Pertussis In Infants Research Articles

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

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

Risk Markers for Pertussis Among Infants

Hispanic infants are at greater risk of pertussis compared with other racial/ethnic groups. Studies have shown that the source of Bordetella pertussis infection for most infants is household members. Using a case-control study, we examined risk markers for pertussis among Hispanic and non-Hispanic infants and evaluated whether maternal parity, a proxy for household size, contributes to the ethnic disparity. We evaluated infants born in California during 2013-2014; cases were infants reported to California Department of Public Health with pertussis occurring before 4 months of age, and controls were infants who survived to at least 4 months of age without pertussis. Bivariate comparisons and multivariate logistic regression models were used to identify risk markers for pertussis in Hispanic and non-Hispanic infants. Increased maternal parity was associated with greater risk of pertussis, with a clear dose response observed with increasing risk for additional prior births. Teenage mothers were more likely to have infants with pertussis. These were both independent risk factors across all racial/ethnic groups, even when adjusting for important covariates. Preterm birth and Medicaid insurance were also identified as independent risk markers among Hispanic infants only. Infants of all races/ethnicities with older siblings or born to younger mothers are at increased risk of pertussis. Among Hispanic infants, prematurity and Medicaid insurance were independent risk markers for pertussis. These factors highlight the need to ensure prompt immunization of pregnant women with Tdap at the earliest opportunity starting at 27 weeks gestation.

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 < 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 < 12 months of age was significantly higher in the preintervention period (6.7%) compared with the cocooning period (3.3%, p = 0.0067).

Effectiveness of Prenatal Tetanus, Diphtheria, Acellular Pertussis Vaccination in the Prevention of Infant Pertussis in the U.S.

Effectiveness of Prenatal Tetanus, Diphtheria, Acellular Pertussis Vaccination in the Prevention of Infant Pertussis in the U.S.

Prévenir la coqueluche chez le nouveau-né : mère vaccinée durant la grossesse, nourrisson protégé

Pertussis is a serious health issue in infants < 3 months. Too young to be vaccinated, they are at higher risk of developing pertussis and vulnerable to severe complications. Two vaccine strategies exist to prevent infant pertussis. The older « cocooning » strategy involves vaccinating parents and close contacts, indirectly protecting newborns. The more effective strategy is to immunize women during pregnancy, providing infants passive protection by transplacental transfer of pertussis antibodies. However, some women and their caregivers are worried about receiving the vaccine during pregnancy. We review the effectiveness, safety, timing and implementation of pertussis antenatal immunization. The aim is to remind practitioners of current recommendations with supporting data. This can be used to reassure future parents and enable informed decisions.

Systematic review found that there was moderate evidence that vaccinating healthcare workers prevented pertussis in infants.

There was moderate evidence that tetanus-diphtheria acellular pertussis vaccinations for healthcare workers were effective in preventing pertussis in all age groups and specifically in infants. The results must be interpreted with caution due to the low quality and heterogeneity of the studies.

Mechanism and prevention of death caused by pertussis in infants

The mortality of severe pertussis has not been significantly decreased in recent years.Persistent pulmonary hypertension, continuous tachycardia, severe respiratory failure in early stage and frequent severe nerve damage, severe hyperlipidemia and hypercholesterolemia, etc.suggest malignant pertussis.Refractory shock and hypoxemia are direct causes of death, and even died after discharge.In addition to anti-infection, symptomatic treatment and life support, early blood replacement can be performed, when children are accompanied refractory pulmonary hypertension and cardiogenic shock caused by hyperlipidemia.Infants in high-risk areas can be vaccinated ahead of plan, and macrolide antibiotics can be used for the people in high risk to prevent onset or delay the progress of disease after exposed. Key words: Pertussis; Malignant; Death mechanism; Prevention

Effectiveness of Vaccination During Pregnancy to Prevent Infant Pertussis

(Abstracted from Pediatrics 2017;139(5):e20164091) Pertussis is a virulent and life-threatening respiratory infection, particularly in infants, caused by the bacteria Bordetella pertussis. Tetanus toxoid, reduced diphtheria toxoid, acellular pertussis (TDaP) vaccination during pregnancy is recommended to protect newborns against pertussis.

