An update of the global burden of pertussis in children younger than 5 years: a modelling study
TL;DR: The estimates suggest that the numbers of cases and deaths of pertussis have fallen substantially compared with the 1999 estimates, and model sensitivity emphasised the importance of better surveillance to improve country-level decision making and pert Mussis control.
Abstract: Summary Background Since the publication in 2003 of a model to estimate the disease burden of pertussis, new evidence of the protective effect of incomplete pertussis vaccination against severe pertussis has been reported. We revised the model to provide new estimates of regional and global pertussis cases and deaths for children younger than 5 years. Methods We developed a revised model with data from 2014 to estimate pertussis cases and deaths. Pertussis cases were defined according to the WHO clinical case definition, as a coughing illness lasting at least 2 weeks with paroxysms of coughing, inspiratory whooping, or post-tussive vomiting. We used UN population estimates and WHO and UNICEF data on national pertussis immunisation coverage. Estimates were made for vaccine effectiveness against pertussis cases and deaths for one, two, and three doses of vaccination, probability of infection in low and high coverage countries, and case fatality ratios in low and high mortality countries in two age groups: infants younger than 1 year and children aged 1–4 years. We did sensitivity analyses with a range of input parameters to assess the effect of uncertainty of the input parameters on the model outputs. Findings We estimated that there were 24·1 million pertussis cases and 160 700 deaths from pertussis in children younger than 5 years in 2014, with the African region contributing the largest proportions (7·8 million [33%] cases and 92 500 [58%] deaths). 5·1 million (21%) estimated pertussis cases and 85 900 (53%) estimated deaths were in infants younger than 1 year. In the sensitivity analyses, the estimated number of cases ranged from 7 million to 40 million and deaths from 38 000 to 670 000. Interpretation Our estimates suggest that, compared with the 1999 estimates published in 2003 (30·6 million pertussis cases and 390 000 deaths from pertussis in children younger than 5 years), the numbers of cases and deaths of pertussis have fallen substantially. Model sensitivity emphasised the importance of better surveillance to improve country-level decision making and pertussis control. Funding None.
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Haramaya University1, University of London2, University of Bristol3, University College London Hospitals NHS Foundation Trust4, University College London5, Baylor College of Medicine6, Johns Hopkins University7, University of the Witwatersrand8, University of Washington9, St George's, University of London10, The Chinese University of Hong Kong11, Imperial College London12, Centers for Disease Control and Prevention13, Bill & Melinda Gates Foundation14, World Health Organization15
TL;DR: These first estimates show the magnitude and the potential impact of maternal vaccination against Group B Streptococcus in pregnant women, stillbirth, and infants.
Abstract: Background: We aimed to provide the first comprehensive estimates of the burden of group B Streptococcus (GBS), including invasive disease in pregnant and postpartum women, fetal infection/stillbirth, and infants. Intrapartum antibiotic prophylaxis is the current mainstay of prevention, reducing early-onset infant disease in high-income contexts. Maternal GBS vaccines are in development. Methods: For 2015 live births, we used a compartmental model to estimate (1) exposure to maternal GBS colonization, (2) cases of infant invasive GBS disease, (3) deaths, and (4) disabilities. We applied incidence or prevalence data to estimate cases of maternal and fetal infection/stillbirth, and infants with invasive GBS disease presenting with neonatal encephalopathy. We applied risk ratios to estimate numbers of preterm births attributable to GBS. Uncertainty was also estimated. Results: Worldwide in 2015, we estimated 205000 (uncertainty range [UR], 101000-327000) infants with early-onset disease and 114000 (UR, 44000-326000) with late-onset disease, of whom a minimum of 7000 (UR, 0-19000) presented with neonatal encephalopathy. There were 90000 (UR, 36000-169000) deaths in infants <3 months age, and, at least 10000 (UR, 3000-27000) children with disability each year. There were 33000 (UR, 13000-52000) cases of invasive GBS disease in pregnant or postpartum women, and 57000 (UR, 12000-104000) fetal infections/stillbirths. Up to 3.5 million preterm births may be attributable to GBS. Africa accounted for 54% of estimated cases and 65% of all fetal/infant deaths. A maternal vaccine with 80% efficacy and 90% coverage could prevent 107000 (UR, 20000-198000) stillbirths and infant deaths. Conclusions: Our conservative estimates suggest that GBS is a leading contributor to adverse maternal and newborn outcomes, with at least 409000 (UR, 144000-573000) maternal/fetal/infant cases and 147000 (UR, 47000-273000) stillbirths and infant deaths annually. An effective GBS vaccine could reduce disease in the mother, the fetus, and the infant.
