Seroprevalence study of B. pertussis infection in health care workers in Catalonia, Spain

Bordetella pertussis infection following relaxation of COVID-19 non-pharmaceutical interventions in 2021-2023 in Vancouver metropolitan area, British Columbia, Canada

BACKGROUND

We recently reported a near disappearance of B. pertussis and a decline in anti-B. pertussis antibodies during the peak implementation of Coronavirus disease 2019 (COVID-19) non-pharmaceutical interventions (NPI) in 2021 in British Columbia (BC), Canada. During 2021-2023, incidence of reported B. pertussis cases remained low in BC at < 1/100,000 population. This study determined how serological evidence of B. pertussis changed after the gradual relaxation of NPI between 2021-2023.

METHODS

Randomly selected blood samples from school staff 25-51 years old (n = 65) were collected yearly between 2021-2023 in the Vancouver metropolitan area, BC, Canada, and tested for anti-pertussis toxin (PT) IgG levels. Serological evidence of B. pertussis infection (thereafter "seroconversion") was defined as a quantifiable anti-PT IgG levels in subjects with anti-PT IgG levels below lower limit of quantification in the preceding year or a > 4-fold increase in anti-PT IgG levels between two subsequent years. Samples were also tested for anti-diphtheria toxoid (DT) IgG, and similar seroconversion criteria were applied to exclude seroconversion due to vaccination with tetanus-diphtheria-acellular-pertussis (Tdap).

RESULTS

Three subjects met seroconversion criteria for anti-PT IgG between 2021 and 2022 and 9 between 2022 and 2023, yielding a seroconversion rate of 4.6 /100 person-years and 14.9/100 person-years, P = 0.127, respectively. None of the subjects met the criteria for vaccination with Tdap. The geometric mean concentration of anti-PT IgG showed a statistically significant decrease in 2022 compared with 2021, 4.8 IU/mL IU/ml (95 % confidence interval [CI], 3.8-5.9) vs. 6.4 IU/ml (95 % CI, 4.9-8.2; p = 0.001), followed by a statistically significant increase in 2023 compared with 2022 6.5 IU/ml (95 % CI, 4.9-8.5) vs. 4.8 IU/ml (95 % CI, 3.8-5.9; p = 0.0006), respectively.

DISCUSSION

Serological evidence of B. pertussis increased between 2022 and 2023 despite low reported cases, which suggests that B. pertussis circulation resumed after relaxing of COVID-19 NPI.

Occupational Health Update: Evaluation and Management of Exposures and Postexposure Prophylaxis

Health care personnel (HCP) are at risk of exposure to infectious agents depending on their job duties and other factors. Risks include percutaneous exposure to blood-borne pathogens via sharp injuries (eg, human immunodeficiency virus, hepatitis B virus, hepatitis C virus); exposure by direct contact, droplet, or airborne transmission of pathogens through direct patient care (eg, pertussis, invasive meningococcus infections, tuberculosis); and through indirect contact transmission related to the contaminated health care environment (eg, Clostridioides difficile). Occupational health programs must effectively identify and respond to potential exposures and provide guidance to HCP on postexposure prophylaxis.

Bordetella pertussis in School-Age Children, Adolescents and Adults: A Systematic Review of Epidemiology and Mortality in Europe

Pertussis (whooping cough) epidemics persist globally despite high vaccine coverage among infants and young children. The resurgence of pertussis in high-income countries is partly due to waning vaccine immunity, resulting in a pool of unprotected adolescents and adults. However, pertussis is generally less severe in adolescents and adults, and this difference in presentation means it can often be unrecognised by healthcare professionals, meaning that it is largely 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 and mortality in school-aged children, adolescents and adults in Europe. A formal statistical comparison (e.g. using meta-analyses) was not possible because of the mix of methodologies reported. There were 69 epidemiological studies and 19 mortality studies identified for review. Over the past decade, the reported incidence of notified pertussis cases varied widely between European countries, which is likely associated with differences in surveillance systems, diagnostic techniques and reporting regulations. However, several studies show that pertussis is circulating among adolescents and adults in Europe, and although pertussis-related morbidity and mortality are highest in infants, there is evidence that adults aged > 50 years are at increased risk. For example, in a hospital-based surveillance study in Portugal, between 2000 and 2015, 94% of hospitalised pertussis cases were infants aged < 1 year, with a case fatality rate (CFR) of 0.8%; however, among hospitalised adult cases of pertussis, the CFRs were 11.5% (aged 18–64 years) and 17.4% (aged > 65 years). Very few European countries currently include pertussis boosters for adults in the national immunisation strategy. In addition to increasing pertussis vaccination coverage in adolescents and adults, mitigation strategies in European countries should include improved diagnosis and treatment in these populations.

