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... extraction methods are commercially available or have been described for extracting viral nucleic acids for am- plification procedures (Table 2). Ideally, an extraction proce- dure should isolate, concentrate, and provide a pure product free of inhibitors; such materials may reduce the efficiency of amplification and ultimately lower the sensitivity of the PCR. ...
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A duplex polymerase chain reaction (PCR) assay for DNA from herpes simplex virus types 1 (HSV-1) and 2 (HSV-2) was applied
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or HSV-2 (HSV-1/2) DNA was found in 19 patients (2%). For the 258 patients for whom a diagnosis was co...
1.
Do not delay antibiotic or antiviral therapy if there is any suspicion of CNS infection
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Get a senior review and seek help from the critical-care team
3.
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Immunocompromised patients may be...
Cerebrospinal fluid (CSF) analysis is an important diagnostic tool for many conditions affecting the central nervous system (CNS), especially CNS infectious diseases. Despite its low specificity, CSF white blood cell counts, CSF protein levels, CSF serum glucose ratio and CSF lactate measurement are useful in differentiating infections caused by di...
Central nervous system (CNS) infections can have various presentations including Cerebrovascular accidents (CVA) which may go unrecognized as a presentation of infection. We describe three cases of different CNS infections complicated by CVA.Presentation Case 1 describes a 27 year old man, presenting with symptoms consistent with a transient ischem...
Citations
... Due to our high suspicion of HSV encephalitis in our patient, we analyze the current literature regarding the potential causes that could have yielded a negative PCR test. Some investigators believe that 1% to 5% of CSF specimens might contain inhibitors that interfere with PCR [8]. For example, a high concentration of porphyrin compounds, which can be derived from the hemolysis of red blood cells, can interfere with PCR reactions [7]. ...
Herpes simplex encephalitis is a rare disease presentation that is usually characterized by its temporal involvement and positive cerebrospinal fluid (CSF) polymerase chain reaction (PCR) for the herpes simplex virus (HSV). HSV PCR has a sensitivity of 96% and specificity of 99%. Even when the test is negative, if clinical suspicion is high, acyclovir therapy should be continued with a repeated PCR within a week. In this case, we report a 75-year-old female patient who presented with signs of hypertensive emergency with rapid deterioration to seizure-like activity on electroencephalogram (EEG) and signs of temporal encephalitis on magnetic resonance imaging (MRI). The patient did not respond to the initial regimen of antibiotics but did show significant clinical response to acyclovir though she had a negative CSF PCR for HSV ten days after the start of her neurological symptoms. In this case, we argue that alternative methods of diagnosis should be considered in cases of acute encephalitis. Our patient had negative PCR but her computerized tomography (CT), EEG, and MRI results pointed to temporal encephalitis caused by HSV.
... The polymerase chain reaction (PCR) test is more useful than the traditional methods for detection viruses (Kannian et al., 2003). the conventional methods like the fluorescence staining by direct smears from the labial lesion lacked for specifity and sensitivity which are also time consuming, moreover some viruses are difficult to cultivate (Tang et al., 1999). Michele and his colleges (Knox et al., 1998) found the PCR technique is more useful method for detection the viral agents. ...
Background
Herpes simplex virus 1 (HSV-1) is considered the primary cause of Labial herpes. The primary diagnostic approach for HSV type is polymerase chain reaction (PCR), sequencing, and commercial qPCR, in which fluorescent-labeled probes are used for detection.
Objective
This study aimed to use a sequencing method to detect novel HSV-1 genotypes, which are anticipated to grow as the number of HSV-1 labials infected increases.
Methods
HSV-1 genomes were amplified and sequenced from 50 patient swabs in the Babylon province of Iraq, The group patients comprised male and female aged 1–78 years diagnosed with HSV-1 infection.
Results
Sequencing showed about 20% (10 out of 50 samples) of patients as positive, 30% (3 out of 10) of positive samples have been recorded for the first time as new isolates. Subsequently, the three novel isolates were registered in the National Center for Biotechnology Information database with ID: MW916900, MW940838, and MZ020781.
Conclusion
Sequencing assay provides a powerful and low-cost tool for HSV-1 detection. Hence, it can be used as a routine in the diagnosis of clinical samples. Moreover, the significance of this tool is distinguish HSV-1 from other Herpeviridae species.
... A fluorescence dye (SYBR green) or TaqMan probe is used in real-time PCR to monitor DNA amplification as the reaction progresses. Over the years, different PCR assays have been used for the detection of HSV [97,[100][101][102][103][104][105]. Marshall et al. have detected HSV from genital infections using a multiplex PCR assay [106]. ...
