Increased detection rate in diagnosis of herpes simplex virus type 2 meningitis by real-time PCR using cerebrospinal fluid samples

A retrospective observational study of 1000 consecutive patients tested with the FilmArray® Meningitis/Encephalitis panel: clinical diagnosis at discharge and microbiological findings

FilmArray® Meningitis/Encephalitis panel (FAME-p) is used to diagnose central nervous system (CNS) infections. In this study, we investigated performance of FAME-p compared to comparator assays (CA), and for the first time, clinical diagnosis at discharge (CDD). 1000 consecutive patients with a cerebrospinal fluid (CSF) sample analyzed with FAME-p were identified. As CA, culture, polymerase chain reaction and cryptococcal antigen test were used. Medical records of patients were obtained. A CDD of CNS infection was made in 139 of 1000 CSF samples. FAME-p was positive in 66 samples with 44 viral and 22 bacterial agents. Thirteen FAME-p findings were not confirmed by CA, with four discrepant results remaining after comparison with the CDD. Positive percentage agreement (PPA) calculated against CA was 100%. Negative percentage agreement (NPA) calculated against CA was 94.4-99.8% for Haemophilus influenzae, Listeria monocytogenes, Streptococcus agalactiae, S. pneumoniae and varicella-zoster virus (VZV). NPA calculated against CDD was higher (compared to CA) for L. monocytogenes, S. agalactiae and VZV (100%), and lower for Escherichia coli, enterovirus and herpes simplex virus 2 (50-83.3%). NPA of FAME-p for human herpes virus 6 was difficult to interpret. Eighty-four cases received diagnosis of CNS-infection despite negative FAME-p. The four most common non-infectious etiologies were primary headache disorders, cranial nerve palsies, neuroinflammatory disorders and seizure. Although FAME-p shows good performance in diagnosis of CNS infections, result of FAME-p should be interpreted carefully. Considering infectious diseases not covered by FAME-p as well as non-infectious differential diagnoses is important in this context.

Benign recurrent lymphocytic meningitis (Mollaret's meningitis) in Denmark: a nationwide cohort study

BACKGROUND AND PURPOSE

Data on clinical features and outcomes of benign recurrent lymphocytic meningitis (BRLM) are limited.

METHODS

This was a nationwide population-based cohort study of all adults hospitalized for BRLM associated with herpes simplex virus type 2 (HSV-2) at the departments of infectious diseases in Denmark from 2015 to 2020. Patients with single-episode HSV-2 meningitis were included for comparison.

RESULTS

Forty-seven patients with BRLM (mean annual incidence 1.2/1,000,000 adults) and 118 with single-episode HSV-2 meningitis were included. The progression risk from HSV-2 meningitis to BRLM was 22% (95% confidence interval [CI] 15%-30%). The proportion of patients with the triad of headache, neck stiffness and photophobia/hyperacusis was similar between BRLM and single-episode HSV-2 meningitis (16/43 [37%] vs. 46/103 [45%]; p = 0.41), whilst the median cerebrospinal fluid leukocyte count was lower in BRLM (221 cells vs. 398 cells; p = 0.02). Unfavourable functional outcomes (Glasgow Outcome Scale score of 1-4) were less frequent in BRLM at all post-discharge follow-up visits. During the study period, 10 (21%) patients with BRLM were hospitalized for an additional recurrence (annual rate 6%, 95% CI 3%-12%). The hazard ratio for an additional recurrence was 3.93 (95% CI 1.02-15.3) for patients with three or more previous episodes of meningitis.

CONCLUSIONS

Clinical features of BRLM were similar to those of single-episode HSV-2 meningitis, whilst post-discharge outcomes were more favourable. Patients with three or more previous episodes of meningitis had higher risk of an additional recurrence.