Clinical Characteristics of Hospitalized Infants With Laboratory-Confirmed Pertussis in Guatemala

Pertussis is an important cause of hospitalization and death in infants too young to be vaccinated (aged <2 months). Limited data on infant pertussis have been reported from Central America. The aim of this study was to characterize acute respiratory illnesses (ARIs) attributable to Bordetella pertussis among infants enrolled in an ongoing surveillance study in Guatemala. As part of a population-based surveillance study in Guatemala, infants aged <2 months who presented with ARI and required hospitalization were enrolled, and nasopharyngeal and oropharyngeal swab specimens were obtained. For this study, these specimens were tested for B pertussis using real-time polymerase chain reaction (PCR). Among 301 infants hospitalized with ARI, we found 11 with pertussis confirmed by PCR (pertussis-positive infants). Compared to pertussis-negative infants, pertussis-positive infants had a higher mean admission white blood cell count (20900 vs 12579 cells/μl, respectively; P = .024), absolute lymphocyte count (11517 vs 5591 cells/μl, respectively; P < .001), rate of admission to the intensive care unit (64% vs 35%, respectively; P = .054), and case fatality rate (18% vs 3%, respectively; P = .014). Ten of the 11 pertussis-positive infants had cough at presentation; the majority (80%) of them had a cough duration of <7 days, and only 1 had a cough duration of >14 days. Fever (temperature ≥ 38°C) was documented in nearly half (45%) of the pertussis-positive infants (range, 38.0-38.4°C). In this study of infants <2 months of age hospitalized with ARI in Guatemala, pertussis-positive infants had a high rate of intensive care unit admission and a higher case fatality rate than pertussis-negative infants.

Effectiveness of Prenatal Tdap Immunization in the Prevention of Infant Pertussis in the United States

BackgroundThe Centers for Disease Control and Prevention recommends that all pregnant women in the United States receive tetanus-diphtheria-acellular pertussis (Tdap) immunization to prevent infant pertussis. While the vaccine may be administered at any time during pregnancy, the recommendations define administration at 27 to 36 weeks of gestation as optimal timing to prevent infant pertussis. These recommendations were primarily based on immunogenicity studies. The objective of this study was to examine the clinical effectiveness of prenatal Tdap, and to understand whether effectiveness varies by gestational age at immunization.MethodsWe performed a nationwide cohort study of pregnant women with deliveries in 2010–2014 and their infants. Commercial insurance claims data were used to identify receipt of Tdap immunization in the pregnant women, and hospitalizations and outpatient visits for pertussis in their infants until 18 months of age. To address the difficulties in diagnosing pertussis, we also employed a “probable pertussis” definition, as an inpatient or outpatient diagnosis of pertussis, plus antibiotic treatment with a macrolide or trimethoprim/sulfamethoxazole within 7 days of diagnosis. Pertussis occurrence was compared between infants of mothers who received prenatal Tdap (overall, and stratified by gestational age at administration) and infants of unvaccinated mothers.ResultsThere were 675,167 mother–infant pairs included in the cohort. Among infants whose mothers received Tdap at any time during pregnancy, the rate of pertussis hospitalization was 50% lower (adjusted hazards ratio (HR) = 0.50, 95% CI: 0.23, 1.09), and the rate of probable pertussis was 42% lower (HR = 0.58, 95% CI: 0.38, 0.89) than infants of unimmunized mothers. Pertussis rates were also lower for infants whose mothers received prenatal Tdap during the third trimester. Infants whose mothers received Tdap before the third trimester also tended to have lower rates of pertussis, but these estimates were imprecise.ConclusionInfants of mothers who received prenatal Tdap experienced half the rate of pertussis as compared with infants of unimmunized mothers. Our results do not provide evidence to support changing the currently recommended timing of Tdap administration in pregnancy.Disclosures S. Becker-Dreps, Pfizer: Consultant and Grant Investigator, Consulting fee and Research grant; A. M. Butler, Astra Zeneca: Consultant, Support to institution; Amgen: Grant Investigator, Investigator initiated grant to institution; D. J. Weber, Merck: Consultant and Speaker’s Bureau, Consulting fee and Speaker honorarium; Pfizer: Consultant, Consulting fee; J. B. Layton, Merck: Member of Center for Pharmacoepidemiology, Support to institution; GlaxoSmithKline: Member of Center for Pharmacoepidemiology, Support to institution; UCB Biosciences: Member of Center for Pharmacoepidemiology, Support to institution

