Enterovirus and herpesviridae family as etiologic agents of lymphomonocytary meningitis, Southern Brazil

Evaluation of enterovirus concentration, species identification, and cerebrospinal fluid parameters in patients of different ages with aseptic meningitis in São Paulo, Brazil

Human enteroviruses (EV) are the most common cause of aseptic meningitis worldwide. Data on EV viral load in cerebrospinal fluid (CSF) and related epidemiological studies are scarce in Brazil. This study investigated the influence of EV viral load on CSF parameters, as well as identifying the involved species. CSF samples were collected in 2018-2019 from 140 individuals at The Hospital das Clínicas, São Paulo. The EV viral load was determined using real-time quantitative polymerase chain reaction, while EV species were identified by 5'UTR region sequencing. Median viral load was 5.72 log10  copies/mL and did not differ by subjects' age and EV species. Pleocytosis was observed in 94.3% of cases, with the highest white blood cell (WBC) counts in younger individuals. Viral load and WBC count were correlated in children (p = 0.0172). Elevated lactate levels were observed in 60% of cases and correlated with the viral load in preteen-teenagers (p = 0.0120) and adults (p = 0.0184). Most individuals had normal total protein levels (70.7%), with higher in preteen-teenagers and adults (p < 0.0001). By sequencing, 8.2% were identified as EV species A and 91.8% as species B. Age-specific variations in CSF characteristics suggest distinct inflammatory responses in each group.

Metagenomic search of viral coinfections in herpes simplex encephalitis patients

Little is known about concomitant central nervous system (CNS) infections by more than one virus. Current diagnostics are based on molecular tests for particular pathogens making it difficult to identify multi-viral infections. In the present study, we applied DNA- and RNA-based next-generation sequencing metagenomics (mNGS) to detect viruses in cerebrospinal fluids from 20 patients with herpes simplex encephalitis. Coinfection was detected in one patient: sequences in cerebrospinal fluids matched enterovirus A (2.660 reads; 4% of recovered genome) and enterovirus B (1.571 reads; 13% of recovered genome). Subsequent PCR combined with serotyping allowed to identify human echovirus 6, a representative of enterovirus B. Several other mNGS hits (human pegivirus, Merkel cell polyomavirus, human papillomavirus type 5) were not considered to represent a genuine signal as they could not be confirmed by specific RT-PCR/PCR. HSV DNA, while being detectable by PCR in every patient, was detected by mNGS in only one. In conclusion, contaminations and false signals may complicate mNGS interpretation; however, the method can be useful in diagnostics of viral coinfections in CNS, particularly in the case of rare pathogens.

Comparison between cerebrospinal fluid biomarkers for differential diagnosis of acute meningitis

OBJECTIVES

Given the difficulty in the differential diagnosis of acute bacterial meningitis (BM) and viral meningitis (VM), we aimed to compare the ability of cerebrospinal fluid (CSF) biomarkers, such as lactate, glucose, lactate dehydrogenase (LDH), C-reactive protein (CRP), total white blood cell count, and predominance of neutrophils, as single tests to differentiate microbiologically defined acute BM and VM.

METHODS

CSF samples were divided into three groups: BM (n=17), VM (n=14) (both with the etiological agent identified), and normal control groups (n=26).

RESULTS

All the biomarkers studied were significantly higher in the BM group than in the VM or control groups (p>0.05). CSF lactate showed the best diagnostic clinical performance characteristics: sensitivity (94.12%), specificity (100%), positive and negative predictive value (100 and 97.56%, respectively), positive and negative likelihood ratio (38.59 and 0.06, respectively), accuracy (98.25%), and AUC (0.97). CSF CRP is excellent for screening BM and VM, as its best feature is its specificity (100%). CSF LDH is not recommended for screening or case-finding. LDH levels were higher in Gram-negative diplococcus than in Gram-positive diplococcus. Other biomarkers were not different between Gram-positive and negative bacteria. The highest level of agreement between the CSF biomarkers was between CSF lactate and CRP [kappa coefficient, 0.91 (0.79; 1.00)].

CONCLUSIONS

All markers showed significant differences between the studied groups and were increased in acute BM. CSF lactate is better than the other biomarkers studied for screening acute BM due to its high specificity.

