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Clinical Infectious Diseases : An... Jun 2020Diphtheria, once a major cause of childhood morbidity and mortality, all but disappeared following introduction of diphtheria vaccine. Recent outbreaks highlight the...
BACKGROUND
Diphtheria, once a major cause of childhood morbidity and mortality, all but disappeared following introduction of diphtheria vaccine. Recent outbreaks highlight the risk diphtheria poses when civil unrest interrupts vaccination and healthcare access. Lack of interest over the last century resulted in knowledge gaps about diphtheria's epidemiology, transmission, and control.
METHODS
We conducted 9 distinct systematic reviews on PubMed and Scopus (March-May 2018). We pooled and analyzed extracted data to fill in these key knowledge gaps.
RESULTS
We identified 6934 articles, reviewed 781 full texts, and included 266. From this, we estimate that the median incubation period is 1.4 days. On average, untreated cases are colonized for 18.5 days (95% credible interval [CrI], 17.7-19.4 days), and 95% clear Corynebacterium diphtheriae within 48 days (95% CrI, 46-51 days). Asymptomatic carriers cause 76% (95% confidence interval, 59%-87%) fewer cases over the course of infection than symptomatic cases. The basic reproductive number is 1.7-4.3. Receipt of 3 doses of diphtheria toxoid vaccine is 87% (95% CrI, 68%-97%) effective against symptomatic disease and reduces transmission by 60% (95% CrI, 51%-68%). Vaccinated individuals can become colonized and transmit; consequently, vaccination alone can only interrupt transmission in 28% of outbreak settings, making isolation and antibiotics essential. While antibiotics reduce the duration of infection, they must be paired with diphtheria antitoxin to limit morbidity.
CONCLUSIONS
Appropriate tools to confront diphtheria exist; however, accurate understanding of the unique characteristics is crucial and lifesaving treatments must be made widely available. This comprehensive update provides clinical and public health guidance for diphtheria-specific preparedness and response.
Topics: Child; Diphtheria; Disease Outbreaks; Humans; Vaccination
PubMed: 31425581
DOI: 10.1093/cid/ciz808 -
Journal of Neurology Jan 2021We conducted a systematic review and wide-angled Mendelian randomization (MR) study to examine the association between possible risk factors and multiple sclerosis (MS).
OBJECTIVES
We conducted a systematic review and wide-angled Mendelian randomization (MR) study to examine the association between possible risk factors and multiple sclerosis (MS).
METHODS
We used MR analysis to assess the associations between 65 possible risk factors and MS using data from a genome-wide association study including 14 498 cases and 24 091 controls of European ancestry. For 18 exposures not suitable for MR analysis, we conducted a systematic review to obtain the latest meta-analyses evidence on their associations with MS.
RESULTS
Childhood and adulthood body mass index were positively associated with MS, whereas physical activity and serum 25-hydroxyvitamin D were inversely associated with MS. There was evidence of possible associations of type 2 diabetes, waist circumference, body fat percentage, age of puberty and high-density lipoprotein cholesterol. Data of systematic review showed that exposure to organic solvents, Epstein Barr virus and cytomegalovirus virus infection, and diphtheria and tetanus vaccination were associated with MS risk.
CONCLUSIONS
This study identified several modifiable risk factors for primary prevention of MS that should inform public health policy.
Topics: Adult; Child; Diabetes Mellitus, Type 2; Epstein-Barr Virus Infections; Genome-Wide Association Study; Herpesvirus 4, Human; Humans; Mendelian Randomization Analysis; Multiple Sclerosis; Risk Factors
PubMed: 32728946
DOI: 10.1007/s00415-020-10119-8 -
The Cochrane Database of Systematic... Jan 2020Adolescent vaccination has received increased attention since the Global Vaccine Action Plan's call to extend the benefits of immunisation more equitably beyond... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Adolescent vaccination has received increased attention since the Global Vaccine Action Plan's call to extend the benefits of immunisation more equitably beyond childhood. In recent years, many programmes have been launched to increase the uptake of different vaccines in adolescent populations; however, vaccination coverage among adolescents remains suboptimal. Therefore, understanding and evaluating the various interventions that can be used to improve adolescent vaccination is crucial.