Epidemiology and Trends of Pertussis among Infants: United States, 2000–2015

BackgroundPertussis, a cyclic respiratory disease, causes the greatest morbidity and mortality among infants, particularly those too young to be vaccinated. Following a resurgence of pertussis in the 1990s, a recommendation was made in 2012 to vaccinate during every pregnancy in order to prevent infant disease. We describe pertussis trends from 2000–2015 among U.S. infants aged <1 year.MethodsWe analyzed infant pertussis cases reported through the National Notifiable Diseases Surveillance System from 2000 to 2015. Incidence rates (cases per 100,000 population) among various age groups (<2, 2– <4, 4– <6, and 6–<12 months) were calculated using National Center for Health Statistics population estimates as denominators. Negative binomial regression was used to estimate the annual average percent change with a linear trend; P < 0.05 was significant.ResultsFrom 2000 to 2015, 48,909 infant pertussis cases and 255 deaths were reported; infants aged <2 months accounted for 38.7% of cases. The age distribution of infant cases was stable from 2000 to 2009 but changed from 2010 to 2015 (Fig. 1), as the proportion of cases aged 4–<12 months increased annually on average by 4.7% (P < 0.001). Annual incidence was highest among <2 month olds; however, rates increased among older infants (Fig. 2): 7% average annual increase among infants aged 4–<6 months and 11% among infants aged 6–<12 months (P < 0.001 for each). The proportion of infants hospitalized decreased over time in each age group (P < 0.001 for all) with the largest annual average declines among 4–<6 (−5.1%) and 6–<12 month (−5.9%) olds. For all age groups, hospitalization rates were relatively stable, but non-hospitalization rates increased (P < 0.05 for all). The case–fatality ratio (CFR) was highest among <2 month olds (1.6%); CFRs decreased over time among <2 and 2–< 4 month olds (P < 0.05 for each).ConclusionPertussis incidence remains highest among infants aged <4 months, although the age distribution appears to be changing. Decreasing proportions of infants hospitalized may suggest a true decline in disease severity or an increase in reporting of less severe disease. Ongoing monitoring of infant pertussis is needed to better understand the impact of vaccinating pregnant women to prevent pertussis in young infants.Disclosures All authors: No reported disclosures.

Bordetella pertussis infection in infants less than three months: analysis of 59 cases from 2011 to 2015 in a single center

Objective To study the epidemiological and clinical characteristics of pertussis in infants younger than three months. Methods Infants younger than three months were enrolled from January 1, 2011 to December 31, 2015 with one or more of the following symptoms: persistent cough, spasmic cough, cyanosis of unknown causes, asphyxia and apnea. Multiplex polymerase chain reaction(PCR) assay was performed to identifyBordetella pertussisand enzyme-linked immunosorbent assay was used to detect antibody to pertussis toxin. Clinical features, complications, treatments and prognosis of the infants confirmed with pertussis were analyzed. Results Altogether 202 cases were enrolled in the five years, and 59 (29.2%) of which were positive for pertussis confirmed by multiplex PCR. Among the 59 cases, 37 were boys and 22 were girls. The youngest baby was 13 days and the oldest one was 85 days. Length of stay ranged from 7 to 21 days. Twelve cases had a contact history with family members having chronic cough. Symptoms occurred in spring or summer in 46 cases (78.0%), and in autumn or winter in 13 (22.0%) cases. Symptoms of spasmic cough, cyanosis after coughing, vomiting after coughing and conjunctival hemorrhage were respectively found in 41 (69.5%), 36 (61.0%), 39 (66.1%) and 33 (55.9%) cases, while only six (10.2%) presented with inspiratory whooping sound on coughing. Forty-nine cases (83.1%) showed increased lymphocyte count (≥10×109/L). Twenty-eight cases (47.5%) developed severe pertussis. Complications including apnea and bradycardia after coughing, respiratory failure and heart failure, pertussis encephalopathy as well as highly increased leucocyte count (≥60×109/L) occurred in 23 (39.0%), 18 (30.5%), five (8.5%) and four (6.8%) cases, respectively. Twenty-four cases with severe pertussis required respiratory support, of which six received invasive ventilation and 18 received non-invasive ventilation. Fifty-eight infants were recovered and discharged, while one baby died. Conclusions Bordetella pertussisinfection is an important cause of persistent cough in unimmunized infants under three months of age. The symptoms of pertussis in infants are untypical, but the incidence of severe pertussis is high.Thus early diagnosis and timely treatment are necessary. Key words: Whooping cough; Infant; Cough; Incidence

