between 2004 and 2014. Outcomes were infant hospitalizations and mortality in the first 6 months of life. We performed a case-control study matching case patients and controls 1:1 and used conditional logistic regression to estimate odds ratios for maternal exposure to influenza and/or Tdap vaccines in pregnancy.

RESULTS

There were 413 034 live births in our population. Of these, 25 222 infants had hospitalizations and 157 infants died in the first 6 months of life. We found no association between infant hospitalization and maternal influenza (adjusted odds ratio: 1.00; 95% confidence interval [CI]: 0.96-1.04) or Tdap (adjusted odds ratio: 0.94; 95% CI: 0.88-1.01) vaccinations. We found no association between infant mortality and maternal influenza (adjusted odds ratio: 0.96; 95% CI: 0.54-1.69) or Tdap (adjusted odds ratio: 0.44; 95% CI: 0.17-1.13) vaccinations.

CONCLUSIONS

We found no association between vaccination during pregnancy and risk of infant hospitalization or death in the first 6 months of life. These findings support the safety of current recommendations for influenza and Tdap vaccination during pregnancy.

Emerging Infections and Pertinent Infections Related to Travel for Patients with Primary Immunodeficiencies

In today's global economy and affordable vacation travel, it is increasingly important that visitors to another country and their physician be familiar with emerging infections, infections unique to a specific geographic region, and risks related to the process of travel. This is never more important than for patients with primary immunodeficiency disorders (PIDD). A recent review addressing common causes of fever in travelers provides important information for the general population Thwaites and Day (N Engl J Med 376:548-560, 2017). This review covers critical infectious and management concerns specifically related to travel for patients with PIDD. This review will discuss the context of the changing landscape of infections, highlight specific infections of concern, and profile distinct infection phenotypes in patients who are immune compromised. The organization of this review will address the environment driving emerging infections and several concerns unique to patients with PIDD. The first section addresses general considerations, the second section profiles specific infections organized according to mechanism of transmission, and the third section focuses on unique phenotypes and unique susceptibilities in patients with PIDDs. This review does not address most parasitic diseases. Reference tables provide easily accessible information on a broader range of infections than is described in the text.

Severe pertussis infection in infants less than 6 months of age: Clinical manifestations and molecular characterization

We conducted a study to determine the main traits of pertussis among unimmunized infants less than 6 months of age. From August 2012 to March 2015, 141 nasopharyngeal aspirates (NPAs) were collected from infants with respiratory symptoms attending 2 major hospitals in Rome. Clinical data were recorded and analyzed. Lab-confirmation was performed by culture and realtime PCR. B. pertussis virulence-associated genes (ptxP, ptxA and prn), together with multilocus variable-number tandem repeat analysis (MLVA), were also investigated by the sequence-based analysis on the DNAs extracted from positive samples. Antibiotic susceptibility with Etest was defined on 18 viable B. pertussis isolates. Samples from 73 infants resulted positives for B. pertussis. The median age of the patients was 45 d (range 7–165); 21 infants were treated with macrolides before hospital admission. Cough was reported for a median of 10 d before admission and 18 d after hospital discharge among infected infants, 84% of whom showed paroxysmal cough. No resistance to macrolides was detected. Molecular analysis identified MT27 as the predominant MLVA profile, combined with ptxP3-ptxA1-prn2 associated virulence genes.

Although our data may not be generalized to the whole country, they provide evidence of disease severity among infants not vaccinated against pertussis. Moreover, genetically related B. pertussis strains, comprising allelic variants of virulence associated genes, were identified.

Pertussis Toxin Exploits Host Cell Signaling Pathways Induced by Meningitis-Causing E. coli K1-RS218 and Enhances Adherence of Monocytic THP-1 Cells to Human Cerebral Endothelial Cells

Pertussis toxin (PTx), the major virulence factor of the whooping cough-causing bacterial pathogen Bordetella pertussis, permeabilizes the blood–brain barrier (BBB) in vitro and in vivo. Breaking barriers might promote translocation of meningitis-causing bacteria across the BBB, thereby facilitating infection. PTx activates several host cell signaling pathways exploited by the neonatal meningitis-causing Escherichia coli K1-RS218 for invasion and translocation across the BBB. Here, we investigated whether PTx and E. coli K1-RS218 exert similar effects on MAPK p38, NF-κB activation and transcription of downstream targets in human cerebral endothelial TY10 cells using qRT-PCR, Western blotting, and ELISA in combination with specific inhibitors. PTx and E. coli K1-RS218 activate MAPK p38, but only E. coli K1-RS218 activates the NF-κB pathway. mRNA and protein levels of p38 and NF-κB downstream targets including IL-6, IL-8, CxCL-1, CxCL-2 and ICAM-1 were increased. The p38 specific inhibitor SB203590 blocked PTx-enhanced activity, whereas E. coli K1-RS218’s effects were inhibited by the NF-κB inhibitor Bay 11-7082. Further, we found that PTx enhances the adherence of human monocytic THP-1 cells to human cerebral endothelial TY10 cells, thereby contributing to enhanced translocation. These modulations of host cell signaling pathways by PTx and meningitis-causing E. coli support their contributions to pathogen and monocytic THP-1 cells translocation across the BBB.