Human enteroviruses (HEV) are frequent human pathogens and, associated in particular with large outbreaks of aseptic meningitis. Here, we have compiled a database of clinical HEV isolates from the Public Hospitals of Marseille, from 1985 to 2005. Amongst 654 isolates that could be characterized by complete sequencing of the VP1 gene, 98% belonged to species HEV-B; the most frequently isolated serotypes were Echovirus E30, E11, E7, E6 and E4. The high incidence of E30 and the recent emergence of E13 are consistent with reports worldwide and peak HEV isolation occurred mostly in the late spring and summer months. The proportion of echoviruses has decreased across the years, while that of coxsackieviruses has increased. Stool (the most frequent sample type) allowed detection of all identified serotypes. MRC5 (Human lung fibroblasts) cell line was the most conducive cell line for HEV isolation (84.9% of 10 most common serotype isolates, 96.3% in association with BGM (Buffalo green monkey kidney cells)). Previous seroneutralization-based serotype identification demonstrated 55.4% accuracy when compared with molecular VP1 analysis. Our analysis of a large number of clinical strains over 20 years reinforced the validity of VP1 serotyping and showed that comparative p-distance scores can be coupled with phylogenetic analysis to provide non-ambiguous serotype identification. Phylogenetic analysis in the VP1, 2C and 3D regions also provided evidence for recombination events amongst clinical isolates. In particular, it identified isolates with dissimilar VP1 but almost identical nonstructural regions.

Enteroviruses are frequent aetiological agents of central nervous system infections in humans. In 2000 and 2005, two large outbreaks of Echovirus 30 (a member of species human enterovirus B) were observed in the University Hospitals of Marseilles (France). Between the two epidemics, the diagnostic protocols for enterovirus infection were modified, moving from viral cultures and classic RT-PCR in 2000 to real-time RT-PCR in 2005. We compared some viral and epidemiological characteristics of the 2000 and 2005 outbreaks with special attention to diagnostic procedures and to the subsequent clinical management of patients. Despite similar virological and epidemiological characteristics during both outbreaks, our results show that real-time RT-PCR techniques used in 2005 noticeably shortened the period of time necessary to deliver diagnostic results and suggest that this was associated with a decrease in the duration of hospitalization for positive cases. In conclusion, this study suggests that the improvement of enterovirus diagnosis had a major financial impact on the management of the 2005 epidemic in Marseilles and may constitute an interesting example of how new diagnostic methods in microbiology can be self-financed through improvement in patient management.

Enterovirus-positive samples diagnosed in Marseille (January 2009 to September 2011) were screened for EV71 by real-time RT-PCR. EV71 was detected in three children below the age of 2 years with no history of overseas travel; two of these cases were associated with severe clinical presentation. Viruses demonstrated genetic similarity to other European genogroup C2 strains. Strain MRS/09/3663 complete sequencing revealed 97.6% identity across the entire genome with a 2008 Singapore isolate, without signs of possible recombination events. To our knowledge, this is the first detection of EV71 infection in Marseille, France, that confirms the current circulation of EV71 in France.