Prevalencia de anticuerpos frente a parotiditis en niños y adolescentes a dos años de haberse introducido la vacuna SRP / Antibody prevalence to mumps in children and adolescents at two years of the introduction of the MMR vaccine

Resumen: Objetivo: Evaluar la prevalencia de anticuerpos antiparotiditis en niños y adolescentes de México, a dos años de haberse introducido la vacuna SRP. Material y métodos: Se estudiaron 2111 niños (1-9 años) y 2484 adolescentes (10-19 años). Se evaluaron anticuerpos IgG con un kit comercial de ELISA indirecto. Resultados: La seroprevalencia fue 70.6% (IC95% 69.3-71.9) y resultó mayor en adolescentes (83.0%, IC95% 81.5-84.5) que en niños (56.0%, IC95% 53.9-58.11) (OR 3.83; IC95% 3.34-4.39, p=0.0000000). Los niños de 1 a 2 y de 6 a 9 años, que a partir de 1998 formaron parte del grupo blanco de vacunación vs parotiditis, tuvieron mayor seroprevalencia que el grupo de 3 a 5 años no vacunado. Conclusiones: La seropositividad en niños de 1 a 2 y de 6 a 9 años fue probablemente atribuible a vacunación durante 1998-2000 y la de otros grupos etarios a exposición natural relacionada con el tiempo transcurrido en cada cohorte de nacimientos hasta el reclutamiento al estudio.

Abstract: Objective: To assess the prevalence of mumps antibodies in children and adolescents of Mexico, two years after the introduction of the mumps-containing vaccine MMR. Materials and methods: Evaluation of IgG antibodies with a commercial kit of indirect ELISA. Results: 2111 children (1-9 years) and 2484 adolescents (10-19 years) were studied. The overall antibody seroprevalence was 70.6% (95% CI 69.3-71.9), being higher in adolescents (83.0%, 95%CI 81.5-84.5) than in children (56.0%, 95%CI: 53.9-58.11) (OR 3.83, 95%CI 3.34-4.39, p=0.0000000). Children 1 to 2 and 6 to 9 years who were part of the target group of mumps vaccination since 1998, they had higher seroprevalence than the group of 3 to 5 years unvaccinated. Conclusions: Seropositivity in children aged 1 to 2 and 6 to 9 years was probably attributable to vaccination during 1998-2000 and in other age groups to natural exposure related to time elapsed in each birth cohort until the study recruitment.

Role of laboratory in rapid diagnosis of atypical mumps

Fairly large number of mumps virus infections present atypically without parotitis leading to delay in diagnosis and increased morbidity. Awareness of such presentations and inclusion of serological test for detecting IgM-specific antibodies could help in solving diagnostic dilemma, especially in unvaccinated individuals from developing countries.

Structure-function analysis of two variants of mumps virus hemagglutinin-neuraminidase protein

A point mutation from guanine (G) to adenine (A) at nucleotide position 1081 in the hemagglutinin-neuraminidase (HN) gene has been associated with neurovirulence of Urabe AM9 mumps virus vaccine. This mutation corresponds to a glutamic acid (E) to lysine (K) change at position 335 in the HN glycoprotein. We have experimentally demonstrated that two variants of Urabe AM9 strain (HN-A1081 and HN-G1081) differ in neurotropism, sialic acidbinding affinity and neuraminidase activity. In the present study, we performed a structure-function analysis of that amino acid substitution; the structures of HN protein of both Urabe AM9 strain variants were predicted. Based on our analysis, the E/K mutation changes the protein surface properties and to a lesser extent their conformations, which in turn reflects in activity changes. Our modeling results suggest that this E/K interchange does not affect the structure of the sialic acid binding motif; however, the electrostatic surface differs drastically due to an exposed short alpha helix. Consequently, this mutation may affect the accessibility of HN to substrates and membrane receptors of the host cells. Our findings appear to explain the observed differences in neurotropism of these vaccine strains.

Rapid response to a case of mumps: implications for preventing transmission at a medical research facility / Respuesta rápida a un caso de paperas: implicaciones para la prevención del contagio en una instalación de investigación biomédica

OBJECTIVE: To prevent transmission among the staff and potentially among the non-human primate (NHP) colony at the U.S. Naval Medical Research Center Detachment in Peru, where an active case of mumps was discovered in a senior laboratory technician in Sep 03, 2007. MATERIAL AND METHODS: Subjects at the research facility were interviewed and potentially susceptible contacts were tested for mumps IgG. RESULTS: In total, 81 out of 106 staff members (76 percent) had close contact with the case. Only 6/81 (7 percent) had MMR, 33 (41 percent) reported having had mumps, and 8 of 45 (18 percent) of the potentially susceptible individuals did not have immunity (IgG > 20.0). All the susceptible, exposed individuals received MMR vaccine. There were no secondary cases and access to the NHP colony was restricted. DISCUSSION: Immediate and thorough investigation and occupational health response were imperative in preventing secondary cases of mumps among humans and NHP.