270 citations
University of Perugia1, Istituto Superiore di Sanità2, Public Health England3, University of Turku4, University of London5, Northwestern University6, Boston Children's Hospital7, Hebron University8, University of Hong Kong9, University of Tartu10, Vanderbilt University11, University of Chile12, University of Milan13
TL;DR: The results of a Consensus Conference organized by the World Association for Infectious Disease and Immunological Disorders on June 22, 2018, in Perugia, Italy, are reported, with the goal of evaluating the most important reasons for the pertussis resurgence and the role of different aPVs in this resurgence.
Abstract: Pertussis is an acute respiratory disease caused by Bordetella pertussis. Due to its frequency and severity, prevention of pertussis has been considered an important public health issue for many years. The development of the whole-cell pertussis vaccine (wPV) and its introduction into the pediatric immunization schedule was associated with a marked reduction in pertussis cases in the vaccinated cohort. However, due to the frequency of local and systemic adverse events after immunization with wPV, work on a less reactive vaccine was undertaken based on isolated B. pertussis components that induced protective immune responses with fewer local and systemic reactions. These component vaccines were termed acellular vaccines and contained one or more pertussis antigens, including pertussis toxin (PT), filamentous haemagglutinin (FHA), pertactin (PRN), and fimbrial proteins 2 (FIM2) and 3 (FIM3). Preparations containing up to five components were developed, and several efficacy trials clearly demonstrated that the aPVs were able to confer comparable short-term protection than the most effective wPVs with fewer local and systemic reactions. There has been a resurgence of pertussis observed in recent years. This paper reports the results of a Consensus Conference organized by the World Association for Infectious Disease and Immunological Disorders (WAidid) on June 22, 2018, in Perugia, Italy, with the goal of evaluating the most important reasons for the pertussis resurgence and the role of different aPVs in this resurgence.
91 citations
TL;DR: Although an increased risk for a diagnosis of fever and chorioamnionitis was detected in pregnant women after pertussis vaccination, there was no association with a higher frequency of clinically relevant sequelae and overall positive benefit-risk ratio.
Abstract: Infants < 3 months of age are at highest risk for developing severe complications after pertussis. The majority of pregnant women has low concentrations of pertussis-specific antibodies and thus newborns are insufficiently protected by maternally transferred antibodies. Acellular pertussis vaccination during pregnancy was recently implemented in various countries. Here, we assessed the evidence for safety and effectiveness of pertussis vaccination during pregnancy. We searched Medline, Embase, and ClinicalTrials.gov from January 1st 2010 to January 10th 2019. We assessed risk of bias (ROB) using the Cochrane ROB tool and ROBINS-I. We evaluated the quality of evidence using the GRADE approach. We identified 1273 articles and included 22 studies (14 for safety; 8 for effectiveness), comprising 1.4 million pregnant women in safety studies and 855,546 mother-infant-pairs in effectiveness studies. No significant differences between vaccinated and unvaccinated women and their infants were observed for safety outcomes with the exception of fever and chorioamnionitis. Compared to no vaccination, three studies showed a significantly increased relative risk for the presence of the ICD-9 code for chorioamnionitis in electronic patient data after pertussis vaccination. However, no study reported an increased risk for clinical sequelae of chorioamnionitis after vaccination during pregnancy, such as preterm birth or neonatal intensive care unit admission. Vaccine effectiveness against pertussis in infants of immunized mothers ranged from 69 to 91% for pertussis prevention, from 91 to 94% for prevention of hospitalization and was 95% for prevention of death due to pertussis. Risk of bias was serious to critical for safety outcomes and moderate to serious for effectiveness outcomes. GRADE evidence quality was moderate to very low, depending on outcome. Although an increased risk for a diagnosis of fever and chorioamnionitis was detected in pregnant women after pertussis vaccination, there was no association with a higher frequency of clinically relevant sequelae. Vaccine effectiveness for prevention of infant pertussis, hospitalization and death is high. Pertussis vaccination during pregnancy has an overall positive benefit-risk ratio. In view of the overall quality of available evidence ongoing surveillance of chorioamnionitis and its potential sequelae is recommended when pertussis vaccination in pregnancy is implemented. PROSPERO CRD42018087814, CRD42018090357.