Molecular identification and clinical characteristics of mumps virus and human herpesviruses associated with aseptic meningitis in South of Iran

Viral infections are the major etiological agent of aseptic meningitis; though, limited data exist on the prevalence and molecular epidemiology of viral pathogens responsible for the occurrence of aseptic meningitis in Iran. Therefore, this study aimed to elucidate the prevalence and clinical features of mumps virus and human herpesviruses associated with aseptic meningitis in the South of Iran. A total of 73 patients with aseptic meningitis were enrolled in this study. Cerebral spinal fluid (CSF) samples were tested for detection of HSV, CMV, VZV and mumps virus using nested PCR assay. Mumps virus, HSV-1 and VZV were found in 4 (5.5%), 4 (5.5%) and 3 (4.1%) of the CSF samples, respectively. The highest rates of mumps virus and HSV infections were observed in infants less than one year, and VZV was more prevalent in patients under 5 years of age. The majority of mumps virus and VZV infections were found among male patients, while HSV was more prevalent among female patients. The highest incidence of aseptic meningitis associated with mumps virus was observed in summer, while HSV and VZV were more prevalent during spring. Headache was the most common symptom in mumps meningitis. About HSV and VZV, the most predominant clinical symptom was fever. The results of this study indicate the importance of molecular assay in the diagnosis of etiological agents of aseptic meningitis. Prompt detection of viral pathogens provides a better chance of managing viral meningitis in health care settings.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13337-021-00718-y.

Clinical performance of amperometry compared with enzymatic ultra violet method for lactate quantification in cerebrospinal fluid

OBJECTIVES

The differential diagnosis between acute bacterial meningitis (BM) and viral meningitis (VM) is crucial for treatment and prognosis. Cerebrospinal fluid (CSF) lactate (LA) is considered a good biomarker for differentiating BM from VM. The objective of this study was to compare the clinical performance of amperometry, which is not validated for measurement of LA in CSF samples, with a validated method (enzymatic ultra violet), for their ability to discriminate between acute BM and VM.

METHODS

It was a retrospective, descriptive comparative study, 320 CSF reports were included; LA was quantified in CSF using either Dimension AR machine (Dade Behring) or amperometry (RAPID Point 500, Siemens). All samples with bacteria (n=54) or virus (n=139) identified, compared with a control with normal CSF (n=127).

RESULTS

CSF LA levels were comparable for amperometry or enzymatic methods on each group studied, in a wide range of LA levels; it was capable to distinguish BM from VM independent of the method used to quantify.

CONCLUSIONS

The findings support the use of the amperometric method in measuring LA concentrations in CSF in a wide range of values. Amperometry is a less expensive method, validated for blood, easily available in small laboratories including in limited resources countries.

Molecular epidemiology of enteroviruses and predominance of echovirus 30 in an Iranian population with aseptic meningitis

Human enteroviruses are the most prevalent causes of aseptic meningitis worldwide. However, despite such predominancy, defining the enteroviral etiology of aseptic meningitis remains a diagnostic dilemma for the clinician in Iran. Therefore, this study was conducted to characterize the prevalence and clinical significance of enteroviral aseptic meningitis as well as the predominant enterovirus serotypes among patients with aseptic meningitis in the South of Iran.Cerebrospinal fluid (CSF) specimens were obtained from 73 patients with aseptic meningitis (52.1% males and 47.9% females), ages ranging from 1 month to 88 years. Following the extraction of nucleic acid, the detection of enteroviruses was performed by RT-PCR, targeting the 5' untranslated region of the genome, and sequencing. Enteroviruses were found in 46.6% of samples (34/73). The most predominant serotype was echovirus 30, followed by coxsackievirus B5 and poliovirus type 1 Sabin strain. The enterovirus infections were more prevalent among female patients (58.8%) and those below 5 years of age (52.9%). Although enterovirus infections were observed throughout the year, the infections were more prevalent during autumn with fever as the predominant clinical symptom. The outcomes revealed that enteroviruses are significant causes of aseptic meningitis in the South of Iran, while suspected cases of aseptic meningitis are usually monitored by bacterial culture and biochemical testing of CSF samples. Therefore, the etiology remains unknown in most cases. Molecular detection of viral pathogens should be included as a common approach in the screening of patients with aseptic meningitis to prevent unnecessary treatment and to improve clinical management.

