Parotiditis en Chile: caracterización clínica y molecular de dos casos en una población altamente inmunizada / Parotiditis in Chile: clinical and molecular characterization of two cases in a highly vaccinated population

Resumen El virus de la parotiditis produce una infección benigna caracterizada por un aumento de volumen parotídeo que, antes de la introducción de la vacuna tres vírica, afectaba principalmente a niños y adolescentes. Luego de que esta vacuna se implementara en el Programa Nacional de Inmunizaciones, se produjo una notable disminución en su incidencia. Además, ocasionó un cambio en la edad y presentación clínica, siendo más frecuente en adultos jóvenes con mayor riesgo de complicaciones. Presentamos dos casos clínicos de parotiditis en adultos jóvenes confirmados por serología y en uno de ellos, por biología molecular. Se caracterizó el virus como del genotipo G, como el descrito en los brotes en E.U.A y Europa, diferente al virus contenido en la vacuna. El virus parotídeo sigue circulando en nuestro país y debemos mantenernos alerta ante eventuales brotes. Se hace relevante optimizar el diagnóstico etiológico por serología o técnicas de biología molecular con fines clínicos y epidemiológicos.

Mumps virus usually produces a benign infection characterized by increased parotid volume which, prior to vaccination, mainly affected children and adolescents. After the introduction of measles, mumps and rubella (MMR) vaccine, mumps incidence decreased dramatically. This intervention also produced a change in its clinical presentation, moving to young adult patients, with an increased risk of complications. We report two clinical mumps cases in young adults with different clinical presentations. In both cases, serologic assays were assessed and, in one case, a polymerase chain reaction (PCR) was performed in order to confirm the diagnosis. The isolated virus was characterized and identifed as G genotype, the same genotype observed during outbreaks in United States and Europe, and different to the vaccinal strain. Mumps virus is currently circulating in Chile and it is important to be aware of possible outbreaks. Viral diagnosis can be difficult, particularly in populations with high vaccination coverage. Therefore, the access to etiologic study through PCR and serology becomes more relevant in order to optimize clinical management and secondary prevention measures.

Mumps virus genotypes identified during disease outbreaks in the state of São Paulo, Brazil: 2011 – 2016 / Genótipos dos vírus da caxumba identificados durante surtos da doença no estado de São Paulo, Brasil: 2011 - 2016

In São Paulo the mumps virus (MuV) outbreaks have been increasing from 2011 to nowadays. MuV epidemiological surveillance has been improving by using the polymerase chain reaction in real time (rRT-PCR) in addition to the specific IgM antibody (IgM-Ab) detection; in some cases, genome sequencing studies were performed. Increased virus transmission and recent outbreaks have raised interest on MuV genotyping, as a means to understand the transmission pathways and to identify the vaccine-associated cases. From January 2011 to August 2016, MuV infection was analyzed at Institute Adolfo Lutz. A total of 232 (77.33 %) throat wash samples showed positivity to mumps genome, and 68 (22.66 %) were negative when analyzed by rRT-PCR. Among 15 samples for molecular analysis, 10 serum samples from respective patients were also available for detecting anti-MuV IgM-Ab; and from these, four (40%) samples were seropositive. Vaccination status was available only for patients from Cedral and Araraquara. Phylogenetic analysis revealed the circulation of the following mumps virus genotypes in the investigated periods: 2011(M), 2012, and 2013 (K); 2014 (N); 2015 (G, K, and N); 2016 (G). Knowledge on MuV molecular epidemiology in São Paulo-Brazil could contribute to the surveillance and epidemiological program in Brazil, and globally as well.

No estado de São Paulo têm ocorrido surtos de caxumba desde 2011. O diagnóstico laboratorial tem sido realizado no Instituto Adolfo Lutz utilizando-se a técnica de identificação de material genético viral por meio de reação de cadeia de polimerase-em tempo real (rRT-PCR) e pela detecção de anticorpos IgM (Ac-IgM) específicos circulantes. Os recentes surtos de caxumba têm aumentado o interesse em investigar os genótipos dos vírus prevalentes para identificar os casos associadas à vacina. De janeiro de 2011 a agosto de 2016, 300 amostras de lavados da orofaringe coletadas de pacientes suspeitos de infecção foram analisadas. O material genético viral específico foi detectado em 232 (77,33 %) amostras e 68 (22,66 %) foram negativas. Das 10 amostras analisadas pelo teste sorológico, quatro (40 %) demonstraram positividade para Ac-IgM específicos anti-vírus da caxumba e seis foram negativas. Somente os municípios Cedral e Araraquara forneceram os dados referentes à vacinação. Análise filogenética mostrou a circulação dos seguintes genótipos do vírus da caxumba no período investigado: 2011 (M), 2012 e 2013 (K); 2014 (N); 2015 (GKN); 2016 (G). A vigilância virológica é mundialmente imprescindível, para identificar a diversidade e a distribuição dos diferentes genótipos, com vistas à composição de vacinas específicas.