Tdap Vaccination During Pregnancy Prevents Infant Pertussis

Research Article| August 01 2017 Tdap Vaccination During Pregnancy Prevents Infant Pertussis AAP Grand Rounds (2017) 38 (2): 15. https://doi.org/10.1542/gr.38-2-15 Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Cite Icon Cite Search Site Citation Tdap Vaccination During Pregnancy Prevents Infant Pertussis. AAP Grand Rounds August 2017; 38 (2): 15. https://doi.org/10.1542/gr.38-2-15 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search toolbar search search input Search input auto suggest filter your search All PublicationsAll JournalsAAP Grand RoundsPediatricsHospital PediatricsPediatrics In ReviewNeoReviewsAAP NewsAll AAP Sites Search Advanced Search Topics: pertussis, tdap vaccine Source: Baxter R, Bartlett J, Fireman B, et al. Effectiveness of vaccination during pregnancy to prevent infant pertussis. Pediatrics. 2017; 139 (5): e20164091; doi: https://doi.org/10.1542/peds.2016-4091Google Scholar Researchers from the Kaiser Permanente (KP) Vaccine Study Center, Oakland, CA, conducted a retrospective cohort study to determine the effectiveness of tetanus-diphtheria–acellular pertussis (Tdap) vaccination of pregnant women in protecting their infants against pertussis. For the study, medical record data on infants born at KP Northern California hospitals from 2010 to 2015 were reviewed; only infants born at >37 weeks’ gestation were included. Vaccine information on mothers of study participants was also abstracted from KP medical records. Mothers were classified as receiving Tdap during pregnancy (>7 days prior to delivery) or not receiving a dose of vaccine during pregnancy. Data on maternal Tdap immunization prior to pregnancy (within 2 years) or after pregnancy (after birth of the study participant) were also collected. Study participants were classified as having pertussis on the basis of a positive polymerase chain reaction finding. The primary study outcome was pertussis in a study infant in the first 2 months after birth, and the main secondary outcome was pertussis in the first year after birth. Cox regression was used to calculate the pertussis hazard ratio (HR) in infants of women vaccinated during pregnancy versus infants of unimmunized women. Vaccine effectiveness (VE) was calculated as 1 - HR. Regression models included potentially confounding variables. Similar analyses were performed to assess the VE for maternal Tdap before or after pregnancy. For the secondary outcome of pertussis in the first year after birth, doses of diphtheria-tetanus–acellular pertussis (DTaP) vaccine in the infant were included in the models. Data on 148,981 infants were included in the analyses; the mothers of 68,168 of these infants received Tdap during pregnancy. There were 17 cases of pertussis in study participants prior to the age of 2 months, including 16 in those whose mothers were not vaccinated (VE, 91.4%; 95% confidence interval [CI], 19.5%–99.1%; P = .032). The estimated VE of maternal Tdap vaccination during pregnancy in preventing pertussis in study infants during the first year after birth was 69.0% (95% CI, 43.6%–82.9%; P < .001). Neither maternal Tdap administered prior to pregnancy or afterward was associated with a decreased risk of pertussis in study infants during the first 2 months after birth (P = .138 and P = .336, respectively). The researchers conclude that maternal Tdap vaccination is highly protective against infant pertussis, especially in the first 2 months after birth. Dr Brady has disclosed no financial relationship relevant to this commentary. This commentary does not contain a discussion of an unapproved/investigative use of a commercial product/device. The results of this study strongly support the Centers for Disease Control and Prevention recommendation that all women receive the Tdap vaccine at 27–36 weeks’ gestation during each pregnancy.1,2 The case-fatality rate of pertussis among infants <120 days of age has been reported to be... You do not currently have access to this content.

Risk Factors Associated With Bordetella pertussis Among Infants ≤4 Months of Age in the Pre-Tdap Era: United States, 2002-2005.

