Resurgence of Bordetella pertussis, including one macrolide-resistant isolate, France, 2024.

As other European countries, France is experiencing a resurgence of pertussis in 2024. Between 1 January and 31 May 2024, 5,616 (24.9%) positive Bordetella pertussis qPCR tests were identified, following a 3-year period of almost null incidence. Of 67 cultured and whole genome sequenced B. pertussis isolates, 66 produced pertactin and 56 produced FIM2, in contrast to pre-COVID-19 years. One isolate of genotype Bp-AgST4 was resistant to macrolides. Pertussis resurgence may favour isolates that produce FIM2 and pertactin.

Transient reemergence of Bordetella parapertussis in France in 2022.

Between March and October 2022, a peak of detection of Bordetella parapertussis by qPCR, real-time PCR was observed in France.Hypothesis/Gap Statement. Whether this peak was due to resurgence from previous circulating lineages or reintroduction into the country was unknown.Objective. The objective of this study is to understand B. parapertussis-transient increase observed in France in 2022 whereas it had virtually stopped being reported since the start of the COVID-19 pandemic in 2020.Methods. We analysed real-time PCR (qPCR) data from the two largest French outpatient laboratories performing whooping cough diagnosis and characterized all B. parapertussis isolates collected in the 2016-2022 period by the French National Reference Centre for Whooping Cough.Results. Microbiological analyses reveal that 13 of 18 bacterial isolates collected in 2022 produce the vaccine antigen pertactin, whereas none of the 22 isolates collected in the 2016-2021 period did.Conclusion. We hypothesize a re-introduction of B. parapertussis from regions of the world where whole-cell vaccines are still in use.

Public health management of pertussis in adults: Practical challenges and future strategies.

A panel of 24 international experts met in July 2022 to discuss challenges associated with pertussis detection, monitoring, and vaccination in adults; conclusions from this meeting are presented. There has been a shift in the epidemiology of pertussis toward older children and adults. This shift has been attributed to the waning of infection- or vaccine-induced immunity, newer detection techniques causing detection bias, and possibly the replacement of whole-cell pertussis with acellular vaccines in high-income countries, which may lead to immunity waning more quickly. The burden of adult pertussis is still likely under-ascertained due to widespread under-recognition by healthcare professionals (HCPs), under-diagnosis, and under-reporting in this age group. Non-standardized testing guidance and varied case definitions have contributed to under-reporting. Key barriers to HCP engagement with the tetanus, diphtheria, and pertussis (Tdap) vaccine include low awareness, lack of time/funding, and lack of motivation due to low prioritization of Tdap.

[Sero-epidemiological study and infection rate evaluation of pertussis in Henan Province].

Objective: To analyze the epidemiological distribution characteristics, influencing factors, and infection rates of pertussis in the population of Henan Province. Methods: From 2022 to 2023, a cross-sectional survey was conducted to investigate the permanent population in Henan Province. Enzyme-linked immunosorbent assay (ELISA) was used to detect anti-pertussis toxin IgG (PT-IgG), analyze the antibody positivity rate (≥20 IU/ml) and median concentration (MC), and estimate the pertussis infection rate based on PT IgG ≥40 IU/ml. The rank sum test was used to compare antibody levels among groups, and the χ2 test was used to compare antibody positive rates and infection rates among groups. Results: A total of 4 810 research subjects were included in this study. The overall positive rate of PT-IgG was 12.10% and MC was 3.04 (0.35, 10.36) IU/ml. There were significant differences both in positive rates and antibody levels of PT-IgG among different regions or age groups (region positive rate: χ2=134.06, P<0.001, MC: H=337.74, P<0.001; age group positive rate: χ2=45.27, P<0.001, MC: H=134.49, P<0.001). Both the positive rate of PT-IgG (25.26%) and MC (8.01 IU/ml) were the highest within one year after completing a full course of vaccination. There were significant differences in positive rates and antibody levels among people receiving different types of pertussis vaccines (positive rate: χ2=12.38, P=0.006, MC: H=17.93, P<0.001). The antibody positivity rate (35.71%) and MC (8.88 IU/ml) of the people who received cell-free pertussis inactivated poliomyelitis influenza type b (combined) vaccine throughout the course were higher than those who received other types of vaccines. The natural infection rate of pertussis was evaluated for individuals aged≥3 years who had no history of pertussis vaccine immunization within the year prior to sampling. With a high vaccination rate, the estimated infection rate of pertussis in the population was 5 757.22/100 000. The infection rates in the 3-year-old (1 940.16/100 000) and 4-year-old (1 765.68/100 000) populations were at a low level among the entire population, reaching their peak at the age of 6 (12 656.71/100 000). Subsequently, although the infection rate continued to decline, it remained at a high level and peaked again at the age of 40-49 years (8 740.39/100 000). There was a statistically significant difference in the estimated infection rate of pertussis among different age groups (χ2=53.21, P<0.001). Conclusion: The PT-IgG level of pertussis in the population of Henan Province is generally at a low level. The estimated infection rate of pertussis is much higher than the reported incidence rate. A booster dose of pertussis vaccine is recommended at 6 years old.