Pertussis in Lao PDR: Seroprevalence and disease

OBJECTIVES

Pertussis is a debilitating vaccine-preventable infection. The aim of this study was to determine susceptibility and exposure to pertussis in Lao PDR in different age groups and subpopulations.

METHODS

A total 3072 serum samples were obtained from different cohorts: children with documented vaccination, pre-schoolers, schoolchildren, blood donors, healthcare workers (HCWs), and pregnant women and paired cord blood. Samples were tested for anti-pertussis toxin IgG antibodies. A history of Bordetella pertussis exposure was defined according to antibody titres. Four hundred and seventy-five throat swabs and nasopharyngeal aspirates were analysed by PCR for the presence of B. pertussis in symptomatic children at the Children's Hospital in Vientiane.

RESULTS

Overall pertussis seroprevalence was 57.5%. The prevalence of titres indicating acute infection or recent vaccination or infection/vaccination within the last 12 months ranged from 7.4% (100/1356) in adults to 21.4% (25/117) in pre-schoolers (age 1-5 years). B. pertussis was detected in 1.05% (5/475) of children with respiratory symptoms in Vientiane Capital.

CONCLUSIONS

It is suggested that routine childhood vaccination, in particular outreach, as well as vaccination of HCWs should be strengthened. A childhood booster and vaccination of pregnant mothers should be considered. There is also a need to improve reporting and to introduce pertussis testing in at least one central facility.

Healthcare workers' vaccination at European and Italian level: a narrative review

Today some vaccine-preventable diseases remain an important cause of morbidity and mortality worldwide despite the availability of new vaccines. Healthcare workers are particularly at risk to acquire an infection disease, playing a fundamental role in nosocomial transmission, which makes them an important target group for vaccination. The vaccination recommendations of HCWs, as well as the general population, differ from country to country. Furthermore, coverage rates vary widely a lot over the world, making HCWs vulnerable to disease and so healthcare settings to outbreaks. The motivations of vaccine hesitancy are many and maybe other studies would help policymakers and stake-holders to shape programs to improve vaccination coverage and the control of infectious diseases through the correct application of guidelines on prevention. (www.actabiomedica.it)

Seroprevalence of Pertussis in Healthcare Workers without Adult Pertussis Vaccine Use at a University Hospital in Korea

BACKGROUND

Pertussis is highly contagious respiratory disease. Healthcare workers (HCWs) can be an important mediator of the disease. A seroprevalence of pertussis was investigated in HCWs to determine the immune status against pertussis and to detect the unidentified pertussis.

METHODS

This study was conducted for HCWs at a hospital located in Korea in 2011. After obtaining written informed consent for HCWs voluntarily participating in the study, 10 mL of blood was collected from each subject. Demographic and medical data were collected using questionnaire. Data on the underlying disease and vaccination history were reviewed again through medical records. The presence of anti-pertussis toxin (anti-PT) immunoglobulin G (IgG), and immunoglobulin A (IgA) was detected by quantitative analysis using a commercially available ELISA kit (EUROIMMUN, Lübeck, Germany).

RESULTS

A total of 412 HCW participated in the study. Among them, 14 were excluded due to the inadequate sample amount or medical history not secured. Of the 398 HCWs analyzed, 16.6% (66/398) were men and the mean age was 33.82 ± 9.10 years (range, 21-67). The mean anti-PT IgG titer was 8.32 ± 20.40 IU/mL (range, 0.4-287.5 IU/mL). The overall seroprevalence (rate of anti-PT IgG antibody [Ab] titer > 5 IU/mL) was 33.7%. Three (0.8%) HCWs had the Ab level > 100 IU/mL indicated acute infection. There was no statistically significant difference in the seroprevalence and mean titer of anti-PT IgG Ab according to age group, type of occupation, patient-facing position, or working in the pediatric department.

