Polymerase chain reaction for the laboratory diagnosis of aseptic meningitis and encephalitis

Arbovirus, herpesvirus, and enterovirus associated with neurological syndromes in adult patients of a university hospital, 2017-2018

INTRODUCTION:

Herpesviruses, enteroviruses, and arboviruses are important because of their clinical relevance and ability to cause meningitis, encephalitis, meningoencephalitis, and other diseases. The clinical virology associated with diagnostic technologies can reduce the morbidity and mortality of such neurological manifestations. Here we aimed to identify the genomes of agents that cause neurological syndromes in cerebrospinal fluid (CSF) samples from patients with suspected nervous system infections admitted to the University Hospital of the University of Campinas, São Paulo, Brazil, in 2017-2018.

METHODS:

CSF samples collected from adult patients with neurological syndrome symptoms and negative CSF culture results were analyzed using polymerase chain reaction (PCR), reverse transcriptase-PCR, and real-time PCR, and their results were compared with their clinical symptoms. One CSF sample was obtained from each patient.

RESULTS:

Viral genomes were detected in 148/420 (35.2%) CSF samples: one of 148 (0.2%) was positive for herpes simplex virus-1; two (0.5%) for herpes simplex virus-2; eight (1.9%) for varicella-zoster virus; four (1%) for Epstein-Barr virus; one (0.2%) for cytomegalovirus; 32 (7.6%) for human herpesvirus-6; 30 (7.1%) for non-polio enterovirus; 67 (16.0%) for dengue virus, three (0.7%) for yellow fever virus, and 21 (5%) for Zika virus.

CONCLUSIONS:

The viral genomes were found in 35.2% of all analyzed samples, showing the high prevalence of viruses in the nervous system and the importance of using a nucleic acid amplification test to detect viral agents in CSF samples.

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

Viral meningitis is a common infectious disease of the central nervous system (CNS) that occurs worldwide. The aim of this study was to identify the etiologic agent of lymphomonocytary meningitis in Curitiba, PR, Brazil. During the period of July 2005 to December 2006, 460 cerebrospinal fluid (CSF) samples with lymphomonocytary meningitis were analyzed by PCR methodologies. Fifty nine (12.8%) samples were positive. Enteroviruses was present in 49 (83%) samples and herpes virus family in 10 (17%), of these 6 (10%) herpes simplex virus, 1 (2%) Epstein Barr virus, 2 (3%) human herpes virus type 6 and 1 (2%) mixed infection of enterovirus and Epstein Barr virus. As conclusion enterovirus was the most frequent virus, with circulation during summer and was observed with higher frequency between 4 to 17 years of age. PCR methodology is an important method for rapid detection of RNA enterovirus and DNA herpesvirus in CSF.

Amplification of bacterial DNA does not distinguish patients with ascitic fluid infection from those colonized by bacteria

OBJECTIVE

To evaluate 16S ribosomal RNA (rRNA) gene amplification to diagnose spontaneous bacterial peritonitis (SBP).

PATIENTS AND METHODS

According to a retrospective protocol, 31 patients with portal hypertensive ascites (serum to ascites albumin gradient > or = 1.1 g/dL) were studied. Ascitic fluid was analyzed as follows: Gram stain, aerobic and anaerobic cultures, polymorphonuclear cell count, and biochemical tests. Bacterial DNA was detected by polymerase chain reaction.

RESULTS

There were 8 episodes of SBP and 4 episodes of bacterascites (BA). Culture was positive in 4 of 8 cases of SBP and bacterial DNA was positive in 7 of 8 cases of SBP. Bacterial DNA was positive in 3 of 4 cases of BA and in 8 of 28 cases of culture-negative non-neutrocytic ascites (CNNNA). The PELD score, serum to albumin ascites gradient, and mortality showed no statistical difference between patients with CNNNA and the result of the bacterial DNA analysis.

CONCLUSIONS

Although the 16S rRNA gene amplification was better than culture to diagnose SBP, bacterial DNA does not seem to allow a distinction between ascites infection and ascites colonization.

Le zona et ses complications neurologiques

INTRODUCTION

Herpes zoster is a disease which occurs secondary to the reactivation of varicella-zoster virus (VZV). Its frequency is high in the general population.

STATE OF ART

Herpes zoster leads to numerous complications, among which there were neurological peripheral or central lesions. Antiviral treatment must be instituted, particularly if neurological complications develop, as soon as possible. Corticosteroid therapy can be used, especially in Ramsay-Hunt syndrome or central nervous system involvement.

CONCLUSION

Herpes-zoster is a frequent disease which can lead to serious neurological complications. Early treatment is necessary in order to improve functional outcome.