In the United States, infants have the highest reported pertussis incidence and death rates. Improved understanding of infant risk factors is needed to optimize prevention strategies. We prospectively enrolled infants ≤4 months of age with incident-confirmed pertussis from 4 sites during 2002-2005 (preceding pertussis antigen-containing vaccination recommendations for adolescents/adults); each case-patient was age and site matched with 2 control subjects. Caregivers completed structured interviews. Infants and their contacts ≥11 years of age were offered serologic testing for IgG; being seropositive was defined as ≥94 antipertussis toxin IgG enzyme-linked immunosorbent assay units per milliliter. Enrolled subjects (115 case-patients; 230 control subjects) had 4396 contacts during incubation periods; 83 (72%) case-patients had ≥1 contact with prolonged (≥5 days) new cough in primary or secondary households. In multivariable analysis, the odds for pertussis were higher for infants with primary/secondary household contacts who had a prolonged new cough, compared with infants who did not. These contacts included mother [adjusted matched odds ratio (aMOR), 43.8; 95% confidence interval (CI), 6.45-298.0] and ≥1 nonmother contact (aMOR, 20.1; 95% CI, 6.48-62.7). Infants receiving breast milk with 0-1 formula feedings daily had decreased pertussis odds (aMOR, 0.27; 95% CI, 0.08-0.89), compared with those receiving more formula. Of 41 tested case-patients, 37 (90%) were seropositive. Pertussis in infants was associated with prolonged new cough (≥5 days) in infants' household contacts. Findings suggest that breastfeeding protects against pertussis and warrants recommendation with pertussis prevention strategies, which currently include pertussis vaccination of pregnant mothers and infants' close contacts.

Effect of Prepregnancy Pertussis Vaccination in Young Infants.

Maternal antibodies to pertussis can hamper infant immune responses to pertussis vaccines. The effect a maternal tetanus, diphtheria, acellular pertussis (Tdap) vaccine booster between 2 consecutive pregnancies is investigated. A prospective study was conducted in Belgium during 2008-2014 on the kinetics of maternal pertussis antibodies in unvaccinated women and their infants (group A; 86 mother-infant pairs) and in siblings born after the women received Tdap vaccine (group B; 58 mother-infant pairs). Levels of antibody to pertussis toxin, antibody to filamentous hemagglutinin, and antibody to pertactin were measured in maternal blood before and after vaccination and at both deliveries, in cord blood from both siblings, and in infants before and after they received a priming series of acellular pertussis containing vaccines. Levels of pertussis antibodies in all group B siblings at birth were significantly higher than those in their siblings at birth, even as the interval since maternal vaccination increased. Blunting of the infant pertussis vaccine response was detected in group B siblings. We estimated the maximum interval between repeat Tdap vaccine doses in adult women that would yield a beneficial effect for the consecutive infant. Prepregnancy Tdap vaccination significantly increases maternal antibody concentrations in consecutive infants. However, similar to the effect of Tdap vaccination during pregnancy, immune responses of later-born infants born to mothers who received a prepregnancy immunization, are blunted.

A case–control study to assess the effectiveness of pertussis vaccination during pregnancy on newborns, Valencian community, Spain, 1 March 2015 to 29 February 2016

In the Valencian Community (Spain), the programme of maternal pertussis vaccination during pregnancy started in January 2015. The objective of this study was to estimate in this region the vaccine effectiveness (VE) in protecting newborns against laboratory-confirmed pertussis infection. A matched case–control study was undertaken in the period between 1 March 2015 and 29 February 2016. Twenty-two cases and 66 controls (+/− 15 days of age difference) were included in the study. Cases were non-vaccinated infants < 3 months of age at disease onset testing positive for pertussis by real-time PCR. For every case three unvaccinated controls were selected. Odds ratios (OR) were calculated by multiple conditional logistic regression for association between maternal vaccination and infant pertussis. Other children in the household, as well as mother- and environmental covariates were taken into account. The VE was calculated as 1 − OR. Mothers of five cases (23%) and of 41 controls (62%) were vaccinated during pregnancy. The adjusted VE was 90.9% (95% confidence interval (CI): 56.6 to 98.1). The only covariate in the final model was breastfeeding (protective effect). Our study provides evidence in favour of pertussis vaccination programmes for pregnant women in order to prevent whooping cough in infants aged less than 3 months.