Herpes is a widespread viral infection caused by the herpes simplex virus (HSV) that has no permanent cure to date. There are two subtypes, HSV-1 and HSV-2, that are known to cause a variety of symptoms, ranging from acute to chronic. HSV is highly contagious and can be transmitted via any type of physical contact. Additionally, viral shedding can also happen from asymptomatic infections. Thus, early and accurate detection of HSV is needed to prevent the transmission of this infection. Herpes can be diagnosed in two ways, by either detecting the presence of the virus in lesions or the antibodies in the blood. Different detection techniques are available based on both laboratory and point of care (POC) devices. Laboratory techniques include different biochemical assays, microscopy, and nucleic acid amplification. In contrast, POC techniques include microfluidics-based tests that enable on-spot testing. Here, we aim to review the different diagnostic techniques, both laboratory-based and POC, their limits of detection, sensitivity, and specificity, as well as their advantages and disadvantages.
... The HSV usually lies dormant in the ganglion of the trigeminal cranial nerve, but upon reactivation, may travel to the brain to cause herpes viral encephalitis. Although not very common, this occurs in 1 in 2,50,000 to 5,00,000 population per year (Tang et al., 1999). ...
Calcium (Ca²⁺) plays fundamental and diverse roles in brain cells as a second messenger of many signaling pathways. Given the high energy demand in the brain and the generally non-regenerative state of neurons, the role of brain mitochondrial calcium [Ca²⁺]m in particular, in regulating ATP generation and determination of cell fate by initiation or inhibition of programmed cell death (PCD) becomes critical. Since [Ca²⁺]m signaling has a central role in brain physiology, it represents an ideal target for viruses to hijack the Ca²⁺ machinery to favor their own persistence, replication and/or dissemination by modulating cell death. This review discusses the ways by which neurotropic viruses are known to exploit the [Ca²⁺]m signaling of their host cells to regulate cell death in the brain, particularly in neurons. We hope our review will highlight the importance of [Ca²⁺]m handling in the virus-infected brain and stimulate further studies towards exploring novel [Ca²⁺]m related therapeutic strategies for viral effects on the brain.
... The detection of HSVs DNA by targeting the TK gene in CSF samples revealed its highly variable nucleotide sequence. However, analyzing a 335-bp amplicon within the TK gene revealed the presence of 51 nucleotides that are consistently present to enable differentiation between HSV 1-2 (Aslanzadeh et al., 1993;Tang et al., 1999). Unlike TK, the DNA polymerase gene comprises highly conserved region and degenerate primers targeting this region are used to amplify DNA from several species of human and animal HSVs. ...
There is a need for a reliable and cost-effective molecular diagnostic assay for the diagnosis of TORCH [Toxoplasma gondii, Other (Varicella-Zoster virus and Parvovirus B19), Rubella virus, Cytomegalovirus, and Herpes Simplex virus] infections. This would enable early and precise detection of pathogens even in a very low copy number. However, the selection of genomic target, specimen matrix, and different PCR methods can significantly affect the sensitivity and specificity of TORCH molecular detection. This review aimed to provide a comparative analysis of clinical sample types, target nucleotide sequences, and PCR detection approaches for molecular detection of TORCH organisms. This review will aid in the development of a sensitive molecular assay for quick and precise detection of TORCH organisms.
... 2,8,27,45 Aunque la PCR puede verse afectada por diversos factores como viremias, contaminación externa o infección genital por VHS8, 46 , su sensibilidad (94%) y especificidad (98%) en el diagnóstico de EH son altas. 8,47,48 El uso de la PCR puede tener valor pronóstico en la EH; un estudio observó que la morbimortalidad era más alta en pacientes con más de 100 copias por mm3 que los que tenían menor ADN viral en LCR. 49 El alto costo de la técnica ha llevado a la aplicación de métodos de selección de los pacientes; los recuentos leucocitarios (>10/mm3) y los niveles de proteínas totales en LCR son buenos indicadores de infección en el SNC. ...
... Las presencias de las dos alteraciones tienen un mayor rendimiento diagnóstico en comparación con la presentación de solo una de ellas. 45,48,50 Entre los criterios alternativos de aceptación se encuentran: >10 células/mm3 en la muestra procedente de pacientes inmunodeprimidos o de niños <2 años, que pueden ayudar a simplificar la aplicación de PCR sin reducir la sensibilidad. 50 Los nuevos avances en el diagnóstico como el sistema multiplex PCR Mag-array han permitido detectar múltiples virus en una sola reacción con un alta especificidad, rendimiento y velocidad. ...