Antibody Levels and Infection Status of Pertussis in the Population under Pertussis Resurgence in Guangxi in 2018: A Cross-Sectional Survey.

Objective: Pertussis cases have increased markedly since 2018 in Guangxi. The aim of this study was to evaluate antibody levels and the infection status of pertussis in the resident population. Method: A total of 10,215 serum samples from residents were collected from August-November 2018 and tested for anti-pertussis IgG and toxin IgG using the enzyme-linked immunosorbent assay (ELISA). Results: Of the collected samples, 1,833 (17.94%) tested positive for anti-pertussis IgG, with the median concentration of 16.06 IU/mL. Antibody level < 10 IU/mL accounted for more than 60% in children under 4 years of age, but declined with age, whereas the percentages of the other three levels (10-40, 40-50, and ≥ 50 IU/mL) increased almost with age ( P < 0.001). Moreover, 7,924 samples were selected for anti-pertussis toxin IgG, of which 653 (8.24%) tested positive (≥ 40 IU/mL) with the median concentration of 5.89 IU/mL, and 204 participants (2.56%) had recent pertussis infection (≥ 100 IU/mL). Among the different age groups, the highest rates of positivity and recent infection were observed at 11-20 years of age, the lowest positivity rate at 5 years of age, and the lowest recent infection rate at 4 years of age ( P < 0.001, P = 0.005, respectively). Conclusion: The survey results showed that all age groups in Guangxi lacked immunity against pertussis, which was one of the main factors contributing to the resurgence of pertussis in 2018. In addition, the prevalence of pertussis is relatively high in Guangxi, and its incidence is seriously underestimated, especially in adolescents and adults.

Nota técnica N. 13/2024 - SES/GVEDT: aumento de casos de coqueluche / Technical note N. 13/2024 - SES/GVEDT: increase in pertussis cases

Nota técnica com o objetivo de alertar os gestores e profissionais de saúde quanto ao aumento de casos confirmados por coqueluche em 17 países em 2024, bem como em alguns estados brasileiros, conforme Nota técnica nº 70/2024 - DPNI/SVSA/MS e também reforçar para a necessidade de alcançar as coberturas vacinais conforme preconizado pelo Ministério da Saúde, além de adoção de medidas para fortalecimento da vigilância epidemiológica e laboratorial do agravo diante da suspeita clínica, diagnóstico e tratamento oportuno da doença a fim de evitar a morbimortalidade pela doença no Estado de Goiás

Technical note with the aim of alerting managers and health professionals regarding the increase in confirmed cases of pertussis in 17 countries in 2024, as well as in some Brazilian states, according to Technical Note nº 70/2024 - DPNI/SVSA/MS and also to reinforce to the need to achieve vaccination coverage as recommended by the Ministry of Health, in addition to adopting measures to strengthen epidemiological and laboratory surveillance of the disease in the face of clinical suspicion, diagnosis and timely treatment of the disease in order to avoid morbidity and mortality due to the disease in the State from Goiás

Increase of pertussis cases in the Vallès region, Catalonia, Spain, September 2023 to April 2024.

