Molecular Epidemiology of Caliciviruses Detected in Sporadic and Outbreak Cases of Gastroenteritis in France from December 1998 to February 2004

Abstract

We compiled sequence and epidemiological data from 172 caliciviruses detected in France from December 1998 to February 2004 in sporadic and outbreak cases. The results showed a cocirculation of strains with a majority of genogroup II (GII) noroviruses. Three groups of noroviruses, not detected before in our laboratory, emerged and spread during the period: the recombinant GGIIb and Norwalk-related strains not amplified in the polymerase gene in 2000 and a new Lordsdale variant in 2002. We observed that (i) GII-4 noroviruses were predominant in nursing home and hospital outbreaks but rare in oyster-and water-related outbreaks despite continuous circulation in the population; (ii) at the opposite, genogroup I strains were detected in the majority of environmental outbreaks; (iii) several strains were frequently found in oyster-and water-linked outbreaks (up to seven), whereas one single strain was detected when transmission was from person to person; and (iv) whereas GII noroviruses were predominant in sporadic cases where patients were under 15 years of age, GI strains were more frequent in outbreaks occurring in this age group. Finally, from a methodology point of view, this compilation shows that detection and characterization in the polymerase gene are not adequate in a significant number of cases and should be completed by amplification and sequencing in the capsid gene.

Epidemiology of norovirus gastroenteritis in Germany 2001–2009: eight seasons of routine surveillance

“…In our convenience sample, outbreaks in childcare settings were less frequently caused by GII.4 (and more frequently by GI) strains than hospital and nursing home outbreaks, which corresponds to a recent publication that reported a higher frequency of GII.4 strains in outbreaks in healthcare settings than in outbreaks involving younger persons [5]. Findings from France suggest that GII noroviruses are more common in sporadic cases whereas GI strains are predominant in outbreaks in children [33].…”

Epidemiology and clinical features of gastroenteritis in hospitalised children: prospective survey during a 2-year period in a Parisian hospital, France

“…In this study, the highest rates of GGIIb detection were observed in January-February 2002 and the fall and winter of [2003][2004]. These periods coincide with GGIIb adult outbreaks in France [41]. So, the rate of detection of GGIIb and GGII.4 norovirus strains identified in children are similar to those circulating in the adult population in the same period.…”

Detección de norovirus en niños con diarrea adquirida en la comunidad o nosocomial en el Hospital Guillermo Grant Benavente de Concepción, Chile

“…Este hallazgo ha sido comunicado también en otros trabajos, en que alrededor de 40 a 50% de los casos permanecen sin un diagnóstico causal 40,42 . La falta de diagnóstico etiológico de diarreas es frecuente, de ahí la importancia de incorporar técnicas diagnósticas más sensibles ya que los tests de rutina generalmente resultan negativos 2,7,8 . La detección de NoV es difícil debido a la gran variabilidad genética que dificulta el diagnóstico de laboratorio de rutina; la técnica de ELISA tiene una baja sensibilidad que obliga a una confirmación de un resultado negativo por métodos moleculares 32,41,43 .…”

“…La introducción del diagnóstico empleando RPC en tiempo real ha sido de gran importancia para mejorar el diagnóstico y establecer el rol relevante de NoV en brotes epidémicos agudos y en casos esporádicos de diarrea. Este método diagnóstico ha permitido demostrar la amplia heterogeneidad y rápida evolución de las variantes genéticas de NoV 8,9,[11][12][13][14][15] ; La diversidad antigénica y la falta de sistema de cultivo in vitro del virus mantendrá al diagnóstico molecular como el mejor método de detección de NoV. La RPC a tiempo real ha emergido como el estándar para el diagnóstico y detección de NoV, ya que combina un alto rendimiento, reproducibilidad, sensibilidad y especificidad 11,27,[42][43][44][45][46] . El 36,6% de los pacientes en este estudio fueron ingresados al hospital con un diagnóstico diferente al de una gastroenteritis, adquiriendo la infección probablemente en forma nosocomial (plazo de latencia para los síntomas de 3 o más días), siendo mayor para NoV (32,1%) que para RV (5,7%).…”

“…La presencia de NoV ha aumentado en la última década, lo que podría deberse a un mejor diagnóstico o a la emergencia de cepas más virulentas 10 . Los NoV son virus ARN de la familia Caliciviridae, de gran diversidad genética, con aparición continua de nuevas variantes genéticas, lo que dificulta su diagnósti-co [6][7][8] . De los cinco genogrupos (G) de NoV, los GI, GII y GIV infectan a humanos 4,7,9 ; el GII es el prevalente y ha causado brotes epidémicos en diferentes regiones del mundo, en tanto que el GI es de menor frecuencia y se ha encontrado principalmente asociado a brotes alimentarios y muestras ambientales 4,11,[14][15] .…”