Neurology of Acute Viral Infections

As specialists in acute neurology, neurohospitalists are often called upon to diagnose and manage acute viral infections affecting the nervous system. In this broad review covering the neurology of several acute viral infections, our aim is to provide key diagnostic and therapeutic pearls of practical use to the busy neurohospitalist. We will review acute presentations, diagnosis, and treatment of human herpesviruses, arboviruses, enteroviruses, and some vaccine-preventable viruses. The neurological effects of coronaviruses, including COVID-19, are not covered in this review.

Varicella Zoster Virus Meningitis with Absence of Rash in an Immunocompetent Child

Only a few cases in the literature have ever reported the reactivation of the varicella zoster virus (VZV) in children especially in the case of immunocompetent patients. It is an uncommon situation that may lead to several neurological complications. We report varicella zoster virus (VZV) meningitis in a 14-year-old healthy boy with no antecedent of rash. On his cerebrospinal fluid (CSF) examination, VZV DNA was detected. The rapid HIV test was negative. The treatment using acyclovir (20 mg/kg/8h) was effective, and the child's clinical condition rapidly improved.

Microbial aspects and potential markers for differentiation between bacterial and viral meningitis among adult patients

OBJECTIVES

Meningitis is a medical emergency with permanent disabilities and high mortality worldwide. We aimed to determine causative microorganisms and potential markers for differentiation between bacterial and viral meningitis.

METHODOLOGY

Adult patients with acute meningitis were subjected to lumber puncture. Cerebrospinal fluid (CSF) microorganisms were identified using Real-time PCR. PCT and CRP levels, peripheral and CSF-leucocyte count, CSF-protein and CSF-glucose levels were assessed.

RESULTS

Out of 80 patients, infectious meningitis was confirmed in 75 cases; 38 cases were bacterial meningitis, 34 cases were viral meningitis and three cases were mixed infection. Higher PCT, peripheral and CSF-leukocytosis, higher CSF-protein and lower CSF-glucose levels were more significant in bacterial than viral meningitis patients. Neisseria meningitides was the most frequent bacteria and varicella-zoster virus was the most common virus. Using ROC analyses, serum PCT and CSF-parameters can discriminate bacterial from viral meningitis. Combined ROC analyses of PCT and CSF-protein significantly improved the effectiveness in predicting bacterial meningitis (AUC of 0.998, 100%sensitivity and 97.1%specificity) than each parameter alone (AUC of 0.951 for PCT and 0.996 for CSF-protein).

CONCLUSION

CSF-protein and serum PCT are considered as potential markers for differentiating bacterial from viral meningitis and their combination improved their predictive accuracy to bacterial meningitis.

Combined testing for herpes simplex virus and Mycobacterium tuberculosis DNA in cerebrospinal fluid of patients with aseptic meningitis in Burkina Faso, West Africa

BACKGROUND

Little is known about the involvement of herpes simplex virus (HSV) or Mycobacterium tuberculosis (MTB) as potentially curable causes of central nervous system (CNS) infections in sub-Saharan Africa.

OBJECTIVE

In this study, we developed a PCR assay dedicated to simultaneous testing of HSV1/HSV2 and MTB in Burkina Faso, a country where HSV is neglected as a cause of CNS infection and where TB prevalence is high.

METHODS

A consensus HSV1/HSV2 set of primers and probe were designed and combined to primers and probe targeting the IS6110 repetitive insertion sequence of MTB. Analytical performances of the assay were evaluated on reference materials. Cerebrospinal fluid (CSF) collected from subjects with aseptic meningitis was tested for HSV1/HSV2 and MTB DNA.

RESULTS

The UL29 gene was chosen as a highly conserved region targeted by the HSV1/HSV2 nucleic acid test. The lower limits of detection were estimated to be 2.45 copies/µL for HSV1, 1.72 copies/µL for HSV2, and 2.54 IS6110 copies per µL for MTB. The PCR was used in 202 CSF collected from subjects suspected of aseptic meningitis. Five samples (2.46%) tested positive, including two children positive for HSV1 (0.99%) and three adults tested positive for MTB (1.47%).