OBJETIVO: Prevenir el contagio de parotiditis al personal y potencialmente a la colonia de primates no humanos (PNH), tras detectarse un caso en el personal técnico de laboratorio en el Centro de Investigación de Enfermedades de la Marina de los EUA (NMRCD). MATERIAL Y MÉTODOS: El personal fue entrevistado y se hizo una prueba de IgG para parotiditis a los contactos potencialmente susceptibles. RESULTADOS: En total, 81 de 106 miembros del personal tuvo contacto cercano con el caso. Sólo 6/81 (7 por ciento) tenían vacuna y 33 (41 por ciento) reportaron haber tenido parotiditis, y 8 de 45 (18 por ciento) de los susceptibles potenciales no tenían inmunidad (IgG > 20.0). Todos los susceptibles expuestos fueron vacunados y no hubo casos secundarios. Se restringió el acceso a la colonia de PNH. CONCLUSIÓN: La investigación inmediata y la respuesta de salud ocupacional fue imperativa para prevenir casos secundarios de parotiditis en el personal y los NHP.

Seroprevalence of antibodies to measles, mumps, and rubella among Thai population: evaluation of measles/MMR immunization programme.

Stored serum specimens, from four regions of Thailand, of healthy children attending well baby clinics and of healthy people with acute illnesses visiting outpatient clinics were randomly sampled and tested for IgG antibody to measles, mumps, and rubella (MMR). The immunity patterns of rubella and mumps fitted well with the history of rubella and MMR vaccination, seroprotective rates being over 85% among those aged over seven years. A high proportion of younger children acquired the infection before the age of vaccination. MMR vaccination should preferably be given to children at an earlier age. For measles, 73% seroprotective rates among children, aged 8-14 years, who should have received two doses of measles/MMR vaccine, were lower than expected. This finding was consistent with the age-group reported in outbreaks of measles in Thailand. The apparent ineffectiveness (in relation to measles) of MMR immunization of 1st grade students warrants further studies.

Frequência de anticorpos para o vírus da caxumba / Frequence of antibody to mumps virus

Introdução: A caxumba é uma infecção viral aguda que ocorre principalmente em crianças e adolescentes na idade escolar. Durante a infecção os anticorpos IgG, geralmente são detectados cerca de duas a três semanas após o inicio dos sintomas, indicando imunidade adquirida. A presença de anticorpos IgM iniciam com eleva- dos títulos até as duas primeiras semanas, com posterior redução desses níveis, possibilitando o diagnóstico de infecção aguda ou recente. Objetivo: Determinar a freqüência de anticorpos das classes G (IgG) eM (IgM) para o vírus da caxumba em indivíduos assintomáticos residentes em dois bairros da área urbana de Belém, Pará, Brasil. Método: Foram coletadas 411 amostras de soro de indivíduos assintomáticos provenientes de dois bairros de Belém, Pará (Terra Firme e Guamá) no período de setembro a novembro de 1994. Todos os espécimes colhidos foram examinados pelo método imunoenzimático (ELISA) utilizado na detecção de anticorpos IgG e IgM específicos para o vírus da caxumba. Resultados: Em 63,5 por cento (261/411) das amostras de soro testadas foram detectados anticorpos da classe IgG e, em 12,9por cento (53/411), anticorpos da classe IgM para o vírus da caxumba. o sexo masculino foi mais acometido que o feminino com 81,8por cento (153/187) e 48,2por cento (108/224), respectivamente, com diferença estatística significativa de P=0,00l. Nossos resultados demonstraram que 52,4por cento (119/227) dos indivíduos investigados com idades abaixo de 15 anos foram susceptíveis à infecção pelo vírus em questão. Conclusão: Esses resultados podem ser utilizados para que sejam intensificadas medidas profiláticas capazes de reduzir o aparecimento dessa virose na população de Belém, Pará, Brasil

Presentación de anemia hemolítica en gemelos post transmisión vertical de parotiditis materna / Report of hemolytic anemia in twins post vertical transmission of maternal parotitis

Reportamos un caso de parotiditis urliana en una embarazada de 32 semanas de gestación, desencadenándose una semana después el trabajo de Parto de su embarazo gemelar, confirmándose posteriormente infección transplacentaria en uno de los gemelos, presentando no obstante ambos similar sintomatología: Hemólisis con marcada disminución del hematocrito (16 por ciento a los 10 días de vida el varón, primer gemelar y 18 por ciento a los 11 días la mujer, 2do. gemelar), Hiperbilirrubinemia de 22 y 26 mg por ciento máxima respectivamente y hematuria. Posterior regresión de la sintomatología con buena recuperación y evolución normal hasta el año de vida.