Varicella seroprevalence in healthcare workers in a tertiary hospital: an audit of cross-sectional data

Immunity to Varicella Zoster Virus in Healthcare Workers: A Systematic Review and Meta-Analysis (2024)

Healthcare workers (HCWs) are occupationally exposed to varicella zoster virus (VZV), and their inappropriate vaccination status could contribute to an outbreak involving both professionals and the patients they care for, with a potential impact on the general population. Therefore, since 2007, the Advisory Committee on Immunization Practices (ACIP) recommends that all HCWs have evidence of immunity against varicella. The present meta-analysis was therefore designed to collect the available evidence on the seronegative status of VZV among HCWs. PubMed, Scopus, and Embase databases were searched without backward limit for articles reporting on the seroprevalence of VZV among HCWs, and all articles meeting the inclusion criteria were included in a random-effect meta-analysis model. From 1744 initial entries, a total of 58 articles were included in the quantitative analysis (publication range: 1988 to 2024), for a pooled sample of 71,720 HCWs. Moreover, the included studies reported on seroprevalence data on measles (N = 36,043 HCWs) and rubella (N = 22,086 HCWs). Eventually, the pooled seronegative status for VZV was estimated to be 5.72% (95% confidence interval [95% CI] 4.59 to 7.10) compared to 6.91% (95% CI 4.79 to 9.87) for measles and 7.21% (5.36 to 9.64) for rubella, with a greater risk among subjects younger than 30 years at the time of the survey (risk ratio [RR] 1.434, 95% CI 1.172 to 1.756). Interestingly, medical history of either VZV infection/vaccination had low diagnostic performances (sensitivity 76.00%; specificity 60.12%; PPV of 96.12% but PNV of 18.64%). In summary, the available data suggest that newly hired HCWs are increasingly affected by low immunization rates for VZV but also for measles and rubella, stressing the importance of systematically testing test newly hired workers for all components of the measles-pertussis-rubella-varicella vaccine.

Seroprevalence of Varicella-Zoster Virus and Measles among Healthcare Workers in a Tertiary Medical Center in Korea

Measles and varicella still occur in the general population despite the widespread vaccination against them, and healthcare workers (HCWs) are still at risk of exposure to these diseases. Here, we evaluated the seroprevalence of measles and varicella-zoster virus (VZV) in HCWs and the trend of seroprevalence according to age, birth year, and occupational group. The serostatuses of measles and VZV of HCWs during new employee medical examinations between October 2015 and October 2021 were included. Thereafter, the trends of seroprevalence according to age, birth year, and occupational groups were evaluated. Overall, 2070 and 1827 HCWs were evaluated for VZV and measles serostatus, respectively. The seroprevalences of VZV and measles were 91% (1884/2070) and 70% (1284/1827), respectively. Younger HCWs had a significantly lower seroprevalence of measles (p = 0.02, age) and VZV (p = 0.003, birth year and p < 0.001, age). The seroprevalence of measles and VZV was significantly higher among doctors and nursing assistants than among nurses and other HCWs (p < 0.001 in both). In conclusion, the seroprevalence of measles and VZV significantly decreased in younger HCWs. Additionally, monitoring the serostatus of measles and VZV and the immunization of susceptible HCWs are required to prepare and control infectious diseases in healthcare facilities.

Seroprevalence of ToRCH Pathogens in Southeast Asia

ToRCH is the acronym for several pathogens associated with pregnancy complications and sequelae in the unborn or newborn child. Particularly primary infections during pregnancy are associated with increased risk. Seroprevalence data of ToRCH infections are important, especially in countries with weak disease surveillance systems, to estimate immunity and vaccination levels, as well as exposure rates and thus the risk of infection during pregnancy. A systematic literature search spanning a 30-year time period was conducted to identify serosurveys on ToRCH pathogens in Southeast Asia. The 96 identified studies showed that some pathogens were well studied, while only limited data were available for others. Studies from the better-developed countries of the region were more abundant. Moreover, seroprevalence data were often limited to a certain geographical region within the country or to certain cohorts, there was an evident lack of recent serosurveys, and the study quality was often not adequate. Well-designed and area-wide serosurveys of ToRCH pathogens are clearly warranted. If combined with risk factor analysis, these studies may guide the development and implementation of effective measures for infection prevention, especially during pregnancy. In addition, educational programs for health care workers and for pregnant women during antenatal care are urgently needed.