CONCLUSION

Using an in-house real-time PCR assay, we showed that both HSV and MTB are etiologic pathogens contributing to aseptic meningitis in Burkina Faso. This molecular test may have clinical utility for early diagnosis for those treatable CNS infections.

Herpes simplex type 2 encephalitis and methotrexate medication: a fortuitous or causative association in a patient with spondyloarthritis?

It is unclear whether immunosuppression is a risk factor for herpes encephalitis. Herein, we describe a rare case of herpes simplex virus type 2 encephalitis in a patient treated with low-dose methotrexate for HLA-B27-associated spondyloarthritis. The patient was successfully treated with acyclovir but presented sequelae of encephalitis. Here we discuss the possible role of low-dose methotrexate therapy as a risk factor of neurological herpes reactivation and severe disease. The host-related and viral risk factors are also addressed.

Varicella Zoster Aseptic Meningitis: Report of an Atypical Case and Literature Review

Patient: Female, 15

Final Diagnosis: Varicella Zoster aseptic meningitis

Symptoms: —

Medication: —

Clinical Procedure: Lumber punctur

Specialty: Infectious Diseases

HSV-2 meningoencephalitis in an immunocompetent young man: what is the pathogenesis and what is the treatment?

Herpes simplex encephalitis is rarely caused by herpes simplex virus type 2 (HSV-2) after the neonatal period. The pathogenesis of HSV-2 encephalitis is not known and its treatment has not been discussed. We report a case of mild meningoencephalitis secondary to HSV-2 primary infection after sexual risk behaviour in a healthy young man. The diagnosis was established upon clinical, biological and electroencephalographic criteria. Aciclovir treatment led to rapid clinical improvement. This case highlights HSV-2 as a rare cause of meningoencephalitis, and questions the management of this rare manifestation of HSV-2 infection.

Diagnostic value of a "wide-range" quantitative nested real-time PCR assay for varicella zoster virus myelitis

Myelitis is one of the rarest neurological complications of varicella zoster virus (VZV) infection. In this study, the authors remodeled the "wide-range" quantitative nested real-time (QNRT) polymerase chain reaction (PCR) assay to quantitatively detect a small amount of VZV-DNA in cerebrospinal fluid (CSF). For use as a specific internal control "calibrator," an original mutation-VZV (MZ) plasmid was developed. The initial copy number of VZV-DNA in CSF specimens was measured by the amplification rate of the MZ-plasmid. For 17 consecutive CSF specimens collected from three elderly patients with VZV myelitis, the diagnostic value of the wide-range QNRT-PCR assay was evaluated and compared with other conventional PCR assays and enzyme immunoassay (EIA). The MZ-plasmid demonstrated statistically uniform amplifications (F=1.016) against a wide range (1-100,000) of copy numbers of mimic VZV-DNA. The wide-range QNRT-PCR assay quantitatively and rapidly (within 48 hr) detected 5,863, 3,052, 958, and 6,721 copies/ml of VZV-DNA in the CSF specimens collected from all patients in the acute phase. Additionally, there was a significant difference (*P=0.023) in the copy number of VZV-DNA between before and after acyclovir treatment. Other conventional single PCR assays all revealed negative results, but were nevertheless time-consuming (7 days). The IgG EIA-value for VZV was continually elevated throughout the clinical course of all patients. The MZ-plasmid was thus regarded as an appropriate "calibrator" in the wide-range QNRT-PCR assay. This assay is a novel, rapid, accurate, quantitative, and highly sensitive technique, and will contribute as a reliable and useful clinical examination for the rapid diagnosis of VZV infection to central nervous system.

