Current perspectives on pertussis outbreaks: Causes and consequences

Objectives To describe the themes identified in the epidemiology of diphtheria and pertussis outbreaks in the Americas (2013–2024), with a particular focus on vaccination coverage, trends and control strategies.DesignScoping review.Data sourcesSystematic searches were conducted in PubMed and Embase (2024), supplemented by a search of Latin American and Caribbean Health Sciences Literature (LILACS) in December 2025. Regional case data and vaccination coverage were sourced from the Pan American Health Organization (PAHO)/WHO and UNICEF electronic joint reporting form (eJRF).Eligibility criteriaThe study reviewed literature and health reports focusing on diphtheria and pertussis outbreaks and vaccination coverage.Data extraction and synthesisThematic analysis identified themes in the literature on the epidemiology and control strategies of diphtheria and pertussis as well as outbreak reporting and mortality. The retrospective regional data analysis encompassed aggregated eJRF data (2013–2024) on cases and on diphtheria-pertussis-containing vaccination coverage.ResultsOf 82 articles identified across 14 countries, 28 met the inclusion criteria. Diphtheria cases peaked in 2017–2018 and have been on an upward trend since. Pertussis cases surged to 66 184 in 2024, with 10 countries reporting high numbers and 17 having their third dose of the vaccine against diphtheria, tetanus and pertussis (DTP3) coverage below 90%. Outbreaks are often linked to low DTP3, inconsistent vaccination coverage, gaps in maternal and booster doses, inadequate surveillance and socioeconomic disparities. However, two countries with high DTP3 coverage (eg, the USA, Canada) still experienced pertussis outbreaks, showing the disease’s complexity. Experts recommend scaling up vaccination and strengthening surveillance to address these challenges.ConclusionsDiphtheria and pertussis are resurging in the Americas. The growing number of ‘zero-dose’ children and socioeconomic disparities in vulnerable communities are exacerbating the problem. A comprehensive approach is recommended, prioritising increased vaccination efforts, strengthened surveillance and ensuring equitable access to healthcare services.

Shifting attitudes to vaccines and outbreaks of disease

Compliance With Azithromycin Versus Erythromycin in the Setting of a Pertussis Outbreak

Background: Outbreaks of pertussis continue to occur despite declines in other vaccine-preventable diseases, with morbidity and mortality primarily in the ≤ two year olds. Idaho had the highest reported incidence of pertussis last year in the nation and the lowest pertussis vaccination coverage levels according to the 1996 National Immunization Survey.

BACKGROUND:To control disease outbreaks and promote the prevention of disease, monitoring the burden of infectious illnesses and their epidemiology is essential. Keeping track of changes in disease rates and, more crucially, the effectiveness of control measures like immunization campaigns for the eradication of certain infectious illnesses depends heavily on national surveillance data.MATERIALS AND METHODS:This study analyzed national surveillance data to illustrate the evolving epidemiology of reportable infectious diseases in the Najran Health Cluster from 2022 to 2024. For each disease, incidence rate (per 100,000 population) with a 95% confidence interval were calculated using population census data from 2022 to 2024. For each year, number of cases were described by sex, nationality, and age. Statistical analysis were performed using SPSS; Pearson’s Chi-Square and Fisher’s exact tests assessed the association between disease incidence and population demographics.RESULTS:The most common bacterial diseases were brucellosis, pulmonary tuberculosis, and salmonellosis. In 2024, there were outbreaks of pertussis and cholera (incidence rate 5.2 and 7.6/100,000, respectively). The most common viral diseases were measles, hepatitis B, dengue fever, and chickenpox. In 2024, there was a marked increase in the number of confirmed hepatitis B cases, from 100 cases in 2023 to 256 in 2024. The most common parasitic diseases were scorpion sting, malaria, cutaneous leishmaniasis, and amebic dysentery. The number of reported cases of malaria almost doubled from 45 in 2023 to 88 in 2024.CONCLUSION:The study highlights the importance of tracing infectious disease data to identify outbreaks early and implement control measures. In 2024, there was an increase in the number of confirmed cases of hepatitis B, pertussis, cholera, and malaria, a situation that requires urgent investigation.

BackgroundVaccine coverage for common infectious diseases such as Measles and Pertussis (also known as whooping cough) have been declining in England and Wales since 2014. Consequently, significant increases in Measles and Pertussis cases are observed in the community.AimTo explore whether Google Trends offers a predictive utility as a health surveillance tool for Meases and Pertussis in England and Wales.Design and SettingGoogle search data related to Measles and Pertussis, including common associated symptoms, were downloaded for 52 weeks from 07/01/2023 – 07/01/2024. Measles and Pertussis case data were retrieved from the weekly Notification of Infectious Disease (NOID) reports.MethodsThe associations between searching and case data were explored using a time-series analyses, including cross-correlations, Prais-Winsten regression and joinpoint analysis.ResultsSignificant cross-correlations were found for Measles cases and “measles” searching (r=.41) at a lag of -1 week. For Pertussis cases, searching for “whooping cough” (r=.31), “cough” (r=.39), “100 day cough” (r.41) and “vomiting” (r=.42) were significantly correlated at a lag of -3 to -2 weeks. In multivariable regression, “measles” remained significantly associated with Measles cases (β=.24, SE=.33,p=.02) as did “whooping cough” (β=.71, SE=.27,p=.01) and “cough” (β=1.99, SE=.54,p=.001) for pertussis. ConclusionIncreases in Measles and Pertussis cases follow increases in online searches for both diseases and selected respective symptoms. Further work is required to explore how GT can be used in conjunction with other health surveillance systems to monitor or even predict disease outbreaks, to better target public health interventions.

