Repeated genomic transfers from echovirus 30 to echovirus 6 lineages indicate co-divergence between co-circulating populations of the two human enterovirus serotypes.

Human echovirus types 6 (E-6) and 30 (E-30) cause seasonal epidemics of aseptic meningitis. These two enteroviruses are frequently observed in co-circulation, an epidemiological pattern that is prerequisite for the occurrence of dual infections, which can lead to recombination between co-infecting virus strains. Viral sequences were determined at loci 1D (VP1 capsid protein) and 3CD (non structural proteins) in 49 E-6 strains recovered in a single geographical region in France from 1999 to 2007, during the epidemiological survey of enterovirus infections. They were compared with previously recorded sequences of E-30 strains to investigate their evolutionary histories and possible recombination patterns. Phylogenetic analyses identified two distinct E-6 populations and different subpopulations. Assuming a relaxed molecular clock model and a Bayesian skyline demographic model in coalescent analyses with the BEAST program, the substitution rate in E-6 was estimated at 8.597×10(-3) and 6.252×10(-3) substitution/site/year for loci 1D and 3CD respectively. Consistent estimates of divergence times (t(MRCA)) were obtained for loci 1D and 3CD indicating that two distinct E-6 populations originated in 1997 and 1999. Incongruent phylogenetic patterns inferred for the two loci were indicative of recombination events between the two populations. Phylogenies including the E-30 3CD sequences showed close genetic relationships between E-6 and discrete E-30 subpopulations. Recombination breakpoints were located with statistical significance in E-6 and E-30 genomes. Estimates of t(MRCA) of phylogenetic recombinant clades indicated directional genetic transfers from E-30 to E-6 populations and their co-divergence over the time period studied.

Impact of rapid enterovirus molecular diagnosis on the management of infants, children, and adults with aseptic meningitis.

Enteroviruses (EV) are the main etiological agents of aseptic meningitis. Diagnosis is made by detecting the genome using RT-PCR. The aim of the study was to evaluate the impact of a positive diagnosis on the management of infants, children, and adults. During 2005, 442 patients were admitted to hospital with suspected meningitis. Clinical and laboratory data and initial treatment were recorded for all patients with enteroviral meningitis. The turnaround time of tests and the length of hospital stay were analyzed. The results showed that EV-PCR detected EV in 69 patients (16%), 23% (16/69) were adults. About 18% of CSF samples had no pleocytosis. After positive PCR results, 63% of children were discharged immediately (mean 2 hr 30 min) and 95% within 24 hr. Infants and adults were discharged later (after 1.8 and 2 days, respectively). The use of antibiotics was significantly lower in children than in infants and adults. The PCR results allowed discontinuation of antibiotics in 50-60% of all patients treated. Patients received acyclovir in 16% of cases (7% children vs. 50% adults) and 23% (11% vs. 69%) underwent a CT scan. Clinical data were compared between patients whose positive EV-PCR results were available within 24 hr (n = 32) and those whose results were available > 24 hr after collection of CSF (n = 14). Duration of antibiotic treatment (difference: 2.3 days; P = 0.05) was reduced between the two groups. No statistical difference in the length of stay was observed. The EV-PCR assay should be performed daily in hospital laboratory practice and considered as part of the initial management of meningitis.

[From prospective molecular diagnosis of enterovirus meningitis...to the prevention of antibiotic resistance]. / Du diagnostic moléculaire initial prospectif des méningites à entérovirus...à la lutte contre l'antibiorésistance.

Meningitis initially presents with intense manifestations that are not generally specific to a given etiology. The first major question for the physician is to decide whether to initiate a probabilistic treatment. Enteroviruses are a major cause of aseptic meningitis, which is benign in immunocompetent patients. Molecular diagnosis is now becoming the gold standard and its prospective use at the time of patient admission, on the sole basis of clinical suspicion of meningitis, has yielded more reliable data. Cytological and biochemical data from CSF analyses are of low predictive value to influence the initial decision to treat with antibiotics. In addition, cases of meningitis during winter are not uncommon. Adults are concerned in about 25% of cases. Thus, if molecular diagnostic tools are not rapidly available, patient management may be inconsistent, leading to unnecessary scans, laboratory investigations and treatment (including overconsumption of antibiotics). Current progress in the automation and practicability of viral genomic detection yields the result within a few hours after admission. Rapid molecular viral diagnosis of a benign disease that does not require treatment but which is initially worrying is of unquestionable advantage. It is of benefit to both the patient and the community because of its input on health economics, the needless consumption of drugs and, as a result, resistance to antibiotics. The diagnosis of meningitis can no longer remain a retrospective diagnosis after elimination of all the possible causes, since not prescribing unnecessary laboratory tests and not treating are true therapeutic decisions.

[Rapid diagnosis of rotavirus infections: comparative prospective study of two techniques for antigen detection in stool]. / Diagnostic rapide des infections à rotavirus: étude prospective comparative de deux techniques de détection d'antigènes dans les selles.

The ability of two commercially available diagnosis rapid assays in detecting rotavirus antigen was compared in a prospective study conducted from September 2002 to May 2003. Five hundred and twelve faecal specimens were studied by IDEIA Rotavirus enzyme immunoassay test (EIA) and Diarlex MB immunochromatographic test (ICG). Specimens giving discrepant results were examined by electron microscopy (EM) and clinical data reconsidered. Out of 512 stool specimens, 155 (30.3%) were positive and 332 (64.8%) negative with the two assays. Discrepant results were obtained for 25 (4.88%) specimens (24 children, 1 adult), with EIA giving more positive results. The retrospective examination by EM, possible for fifteen stools on the 25 that gave discrepant results, confirmed the presence of rotavirus in 7/14 stools which were positive only by EIA and in the stool specimen that was found positive only by ICG. The 25 clinical observations re-examination showed the presence of GEA signs in all cases. The statistical analysis shows an excellent concordance between the EIA and the ICG tests (kappa = 0.89, IC(95%) = [0.85-0.93]) in spite of the underestimation of ICG test in comparison with EIA test (P < 0.0001).

Circulation of enteroviruses and persistence of meningitis cases in the winter of 1999-2000.

The seasonal incidence of enterovirus meningitis was analyzed in a prospective study of patients admitted for suspected meningitis from October 1, 1998 to April 30, 2000. In-house reverse transcription-polymerase chain reaction (RT-PCR) in cerebrospinal fluid (CSF) was used irrespective of cytological results. Fifty-two (45.2%) of the 115 patients had positive RT-PCR in CSF, including 44/86 children (51.2%) and 8/29 adults (27.6%). Six of the 52 (11.5%) had no pleocytosis. The numbers of CSF specimens with a predominance of lymphocytes or a predominance of neutrophils were closely similar. In 33 of the positive patients, an enterovirus, mainly echoviruses type 6 (48%) and 30 (24%), was recovered in one or more specimens. Sixteen cases of enteroviral meningitis were observed between November 1999 and March 2000 as against 2 cases between November 1998 and March 1999, showing that the disease persisted through the winter months of 1999-2000. During the same period, 96 enterovirus isolates were recovered from clinical specimens from other patients. The number of isolates was higher in the winter of 1999-2000 (P < 0.01) than in the winter of 1998-1999, indicating that the risk of enterovirus infection increased significantly in winter 1999-2000. Sixteen patients had aseptic meningitis, made a rapid recovery and had an enterovirus in throat swabs and stools (9/16) or in one of the two (7/16). RT-PCR was not requested. Nine patients were admitted during the cold months. The clinical management of both adult and child patients could be improved by year-round use of enterovirus generic RT-PCR.