CONCLUSION

The seroprevalence of pertussis of the HCWs of a university hospital in Korea was low, and there were some unrecognized acute infections. Therefore, booster immunization of pertussis to HCWs should be actively considered.

Seroprevalence of pertussis among healthcare workers: A cross-sectional study from Tunisia

This cross-sectional study aimed to assess pertussis seroprevalence among healthy healthcare workers (HCW) of the Children's Hospital of Tunis, Tunisia. During the study period, 236 blood samples were obtained to determine HCW exposure to pertussis. Concentrations of immunoglobulin G (IgG) to pertussis toxin (PT) were measured using a commercial enzyme-linked immunosorbent assay. Cut-offs values used were 40 and 100 IU/ml, respectively indicative of an infection within the last year and a current/recent infection. Overall, seropositivity rate was 11.4% (95% CI 7.4-15.5) and 2.5% (95% CI 0.5-4.6) of ELISA results were indicative of a current infection. Seroprevalence was significantly most important in nurses (p = 0.03) and in participants aged 21-31y (p = 0.009). Our study confirmed that pertussis is circulating in hospital settings and affecting Tunisian HCW, in close contact with infants. Therefore, a booster dose of acellular pertussis vaccine needs to be considered.

Les vaccins dans la prévention des infections associées aux soins

Les infections associées aux soins (IAS) constituent un véritable problème de santé publique. Escherichia coli, Staphylococcus aureus, Clostridium difficile sont les plus souvent à l’origine des IAS. L’antibiorésistance fréquente complique encore la prise en charge et des impasses thérapeutiques existent à présent. Les mesures d’hygiène hospitalière bien qu’essentielles sont insuffisantes pour diminuer drastiquement les IAS. Ainsi, des stratégies alternatives à l’antibiothérapie s’avèrent nécessaires pour prévenir et traiter les IAS. Parmi celles-ci, la vaccination et l’immunisation passive sont probablement les plus prometteuses. Nous avons fait une mise au point sur les vaccins disponibles et en développement clinique pour lutter contre les IAS, chez les patients à risque d’IAS et les soignants. L’intérêt de la vaccination grippale et rotavirus chez les patients pour prévenir ces IAS virales a été examiné. Le développement d’un vaccin anti-S. aureus, déjà émaillé de 2 échecs est complexe. Toutefois, ces échecs ont permis d’améliorer les connaissances sur l’immunité anti-S. aureus. La mise à disposition d’un vaccin préventif anti-C. difficile semble plus proche. Pour les autres bactéries gram négatif responsables d’IAS, le développement est moins avancé. La vaccination des patients à risques d’IAS pose également des problèmes de réponse vaccinale qu’il faudra résoudre pour utiliser cette stratégie. Ainsi, la vaccination des soignants, de par l’effet de groupe permet également de prévenir les IAS. Nous faisons ici le point sur l’intérêt de la vaccination des soignants contre la rougeole, la coqueluche, la grippe, la varicelle, l’hépatite B pour réduire les IAS avec des vaccins déjà disponibles.

Lack of Pertussis Protective Antibodies in Healthcare Providers Taking Care of Neonates and Infants in a Children's Hospital

Contact tracing and seroepidemiologic studies were done after a premature baby contracted pertussis in a children's hospital. No infection source was confirmed. Four (3.5%) healthcare providers were positive for anti-pertussis IgM, while only 23% (26/113) were positive for IgG in a following survey. Pertussis vaccination for healthcare providers is needed.

Immunity against vaccine-preventable diseases in Finnish pediatric healthcare workers in 2015

Healthcare workers (HCWs) pose a risk to themselves and their patients if not protected against vaccine-preventable diseases. Alarmingly, lacking immunity has been reported in several studies. We assessed the immunity against vaccine-preventable diseases in 157 pediatric HCWs in Helsinki Children's Hospital. The HCWs enrolled answered a questionnaire and gave a serum sample. Antibodies were measured with EIA against MMR-diseases, tetanus and diphtheria toxins, Hepatitis B (HBV), Hepatitis A (HAV), varicella zoster and pertussis toxin. Neutralizing antibodies against poliovirus 1, 2 and 3 were measured. All of the HCWs had antibodies against tetanus and 89.8% against diphtheria. All had measurable levels of polio antibodies to all three polioviruses. 41% had suboptimal levels of antibodies against at least one of the antigens tested: MMR-viruses, diphtheria, HBV or polio. Measles, mumps and rubella antibodies were detectable in 81.5%, 89.2% and 93%, respectively. Only one HCW had no varicella-antibodies. Hepatitis B surface antibodies (HBsAb) were detected in 89.8% of the nurses. 67.5% had HAV-antibodies. A poor correlation between detected antibody levels and reported vaccination history was noticed, indicating a need for a universal record system for registering the vaccines given to each individual.