Enteric viruses circulating in undiagnosed central nervous system infections at tertiary hospital in São José do Rio Preto, São Paulo, Brazil

Enterovirus (EV) is commonly associated with central nervous system (CNS) syndromes. Recently, gastroenteric viruses, including rotavirus (RVA), human astrovirus (HAstV), and norovirus (NoV), have also been associated with CNS neurological disorders. The aim of the present study was to investigate the presence of EV, RVA, HAst, and NoV associated to CNS infections with undiagnosed etiology in Northwest region of São Paulo State, Brazil, and to conduct the molecular characterization of the positive samples detected. A total of 288 cerebrospinal fluid samples collected from July to December 2017 were tested for EV and NoV by quantitative real-time polymerase chain reaction (RT-qPCR), HAstV by conventional RT-PCR, and RVA by enzyme-linked immunosorbent assay. Positive-EV samples were inoculated in cells lines, amplified by RT-PCR and sequenced. RVA, NoV, and HAstV were not detected. EV infection was detected in 5.5% (16/288), and five samples successful genotyped: echovirus 3 (E3) (1/5), coxsackie virus A6 (CVA6) (1/5), and coxsackie virus B4 (CVB4) (3/5). Meningitis was the main syndrome observed (12/16; 75%). CVA6, CVB4, and E3 were identified associated with aseptic meningitis. Reports of CVA6 associated with aseptic meningitis are rare, E3 had not been previously reported in Brazil, and epidemiological data on CVB4 in the country is virtually unknown. The present investigation illustrates the circulation of diverse EV types in a small regional sample set and in a short period of time, highlighting the importance of an active EV surveillance system in CNS infections. Enhanced understanding of undiagnosed CNS infections will assist in public health and health care planning.

World-Wide Prevalence and Genotype Distribution of Enteroviruses

Enteroviruses (EVs) are highly prevalent viruses world-wide, causing a wide range of diseases in both children and adults. Insight in the global prevalence of EVs is important to define their clinical significance and total disease burden, and assists in making therapeutic decisions. While many studies have been conducted to describe epidemiology of EVs in specific (sub)populations and patient cohorts, little effort has been made to aggregate the available evidence. In the current study, we conducted a search in the PubMed and Embase (Ovid) databases to identify articles reporting EV prevalence and type distribution. We summarized the findings of 153 included studies. We found that EVs are highly prevalent viruses in all continents. Enterovirus B was the most detected species worldwide, while the other species showed continent-specific differences, with Enterovirus C more detected in Africa and Enterovirus A more detected in Asia. Echovirus 30 was by far the most detected type, especially in studies conducted in Europe. EV types in species Enterovirus B-including echovirus 30-were often detected in patient groups with neurological infections and in cerebrospinal fluid, while Enterovirus C types were often found in stool samples.

Distribution of species enterovirus B in patients with central nervous system infections in São Paulo State, Brazil

Enteroviruses (EV) are most common cause of central nervous system (CNS) infection, mainly aseptic meningitis. In Brazil, data available concerning the distribution of EV types are scarce. The aim of this study was to describe of types EV in patients with infection of the CNS in São Paulo State. This retrospective study was conducted in clinical samples collected from patients with infections of the CNS from 2004 to 2014. We investigated the presence of EV by virus isolation in cell culture. The samples that showed cytopathic effect in the cell culture were submitted by indirect immunofluorescence assay, reverse transcription polymerase chain reaction and VP1 partial sequencing to identification of EV isolated. A total of 176 EV isolated in cell culture was detected and typed in 14.5% (n = 176/1215) of clinical samples analyzed; corresponding to 71.0% of AM, and 19.3% of encephalitis and meningoencephalitis. Echoviruses (E) were isolated most frequently, with 155 strains (88.1%), Coxsackievirus B (CV-B), with 20 cases (11.4%), CV-A, with 01 case (0.6%). E-6 was the most commonly identified followed in decreasing order by E-30; E-18; CV-B5; E-4; E-11; CV-B2 and E-9; E-7; CV-A9, CV-B1, CV-B3, CV-B4, E-13, E-14, and E-21. EV detected were classified as belonging to the species enterovirus B. EV were detected in all the period of the year with the highest rate in the spring and summer months. Data obtained in this study contribute to the knowledge about EV circulation implicated in CNS infections over a 11-year period in São Paulo State, Brazil.

Acute Childhood Viral Encephalitis in Southern Brazil

BACKGROUND

Viral meningoencephalitis is highly heterogeneous, varying by geographic location. The aim of this study was to characterize the etiology and reporting the clinical findings and outcome of viral encephalitis in children in southern Brazil.

METHODS

A cross-Sectional study was conducted at Hospital Pequeno Príncipe, Curitiba, Brazil, between January 2013 and December 2017. It included patients younger than 18 years, who fulfilled the criteria: altered mental status as a major criteria and 2 or more minor criteria (1) fever, (2) seizures, (3) focal neurologic findings, (4) central system fluid white cell count of ≥5 cells/mm, (5) abnormal brain imaging, and/or (6) electroencephalogram abnormalities.