OBJECTIVES
To evaluate the effects of interventions to improve vaccine uptake among adolescents.
SEARCH METHODS
In October 2018, we searched the following databases: CENTRAL, MEDLINE Ovid, Embase Ovid, and eight other databases. In addition, we searched two clinical trials platforms, electronic databases of grey literature, and reference lists of relevant articles. For related systematic reviews, we searched four databases. Furthermore, in May 2019, we performed a citation search of five other websites.
SELECTION CRITERIA
Randomised trials, non-randomised trials, controlled before-after studies, and interrupted time series studies of adolescents (girls or boys aged 10 to 19 years) eligible for World Health Organization-recommended vaccines and their parents or healthcare providers.
DATA COLLECTION AND ANALYSIS
Two review authors independently screened records, reviewed full-text articles to identify potentially eligible studies, extracted data, and assessed risk of bias, resolving discrepancies by consensus. For each included study, we calculated risk ratios (RR) or mean differences (MD) with 95% confidence intervals (CI) where appropriate. We pooled study results using random-effects meta-analyses and assessed the certainty of the evidence using GRADE.
MAIN RESULTS
We included 16 studies (eight individually randomised trials, four cluster randomised trials, three non-randomised trials, and one controlled before-after study). Twelve studies were conducted in the USA, while there was one study each from: Australia, Sweden, Tanzania, and the UK. Ten studies had unclear or high risk of bias. We categorised interventions as recipient-oriented, provider-oriented, or health systems-oriented. The interventions targeted adolescent boys or girls or both (seven studies), parents (four studies), and providers (two studies). Five studies had mixed participants that included adolescents and parents, adolescents and healthcare providers, and parents and healthcare providers. The outcomes included uptake of human papillomavirus (HPV) (11 studies); hepatitis B (three studies); and tetanus-diphtheria-acellular-pertussis (Tdap), meningococcal, HPV, and influenza (three studies) vaccines among adolescents. Health education improves HPV vaccine uptake compared to usual practice (RR 1.43, 95% CI 1.16 to 1.76; I² = 0%; 3 studies, 1054 participants; high-certainty evidence). In addition, one large study provided evidence that a complex multi-component health education intervention probably results in little to no difference in hepatitis B vaccine uptake compared to simplified information leaflets on the vaccine (RR 0.98, 95% CI 0.97 to 0.99; 17,411 participants; moderate-certainty evidence). Financial incentives may improve HPV vaccine uptake compared to usual practice (RR 1.45, 95% CI 1.05 to 1.99; 1 study, 500 participants; low-certainty evidence). However, we are uncertain whether combining health education and financial incentives has an effect on hepatitis B vaccine uptake, compared to usual practice (RR 1.38, 95% CI 0.96 to 2.00; 1 study, 104 participants; very low certainty evidence). Mandatory vaccination probably leads to a large increase in hepatitis B vaccine uptake compared to usual practice (RR 3.92, 95% CI 3.65 to 4.20; 1 study, 6462 participants; moderate-certainty evidence). Provider prompts probably make little or no difference compared to usual practice, on completion of Tdap (OR 1.28, 95% CI 0.59 to 2.80; 2 studies, 3296 participants), meningococcal (OR 1.09, 95% CI 0.67 to 1.79; 2 studies, 3219 participants), HPV (OR 0.99, 95% CI 0.55 to 1.81; 2 studies, 859 participants), and influenza (OR 0.91, 95% CI 0.61 to 1.34; 2 studies, 1439 participants) vaccination schedules (moderate-certainty evidence). Provider education with performance feedback may increase the proportion of adolescents who are offered and accept HPV vaccination by clinicians, compared to usual practice. Compared to adolescents visiting non-participating clinicians (in the usual practice group), the adolescents visiting clinicians in the intervention group were more likely to receive the first dose of HPV during preventive visits (5.7 percentage points increase) and during acute visits (0.7 percentage points for the first and 5.6 percentage points for the second doses of HPV) (227 clinicians and more than 200,000 children; low-certainty evidence). A class-based school vaccination strategy probably leads to slightly higher HPV vaccine uptake than an age-based school vaccination strategy (RR 1.09, 95% CI 1.06 to 1.13; 1 study, 5537 participants; moderate-certainty evidence). A multi-component provider intervention (including an education session, repeated contacts, individualised feedback, and incentives) probably improves uptake of HPV vaccine compared to usual practice (moderate-certainty evidence). A multi-component intervention targeting providers and parents involving social marketing and health education may improve HPV vaccine uptake compared to usual practice (RR 1.41, 95% CI 1.25 to 1.59; 1 study, 25,869 participants; low-certainty evidence).