Varicella zoster virus myelitis in two elderly patients: diagnostic value of nested polymerase chain reaction assay and antibody index for cerebrospinal fluid specimens

Background

Myelitis is one of the rarest neurological complications of the varicella zoster virus (VZV) infection. Focal muscle weakness with or without sensory disturbance occurs in approximately 5% of the cases after acute VZV infection, with complete recovery in 50–70%.

Case Presentation

This report describes two rare cases of elderly patients with VZV myelitis secondary to dermatomal zoster rash. Patient 1 was a 79-year-old woman who developed paraplegia, numbness and decreased sensation in the left arm and below thoracic (Th)-10 after sacral zoster. Spinal cord MRI showed a high-signal-intensity lesion at the cervical spinal nerve 2 on a T₂-weighted image. Patient 2 was a 73-year-old man who developed right flaccid leg weakness and urinary retention after right dorsal Th 5–8 zoster. Spinal cord MRI showed a high-signal-intensity lesion at Th 3–4 on a T₂-weighted image. In both cases, although the conventional single polymerase chain reaction (PCR) assays all showed negative results, the original nested PCR assay detected VZV DNA in the cerebrospinal fluid (CSF) specimen collected on admission. In addition, the anti-VZV IgG antibody by enzyme immunoassay and antibody index were elevated in the CSF specimens during the clinical courses of both patients. On the basis of these findings, both patients were diagnosed with VZV myelitis and were treated with high-dose acyclovir and corticosteroid. This combined treatment was appropriate and effective for the improvement of their functional outcomes.

Conclusion

The detection of VZV DNA in CSF by nested PCR assay and the evaluation of the antibody index to VZV had significant diagnostic value.

Detection of herpes viruses in the cerebrospinal fluid of adults with suspected viral meningitis in Malawi

PURPOSE

We looked for herpes simplex virus types 1 and 2 (HSV-1 and HSV-2, respectively), varicella zoster virus (VZV), Epstein-Barr virus (EBV) and cytomegalovirus (CMV) DNA in Malawian adults with clinically suspected meningitis.

METHODS

We collected cerebrospinal fluid (CSF) from consecutive adults admitted with clinically suspected meningitis to Queen Elizabeth Central Hospital (QECH), Blantyre, Malawi, for a period of 3 months. Those with proven bacterial or fungal meningitis were excluded. Real-time polymerase chain reaction (PCR) was performed on the CSF for HSV-1 and HSV-2, VZV, EBV and CMV DNA.

RESULTS

A total of 183 patients presented with clinically suspected meningitis. Of these, 59 (32 %) had proven meningitis (bacterial, tuberculous or cryptococcal), 39 (21 %) had normal CSF and 14 (8 %) had aseptic meningitis. For the latter group, a herpes virus was detected in 9 (64 %): 7 (50 %) had EBV and 2 (14 %) had CMV, all were human immunodeficiency virus (HIV)-positive. HSV-2 and VZV were not detected. Amongst those with a normal CSF, 8 (21 %) had a detectable herpes virus, of which 7 (88 %) were HIV-positive.

CONCLUSIONS

The spectrum of causes of herpes viral meningitis in this African population is different to that in Western industrialised settings, with EBV being frequently detected in the CSF. The significance of this needs further investigation.

Long-term valacyclovir suppressive treatment after herpes simplex virus type 2 meningitis: a double-blind, randomized controlled trial

BACKGROUND

Herpes simplex virus type 2 (HSV-2) is a common cause of acute and recurrent aseptic meningitis. Our aim was to determine the impact of antiviral suppression on recurrence of meningitis and to delineate the full spectrum of neurological complications.

METHODS

One hundred and one patients with acute primary or recurrent HSV-2 meningitis were assigned to placebo (n = 51) or 0.5 g of valacyclovir twice daily (n = 50) for 1 year after initial treatment with 1 g of valacyclovir 3 times daily for 1 week in a prospective, placebo-controlled, multicenter trial. The primary outcome was time until recurrence of meningitis. The patients were followed up for 2 years.