Seroprevalence survey for Varicella among healthcare workers and medical students in Italy

Varicella is a potentially serious infectious disease caused by Varicella-Zoster Virus (VZV). In Italy childhood varicella vaccine have gradually introduced into national immunization program since 2003 and from 2017 a two-doses schedule has been stated nationally for all newborns and has become compulsory for school attendance. VZV exposures among healthcare workers (HCWs) and patients can be really dangerous and expensive. According to Centers of Disease Control and Italian national immunization plan health care, institutions should verify that all HCWs have clear evidence of immunity to VZV and should ensure that susceptible subjects will receive 2 doses of VZV vaccine. Currently, the vaccination of HCWs is not compulsory in Italy and the risk of varicella infection among these subjects is not well known. We evaluated the clinical records of 840 HCWs (256 male and 584 female) who underwent the annual occupational screening, from 1st January to 31st August 2018. HCWs were divided into three subgroups according to their age: 18-30, 31-40, and over 40 years old. We compared the mean values of IgG-specific antibodies between the age group through analysis of variance (ANOVA). A total of 784 (93.33%) HCWs were protected for VZV IgG antibodies level. There wasn't a significant difference between male and female while was found between age group (P < 0.001). Protection levels for varicella are inadequate among HCWs. Despite the epidemiology of varicella in general population has changed with the implementation of the childhood varicella vaccination program transmission of VZV in hospitals is still a serious problem, so it is necessary to increase prevention activities in these settings, including vaccination.

Varicella Seroprevalence in Healthcare Workers at a Medical Center Following Changes in National and Local Hospital Vaccination Policies

BACKGROUND

Varicella seroprevalence in healthcare workers at a tertiary care hospital in Taiwan was assessed following the inclusion of varicella zoster vaccination in the national vaccination schedule in 2004 and was made a hospital policy in 2008.

METHODS

Seroprevalence data were extracted from records of pre-employment health check-ups performed between 2008 and 2018 at a single medical center. Staff with complete medical records and anti-varicella zoster virus immunoglobulin G (VZV IgG) titers were included. Sex and age group differences in terms of geometric mean titer (GMT) were compared using analysis of variance and chi-squared tests. The significance of the correlation between age and the anti-VZV IgG titer was tested by linear regression. The odds of significant associations among age, sex, vocation, and the years of national and hospital adoption of vaccination were determined using univariate and multivariate analyses. p < 0.05 was considered statistically significant.

RESULTS

Of the 7314 eligible participants, 5625 (76.90%) were women, and the mean patient age was 26.80 ± 8.00 years. The lowest VZV-positivity rates were in 18-20-year-old women (85.16%; GMT, 362.89 mIU/mL) and men (87.59%; GMT, 288.07 mIU/mL). VZV positivity increased with age (p < 0.001). Participants born before 2002 were more likely to be seropositive than those born after 2003 (odds ratio, 2.51 vs. 1.0; p < 0.001). The lowest seropositive rate was found in the nursing staff (88.91%; 95% confidence interval, 87.74%-90.05%). Varicella vaccine boosters have been required at pre-employment health check-ups since 2008 if anti-VZV antibodies were not detectable. A follow-up evaluation found marginal significant differences in the odds ratios of seropositivity after 2007 (p = 0.052), especially in 2008 and 2014 (p < 0.05) after the hospital policy launched.

CONCLUSIONS

Despite public health efforts, a small number of healthcare workers were inadequately protected, and antibody titers were lower than required to maintain herd immunity. For effective prevention of nosocomial infection, VZV IgG status should be documented for all HCWs, and susceptible HCWs should be vaccinated to avoid outbreaks. Pre-employment screening and vaccination have increased immunity and need to be conducted to ensure protection of vulnerable patients.

Varicella zoster and fever rash surveillance in Lao People's Democratic Republic

Background

In Lao PDR, the epidemiology of varicella infection is uncertain, since it is not a notifiable disease and VZV outbreaks are rarely reported as fever/rash (F/R) diseases.