AUTHORS' CONCLUSIONS
Various strategies have been evaluated to improve adolescent vaccination including health education, financial incentives, mandatory vaccination, and class-based school vaccine delivery. However, most of the evidence is of low to moderate certainty. This implies that while this research provides some indication of the likely effect of these interventions, the likelihood that the effects will be substantially different is high. Therefore, additional research is needed to further enhance adolescent immunisation strategies, especially in low- and middle-income countries where there are limited adolescent vaccination programmes. In addition, it is critical to understand the factors that influence hesitancy, acceptance, and demand for adolescent vaccination in different settings. This is the topic of an ongoing Cochrane qualitative evidence synthesis, which may help to explain why and how some interventions were more effective than others in increasing adolescent HPV vaccination coverage.
Topics: Adolescent; Child; Controlled Before-After Studies; Health Education; Health Personnel; Humans; Parents; Randomized Controlled Trials as Topic; Vaccination
PubMed: 31978259
DOI: 10.1002/14651858.CD011895.pub2 -
Global Epidemiology Dec 2023To identify modifiable risk factors for diphtheria and assess their strengths of association with the disease. (Review)
Review
OBJECTIVE
To identify modifiable risk factors for diphtheria and assess their strengths of association with the disease.
METHODS
This review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement. Electronic databases and grey literature were searched from inception until January 2023. Studies had to report on diphtheria cases and estimates of association for at least one potential risk factor or sufficient data to calculate these. The quality of non-ecological studies was assessed using the Newcastle-Ottawa Scale (NOS), while the quality of evidence was evaluated using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) criteria.
RESULTS
The search yielded 37,705 papers, of which 29 were ultimately included. All the non-ecological studies were of moderate to high quality. Meta-analysis of 20 studies identified three factors increasing the risk of diphtheria: incomplete vaccination (<3 doses) (pooled odds ratio (POR) = 2.2, 95% confidence interval (CI) = 1.4-3.4); contact with a person with skin lesions (POR = 4.8, 95% CI = 2.1-10.9); and low knowledge of diphtheria (POR = 2.4, 95% CI = 1.2-4.7). Contact with a case of diphtheria; sharing a bed or bedroom; sharing utensils, cups, and glasses; infrequent bathing; and low parental education were associated with diphtheria in multiple studies. Evidence for other factors was inconclusive. The quality of evidence was low or very low for all the risk factors.
CONCLUSIONS
Findings from the review suggest that countries seeking to control diphtheria need to strengthen surveillance, improve vaccination coverage, and increase people's knowledge of the disease. Future research should focus on understudied or inconclusive risk factors.
PubMed: 37638375
DOI: 10.1016/j.gloepi.2023.100100 -
BMJ Global Health Oct 2023Maternal vaccination is a promising strategy to reduce the burden of vaccine-preventable diseases for mothers and infants. We aimed to provide an up-to-date overview of... (Meta-Analysis)
Meta-Analysis
INTRODUCTION
Maternal vaccination is a promising strategy to reduce the burden of vaccine-preventable diseases for mothers and infants. We aimed to provide an up-to-date overview of the efficacy and safety of all available maternal vaccines.
METHODS
We searched PubMed, Embase, CENTRAL and ClinicalTrials.gov on 1 February 2022, for phase III and IV randomised controlled trials (RCTs) that compared maternal vaccination against any pathogen with placebo or no vaccination. Primary outcomes were laboratory-confirmed or clinically confirmed disease in mothers and infants. Secondary safety outcomes included intrauterine growth restriction, stillbirth, maternal death, preterm birth, congenital malformations and infant death. Random effects meta-analysis were used to calculate pooled risk ratio's (RR). Quality appraisal was performed using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE).