Implementation of mandatory vaccinations against diphtheria, tetanus and pertussis in preterm infants as part of the Polish Immunization Programme

Introduction: Children born before the 30 week of pregnancy, especially with extremely low birth weight, are to a large degree deprived of the protective level of antibodies normally conveyed by the mother, which makes them more prone to sepsis, pertussis, pneumococcal infections, and influenza. Preterm infants are more likely to be hospitalized due to a pertussis infection than full-term children with normal body weight. Meanwhile, the level of active prevention of infectious diseases is lower in the case of preterm infants than for infants born between the 37th and 40th week of pregnancy, since vaccinations are delayed all too often in the former group. Since 2009, preterm infants hospitalized at the neonatal ward of the University Hospital CMUJ for more than 42 days receive vaccinations against diphtheria, tetanus, pertussis and pneumococcal infections, in addition to routine BCG and HBV immunization. Active prevention of infectious diseases in preterm infants hospitalized at this ward was carried out at the Infectious Diseases Clinic that is part of St. Louis Specialized Regional Children's Hospital in Cracow. Research material and methodology: A group of preterm infants with birth weight below 1500g was selected from a group of preterm infants registered at the Clinic and born before the 30th week of pregnancy in the period from September 2009 to September 2014. These criteria were met by 123 children. Fourteen children who did not receive the three doses of primary DTPa vaccinations either at the Clinic or at the neonatal wards were excluded. The gestational age at birth in the analyzed group 109 children ranged from 22 to 30 weeks, with a mean of 26.8 weeks. Birth weight ranged from 520g to 1480g; the mean weight was 953.4g. The studied group of 109 patients was divided into two subgroups, the first consisted of 57 children who received their initial DTPa vaccinations at neonatal ward and the second were first administered DTPa vaccines at the Clinic. Of 109 children, only 14 (12.84%) were vaccinated on schedule. Sixty-one children (56%) received the DTPa-IPV-Hib-HBV hexavalent vaccine, while the remaining 48 children (44%) were vaccinated with DTPa. In subgroup vaccinated at the neonatal ward, the proportion of children who received the hexavalent vaccine was higher (73.7%) than in second subgroup, in which the polyvalent vaccine was administered to 36.5% of the children. There were no significant differences in terms of the time of the first vaccination in subgroup vaccinated in the hospital setting. However, the time of the second vaccination at the Clinic was statistically significant. Children who had received the hexavalent vaccine received the second dose earlier. Both in subgroup vaccinated at the Clinic as well as across the entire studied group, statistically significant differences in the implementation of the Immunization Programme were found to be in favor of the children who had received the hexavalent vaccine. The geometric mean levels of tetanus toxoid-specific, diphtheria toxoid-specific, and pertussis-specific antibodies as well as anti-HBs were all found to be sufficient to provide adequate protection. The children vaccinated in the hospital setting did not develop any adverse symptoms. Neither of the subgroups experienced any serious adverse events related to vaccination at the Clinic. Conclusions: 1. Even during prolonged hospitalization at a neonatal intensive care unit, immunization with the DTPa vaccine should be performed in addition to vaccination against tuberculosis and HBV. 2. DTPa-IPV-Hib-HBV hexavalent vaccines provide an optimal solution for the implementation of immunization schedules, especially in preterm infants and – even more so – preterm infants with extremely low birth weight. 3. Results from the monitoring of episodes of apnea, bradycardia and saturation levels before and after vaccination at the neonatal ward provide valuable information to the physician that continues vaccination as part of outpatient care.

Epidemiology of pertussis in Casablanca (Morocco): contribution of conventional and molecular diagnosis tools