Methods

We estimated the seroprevalence of VZV (IgG ELISA) in different age cohorts (9 months to 46 years; N = 3139) and investigated VZV and 6 other viruses in patients during F/R outbreaks and in an ad hoc sentinel site in the context of the national reporting system (IgM ELISA, PCR).

Results

At least 80% of the sampled population had evidence of VZV infection before the age of 15. The largest increase in seroprevalence occurred between the age groups 1 to 5 and 6 to 7 year-olds. A VZV outbreak (clade 2) also occurred in this age group mostly during the first year of primary school (median age 6 years, interquartile range 4.0–7.5). During a dengue outbreak, 6% had varicella. At our F/R sentinel site, 14% of children with viral etiology were laboratory diagnosed as varicella and among others, a sizeable number of measles (N = 12) and rubella cases (N = 25) was detected compared to those reported for the whole country (N = 56 and 45), highlighting nationwide a large challenge of underreporting or misdiagnosis of these notifiable diseases because of lack of diagnostic laboratory capacity.

Conclusion

We recommend strengthening the clinical and laboratory diagnosis of VZV, measles and rubella, the surveillance and reporting of notifiable F/R diseases by retraining of healthcare workers and by setting up sentinel sites and enhancing laboratory capacity.

Electronic supplementary material

The online version of this article (10.1186/s12879-019-3990-7) contains supplementary material, which is available to authorized users.

Seroprevalence of varicella-zoster virus among pregnant women in Fayoum Governorate, Egypt

Background

Chickenpox infection acquired during pregnancy is a serious condition. There may be congenital malformations and neonatal varicella syndrome with significant morbidity and mortality. Egypt has no routine varicella-zoster vaccination program.

Objective

To assess the immune status against varicella-zoster virus (VZV) antibodies among a group of pregnant women and to study the relationship between VZV seroprevalence and some sociodemographic characteristics.

Subjects and methods

A descriptive cross-sectional study was conducted on a group of pregnant women (n = 333) attending antenatal care (ANC) clinic at Fayoum University Hospital. Serologic testing for VZV was performed using ELISA through the years 2016-2017.

Results

VZV seroprevalence was detected in 294 (88.3%) of the 333 recruited pregnant women. Older age > 25 years old was significantly associated with low percent of VZV-negative antibodies (6.7% in versus 17.4% in younger age, OR (95%CI) 0.34 (0.17-0.70)), also having more than one child was significantly associated with a low percent of VZV-negative antibodies (8.2% versus 16.1% among participants with no children or having one child, OR 0.34 (0.17-0.70)).

Conclusions

Despite the absence of a routine VZV vaccination program in Egypt, VZV immunity was high among pregnant women, but less than that reported in many developed countries. We recommend targeted vaccination for women in the reproductive age especially young and primipara.

Trial registration

Ethical Committee Registration number R67 session 42: date 12/11/2017(retrospectively registered).

Prevalence and Characteristics of Pediatric Healthcare Workers without Immunity to Varicella zoster Virus

This study aimed to determine the proportion of varicella non-immune pediatric healthcare workers (HCWs) of the Pediatrics Department of King Chulalongkorn Memorial Hospital and to determine cost-effective strategies for identifying non-immune personnel. A cross-sectional study using a self-administered questionnaire to determine HCWs' histories of chickenpox or 2-dose varicella vaccination was conducted. From a total of 699 HCWs, 653 HCWs (93%), including 145 physicians (22%), 297 nurses (46%), and 211 administrative staff (32%), responded to questionnaires. There were 475 HCWs (73%) who had a history of chickenpox, 58 (9%) who had completed the 2-dose varicella vaccine schedule, and 120 (18%) whose varicella-zoster virus (VZV) immunity status was uncertain. In total, 107 HCWs (89%) were tested for VZV IgG, 90 of whom had immunity, and 17 were determined to be non-immune. After combining history and VZV IgG test results, the prevalence of non-immune HCWs was 2.6% (95%CI 1.4-3.8), with those ≤40 years of age at higher risk of non-immunity. Implementing a strategy that involves testing of only those with an unknown VZV status and vaccination for only those determined to be non-immune costs 1,801 United States dollar (USD), less than the total cost (4,601 USD) for vaccinating all HCWs with uncertain status.

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.