[Neurolisteriosis in adults: report of six clinical cases]

INTRODUCTION

Listeria monocytogenes shows a special attraction to infect the central nervous system and its meningeals coats. It affects newborn as well as elderly people, patients with deficiencies in their cellular immune systems, and healthy adults. It presents most commonly as an acute meningitis, although it can present itself as cerebritis, brain stem encephalitis (rhomboencephalitis), and exceptionally as myelitis.

PATIENTS

We describe six clinical cases of neurolisterioris, five of which in healthy adults; we also describe the images and cerebrospinal fluid (CSF) findings,

RESULTS

Three patients contracted acute meningitis, one of them meningoencephalitis, one cerebritis and the last one rhomboencephalitis. The CSF was turbid or slightly turbid with normal glycorrachia in three patients. The diagnosis was made in five through culture of CSF. The patient with the rhomboencephalitis had brain stem microabscesses in the brain magnetic resonance. All the patients had a good outcome under antibiotics treatment.

CONCLUSION

Neurolisteriosis has to be kept in mind as a feasible diagnosis not only in immunocompromised but also in newborn as well as elderly patients. It should also be taken into account in young healthy adults living in regions under poor sanitary conditions where there is no adequate control of food manufacturing.

Molecular genetic methods in diagnosis and direct characterization of acute bacterial central nervous system infections

Acute bacterial infection of the central nervous system requires rapid and adequate management. Etiological diagnosis is hence crucial. Moreover, the epidemic threat of certain bacteria necessitates a reliable characterization of the involved bacterial strains to follow the spread of epidemic strains. Conventional identification and characterization of etiological agents are basically based on culture and identification of bacterial markers most frequently by serological assays. Molecular identification and characterization of bacteria have been employed. They provide more reliable analysis of bacterial isolates. Molecular methods for non-culture diagnosis of bacterial infections have recently been developed. In many cases, the molecular assays have decreased the identification time of positive cultures and rescued detection of pathogens in culture-negative clinical samples.

Acute hemorrhagic leukoencephalitis mimicking herpes simplex encephalitis: case report

Acute hemorrhagic leukoencephalitis (AHLE) is a more severe form of acute disseminated encephalomyelities (ADEM) characterized by a fulminant clinical course and the presence of hemorrhagic necrosis of the white matter. We report the case of a 57-year-old woman who developed delirium following a respiratory infection. Magnetic resonance imaging of the brain disclosed signal abnormalities in the frontal and temporal lobes, usually found in herpes simplex encephalitis (HSE). Gram stain, India ink and acid-fast bacilli staining were all negative in CSF as was a polymerase chain reaction (PCR) for herpes simplex virus. A diagnosis of AHLE was made and the patient was treated with IV methylprednisolone 1g/day for 5 days. Despite treatment, the patient developed several neurological sequelae compatible with the severity of her illness.

La PCR múltiple en microbiología clínica

The introduction of molecular biology methods in clinical microbiology laboratories brings important insights to obtain sensitive and specific diagnoses as fast as possible. These methods are not intended for replacement but for complement of the already applied microbiologic methods. The integrated analyses of all of them is bringing to the most feasible and efficient results. Within the molecular techniques applied, polymerase chain reaction (PCR) has acquired a great diagnostic value, permitting the identification of etiologic agents and the fast and sensitive detection of their virulence and resistance genotypes. Since some years ago, the development of the so called multiplex PCRs has gained deep interest. Those are reactions that get the simultaneous single tube amplification of different target sequences, allowing the simultaneous detection and identification of various genes of interest. In the present article, the most relevant applications of multiplex PCR for clinical microbiology are summarized.

Aseptic meningitis epidemic during a West Nile virus avian epizootic

While enteroviruses have been the most commonly identified cause of aseptic meningitis in the United States, the role of the emerging, neurotropic West Nile virus (WNV) is not clear. In summer 2001, an aseptic meningitis epidemic occurring in an area of a WNV epizootic in Baltimore, Maryland, was investigated to determine the relative contributions of WNV and enteroviruses. A total of 113 aseptic meningitis cases with onsets from June 1 to September 30, 2001, were identified at six hospitals. WNV immunoglobulin M tests were negative for 69 patients with available specimens; however, 43 (61%) of 70 patients tested enterovirus-positive by viral culture or polymerase chain reaction. Most (76%) of the serotyped enteroviruses were echoviruses 13 and 18. Enteroviruses, including previously rarely detected echoviruses, likely caused most aseptic meningitis cases in this epidemic. No WNV meningitis cases were identified. Even in areas of WNV epizootics, enteroviruses continue to be important causative agents of aseptic meningitis.