RESULTS

The first year, no significant difference was found between the valacyclovir and placebo groups. The second year, without study drugs, the risk of recurrence of verified and probable HSV-2 meningitis was significantly higher among patients exposed to valacyclovir (hazard ratio, 3.29 [95% confidence interval, 10.06-10.21]). One-third of the patients experienced 1-4 meningitis episodes during the study period. A considerable morbidity rate, comprising symptoms from the central, peripheral, and autonomous nervous system, was found in both groups.

CONCLUSIONS

Suppressive treatment with 0.5 g of valacyclovir twice daily was not shown to prohibit recurrent meningitis and cannot be recommended for this purpose after HSV meningitis in general. Protection against mucocutaneous lesions was observed, but the dosage was probably inappropriate for the prevention of HSV activation in the central nervous system. The higher frequency of meningitis, after cessation of active drug, could be interpreted as a rebound phenomenon.

Increased cell-mediated immune responses in patients with recurrent herpes simplex virus type 2 meningitis

The clinical picture of herpes simplex virus type 2 (HSV-2) infection includes genital blisters and less frequently meningitis, and some individuals suffer from recurrent episodes of these manifestations. We hypothesized that adaptive and/or innate immune functional deficiencies may be a major contributing factor in susceptibility to recurrent HSV-2 meningitis. Ten patients with recurrent HSV-2 meningitis were studied during clinical remission. For comparison, 10 patients with recurrent genital HSV infections as well as 21 HSV-seropositive and 19 HSV-seronegative healthy blood donors were included. HSV-specific T cell blasting and cytokine secretion were evaluated in whole blood cultures. HSV-2-induced NK cell gamma interferon production, dendritic cell Toll-like receptor (TLR) expression, and TLR agonist-induced alpha interferon secretion were analyzed. Patients with recurrent HSV-2 meningitis had elevated T cell blasting and Th1 and Th2 cytokine production in response to HSV antigens compared to those of patients with recurrent genital infections. A somewhat increased NK cell response, increased dendritic cell expression of TLR3 and -9, and increased TLR-induced alpha interferon responses were also noted. Contrary to our expectation, recurrent HSV-2 meningitis patients have increased HSV-specific adaptive and innate immune responses, raising the possibility of immune-mediated pathology in the development of recurrent HSV2 meningitis.

Recurrent lymphocytic meningitis positive for herpes simplex virus type 2

We found the prevalence of recurrent lymphocytic meningitis associated with herpes simplex virus type 2 (HSV-2) was 2.2/100,000 population in Finland during 1996-2006, higher than previous estimates. PCR was most sensitive in detecting HSV-2 DNA from cerebrospinal fluid if the sample was taken 2-5 days after symptom onset.

Molecular diagnostics of infectious diseases

PURPOSE OF REVIEW

The purpose of this article is to review the molecular methods commonly used in medical microbiology as well as to update the clinician as to newer molecular technologies that show promise in the identification of microorganisms as well as evaluation of the presence of virulence factors and antibiotic resistance determinants.

RECENT FINDINGS

Numerous molecular assays have been developed recently using a variety of technologies. Direct hybridization techniques have allowed analysis of blood culture bottles for organisms such as methicillin-resistant Staphylococcus aureus. Target amplification methods allow postamplification analysis using a variety of technologies depending on the clinical needs for the assay. Postamplification analysis includes methods such as Sanger sequencing, pyrosequencing, reverse hybridization, and Luminex analysis, which are becoming more widely utilized. In the future, whole genome sequencing, mass spectrometry, and microarray analysis may provide a wealth of information that can be used to specifically tailor the treatment of infectious diseases.

SUMMARY

The implications of current trends in molecular infectious diseases are moving towards high-throughput, simple, array-type technologies that will provide a wealth of data regarding types of organisms present in a sample and the virulence factors/resistance determinants that influence the severity of disease. As a result of these developments, infectious diseases will be more accurately and effectively treated.