86 citations
TL;DR: Morbidity and mortality from childhood pneumonia has decreased but a considerable preventable burden remains, and widespread implementation of available, effective interventions and development of novel strategies are needed.
86 citations
TL;DR: This review will broadly explore the connections between bacterial infection, immune dysregulation, and CNS disorders and how bacterial pathogenesis contributes to the “multiple-hit hypothesis” of neurodegeneration.
Abstract: Despite major strides in personalized genomics, it remains poorly understood why neurodegenerative diseases occur in only a fraction of individuals with a genetic predisposition and conversely, why individuals with no genetic risk of a disorder develop one. Chronic diseases like Alzheimer's, Parkinson's, and Multiple sclerosis are speculated to result from a combination of genetic and environmental factors, a concept commonly referred to as the "multiple hit hypothesis." A number of bacterial infections have been linked to increased risk of neurodegeneration, and in some cases, clearance of bacterial pathogens has been correlated with amelioration of central nervous system (CNS) deficits. Additionally, mutations in several genes known to contribute to CNS disorders like Parkinson's Disease have repeatedly been implicated in susceptibility to intracellular bacterial infection. Recent data has begun to demonstrate roles for these genes (PARK2, PINK1, and LRRK2) in modulating innate immune outcomes, suggesting that immune dysregulation may play an even more important role in neurodegeneration than previously appreciated. This review will broadly explore the connections between bacterial infection, immune dysregulation, and CNS disorders. Understanding this interplay and how bacterial pathogenesis contributes to the "multiple-hit hypothesis" of neurodegeneration will be crucial to develop therapeutics to effectively treat both neurodegeneration and infection.
68 citations
Cites background from "An update of the global burden of p..."
...pertussis infection and spread, incidences of pertussis are high in regions where vaccination coverage is low; a recent modeling study purports there may be as many as 24 million cases of pertussis per year worldwide (Yeung et al., 2017)....
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TL;DR: In the Global Burden of Disease Study 2013 (GBD 2013) as discussed by the authors, the authors used the GBD 2010 methods with some refinements to improve accuracy applied to an updated database of vital registration, survey, and census data.
5,792 citations
TL;DR: The Global Burden of Disease 2015 Study provides a comprehensive assessment of all-cause and cause-specific mortality for 249 causes in 195 countries and territories from 1980 to 2015, finding several countries in sub-Saharan Africa had very large gains in life expectancy, rebounding from an era of exceedingly high loss of life due to HIV/AIDS.
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TL;DR: The authors' projection results provide concrete examples of how the distribution of child causes of deaths could look in 15-20 years to inform priority setting in the post-2015 era.
2,600 citations
TL;DR: The five-component acellular pertussis vaccine evaluated can be recommended for general use, since it has a favorable safety profile and confers sustained protection against pertussi.
Abstract: Background Because of concern about safety and efficacy, no pertussis vaccine has been included in the vaccination program in Sweden since 1979. To provide data that might permit the reintroduction of a pertussis vaccine, we conducted a placebo-controlled trial of two acellular and one whole-cell pertussis vaccines. Methods After informed consent was obtained, 9829 children born in 1992 were randomly assigned to receive one of four vaccines: a two-component acellular diphtheria–tetanus–pertussis (DTP) vaccine (2566 children), a five-component acellular DTP vaccine (2587 children), a whole-cell DTP vaccine licensed in the United States (2102 children), or (as a control) a vaccine containing diphtheria and tetanus toxoids (DT) alone (2574 children). The vaccines were given at 2, 4, and 6 months of age, and the children were then followed for signs of pertussis for an additional 2 years (to a mean age of 21/2 years). Results the whole-cell vaccine was associated with significantly higher rates of protracted ...
705 citations
TL;DR: The whole-cell vaccine was highly immunogenic for fimbriae, pertactin, and filamentous haemagglutinin, but had a low antipertussis toxin response.
305 citations