RESULTS
Six RCTs on four maternal vaccines, influenza, tetanus, diphtheria and pertussis (Tdap), pneumococcal and respiratory syncytial virus (RSV) were eligible. The overall risk of bias and certainty of evidence varied from low to high. Maternal influenza vaccination significantly reduced the number of laboratory-confirmed influenza cases (RR 0.58, 95% CI 0.42 to 0.79, event rate 57 vs 98, 2 RCTs, n=6003, I=0%), and clinically confirmed influenza cases in mothers (RR 0.88, 95% CI 0.78 to 0.99, event rate 418 vs 472, 2 RCTs, n=6003, I=0%), and laboratory-confirmed influenza in infants (RR 0.66, 95% CI 0.52 to 0.85, event rate 98 vs 148, 2 RCTs, n=5883, I=0%), although this was not significant for clinically confirmed influenza in infants (RR 0.99, 95% CI 0.94 to 1.05, event rate 1371 vs 1378, 2 RCTs, n=5883, I=0%). No efficacy data were available on maternal Tdap vaccination. Maternal pneumococcal vaccination did not reduce laboratory-confirmed and clinically confirmed middle ear disease (RR 0.49, 95% CI 0.24 to 1.02, event rate 9 vs 18, 1 RCT, n=133 and RR 0.88 95% CI 0.69 to 1.12, event rate 42 vs 47, 1 RCT, n=133, respectively), and clinically confirmed lower-respiratory tract infection (LRTI) (RR 1.08, 95% CI 0.82 to 1.43, event rate 18 vs 34, 1 RCT, n=70) in infants. Maternal RSV vaccination did not reduce laboratory-confirmed RSV LRTI in infants (RR 0.75, 95% CI 0.56 to 1.01, event rate 103 vs 71, 1 RCT, n=4527). There was no evidence of a significant effect of any of the maternal vaccines on the reported safety outcomes.
CONCLUSIONS
The few RCTs with low event rates suggest that, depending on the type of maternal vaccine, the vaccine might effectively prevent disease and within its size does not show safety concerns in mothers and infants.
PROSPERO REGISTRATION NUMBER
CRD42021235115.
Topics: Infant, Newborn; Female; Humans; Infant; Influenza, Human; Influenza Vaccines; Mothers; Vaccination; Respiratory Tract Infections; Randomized Controlled Trials as Topic
PubMed: 37899087
DOI: 10.1136/bmjgh-2023-012376 -
Microorganisms Apr 2024(1) Background: We aim to systematically review the current evidence on immunity against tetanus, diphtheria, and pertussis in adult solid organ transplantation (SOT)... (Review)
Review
(1) Background: We aim to systematically review the current evidence on immunity against tetanus, diphtheria, and pertussis in adult solid organ transplantation (SOT) recipients, either through natural infection or vaccination. (2) Methods: This systematic review was conducted per PRISMA guidelines. We assessed the risk of bias using the Cochrane RoB 2 and ROBINS-I and summarized the findings narratively due to the heterogeneity of the studies. (3) Results: Of the 315 screened articles, 11 were included. Tetanus immunity varied between 55% and 86%, diphtheria immunity from 23% to 75%, and pertussis immunity was between 46% and 82%. Post-vaccination immunity showed variation across the studies, with some indicating reductions and others no change, with antibody responses influenced by transplanted organs, gender, age, and immunosuppressive regimens. The single randomized study exhibited a low risk of bias, while of the ten non-randomized studies, six showed moderate and four serious risks of bias, necessitating cautious interpretation of results. (4) Conclusions: SOT recipients exhibit considerable immunity against tetanus and diphtheria at transplantation, but this immunity decreases over time. Although vaccination can enhance this immunity, the response may be suboptimal, and the increased antibody levels may not persist, underscoring the need for tailored vaccination strategies in this vulnerable population.