Occupational Health Update: Focus on Preventing the Acquisition of Infections with Pre-exposure Prophylaxis and Postexposure Prophylaxis

Health care personnel are commonly exposed to infectious agents via sharp injuries (eg, human immunodeficiency virus, hepatitis B virus, and hepatitis C virus), direct patient care (eg, pertussis and meningococcus), and the contaminated environment (eg, Clostridium difficile). An effective occupational program is a key aspect of preventing acquisition of an infection by offering the following: (1) education of health care personnel regarding proper handling of sharps, early identification and isolation of potentially infectious patients, and hand hygiene; (2) assuring immunity to vaccine-preventable diseases; and, (3) immediate availability of a medical evaluation after a nonprotected exposure to an infectious disease.

Vaccination of healthcare workers: A review

Vaccine-preventable diseases are a significant cause of morbidity and mortality. As new vaccines are proving to be effective and as the incidence of some infections decreases, vaccination practices are changing. Healthcare workers (HCWs) are particularly exposed to and play a role in nosocomial transmission, which makes them an important target group for vaccination. Most vaccine-preventable diseases still carry a significant risk of resurgence and have caused outbreaks in recent years. While many professional societies favor vaccination of HCWs as well as the general population, recommendations differ from country to country. In turn, vaccination coverage varies widely for each microorganism and for each country, making hospitals and clinics vulnerable to outbreaks. Vaccine mandates and non-mandatory strategies are the subject of ongoing research and controversies. Optimal approaches to increase coverage and turn the healthcare workforce into an efficient barrier against infectious diseases are still being debated.

Immunization of Health-Care Providers: Necessity and Public Health Policies

Health-care providers (HCPs) are at increased risk for exposure to vaccine-preventable diseases (VPDs) in the workplace. The rationale for immunization of HCPs relies on the need to protect them and, indirectly, their patients from health-care-associated VPDs. Published evidence indicates significant immunity gaps for VPDs of HCPs globally. Deficits in knowledge and false perceptions about VPDs and vaccines are the most common barriers for vaccine uptake and may also influence communication about vaccines between HCPs and their patients. Most countries have immunization recommendations for HCPs; however, there are no universal policies and significant heterogeneity exists between countries in terms of vaccines, schedules, frame of implementation (recommendation or mandatory), and target categories of HCPs. Mandatory influenza immunization policies for HCPs have been implemented with high vaccine uptake rates. Stronger recommendations for HCP immunization and commitment at the level of the health-care facility are critical in order to achieve high vaccine coverage rates. Given the importance to health, mandatory immunization policies for VPDs that can cause serious morbidity and mortality to vulnerable patients should be considered.

Seroprevalence of pertussis amongst healthcare professionals in Spain

INTRODUCTION

This multi-center, hospital-based observational study determined the seroprevalence of pertussis antibodies amongst healthcare professionals from three different hospitals in Spain to ascertain the health status of professionals attending to susceptible groups who are at risk of contracting and transmitting pertussis.

METHODS

Medical professionals from three hospitals in Spain were recruited for this study (NCT01706224). Serum samples from subjects were assessed for anti-pertussis antibodies by ELISA. The percentage of subjects positive for anti-pertussis antibodies were determined by age-strata, gender, vaccination status, professional level (physicians, nurses, ancillary nurses and midwives), hospital department, number of working years, numbers of hours spent with the patient as well as number of children in the household.

RESULTS

Overall, 31.2% of subjects were seropositive; 3.3% of these healthcare professionals had ELISA values indicative of current or recent infection. There were no significant differences in terms of pertussis prevalence with respect to age, gender, hospital department, profession, number of working years and number of hours spent with patients. These levels of seronegativity amongst healthcare workers further strengthen the rationale for vaccination amongst this specific population against pertussis.