Enteroviral central nervous system infections in children of the region of monastir, Tunisia: diagnosis, laboratory findings of cerebrospinal fluid and clinical manifestations

First detection and characterization of EV-A71 and a new genogroup of CVA-24 causing neurological disease in Tunisia

Aim: Molecular characterization of enterovirus A71 (EV-A71) and coxsackievirus A24 (CVA-24) strains isolated during neurological diseases surveillance activities in Tunisian patients. Materials & methods: Specimens were obtained from two Tunisian children and analyzed for enterovirus with quantitative reverse transcription PCR (RT-qPCR). We sequenced the whole genome of strains detected. Results: The EV-A71 sequence reported was assigned to subgenogroup C2 with a high nucleotide sequence identity to other EV-A71 C2 detected in other countries, which suggests virus migration. Interestingly, in the VP1 coding region, the Tunisian CV-A24 strain displayed high sequence divergence from other CV-A24, which confirms that it represents a new genogroup. Conclusion: This is the first report of EV-A71 in Tunisia and the first report of a CV-A24 strain causing aseptic meningitis.

Molecular characterization of enterovirus detected in cerebrospinal fluid and wastewater samples in Monastir, Tunisia, 2014-2017

Background

Enteroviruses (EVs) are considered the main causative agents responsible for aseptic meningitis worldwide. This study was conducted in the Monastir region of Tunisia in order to know the prevalence of EV infections in children with meningitis symptoms. Detected EV types were compared to those identified in wastewater samples.

Methods

Two hundred CSF samples collected from hospitalized patients suspected of having aseptic meningitis for an EV infection between May 2014 and May 2017 and 80 wastewater samples collected in the same time-period were analyzed. EV detection and genotyping were performed using PCR methods followed by sequencing. Phylogenetic analyses in the 3′-VP1 region were also carried-out.

Results

EVs were detected in 12% (24/200) CSF and in 35% (28/80) wastewater samples. EV genotyping was reached in 50% (12/24) CSF-positive samples and in 64% (18/28) sewage. Most frequent types detected in CSF were CVB3, E-30 and E-9 (25% each). In wastewater samples, the same EVs were identified, but also other types non-detected in CSF samples, such as E-17,CVA9 and CVB1 from EV species B, and EV-A71 and CVA8 from EV-A, suggesting their likely lower pathogenicity. Phylogenetic analysis showed that within the same type, different strains circulate in Tunisia. For some of the EV types such as E-9, E-11 or CVB3, the same strains were detected in CSF and wastewater samples.

Conclusions

Epidemiological studies are important for the surveillance of the EV infections and to better understand the emergence of certain types and variants.

Topics and trends in artificial intelligence assisted human brain research

Artificial intelligence (AI) assisted human brain research is a dynamic interdisciplinary field with great interest, rich literature, and huge diversity. The diversity in research topics and technologies keeps increasing along with the tremendous growth in application scope of AI-assisted human brain research. A comprehensive understanding of this field is necessary to assess research efficacy, (re)allocate research resources, and conduct collaborations. This paper combines the structural topic modeling (STM) with the bibliometric analysis to automatically identify prominent research topics from the large-scale, unstructured text of AI-assisted human brain research publications in the past decade. Analyses on topical trends, correlations, and clusters reveal distinct developmental trends of these topics, promising research orientations, and diverse topical distributions in influential countries/regions and research institutes. These findings help better understand scientific and technological AI-assisted human brain research, provide insightful guidance for resource (re)allocation, and promote effective international collaborations.

Molecular identification of human enteroviruses associated with aseptic meningitis in Yunnan province, Southwest China

Human enteroviruses (EVs) are the major causative agents of aseptic meningitis. In this study, a total of 524 children were admitted to the children Kunming hospital (continental China) for aseptic meningitis manifestations in 2009 and 2010. An EV infection was diagnosed in 85/524 children (16.2 %) and the viruses detected were assigned to 16 serotypes. Most serotypes belonged to the enterovirus B species. Echovirus 9 was predominant (24.7 %), followed by coxsackievirus B5 (23.5 %) and then echovirus 30 (16.5 %). Echovirus 9 was firstly identified as the predominant serotype in sporadic aseptic meningitis which occurred in Yunnan, Southwest China. This work indicates the need to perform large-scale surveillance to gain a better insight into the epidemiology of enteroviruses associated with aseptic meningitis in China.

Virological testing of cerebrospinal fluid in children aged less than 14 years with a suspected central nervous system infection: A retrospective study on 304 consecutive children from January 2012 to May 2015

OBJECTIVE

The study aimed to describe the prevalence of HSV DNA, VZV DNA, Enterovirus RNA, Parechovirus RNA, CMV DNA, EBV DNA, adenovirus DNA, HHV-6 DNA, HHV-7 DNA, HHV-8 DNA and Parvovirus B19DNA in children aged less 14 years with a suspected viral infection of the central nervous system in a clinical practice setting.

METHODS

Between January 2012 and May 2015, cerebrospinal fluids from 304 children were tested with an in-house real-time PCR method.

