Pierre Jacques

Occupational risk of infection by varicella zoster virus in Belgian healthcare workers: a seroprevalence study.

OBJECTIVES To assess the prevalence of varicella zoster virus (VZV) antibodies in Flemish (Belgian) healthcare workers, to investigate the association between seronegativity and selected variables, and to assess the reliability of recall about disease as a predictor of immunity. METHODS A seroprevalence study of VZV antibodies (IgG) was conducted among a systematic sample of 4923 employees in various professional groups, employed in 22 hospitals in Flanders and Brussels (Belgium). Information about sex, age, department, job, and years of employment, the country of origin, and history of varicella was obtained. The presence of VZV antibodies was investigated with the enzyme linked immunosorbent assay (ELISA), Enzygnost anti VZV / IgG (Dade Behring, Marburg, Germany). Statistical analysis was performed by calculating prevalences and prevalence ratios (PRs) and their 95% confidence intervals (95% CIs). Sensitivity, specificity, and positive and negative predictive values (PPV and NPV) of the recalled history were determined. RESULTS The prevalence of VZV seropositivity in Flemish healthcare workers was 98.5% (95% CI 98.1 to 98.8). Seronegativity was significantly associated with age and job, increasing with both older and younger age. The prevalence of seronegative workers was significantly less in nursing staff than non-nursing staff. There was no significant difference for sex and years of employment. The PPV and NPV of recalled history were 98.9% and 3.4%. Sensitivity and specificity were 83% and 38.9%. CONCLUSION The prevalence of VZV seropositivity was very high in this sample of Flemish healthcare workers. Because of this low overall susceptibility, VZV infection seems not to be an important occupational risk among healthcare workers in Flanders. The increasing seronegativity above the age of 45 is possibly due to a loss of detectable antibodies. A positive history of varicella was a good predictor of immunity, but a negative history had no value as a predictor of susceptibility in adults.

Hepatitis B Vaccination Coverage in Belgian Health Care Workers

Abstract.Background:The hepatitis B virus (HBV) vaccination policy for health care workers (HCW) started in Belgium in 1983. An update of vaccination coverage and rates of seroconversion and seroprotection among HCW can give an insight into the actual status and encourage further development of vaccination programs.Patients and Methods:5,064 HCW were tested for anti-HBs. We considered those who had a positive anti-HBs test as seroconverted (SC) and those who had an anti-HBs titer > 10 IU/l as seroprotected (SP).Results:4,771 HCW were eligible for vaccination; 84.9% of them were effectively vaccinated. Among high-risk professions (nurses, care and laboratory workers), 94.79% were vaccinated; for other professions the vaccination coverage was 69.26%. Of the 1,015 non-vaccinated persons, 293 were anti-HBs positive. Among these 54.95% declared they had had a previous hepatitis infection that was serologically proven to be HBV (anti-HBc positive). Of the remaining 132 positives, 70.45% had previously undergone surgery and/or transfusion. Among these 1,015 non-vaccinated HCW, 59.03% were anti-HBs positive. Of these, 373 were nurses, care or laboratory workers. This contrasts with the results for HCW in other sectors, where 11.49% were anti-HBs positive.Conclusion:In our sample, high vaccination, seroconversion and seroprotection rates were achieved, at least for higher risk HCW. The same conclusion can be drawn if we consider hospital departments which carry a higher risk of bloodborne infections.

Prevalence of hepatitis C antibodies in a large sample of Belgian healthcare workers.

OBJECTIVE To assess the risk of hepatitis C virus (HCV) infection among Belgian (Flemish) healthcare workers. DESIGN A seroprevalence survey of HCV IgG antibodies. SETTING AND PARTICIPANTS A systematic sample of 5,064 employees from 22 general hospitals in Flanders and Brussels, Belgium, was tested at the annual occupational medical examination. Together with demographic and occupational data, information was collected on the frequency of blood contact, needlestick injuries, and medical and surgical history. The blood samples were tested using the third-generation Abbott Screen Kit test, with confirmation by Matrix, LIA, and an in-house polymerase chain reaction and the Quantiplex-HCV b-DNA test. RESULTS 21 persons were found to be positive for HCV markers. The overall prevalence was 0.41% (95% confidence interval [CI95], 0.24-0.59). A statistically significant association was found with a history of blood transfusion (odds ratio [OR], 4.14; CI95, 1.67-10.31) and with history of a clinically apparent hepatitis (OR, 3.98; CI95, 1.60-9.90). Although the ORs for the frequency of blood contact were slightly elevated (between 1.17 and 2.73), this association was not significant. Moreover, a history of needlestick injuries showed a nonsignificant OR of 1.28 (CI95, 0.53-3.09), and no statistically significant difference was found with a variety of duties and tasks. The ORs for potential occupational risk factors were adjusted according to age, gender, antecedents, and other confounders using a logistic regression analysis. Based on this procedure, the ORs decreased slightly. CONCLUSIONS Flemish healthcare workers showed a lower HCV seropositivity than is seen in the general population; a history of blood transfusion and of clinically apparent hepatitis was most strongly associated with the presence of HCV markers. We concluded that employees in Flemish regional general hospitals are not at an overall increased risk for HCV infection, although occasional transmission through percutaneous injuries is possible, and prevention therefore remains imperative.

Prevalence of hepatitis A antibodies in a large sample of Belgian health care workers.

SummaryHealth care workers (HCW), especially women (for example, pediatric nurses and day nursery workers), have been shown to be at risk for viral hepatitis A infections. In order to obtain a more precise estimate of the risk in Belgian HCW, a seroprevalence study was undertaken. The date from this study have been compared with the age-specific seroprevalence of anti-HAV in the general population (GP) as recently estimated. During 1996–1997, a sample of 5,068 employees in 22 general hospitals, geographically distributed over the Flemish and Brussels regions of Belgium, was tested for the presence of anti-HAV. Comparison of the anti-HAV prevalences in HCW and GP shows a significantly lower prevalence in HCW for the age groups 25–34, 35–44 and 45–54 years. Within these age-groups, employees performing catering tasks have the highest prevalence. This difference could be explained by socioeconomic parameters: overrepresentation of higher social classes in better educated HCW. The number of unprotected individuals in young and older age groups (25–54 years) is greater than in the general population. In view of the changing HAV epidemiology in western Europe, the number of unprotected persons will rise in the coming years. Considering the more severe course of the disease as age increases, vaccination may become important in the occupational health strategy for HCW.