Du diagnostic moléculaire initial prospectif des méningites à entérovirus⋯ à la lutte contre l'antibiorésistance

Clinical and biological features of enteroviral meningitis among adults and children and factors associated with severity and length of stay

BACKGROUND

Enterovirus (EV) meningitis is the most common form of meningitis. Clinical and biological manifestations may be non-specific, leading to prolonged and costly investigations.

OBJECTIVES

To determine the different aspects of EV meningitis and the variables associated with length of stay (LOS) in hospital independently of patients' age.

STUDY DESIGN

Single center retrospective study of all EV PCR positive CSF samples during 3.5 years in Bordeaux University Hospital, France.

RESULTS

172 patients were included. 65 were under 3 years old and 49 over 18 years old. 10% of patients had severe forms of the disease. 47 patients (27.3%) had normal CSF count and in 63 patients (36.6%) polynuclear cells predominated in CSF. Procalcitonin, Hoens' score or PCR in stool samples appeared as good markers for enteroviral diagnosis. Time elapsed before PCR results was associated with LOS (p = .002) and should help in limiting investigations in case of aseptic meningitis.

CONCLUSION

Rapid availability of EV PCR reduces LOS for patients and contributes to diminish unnecessary procedures and further tests.

[Enterovirus nosocomial infections in a neonatal care unit: from diagnosis to evidence, from a clinical observation of a central nervous system infection]

Although enteroviruses generally cause asymptomatic or mild disease, neonates are at higher risk for severe illnesses, among which systemic disease characterized by multiorgan involvement is a potentially fatal condition. Enterovirus neonatal infections may be the source of nosocomial infections in neonatology or in pediatric intensive care units. We report central nervous system infections due to Echovirus 11 in two neonates and the molecular evidence of nosocomial transmission of this strain in a neonatal unit by enterovirus genotyping and phylogenetic analysis. This report illustrates the importance of including enterovirus genome detection in the sepsis screening concomitantly with bacteriological investigations performed at admission of a neonate. Rapid diagnosis and subsequent genotyping could have a beneficial impact on clinical practices at the individual level (reducing the length of antibiotic therapy) and public health policy at the collective level by reinforcing hygiene measures to prevent nosocomial infections, with nurseries and neonatal units being at greater risks.

Travel-related cerebro-meningeal infections: the 8-year experience of a French infectious diseases unit

BACKGROUND

The etiological spectrum of cerebro-meningeal infections (CMI) in travelers has never been specifically analyzed.

OBJECTIVES

To assess the etiologies of CMI in hospitalized travelers and to propose a diagnostic approach to travel-related CMI.

METHODS

During an 8-year period, we retrospectively collected data on all travelers hospitalized in our department for a CMI occurring during travel or in the month after their return.

RESULTS

Fifty-six patients (35 men and 21 women; mean age 29 years (16-83); 44.6% tourists, 26.8% military, 16% immigrants, 12.5% expatriates) were included. The main destinations were Africa (57.2%), Europe (19.5%), and Asia (12.5%). The median duration of travel was 24 days (5-550). Symptoms occurred during travel in 20 patients (11 of which required a medical evacuation). In the remaining 36 patients, the median duration between return and clinical onset was 10 days. The median time from clinical onset to hospitalization was 4 days (0.5-96). Twenty-four patients presented with a meningeal syndrome and 20 others with encephalitic features. The remaining 12 patients had an incomplete clinical presentation (headaches or fever). The etiology was confirmed in 42 cases (75%) of which tropical diseases (n = 14) were less common than cosmopolitan ones (n = 28). Sub-Saharan Plasmodium falciparum malaria (n = 12) was the leading tropical infection, whereas viral infections (enterovirus, herpesviridae, HIV) were the main cosmopolitan etiologies. Only four bacterial infections were reported (Neisseria meningitidis, Mycoplasma pneumoniae, Brucella melitensis, Salmonella typhi). Sixteen patients were admitted to intensive care for a median time of 9.5 days (1-63). The average duration of hospitalization was 14 days (3-63). One death by herpes simplex virus 1 encephalitis was recorded. Four patients (7%) had neurological sequelae.

CONCLUSIONS

Among the diversified etiological spectrum of CMI, cosmopolitan infections are widely predominant, particularly viral infections, followed by tropical causes, of which malaria is the leading disease in returnees from endemic areas. The diagnostic approach should be driven by history and physical examination. Key investigations include: blood smear, cerebrospinal fluid polymerase chain reaction and culture as well as neuroimaging. Management should focus on curable causes.

[Rapid enterovirus genotyping in cerebrospinal fluids: a two-year prospective study in a virology laboratory setting]

Enterovirus (EV - 68 serotypes) infections comprise a wide spectrum of clinical presentations including infections of the central nervous system. In severe clinical presentation or epidemics, the precise identification of the involved serotype is necessary.