BackgroundThere is limited information on the roles of different age groups in propagating pertussis outbreaks, and on the impact of vaccination on pertussis transmission in the community.MethodsThe relative roles of different age groups in propagating the 2012 pertussis outbreak in Wisconsin were evaluated using the relative risk (RR) statistic that measures the change in the group’s proportion among all detected cases before vs after the epidemic peak. The impact of vaccination in different age groups against infection (that is potentially different from the protective effect against detectable disease) was evaluated using the odds ratios (ORs), within each age group, for being vaccinated vs undervaccinated before vs after the outbreak’s peak.ResultsThe RR statistic suggests that children aged 13–14 years played the largest relative role during the outbreak’s ascent (with estimates consistent across the 3 regions in Wisconsin that were studied), followed by children aged 7–8, 9–10, and 11–12 years. Young children and older teenagers and adults played more limited relative roles during the outbreak. Results of the vaccination status analysis for the fifth dose of DTaP (for children aged 7–8 years: OR, 0.44; 95% confidence interval [CI], 0.23–0.86; for children aged 9–10 years: OR, 0.51; 95% CI, 0.27–0.95); and for Tdap for children aged 13–14 years (OR, 0.38, 95% CI, 0.16–0.89) are consistent with protective effect against infection.ConclusionsWhile our epidemiological findings for the fifth dose of DTaP and for Tdap are consistent with protective effect against infection, further studies, including those estimating vaccine effectiveness against infection/transmission to others particularly for pertussis vaccines for adolescents, are needed to evaluate the impact of vaccination on the spread of pertussis in the community.

Policy Failure, Not "Hesitancy": Lessons From Recent Measles and Pertussis Outbreaks in the United States.

Four recent outbreaks of pertussis in Massachusetts illustrate some features that contribute to the increased incidence of the disease. The outbreaks involved unimmunized groups of children with philosophical or religious exemptions from school or day-care immunization requirements and children and adults who were reluctant to undergo antibiotic prophylaxis or therapy. Parents and physicians should be aware that failure to immunize and to cooperate in follow-up preventive measures can have public health and potential medicolegal repercussions.

The comparative performance of wavelet-based outbreak detector, exponential weighted moving average, and Poisson regression-based methods in detection of pertussis outbreaks in Iranian infants: A simulation-based study.

Cost-effectiveness analysis of a pertussis vaccination programme for Japan considering intergenerational infection

Pertussis outbreaks continue to challenge public health efforts in the Deep South of Thailand. Low vaccination coverage is among many key contributory factors. The objective of this study is to explore policy alternatives aiming to expand vaccination coverage in Thailand’s Deep South. We applied a compartmental model alongside rapid cost-effectiveness analysis to examine how different vaccination strategies impact pertussis cases and associated costs. Four vaccination scenarios with varying coverage levels (ranging from 62% to 91% within a 120-day timeframe) were compared against a scenario with the baseline vaccine coverage (61%). With a reproduction number (R0) of five, the model predicted a remarkable decrease in pertussis cases and fatalities as the vaccination coverage increases. All scenarios yielded cost-saving outcomes, with the scenario of an increase of 10% coverage being the most cost-effective relative to the status quo. However, in high epidemic states (R0=6), the scenario of an increase of 30% coverage was the most optimal for cost-saving in deaths prevention. These results highlight the need for expedite vaccine roll-out and the integration of non-pharmaceutical interventions for pertussis control. Further studies that explore various aspects of the model while incorporating more intricate parameters are recommended.

Objective. To analyze vaccination coverage and identify the characteristics of measles and pertussis morbidity among children in 2023. Materials and methods. The study involved an analysis of outpatient records from the City Children's Polyclinic No. 6 in Kazan. A total of 305 children aged 1 to 18 years (mean age 10.2 ± 0.33 years) were examined during the first quarter of 2023. The distribution by sex was as follows: boys – 54.75 % (n = 167), girls – 45.25 % (n = 138). Results. The analysis of outpatient records, vaccination certificates, and patient examinations revealed that 228 children (74.75 % of those examined) had received complete vaccinations, 41 children (13.45 %) had received partial vaccinations, and 36 children (11.8 %) had not been vaccinated at all with the adsorbed pertussis-diphtheria-tetanus vaccine. The analysis of measles vaccination coverage indicated that 74 children (48.68 % of those examined) had received complete vaccinations, 58 children (38.1 %) had received partial vaccinations, and 20 children (13.5 %) had not been vaccinated against measles. Conclusion. Reducing herd immunity to 74.75 % determines the necessity for vaccination initiatives aimed at increasing herd immunity to the target level of 95 %.

*Articles free to read on journal website 12 months after publication. Abstract: To the Editor—Diphtheria-tetanus-pertussis whole-cell (DTwP) and acellular (DTaP) vaccines are the 2 main pertussis-contained vaccines. DTwP, developed in the 1930s, has contributed to the reduction of pertussis, but has often been associated with vaccine-related adverse reactions (ARs) [1]. This had severely affected the public confidence in immunization programs, followed by decreased vaccine coverage and pertussis outbreaks in many industrialized countries in the 1970s [2]. DTaP, which was developed in the 1980s and replaced DTwP in developed countries in the 1990s, has been associated with fewer ARs due to removal/reduction of endotoxin [1]. China began replacing DTwP with DTaP in its national immunization programs in December 2007, and its passive Adverse Events Following Immunization (AEFI) surveillance system was established in 2005 [3]. The Intergovernmental Panel on Climate Change Fifth Assessment Report indicates that the planet is warming at...

Acute cough