We describe a pertussis outbreak in the Vallès region of Catalonia, from September 2023 to April 2024. Incidence was high in children aged 10-14 years compared with previous outbreaks. Limited impact in newborns could be explained by the high vaccination coverage during pregnancy and at 11 months of age in 2022, at 85% and 94.1 %, respectively. A third booster vaccine dose during preadolescence should be considered and vaccination coverage in pregnant women be improved to control future outbreaks.

Pertussis outbreak in neonates and young infants across Italy, January to May 2024: implications for vaccination strategies.

Since January 2024, Italy experiences a pertussis outbreak, primarily affecting neonates and unvaccinated infants at high risk of severe complications and mortality; 11 major paediatric centres noted 108 hospitalisations and three deaths by 10 May. The outbreak reflects increased circulation of Bordetella pertussis and non-adherence to immunisation recommendations during pregnancy. Public health interventions, including maternal immunisation, vaccination of infants as early as possible and post-exposure prophylaxis, are critical for reducing the burden of pertussis and preventing further mortality.

Pertussis notifications decline in Australia during COVID-19 non-pharmaceutical interventions, 2020-2021.

Background: Following implementation of coronavirus diseases 2019 (COVID-19) non-pharmaceutical interventions (NPIs) in early 2020, declines in the incidence of other respiratory pathogens have been reported. This study aimed to assess the impact of these interventions on pertussis notifications in Australia. Methods: We compared monthly national notification rates for pertussis during the first two years of the COVID-19 pandemic (2020 and 2021) to those during the three pre-pandemic years (2017 to 2019). Incidence rate ratios (IRR) by age group and jurisdiction were calculated for 2020 and 2021 compared to the mean prepandemic annual notification rate. Results: A substantial progressive decline in pertussis notifications was seen across all age groups, with all-age notification rates more than 40% lower than the pre-pandemic period in all jurisdictions in 2020, and more than 80% lower in 2021. Notification rates decreased more slowly from a lower baseline in Victoria than in other states and territories, despite the stricter, more sustained NPIs implemented in Victoria. Conclusion: The significant decrease in pertussis notifications across all jurisdictions and age groups has likely resulted in reduced infection-acquired immunity, making maintenance of high vaccine uptake, particularly among pregnant women and young infants, of key importance.

Attack Rate, Case Fatality Rate and Predictors of Pertussis Outbreak During Pertussis Outbreak Investigation in Ethiopia: Systematic Review and Meta-Analysis.

BACKGROUND: Pertussis, a highly contagious, vaccine-preventable respiratory infection caused by Bordetella pertussis, is a leading global public health issue. Ethiopia is currently conducting multiple pertussis outbreak investigations, but there is a lack of comprehensive information on attack rate, case fatality rate, and infection predictors. This study aimed to measure attack rates, case fatality rates, and factors associated with pertussis outbreak. METHODS: This study conducted a systematic review and meta-analysis of published and unpublished studies on pertussis outbreaks in Ethiopia from 2009 to 2023, using observational study designs, using the guideline Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). The study utilized databases like Science Direct, MEDLINE/PubMed, African Journals Online, Google Scholar and registers. The data were collected using an Excel Spreadsheet and then exported to STATA version 17 for analysis. Subgroup analysis was conducted to identify potential disparities. A random effects model was used to consider heterogeneity among studies. I2-squared test statistics were used to assess heterogeneity. The attack rate, case fatality rate, and odds ratio (OR) were presented using forest plots with a 95% confidence interval. Egger's and Begg's tests were used to evaluate the publication bias. RESULTS: Seven pertussis outbreak investigations with a total of 2824 cases and 18 deaths were incorporated. The pooled attack and case fatality rates were 10.78 (95% CI: 8.1-13.5) per 1000 population and 0.8% (95% CI: 0.01-1.58%), respectively. The highest and lowest attack rates were in Oromia (5.57 per 1000 population and in the Amhara region (2.61 per 1000 population), respectively. Predictor of pertussis outbreak were being unvaccinated [odds ratio (OR) = 3.05, 95% CI: 1.83-4.27] and contact history [OR = 3.44, 95% CI: 1.69-5.19]. CONCLUSION: Higher and notable variations in attack and case fatality rates were reported. Being unvaccinated and having contact history were the predictors of contracting pertussis disease in Ethiopia. Enhancing routine vaccination and contact tracing efforts should be strengthened.