PubMed: 38792678
DOI: 10.3390/microorganisms12050847 -
Infectious Diseases and Therapy Sep 2021Cyclic epidemics of pertussis (whooping cough) have been observed globally over the past twenty years despite high infant vaccine coverage. The resurgence of pertussis... (Review)
Review
Cyclic epidemics of pertussis (whooping cough) have been observed globally over the past twenty years despite high infant vaccine coverage. The resurgence of pertussis in high-income countries is partly due to waning vaccine immunity in older children and adults, as well as better surveillance and diagnostics. Moreover, in adolescents and adults, pertussis symptoms are mild and similar to common cough syndromes, meaning that it is under-diagnosed in older populations. A systematic search of MEDLINE, EMBASE, and BIOSIS was undertaken to identify studies published between 1 January 1990 and 17 June 2019, with information on pertussis epidemiology, burden of illness, and mortality in school-aged children, adolescents, and adults in Asia. Studies identified for inclusion were reviewed narratively because a statistical comparison was not possible due to the mix of methodologies used. The results showed that in East Asia, including Japan, South Korea, China, and Taiwan, pertussis is circulating in older children and adults. Diphtheria-tetanus-pertussis (DTP4) coverage is high in East Asia, yet outbreaks observed in Japan and South Korea suggest that vaccine-acquired immunity had waned in adolescents and adults. Several school outbreaks in China show that pertussis is circulating in young children, with continued circulation in adolescents and adults. There was a lack of information from Southeast/South Asian countries, although pan-Asian serosurveys showed that recent pertussis infection was common in adolescents and in adults with persistent cough. To conclude, the circulation of pertussis in Asian countries with high DTP4 coverage supports the expansion of routine vaccination to include booster doses for children at school entry and adolescents. However, surveillance is weak or absent in many countries, meaning that the true burden of pertussis, particularly among older populations, is unknown.
PubMed: 33928533
DOI: 10.1007/s40121-021-00439-1 -
Revista Espanola de Salud Publica Mar 2023Vaccine-preventable infectious diseases are a cause of morbidity and mortality in transplanted children. The main objective of this study was to synthesize the available... (Review)
Review
OBJECTIVE
Vaccine-preventable infectious diseases are a cause of morbidity and mortality in transplanted children. The main objective of this study was to synthesize the available evidence of vaccination coverage in children and adolescents who are candidates or transplant recipients and to analyze beliefs, attitudes, and experiences about vaccination.
METHODS
A mixed-methods systematic review was performed (Open Science Framework registration: https://osf.io/auqn3/). Searches were conducted in PubMed/MEDLINE, EMBASE, IBECS and LILACS (from January 2000 to August 2021) and in gray literature. Quantitative and qualitative studies reported information on coverage, beliefs, attitudes and/or experiences about recommended vaccines in children who are candidates or recipients of solid organ or hematopoietic progenitor transplantation. Quality assessment was undertaken using Mixed Methods Appraisal Tool (MMAT). A narrative synthesis of the studies was carried out.
RESULTS
A total of thirty-two studies in thirty-five publications were included. The most studied interventions were vaccines against measles (n=21; 66%) and hepatitis B (n=20; 62%). Vaccination rates showed a high variability for the most represented vaccines (specifically, 2%-100% for measles, 0.4%-100% for hepatitis B, diphtheria-tetanus-pertussis and rubella), with coverages lower than 90% in at least 70% of the studies. The lowest rates were reported in post-transplantation and hematopoietic stem cell transplantation. Only one qualitative study was identified reporting information on beliefs and/or attitudes, although nine quantitative studies explored cognitive aspects.
CONCLUSIONS
This review shows a high variability in vaccination coverage in children and adolescents who are transplant candidates or recipients, with rates lower than those recommended. Further studies would be needed to identify beliefs and attitudes about immunization in this context.
