Seroprevalence of measles, mumps, rubella and varicella among staff of a hospital in Riyadh, Saudi Arabia

This study aimed at screening immune status of Health Care Workers [HCWs] against measles, mumps, rubella, and varicella, and assessing the reliability of the history of previous illness due to these infections or vaccination against them as an indicator of the immune status, as checked by laboratory tests. Demographic data, history of previous illnesses and previous vaccinations were collected using a self-administered questionnaire. Also, serologic screening was done for these infections. Antibodies tested using ELISA. Among tested hospital staff, 71.8%, 60.3%, 47.9% and 68.4% reported history of infection or vaccination against measles, mumps, rubella and varicella respectively, while laboratory results proved that 4.5%, 10.8%, 12.9% and 11.3% were susceptible respectively. Susceptibility was most frequent among housekeeping staff against measles and varicella, while administrative staff were the most susceptibles to mumps, and nurses were the most susceptibles to rubella. Sensitivity of past history of illness as an indicator of the immune status, was found to be [85%, 83%, 66%, 86%]; Specificity was [81%, 81%, 89%, 87%]; Positive Predictive value [PV] was [99%, 98%, 98%, 98%] and Negative PV was [16%, 29%, 22%, 39%] for measles, mumps, rubella and varicella respectively. Screening for measles, mumps, rubella and varicella among hospital staff is mandatory to detect those who are susceptible for infections and should be vaccinated, and so preventing transmission of these infections to their colleagues or patients

Prevalence of antibodies against measles, mumps, and rubella before and after vaccination of school-age children with three different triple combined viral vaccines, Rio Grande do Sul, Brazil, 1996

OBJECTIVE: We evaluated the seroprevalence for measles, mumps, and rubella in school-age children (6-12 years old) before and after the administration of three triple combined viral vaccines. METHODS: In two municipal schools of Rio Grande do Sul, Brazil, 692 blood samples were collected before vaccination and 636 samples 21 to 30 days after vaccination during 1996. IgG antibody seropositivity was investigated by enzyme-linked immunosorbent assay (measles and mumps with Enzygnost [Behring, Marburg, Germany]; rubella with Rubenostika [Organon Teknica, Boxtel, the Netherlands]). The vaccines compared were: A: E-Zagreb, L-Zagreb, and Wistar RA 27/3 (Tresivac); B: Moraten, J-Lynn, and Wistar RA 27/3 (M-M-R II); and C: Schwarz, Urabe AM-9, and Wistar RA 27/3 (Trimovax). RESULTS: Before vaccination, 79.2 percent [95 percent confidence interval (CI) = 76.0 percent-82.2 percent] of the samples were positive for measles, 69.4 percent (95 percent CI = 65.8 percent-72.8 percent) for mumps, and 55.4 percent (95 percent CI = 51.6 percent-59.2 percent) for rubella. After vaccination with the A, B, and C vaccines, seropositivity was 100.0 percent, 99.5 percent, and 100.0 percent, respectively for measles; 99.5 percent, 94.5 percent, and 92.0 percent for mumps; and 92.6 percent, 91.3 percent, and 88.6 percent for rubella. CONCLUSIONS: About one-fifth (20.8 percent) of the schoolchildren who could have been vaccinated against measles at age 9 months had levels of antibodies insufficient for protection. In the sample of schoolchildren without previous vaccination against mumps and rubella, high proportions of susceptible levels were found. All vaccines were immunogenic, but vaccine A yielded a seroconversion rate of 99.5 percent for the mumps component, which was significantly higher than the other two vaccines (P < 0.01).

OBJETIVO: Se evaluó la seroprevalencia para sarampión, paperas y rubéola en niños en edad escolar (6-12 años) antes y después de la administración de tres vacunas triples antivirales combinadas. MÉTODOS: Se colectaron 692 muestras de sangre antes de la vacunación y 636 muestras entre 21 y 30 días después de la vacunación a niños de dos escuelas municipales de Rio Grande do Sul, Brasil, durante 1996. Se investigó la seropositividad de anticuerpos de la clase IgG mediante un ensayo de inmunoadsorción enzimática tipo ELISA (sarampión y paperas con Enzygnost [Behring, Marburgo, Alemania] y rubéola con Rubenostika [Organon Teknica, Boxtel, Países Bajos]). Las vacunas comparadas fueron: a) E-Zagreb, L-Zagreb y Wistar RA 27/3 (Tresivac); b) Moraten, J-Lynn y Wistar RA 27/3 (M-M-R II); y c) Schwarz, Urabe AM-9 y Wistar RA 27/3 (Trimovax). RESULTADOS: Antes de la vacunación, 79,2 por ciento (intervalo de confianza [IC] 95 por ciento: 76,0 a 82,2) de las muestras fueron positivas para sarampión, 69,4 por ciento (IC 95 por ciento: 65,8 a 72,8) para paperas y 55,4 por ciento (IC 95 por ciento: 51,6 a 59,2) para rubéola. Después de la vacunación con las vacunas A, B y C, la seropositividad fue de 100 por ciento, 99,5 por ciento y 100 por ciento, respectivamente para sarampión; de 99,5 por ciento, 94,5 por ciento y 92,0 por ciento para paperas; y de 92,6 por ciento, 92,3 por ciento y 88,6 por ciento para rubéola. CONCLUSIONES: Alrededor de un quinto (20,8 por ciento) de los escolares que pudieron haber sido vacunados contra el sarampión a los 9 meses de edad tenían niveles de anticuerpos insuficientes para protegerlos. En la muestra de escolares sin vacunación previa contra paperas y rubéola se encontró una alta proporción de niños susceptibles. Todas las vacunas fueron inmunogénicas, pero la vacuna A produjo una tasa de seroconversión de 99,5 por ciento para el componente de paperas, significativamente mayor que la de las otras dos vacunas (P < 0,01).