RESULTS

A positive PCR was detected in 64 subjects (21%): the mean number of tests performed in patients who showed a viral infection was 7.5, significantly higher (p = 0.001) with respect to that reported in negative samples (6.4). Enterovirus is the leading virus detected: 12 out of the 37 positive children reported were newborns (85.7% of all the newborns with a positive result). The second most frequently identified virus was HHV-7 (5 positive PCR out of 105 samples tested, 4.8%, if we excluded a child with a concomitant S. pneumoniae isolated), a prevalence significantly higher with respect to VZV (p = 0.02) and to CMV (p = 0.04). HHV-6 was the third most commonly identified aetiology (4.2%). All children were immunocompetent.

SIGNIFICANCE

Only a minority of children had a specific viral aetiology identified: the rate of HHV-7 positivity suggests a routine testing of these viruses within the diagnostic algorithm in immunocompetent paediatric patients. This approach could help to define the clinical role of this herpesvirus.

Enterovirus Migration Patterns between France and Tunisia

The enterovirus (EV) types echovirus (E-) 5, E-9, and E-18, and coxsackievirus (CV-) A9 are infrequently reported in human diseases and their epidemiologic features are poorly defined. Virus transmission patterns between countries have been estimated with phylogenetic data derived from the 1D/VP1 and 3CD gene sequences of a sample of 74 strains obtained in France (2000–2012) and Tunisia (2011–2013) and from the publicly available sequences. The EV types (E-5, E-9, and E-18) exhibited a lower worldwide genetic diversity (respective number of genogroups: 4, 5, and 3) in comparison to CV-A9 (n = 10). The phylogenetic trees estimated with both 1D/VP1 and 3CD sequence data showed variations in the number of co-circulating lineages over the last 20 years among the four EV types. Despite the low number of genogroups in E-18, the virus exhibited the highest number of recombinant 3CD lineages (n = 10) versus 4 (E-5) to 8 (E-9). The phylogenies provided evidence of multiple transportation events between France and Tunisia involving E-5, E-9, E-18, and CV-A9 strains. Virus spread events between France and 17 other countries in five continents had high probabilities of occurrence as those between Tunisia and two European countries other than France. All transportation events were supported by BF values > 10. Inferring the source of virus transmission from phylogenetic data may provide insights into the patterns of sporadic and epidemic diseases caused by EVs.

Enterovirus meningitis in Tunisia (Monastir, Mahdia, 2011-2013): identification of virus variants cocirculating in France

Acute enterovirus (EV) meningitis is a frequent cause of hospitalisation, and over 100 EV serotypes may be involved. A total of 215 patients of all ages with meningitis signs were investigated in 2 Tunisian hospitals. Their cerebrospinal fluid (CSF) was analysed retrospectively for EVs with a TaqMan real-time RT-qPCR. The virus strains were typed, and their evolutionary relationships were determined by Bayesian phylogenetic methods. An EV genome was detected in 21/215 patients (9.8%). The CSF viral loads ranged from 3.27 to 5.63 log10 genome copies/mL. The strains were identified in 13/21 patients and assigned to EV-B types. Viruses identified in Tunisian patients were genetically related to variants detected in France. The viral loads were similar in Tunisian and French patients for most EV types. The phylogenetic data and viral loads determined in Tunisian and French patients suggest that close EV variants were involved in aseptic meningitis in the 2 countries over a same period.

Divergent cerebrospinal fluid cytokine network induced by non-viral and different viral infections on the central nervous system

Background

Meningoencephalitis is one of the most common disorders of the central nervous system (CNS) worldwide. Viral meningoencephalitis differs from bacterial meningitis in several aspects. In some developing countries, bacterial meningitis has appropriate clinical management and chemotherapy is available. Virus-associated and virus not detected meningoencephalitis are treatable, however, they may cause death in a few cases. The knowledge of how mediators of inflammation can induce disease would contribute for the design of affordable therapeutic strategies, as well as to the diagnosis of virus not detected and viral meningoencephalitis. Cytokine-induced inflammation to CNS requires several factors that are not fully understood yet.

Methods

Considering this, several cytokines were measured in the cerebrospinal fluid (CSF) of patients with undiagnosed and viral meningoencephalitis, and these were correlated with cellularity in the CSF.

Results

The results demonstrate that an altered biochemical profile alongside increased cellularity in the cerebrospinal fluid is a feature of patients with meningoencephalitis that are not associated with the detection of virus in the CNS (P < 0.05). Moreover, HIV-positive patients (n = 10) that evolve with meningoencephalitis display a distinct biochemical/cytological profile (P < 0.05) in the cerebrospinal fluid. Meningoencephalitis brings about a prominent intrathecal cytokine storm regardless of the detection of virus as presumable etiological agent. In the case of Enterovirus infection (n = 13), meningoencephalitis elicits robust intrathecal pro-inflammatory cytokine pattern and elevated cellularity when compared to herpesvirus (n = 15) and Arbovirus (n = 5) viral infections (P < 0.05).

Conclusion

Differences in the cytokine profile of the CSF may be unique if distinct, viral or presumably non-viral pathways initially trigger the inflammatory response in the CNS.