Serological survey of mumps immunity among health care workers in the Catalonia region of Spain

Vaccination Offer during the Occupational Health Surveillance Program for Healthcare Workers and Suitability to Work: An Italian Retrospective Cohort Study

The active immunization of health care workers (HCWs) is a crucial measure to avoid nosocomial infection; nevertheless, vaccine coverage (VC) among health personnel in Italy is unsatisfactory. To improve VC in the healthcare set, the Hygiene and Occupational Medicine departments of Bari Policlinico General University Hospital applied a specific program. The operative procedure demands that in the context of the occupational medical examination, all workers are evaluated for susceptibility to vaccine-preventable diseases (VDPs), with immunization prophylaxis offered to those determined to be susceptible. This study analyzed data from workers who attended the biological risk assessment protocol from December 2017 to October 2021 (n = 1477), who were evaluated for the immune status for measles, mumps, rubella, and varicella. Among the enrolled subjects, non-protective antibody titers were higher for measles and mumps (13%), followed by rubella (11%) and varicella (8%). Appropriate vaccinations were offered to all susceptible HCWs, and HCWs were re-tested one month after immunization. The seroconversion rate after the administration of one or more booster dose(s) was over 80%. Overall, 2.5% of the subjects refused the offered vaccine(s); the main determinant of immunization compliance was younger age (aOR = 0.86; 95%CI = 0.80–0.92). Especially during the COVID-19 pandemic, VPDs may still present a hazard in nosocomial environment. Our experience suggests that, despite hospital procedures and dedicated human assets, satisfactory VC cannot be reached without the provision of federal regulations. Nevertheless, public health policymakers have to improve the promotion of vaccine prophylaxis and education to reach higher VC.

Evaluation of Immunity for Mumps among Vaccinated Medical Students

Healthcare workers are considered at higher risk for mumps infection than the general population. Since 2017, the national immunization plan recommended the administration of a dose of measles–mumps–rubella (MMR) vaccine to the healthcare operators who are unable to demonstrate a complete vaccination history or that are seronegative for at least one of the three agents. Regarding mumps infection, based on actual concerns regarding the loss of protection over the years after vaccination, the Advisory Committee on Immunization Practices (ACIP) recommended to administer a third dose of vaccine to operators previously vaccinated with two doses of MMR vaccine who belong to a group at increased risk of mumps infection in the event of an epidemic. This guideline, however, is not currently followed in Italy, resulting in a potential risk for vaccinated operators to become unprotected from mumps over the years. The aim of our study is to evaluate the persistence of a protective antibody level for mumps among medical students vaccinated during infancy or adolescence, at the start of their hospital internship. We retrospectively evaluated mumps-specific IgG levels in a group of medical students, in the period from 1 January to 31 December 2020. We evaluated the persistence of the detectable level of mumps-specific antibodies in relation to their vaccinal status, gender and time elapsed from vaccination. We found that 17.4% (65 subjects) of our sample were seronegative for mumps. The univariate analysis showed a significant difference in serological protection between male and female gender (77.0% vs. 86.2%; p < 0.05 with chi² test) and between age classes (86.5% vs. 76.4%; p < 0.05 for subjects aged 18–23 years and over 23 years, respectively). Female gender was significantly related to higher serological protection even after adjusting for age classes and number of vaccine doses administered in a multivariate analysis model. Our study shows a substantial percentage of subjects lacking a protective mumps titer among medical students who were vaccinated in childhood. Given the higher risk of infection among those subjects, routine pre-employment screening should be performed among those operators regardless of their vaccination history and a third dose of MMR should be offered to unprotected students.

Compliance with immunization and a biological risk assessment of health care workers as part of an occupational health surveillance program: The experience of a university hospital in southern Italy

BACKGROUND

The active immunization of health care workers (HCWs) is a primary measure to prevent nosocomial infection; despite this, vaccine coverage among HCWs in most countries is low. To increase vaccine coverage in the health care setting, the hygiene and occupational medicine departments of Bari Policlinico General University-Hospital implemented a vaccination procedure. This operative procedure requires that during the occupational medical examination, all employees are evaluated for immunity/susceptibility to vaccine-preventable diseases, with vaccination offered to those determined to be susceptible.

METHODS

The study sample comprised HCWs who attended the biological risk assessment program from December 2017 to January 2019 (n = 449).

RESULTS

Susceptibility was higher for hepatitis B virus (23%), followed by rubella (11%), varicella (9%), mumps (8%), and measles (7%). The seroconversion rate after the administration of booster dose(s) was >80% for all vaccines. Overall, 15% of the HCWs refused the offered vaccine(s), and the main determinants of vaccination compliance were younger age (P < .0001) and being a physician (P < .05).

DISCUSSION

Despite the several recommendations and campaigns to promote vaccinations, achieving high immunization rates among HCWs is still a challenge.

CONCLUSIONS

In this scenario, public health institutions have to choose between the enforcement of the promotion or the adoption of a mandatory policy.

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.

[General epidemiology of infections acquired by health-care workers: immunization of health-care workers]

Healthcare workers are exposed to multiple occupational hazards, the most common being the biological risk. Moreover, colonized staff, or those in incubation period, or with an active infectious disease, could be at risk of transmitting these infections to others, such as patients, relatives or other workers. Therefore, measures to prevent biological risks in the healthcare environment are essential. In this chapter, the main recommendations for the prevention and control of infectious diseases that can affect health care personnel are reviewed. Specific measures recommended for each infection, including vaccination guidance, are described. These recommendations were updated according to the available evidence and the epidemiological changes described in recent years.