RESULTS

Viral meningoencephalitis was diagnosed in 270 children, with median age of 2 years (interquartile range: 0-4), The etiology of viral meningoencephalitis was confirmed in 47% of patients. Enterovirus (18%) was the major cause of encephalitis in Southern Brazilian children, and a high prevalence of Epstein-Barr virus (6%) was demonstrated. Most patients presented with fever (81%), followed by vomiting (50%), focal neurologic findings (46%), seizures (31%) and headache (30%). Few abnormalities were detected on electroencephalograms and brain magnetic resonance images. On discharge from hospital, symptoms resolved completely in 87% of children. Sequelae were mainly observed in patients with focal neurologic symptoms (P<0.001), presence of seizures (P<0.001) and electroencephalogram abnormalities (P=0.024).

CONCLUSIONS

Enterovirus was the major cause of encephalitis. Etiologic agent of encephalitis seems to be influenced by the local virologic pattern. A poor outcome was identified in patients with seizures, focal neurologic findings and electroencephalogram abnormalities.

Comparison of Cerebrospinal Fluid Biomarkers for Differential Diagnosis of Acute Bacterial and Viral Meningitis with Atypical Cerebrospinal Fluid Characteristics

OBJECTIVE

Several cerebrospinal fluid (CSF) biomarkers are used to distinguish between acute bacterial meningitis (BM) and viral meningitis (VM). We compared the ability of lactate and glucose (GL) in CSF and the CSF/blood GL ratio to distinguish between acute BM and VM with typical and atypical CSF characteristics.

METHODS

Three hundred and twenty-four CSF reports were included, which were distributed as the acute BM, VM, and normal control groups (n = 63, 139, and 122, respectively).

RESULTS

Lactate level in the CSF of acute BM group was 4-fold higher than that in the acute VM and control groups (p < 0.0001). CSF lactate presented higher specificity (92%) and negative predictive value (94%) compared to CSF GL and CSF/blood GL ratio in distinguishing acute BM and VM. Definitive acute BM or VM with atypical CSF cell characteristics was observed in 23.2 and 21.6% of samples, respectively, and these groups showed reduced performance of characteristics of all CSF biomarkers. CSF lactate showed better operational characteristics than those of CSF GL and CSF/blood GL ratio, presenting the highest positive likelihood ratio, and thus aided in the differential diagnosis of VM with atypical CSF.

CONCLUSION

The CSF lactate assay can be routinely used in laboratories as a rapid, automated, and easy method that is independent of lactate blood levels.

Human adenovirus meningoencephalitis: a 3-years' overview

Human adenovirus (HAdV) has been recognized as a significant viral pathogen implicated in neurological diseases, particularly in immunocompromised patients. However, its involvement in meningoencephalitis remains unclear. The aim of this study was to investigate HAdV and other viral co-infections in the cerebrospinal fluid (CSF) of patients suspected of having either meningoencephalitis or encephalitis. A total of 373 CSF samples from patients under clinical suspicion of neurological viral infection were included in this study. HAdV was investigated by conventional or multiplex real-time PCR, for different time periods. The frequency of HAdV central nervous system (CNS) infection was 1.08%, predominating in female patients with a predisposing condition, and presented with HAdV encephalitis. HAdV CNS infection was found to occur during the months of autumn and winter. The frequency of HAdV detected in CSF positive samples increased after the change in the diagnostic method from conventional to multiplex real-time PCR. There were no specific NMRI or EEG characteristics and two CSF samples with HAdV encephalitis had normal CSF WBC count. There were two cases of co-infection with HIV; no other co-infections with enterovirus or herpes family viruses were detected. All patients had good outcome. Although HAdV is rarely observable in CNS infectious syndromes, it must be investigated particularly in immunocompromised patients.

Molecular investigations of viral meningitis among HIV-infected adults in Accra, Ghana

Objective

Meningitis is one of the leading causes of death among patients living with the human immunodeficiency virus (HIV) in sub-Saharan Africa. Based on clinical presentations alone, the different types of meningitis may not be distinguished from each other, consequently accurate laboratory diagnosis is extremely essential. Viruses such as Enteroviruses (EV), Mumps virus (MuV) and Herpes Simplex Virus-1 (HSV-1) are implicated in cases of meningitis. We sought to detect and characterize viral aetiologies of meningitis among HIV-infected adults with the use of molecular tools.