Topics: Child; Humans; Adolescent; Vaccination Coverage; Spain; Vaccines; Vaccination; Measles; Hepatitis B; Attitude
PubMed: 36999242
DOI: No ID Found -
Conflict and Health Apr 2024Conflict situations, armed or not, have been associated with emergence and transmission of infectious diseases. This review aims to identify the pathways through which... (Review)
Review
BACKGROUND
Conflict situations, armed or not, have been associated with emergence and transmission of infectious diseases. This review aims to identify the pathways through which infectious diseases emerge within conflict situations and to outline appropriate infectious disease preparedness and response strategies.
METHODS
A systematic review was performed representing published evidence from January 2000 to October 2023. Ovid Medline and Embase were utilised to obtain literature on infectious diseases in any conflict settings. The systematic review adhered to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analysis). No geographical restrictions were imposed.
FINDINGS
Our review identified 51 studies covering AIDS, Hepatitis B, Tuberculosis, Cholera, Coronavirus 2, Ebola, Poliomyelitis, Malaria, Leishmaniasis, Measles, Diphtheria, Dengue and Acute Bacterial Meningitis within conflict settings in Europe, Middle East, Asia, and Africa since October 2023. Key factors contributing to disease emergence and transmission in conflict situations included population displacement, destruction of vital infrastructure, reduction in functioning healthcare systems and healthcare personnel, disruption of disease control programmes (including reduced surveillance, diagnostic delays, and interrupted vaccinations), reduced access by healthcare providers to populations within areas of active conflict, increased population vulnerability due to limited access to healthcare services, and disruptions in the supply chain of safe water, food, and medication. To mitigate these infectious disease risks reported preparedness and response strategies included both disease-specific intervention strategies as well as broader concepts such as the education of conflict-affected populations through infectious disease awareness programmes, investing in and enabling health care in locations with displaced populations, intensifying immunisation campaigns, and ensuring political commitment and intersectoral collaborations between governments and international organisations.
CONCLUSION
Conflict plays a direct and indirect role in the transmission and propagation of infectious diseases. The findings from this review can assist decision-makers in the development of evidence-based preparedness and response strategies for the timely and effective containment of infectious disease outbreaks in conflict zones and amongst conflict-driven displaced populations.
FUNDING
European Centre for Disease Prevention and Control under specific contract No. 22 ECD.13,154 within Framework contract ECDC/2019/001 Lot 1B.
PubMed: 38584269
DOI: 10.1186/s13031-023-00568-z -
Infectious Diseases and Therapy Sep 2021The Global Pertussis Initiative recommends diphtheria-tetanus-pertussis (DTP3) vaccination of infants aged < 1 year for all African countries, and recommends the... (Review)
Review
The Global Pertussis Initiative recommends diphtheria-tetanus-pertussis (DTP3) vaccination of infants aged < 1 year for all African countries, and recommends the vaccination of pregnant women as a primary prevention strategy. However, the role of older children and adults in the transmission of pertussis in Africa is not clear. A systematic search of MEDLINE, EMBASE, and BIOSIS was undertaken to identify studies published between 1 January 1990 and 17 June 2019, with information on pertussis epidemiology, burden of illness, and mortality in school-aged children, adolescents, and adults in Africa. Studies identified for inclusion were reviewed narratively because a statistical comparison was not possible because of the mix of methodologies used.Studies from North Africa (Morocco, Tunisia, and Algeria) reported that although DTP4 vaccine coverage is high, severe pertussis-related complications persist in young children, vaccine-acquired immunity wanes in adolescents, and household contacts are important transmitters of infection. A serosurvey in Gambia showed that 6% of the general population had pertussis antibody levels suggesting recent infection, and studies from Senegal showed that pertussis infection was endemic despite high DTP3 coverage. During a pertussis outbreak in Ethiopia, the case fatality rate was 3.7% overall, and 6.3% among children aged 5-9 years. In a case-surveillance study in South Africa, the incidence of pertussis among hospitalized children was 526/100,000, and infection rates were higher in HIV-exposed and -infected children compared with uninfected children. In conclusion, the highest burden of pertussis in Africa is among infants, and surveillance is lacking in many African countries meaning that the burden of pertussis among infants and infection rates among older children and adults are not well reported, and likely underestimated.
PubMed: 33881713
DOI: 10.1007/s40121-021-00442-6