OBJECTIVES

To perform enterovirus genotyping directly in cerebrospinal fluid (CSF) samples, and to assess its feasibility in a laboratory setting.

METHODS

Enterovirus genotyping was carried out directly with CSF specimens tested for the diagnostic procedure by amplifying the complete 1D gene encoding the VP1 protein of the HEV-B serotypes (the most frequent) - providing results in two days. Secondly, sequences 1A/1B encoding the VP4/VP2 capsid proteins, respectively, were analysed (results in five days).

RESULTS

Direct enterovirus genotyping allowed the identification of enterovirus involved in 77 out of 81 (95%) meningitis cases between January 2006 and December 2007. In combination with the indirect genotyping of enterovirus isolates, identification of the type was achieved in 94 out of 97 (96.9%) patients included in the study. The most frequent serotypes were echovirus 6 (E6) and 13 in 2006, coxsackievirus B2 and E30 in 2007. Four children presented an EV71 associated meningitis.

CONCLUSION

When prospectively applied in a laboratory setting, direct enterovirus genotyping in CSF samples allows the identification of the involved enterovirus in two to five days. This time frame is relevant for an optimal patient management, the rapid identification of a new enterovirus variant or in the context of an epidemic alert.

Prospective identification of enteroviruses involved in meningitis in 2006 through direct genotyping in cerebrospinal fluid

Enterovirus infections were investigated with special emphasis on performing rapid molecular identification of enterovirus serotypes responsible for aseptic meningitis directly in cerebrospinal fluid (CSF). Enterovirus genotyping was carried out directly with specimens tested for the diagnostic procedure, using two seminested PCR assays designed to amplify the complete and partial gene sequences encoding the VP1 and VP4/VP2 capsid proteins, respectively. The method was used for identifying the enterovirus serotypes involved in meningitis in 45 patients admitted in 2005. Enterovirus genotyping was achieved in 98% of the patients studied, and we obtained evidence of 10 of the most frequent serotypes identified earlier by genotyping of virus isolates. The method was applied for the prospective investigation of 54 patients with meningitis admitted consecutively in 2006. The enterovirus serotypes involved were identified with the cerebrospinal fluid (CSF) of 52 patients (96%) and comprised 13 serotypes within the human enterovirus B species and 1 within the human enterovirus A species. The three most common serotypes were echovirus 13 (E13; 24%), E6 (23%), and coxsackievirus B5 (11.5%), a pattern different from that observed in 2005. Genotyping of virus isolates was also performed in 35 patients in 2006 (meningitis, n = 31; other diseases, n = 4). By comparison, direct genotyping in CSF yielded a more complete pattern of enterovirus serotypes, thereby allowing the detection of rare serotypes: three less common serotypes (CB2, E21, and E27) were not detected by indirect genotyping alone. The study shows the feasibility of prospective enterovirus genotyping within 1 week in a laboratory setting.

Prospective identification of HEV-B enteroviruses during the 2005 outbreak

Enteroviruses (EVs) represent the main etiological agents of epidemics of viral meningitis and especially the serotypes related to the human enterovirus B species. Genetic typing by sequencing a PCR-amplified portion of the genome has proved to be useful for identifying EVs and is more rapid than standard seroneutralization tests. However, prospective genotyping has not been reported in routine practice within a clinical diagnostic laboratory. A genetic typing assay using two sets of primers was developed for the amplification and sequencing of the VP1 coding sequence of the HEV-B serotypes. Identification was carried out by sequence comparisons with EV sequences in GenBank using the BLAST search tool and confirmed by phylogenetic analysis. This method was used to identify prospectively the 48 enteroviruses isolated in patients with either enterovirus-proved meningitis (n = 41) or other clinical manifestations (n = 7) admitted to the University Hospital of Clermont-Ferrand (France) in 2005. The assay was also used to type retrospectively EVs isolated in cerebrospinal fluid specimens of 25 patients admitted to the Trousseau Paediatric Hospital in Paris (France) between February and August 2005. In both prospective and retrospective investigations of meningitis, echovirus 30 (E30) was the most frequent serotype, followed in decreasing order by E18, E13, coxsackievirus B5, B3, E6, E4, E7, E11, E33, and coxsackievirus A9. In patients with other manifestations, coxsackievirus B3, B5, and E3 were each identified twice, and E2 once. In E30 infected patients, nine different lineages were demonstrated by phylogenetic analysis. Genetic typing allowed the prospective, effective and rapid identification of all EV isolates involved in the 2005 outbreak. Molecular typing in combination with phylogenetic analysis will be a reliable means to confirm the emergence of new EV variants, and is of interest of both individual patients and public health.