Prevalence of measles antibodies among health care workers in Catalonia (Spain) in the elimination era

Abstract

BackgroundInterruption of measles transmission was achieved in Catalonia (Spain) in 2000. Six years later, a measles outbreak occurred between August 2006 and June 2007 with 381 cases, 11 of whom were health care workers (HCW).The objective was to estimate susceptibility to measles in HCW and related demographic and occupational characteristics.MethodsA measles seroprevalence study was carried out in 639 HCW from six public tertiary hospitals and five primary healthcare areas. Antibodies were tested using the Vircell Measles ELISA IgG Kit. Data were analyzed according to age, sex, type of HCW, type of centre and vaccination history.The odds ratios (OR) and their 95% CI were calculated to determine the variables associated with antibody prevalence. OR were adjusted using logistic regression.Positive predictive values (PPV) and the 95% confidence intervals (CI) of having two documented doses of a measles containing vaccine (MCV) for the presence of measles antibodies and of reporting a history of measles infection were calculated.ResultsThe prevalence of measles antibodies in HCW was 98% (95% CI 96.6-98.9), and was lower in HCW born in 1981 or later, after the introduction of systematic paediatric vaccination (94.4%; 95% CI 86.4-98.5) and higher in HCW born between 1965 and 1980 (99.0%; 95% CI 97.0-99.8). Significant differences were found for HCW born in 1965–1980 with respect to those born in 1981 and after (adjusted OR of 5.67; 95% CI: 1.24-25.91).A total of 187 HCW reported being vaccinated: the proportion of vaccinated HCW decreased with age. Of HCW who reported being vaccinated, vaccination was confirmed by the vaccination card in 49%. Vaccination with 2 doses was documented in only 50 HCW, of whom 48 had measles antibodies. 311 HCW reported a history of measles.The PPV of having received two documented doses of MCV was 96% (95% CI 86.3-99.5) and the PPV of reporting a history of measles was 98.7% (95% CI 96.7-99.6).ConclusionsScreening to detect HCW who lack presumptive evidence of immunity and vaccination with two doses of vaccine should be reinforced, especially in young workers, to minimize the risk of contracting measles and infecting the susceptible patients they care for.

Implication of health care personnel in measles transmission

“…In our study we found that cases in HCP were mostly (55.8%) in the 25-34 y age group in concordance with the fore mentioned susceptibility study. 20 These findings are similar to those of Botelho-Nevers et al 1 suggesting that, in younger subjects, vaccination coverage remained low. Therefore, even if the prevalence of non-immune HCP seems to be low, the low uptake of MMR immunization and the appearance of measles outbreaks increase the risk of nosocomial transmission as seen in the rising trend observed in large outbreaks occurred in Catalonia during the study period.…”

Decreasing Seroprevalence of Measles Antibodies after Vaccination – Possible Gap in Measles Protection in Adults in the Czech Republic

“…This illustrates the fact that in the era of low incidence of the disease, a high risk of nosocomial spread exists due to a lesser experience of health care workers with the disease. While infected, health care workers may be subsequently the source of spreading measles to susceptible individuals both within health care facilities and within the general population [14–18]. For this reason it is necessary to ensure sufficient education of health care workers in matters of epidemiology, transmission, clinical manifestations and measles prevention.…”

<p>Healthcare Workers’ Preparedness: An Exploratory Study for Measles Control in a Middle-Income Country</p>

“…In response, this time has been changed later to be at 12 months. [22][23][24] In the current study, only one participant showed a seronegative response, despite being vaccinated. When interviewed, he stated that he only received one dose of the vaccine and forgot the second one.…”

“…Vaccine-related ones include inadequate attenuation, wrong route or interrupted schedule and interruption of cold chain. [21][22][23][24] In Egypt, measles vaccine was introduced as a compulsory vaccine to children at the age of 9 months, in which the vaccine might interfere with maternal Abs. In response, this time has been changed later to be at 12 months.…”