Results

As a subset of a main research work, cerebrospinal fluid specimens were collected from a cross-section of HIV patients at the Fevers Unit of the Korle Bu Teaching Hospital with clinical features suggestive of meningitis but without laboratory confirmation. Laboratory investigations were performed with the use of the real time polymerase chain reaction for pan EV, MuV and HSV-1. None of the viruses investigated in this study was found to be positive for meningitis. However, lymphocytic pleocytosis, normal glucose and elevated protein levels were observed in some of the study participants.

Red blood cells in cerebrospinal fluid as possible inhibitory factor for enterovirus RT-PCR

The presence of hemoglobin in samples are considered an important inhibitory factor for polymerase chain reaction (PCR). The aim of this study was to examine the influence of red blood cells (RBC)s in cerebrospinal fluid (CSF) as an inhibitory factor to reverse transcription polymerase chain reaction (RT-PCR) for enteroviruses (EV). Forty-four CSF samples from patients showing characteristics of viral meningitis were assessed for EV by RT-PCR. Viral RNA extracted with guanidine isothyocianate buffer and virus detection was performed by in-house nested PCR. Positivity for EV RT-PCR was higher in CSF samples without RBCs than in samples with RBCs: 13(26%) and 36(9.2%), p = 0.001. In the group with positive EV RT-PCR, the mean + SD CSF RBC was 37 ± 183 cell/mm3; the group with negative results had 580 + 2,890 cell/mm3 (p = 0.007). The acceptable upper limit for CSF RBCs that could not influence RT-PCR was 108 cells/mm3. CSF samples with negative results for EV RT-PCR have more erythrocytes.

Clinical application of viral cerebrospinal fluid PCR testing for diagnosis of central nervous system disorders: a retrospective 11-year experience

The cerebrospinal fluid (CSF) polymerase chain reaction (PCR) is the gold standard to detect cerebral viral activity. As positive findings do not prove an impact on the neurological disorder, data interpretation is difficult. To better assess the impact of positive CSF PCR findings in different neurological diseases and to identify coherences facilitating CSF PCR data interpretation, we performed this retrospective analysis of CSF PCR data of 481 pediatric and 2604 adult patients, including herpes simplex virus (HSV), varicella zoster virus (VZV), Epstein-Barr virus (EBV), cytomegalovirus (CMV), human herpesvirus 6 (HHV-6), and enteroviruses (EV). Nucleic acid of EBV was detected in 1.6% (39/2449), of VZV in 1.3% (34/2624), of HSV in 1.24% (37/2994), of EV in 0.4% (10/2364), of HHV-6 in 0.17% (4/2417), and of CMV in 0.2% (5/2514) of the patients. Newborns and elderly people showed highest infection rates. HSV, VZV, and EV prevailed in typical infectious central nervous system (CNS) diseases; EBV, in further inflammatory neurological diseases; HSV and EBV, in immunocompromised patients; and EBV, HSV, and HHV-6, in further non-inflammatory neurological diseases. Analysis of successive PCR studies revealed delayed viral detection for EBV (6/147) and HSV (1/217), respectively. Rapid viral clearance was typical for HSV, VZV, CMV, and EV infections, although the maximum duration of viral detection was 15days for HSV and 12days for VZV, respectively. This suggests that the detection of HSV, VZV, CMV, and EV strongly indicates symptomatic viral CNS disease. Secondary viral reactivation mostly underlies positive EBV and HHV-6 findings. Their detection does not rule out clinical impact but recommends searching for additional underlying conditions.

Detection of Herpesvirus, Enterovirus, and Arbovirus infection in patients with suspected central nervous system viral infection in the Western Brazilian Amazon

Acute infections of the central nervous system (CNS) can be caused by various pathogens. In this study, the presence of herpesviruses (HHV), enteroviruses (EVs), and arboviruses were investigated in CSF samples from 165 patients with suspected CNS viral infection through polymerase chain reaction (PCR) and reverse transcriptase PCR. The genomes of one or more viral agents were detected in 29.7% (49/165) of the CSF samples. EVs were predominant (16/49; 32.6%) followed by Epstein-Barr virus (EBV) (22.4%), Varicella-Zoster virus (VZV) (20.4%), Cytomegalovirus (CMV) (18.4%), herpes simplex virus (HSV-1) (4.1%), (HSV-2) (4.1%), and the arboviruses (14.3%). Four of the arboviruses were of dengue virus (DENV) and three of oropouche virus (OROV). The detection of different viruses in the CNS of patients with meningitis or encephalitis highlight the importance of maintaining an active laboratory monitoring diagnostics with rapid methodology of high sensitivity in areas of viral hyperendemicity that may assist in clinical decisions and in the choice of antiviral therapy.