A retrospective clinical, laboratory and outcome analysis in 43 cases of acute aseptic meningitis

Forty-three consecutive cases of acute aseptic meningitis (AAM) presenting within a 24-months period were retrospectively analysed with respect to clinical symptomatology, cerebrospinal fluid (CSF) findings, clinical course, treatment and outcome. Nineteen of the 43 AAM cases (44%) were caused by enterovirus, one by HIV (2%), two by Varicella zoster virus (5%), three due to herpes simplex virus I (7%), two due to herpes simplex virus II (5%), one due to Central European encephalitis virus (2%), and in 15 patients (35%) the aetiology of AAM remained unknown. Headache (100%) and fever (93%) were the presenting symptoms in the majority of cases. Signs of preceding infection were predominantly gastrointestinal in the enterovirus subgroup, but were inconsistently observed in the other subgroups. CSF findings at the first lumbar tap on admission generally revealed lymphomonocytic pleocytosis of less than 500 cells per micro l, mild to moderately elevated protein and normal lactate and glucose levels. Initial therapy consisted of an empirical antiviral and antibiotic regimen until a serological diagnosis was available. Acyclovir, effective only in herpes family viruses, was initially administered to all AAM cases. Effective therapy for other viral pathogens are not broadly available and treating AAM of unknown aetiology imposes a particular problem. The average hospitalization time ranged from 16 to 31 days. Patients were either discharged home (72%) or transferred to a rehabilitation centre (28%). The outcome was good (40%) to fair (51%) in the majority of cases.

Viral Meningitis and Encephalitis

Many viruses can invade the central nervous system (CNS). Viral CNS infections (often called aseptic meningitis) may be asymptomatic or associated with only mild symptoms, but they can occasionally cause severe meningitis or encephalitis. The diagnostic criteria for the acute aseptic meningitis syndrome are as follows:▪

Signs and symptoms of acute meningeal irritation

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Mononuclear cell predominance in cerebrospinal fluid (CSF)

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Absence of detectable bacteria in the CSF

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Absence of parameningeal or systemic illness

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Brief and benign illness

The diagnostic criterion for encephalitis is alteration of consciousness or focal neurologic findings with evidence of meningeal inflammation. Therefore, the term meningoencephalitis may be appropriate in many cases.

An estimated 8000 to 12,000 cases of acute aseptic meningitis occur annually in the United States. Approximately 1000 to 2000 cases of encephalitis are reported annually to the Centers for Disease Control. Viral causes of meningoencephalitis are numerous, but clinical signs and symptoms alone usually cannot establish a specific diagnosis. However, new laboratory methods are becoming available that will aid in rapid and specific identification of viral agents and will lead to new knowledge of the epidemiology of these viral infections.

Evaluation of a rapid real-time RT-PCR assay for detection of enterovirus RNA in cerebrospinal fluid specimens

BACKGROUND

We previously described the characteristics of a single-tube real-time enterovirus reverse transcriptase polymerase chain reaction (RT-PCR) assay based on a fluorogenic probe and primers directed to highly conserved sequences in the 5'-untranslated region (UTR) of the enterovirus genome.

OBJECTIVES

To evaluate the performance of the assay on a larger number of cerebrospinal fluid (CSF) specimens from patients suspected of having viral meningitis.

STUDY DESIGN

Real-time enterovirus RT-PCR and viral culture were performed on CSF specimens received from March 2000 to November 2001. Patient records were retrospectively reviewed for final clinical diagnosis.

RESULTS

From the 186 CSF specimens tested, culture was positive for enterovirus in 31 cases, whereas real-time RT-PCR detected enterovirus RNA in 45 CSF specimens. The sensitivity of real-time RT-PCR in relation to the clinical diagnosis of viral meningitis was 72.6%, whereas the sensitivity of viral culture reached only 57.4%. Enterovirus RNA was also found in a number of specimens with low leukocyte counts.

CONCLUSIONS

We confirm that the real-time enterovirus RT-PCR assay for CSF specimens is significantly more sensitive than viral culture.

Cerebelite aguda causada por vírus Epstein-Barr: relato de caso

A cerebelite aguda pode ocorrer em associação a infecção pelo vírus da varicela-zoster, enterovirus, caxumba, micoplasma e outros agentes infecciosos. A cerebelite aguda é uma complicação rara da infecção pelo vírus Epstein-Barr (EBV). Relatamos o caso de uma mulher de 21 anos com história de 12 dias de evolução com náuseas, vômitos, ataxia de marcha e membros, tremor cefálico e de membros, opsoclono, mioclonias e rash cutâneo. Sorologia para EBV foi positiva. A infecção pelo EBV, com complicações neurológicas, pode não se apresentar com os sinais e sintomas clássicos da mononucleose infeciosa.