BackgroundPertussis, a vaccine preventable disease, is still responsible of significant morbidity and mortality around the world, mostly in newborns. The aim of the present study was (1) to introduce pertussis surveillance in the major pediatric hospital of Casablanca (2) to analyze the prevalence of pertussis among children under 14 years of age and their entourage in Casablanca, Morocco.MethodsThis is a prospective and non-case controlled study, including children suspected of Pertussis admitted at the Abderrahim Harouchi Pediatric Hospital in Casablanca, from January 2013 to June 2015. Nasopharyngeal samples were obtained for Bordetella spp. culture and Real time PCR detection (RT-PCR) with specific primers of Bordetella spp., B. pertussis, B. parapertussis and B. holmesii. The detection of Bordetella spp. was also performed in some household contacts of the children suspected of pertussis.ResultsDuring the 2.5-years period, a total of 282 samples were collected from hospitalized children (156) and in some of their contacts (126). Among 156 samples from the children (from whom 57% were under 2 month of age), Bordetella DNA was detected in 61% (96/156) by RT-PCR. Among these positive samples, 91.7% (88/96) corresponded to B. pertussis DNA. Furthermore, in 39.5% (38/96) of the Bordetella positive samples, B. holmesii DNA was also detected. B. parapertussis DNA was detected in only one sample (1/156). Out of the 156 samples collected from the hospitalized children, only 48 were tested by culture, and 4 B. pertussis were isolated (8.3%). Among the 126 samples from the contacts of the children, mostly mothers (115 cases), Bordetella DNA was detected in 47% (59/126), 90% (53/59) being B. pertussis DNA. Moreover, B. holmesii DNA was also detected in 18.6% (11/59) of the Bordetella positive samples, and coexistence of B. pertussis and B. holmesii DNA in 36.5% (35/96). Two B. pertussis were isolated by culture performed on 43 samples of the contacts of the children (4.6%).ConclusionsThis study highlights the circulation of B. pertussis but also of B. holmesii in Casablanca-Morocco with a high proportion of co-infections B. holmesii/B. pertussis in infants and their mothers, indicate that infection of non-vaccinated infants could be more associated with young parents. Moreover, the RT- PCR provides a sensitive and specific diagnosis of B. pertussis infections and distinguishes it from other Bordetella species, and is therefore suitable for implementation in the diagnostic laboratory.

Risk of Pertussis in Relation to Degree of Prematurity in Children Less Than 2 Years of Age.

A few previous studies reported increased risk of pertussis in children with birth weight less than 2500 g. The risk of pertussis by degree of prematurity has not been determined in a cohort study. The vaccine effectiveness (VE) against reported pertussis in preterm infants is unknown. Data were obtained from the Medical Birth Registry of Norway (1998-2010) and linked to other national registries. In total, 713,166 children were included in our study and followed until 2 years of age. Incidence rate ratios (IRRs) and confidence intervals (CIs) were estimated with Poisson regression. We identified 999 reported cases of pertussis. We observed a higher rate of reported pertussis in preterm than in full-term infants, IRR = 1.65 (95% CI: 1.32-2.07). Compared to full-term infants, the risk of reported pertussis in infants born at gestational age (GA) 35-36, 32-34 and 23-27 weeks were higher [IRRs = 1.49 (95% CI: 1.11-2.01), 1.63 (95% CI: 1.06-2.51) and 4.49 (95% CI: 2.33-8.67), respectively]. Moreover, preterm infants had a higher rate of pertussis-related hospitalization than full-term infants [IRR = 1.99 (95% CI: 1.47-2.71)]. The VE against reported pertussis for the third dose was 88.8% (95% CI: 84.3-92.0) in full-term infants and 93.0% (95% CI: 85.8-96.5) in preterm infants. In this cohort study, preterm infants including those born at GA 35 and 36 weeks had increased risk of reported pertussis. The VE was similar in preterm and full-term infants.

Effectiveness of Vaccination During Pregnancy to Prevent Infant Pertussis.

Vaccination against pertussis during pregnancy is recommended to protect newborns, yet there is limited information about the effectiveness of maternal tetanus toxoid, reduced diphtheria toxoid, acellular pertussis (Tdap) vaccine before the first infant dose of diphtheria, tetanus and acellular pertussis (DTaP) vaccine and during the first year of life in infants who have received DTaP. In a retrospective cohort study of infants born at Kaiser Permanente Northern California from 2010 to 2015, we estimated the effectiveness of maternal pertussis vaccination for protecting newborns against pertussis in the first 2 months of life and in the first year of life accounting for each infant DTaP dose. Among 148 981 newborns, the vaccine effectiveness of maternal Tdap was 91.4% (95% confidence interval [CI], 19.5 to 99.1) during the first 2 months of life and 69.0% (95% CI, 43.6 to 82.9) during the entire first year of life. The vaccine effectiveness was 87.9% (95% CI, 41.4 to 97.5) before infants had any DTaP vaccine doses, 81.4% (95% CI, 42.5 to 94.0) between doses 1 and 2, 6.4% (95% CI, -165.1 to 66.9) between doses 2 and 3, and 65.9% (95% CI, 4.5 to 87.8) after infants had 3 DTaP doses. Maternal Tdap vaccination was highly protective against infant pertussis, especially in the first 2 months of life. Even after infant DTaP dosing, there was evidence of additional protection from maternal Tdap vaccination for the first year of life. This study strongly supports the United States' current recommendation to administer Tdap during each pregnancy.