Seroprevalence of IgG antibodies against pertussis toxin in the Chinese population: A systematic review and meta-analysis.

Pertussis is a vaccine-preventable infectious disease; however, data on pertussis antibody levels in a nationwide population are still limited in China. We aimed to pool the seropositivity rates of IgG antibodies against pertussis toxin (PT-IgG) across the country. We systematically searched PubMed, Web of Science, Embase, and the China National Knowledge Infrastructure Database for studies published between January 1, 2010, and June 30, 2023. Studies reporting the seroprevalence of PT-IgG among a healthy Chinese population were included. Pooled estimates were obtained using random-effects meta-analyzes. The meta-analysis included 39 studies (47,778 participants) reporting anti-PT IgG seropositivity rates. The pooled rate for all ages was 7.06% (95% CI, 5.50%-9.07%). Subgroup analyzes showed rates ranging from 6.36% to 12.50% across different age groups. This meta-analysis indicated a low anti-PT IgG seropositivity rate in the Chinese population, particularly among school-aged children and young adults. This finding underscores the urgent need to refine immunization strategies.

Seroepidemiology of pertussis in Huzhou: A population-based, cross-sectional study.

PURPOSE: The resurgence of pertussis has occurred around the world. However, the epidemiological profiles of pertussis cannot be well understood by current diseases surveillance. This study was designed to understand the seroepidemiological characteristics of pertussis infection in the general population of Huzhou City, evaluate the prevalence infection of pertussis in the population, and offer insights to inform adjustments in pertussis prevention and control strategies. METHODS: From September to October 2023, a cross-sectional serosurvey was conducted in Huzhou City, involving 1015 permanent residents. Serum samples were collected from the study subjects, and pertussis toxin IgG antibodies (Anti-PT-IgG) were quantitatively measured using enzyme-linked immunosorbent assay (ELISA). The analysis included the geometric mean concentration (GMC) of Anti-PT-IgG, rates of GMC≥40IU/mL, ≥100IU/mL, and <5IU/mL. Stratified comparisons were made based on age, vaccination history, and human categories. RESULTS: Among the 1015 surveyed individuals, the geometric mean concentration (GMC) of Anti-PT-IgG was 10.52 (95% CI: 9.96-11.11) IU/mL, with a recent infection rate of 1.58%, a serum positivity rate of 11.43%, and a proportion with <5IU/mL of 40.49%. Among 357 children with clear vaccination history, susceptibility decreased with an increasing number of vaccine doses (Z = -6.793, P < 0.001). The concentration of Anti-PT-IgG exhibited a significant post-vaccination decline over time (Z = -5.143, P < 0.001). In women of childbearing age, the GMC of Anti-PT-IgG was 7.71 (95% CI: 6.90-8.62) IU/mL, with no significant difference in susceptibility among different age groups (χ2 = 0.545, P = 0.909). The annual pertussis infection rate in individuals aged ≥3 years was 9321 (95%CI: 3336-16039) per 100,000, with peak infection rates in the 20-29, 40-49, and 5-9 age groups at 34363 (95%CI: 6327-66918) per 100,000, 22307.72 (95%CI: 1380-47442) per 100,000, and 18020(95%CI: 1093-37266) per 100,000, respectively. CONCLUSIONS: In 2023, the actual pertussis infection rate in the population of Huzhou City was relatively high. Vaccine-induced antibodies exhibit a rapid decay, and the estimated serum infection rate increases rapidly from post-school age, peaking in the 20-29 age group. It is recommended to enhance pertussis monitoring in adolescents and adults and refine vaccine immunization strategies.