La inflamación del sistema nervioso central secundaria a la infección por la familia herpesviridae puede generar un compromiso difuso del parénquima encefálico, la cual puede ser fatal en ausencia de un rápido diagnóstico y tratamiento. Objetivo: revisar las diferentes características biológicas, fisiopatológicas, clínicas, terapéuticas y pronóstico de la meningoencefalitis causada por VHS-1 y 2. Materiales y métodos: revisión de la literatura científica (revisión crítica), llevada a cabo mediante las bases de datos Medline y buscadores específicos IMBIOMED, PUBMEDE, SCIENCEDIRECT, SCIELO, con un total de 150 artículos, se priorizaron 67 los cuales fueron leídos a profundidad. Resultados y discusión: debido el neurotropismo del herpes virus simple puede causar neuroinvasividad, neurotoxicidad y latencia en el SNC. Por sus características semiológicas inespecíficas se requiere un estudio exhaustivo para lograr el diagnóstico acertado. Los métodos actuales tales como neuroimágenes y PCR han aportado al esclarecimiento del diagnóstico etiológico de esta patología. La detección temprana de la entidad y la instauración precoz del tratamiento, se asocian con un aumento en la tasa de supervivencia y a una disminución de las secuelas neurológicas. Conclusión: conocer la biología del virus, su comportamiento, las características clínicas y el tratamiento de la entidad es una estrategia eficaz para disminuir secuelas y desenlaces fatales.
... Brain biopsies for the diagnosis of central nervous system infections caused by herpes simplex viruses, toxoplasmosis, and the JC polyoma virus have become a rarity given the widespread use of highly sensitive PCRbased methods. [14][15][16][17][18] We have previously called for the enhanced development and application of molecular diagnostics for improvements in the diagnosis and treatment of patients at risk for fungal infections. 19,20 There have been several advances in the use of molecular diagnostics for the diagnosis of some fungal infections. ...
Context.—:
New molecular diagnostic tests regularly become available, and they may be assumed to be superior to traditional diagnostic studies. The added cost of these studies should be considered in conjunction with the value provided for patient care.
Objective.—:
To assess the cost and diagnostic value of broad-range polymerase chain reaction (PCR) and DNA sequencing for the diagnosis of fungal infections compared with traditional studies.
Design.—:
We reviewed the cost and clinical impact of broad-range fungal PCR/DNA sequencing for 65 specimens for which this test, a direct fungal examination, fungal culture, and a histopathologic assessment were performed.
Results.—:
The sensitivity, specificity, and positive and negative predictive values for each of the assays studied were, respectively: histopathology (83.3%, 100%, 100%, and 98.3%); direct examination (66.7%, 100%, 100%, and 96.7%); fungal culture (83.3%, 100%, 100%, and 98.3%); and broad-range fungal PCR/DNA sequencing (83.3%, 95.0%, 62.5%, and 98.3%). The cost for broad-range fungal PCR/DNA sequencing was $32,500, compared with $8,591.70 for all traditional tests combined, for the 65 specimens included in this review.
Conclusions.—:
Broad-range fungal PCR/DNA sequencing did not detect any infecting fungal pathogen that was not detected by at least 1 of the traditional methods, but 3 false-positives occurred. Broad-range fungal PCR/DNA sequencing is not a substitute for traditional laboratory studies and should be used judiciously to promote care affordability.
... Herpes viruses composed of a group of viruses that are large, DNA-containing, enveloped viruses that are an important cause of CNS infections [4][5][6][7]. Among these viruses, Herpes simplex viruses (HSVs) accounts for approximately 2 to 19% of all cases of encephalitis and 20 to 25% of all cases of necrotizing encephalitis [8][9][10]. In addition to this, HSVs cause various acute, sub-acute and chronic neurological diseases which are associated with significant morbidity and even mortality in both immunocompetent and immunocompromised subjects. ...
Background: Viral meningitis (VM) is the most prevalent type of meningitis and mainly characterized by the meningeal inflammation caused by Herpes simplex
viruses. Cerebrospinal fluid (CSF) samples of patients of neurological diseases were screened for viral etiological agents i.e. Herpes simplex virus 1 (HSV1) and
Herpes simplex virus 2 (HSV2) and occurrence of co-infection of both the viral strains.
Methods: 92 CSF samples were collected from different mentally ailed patients admitted in the local hospitals of Karachi. Out of which 30 bacteria negative CSF
samples were selected for the screening of viral etiology. Total cellular DNA extraction was done by the conventional methods. HSV1 and HSV2 specific primers
targeting the glycoprotein G gene were used for the viral detection by polymerase chain reaction (PCR).
Results: Presence of HSV2 was confirmed in (26.6%) clinical samples of CSF whereas HSV1 was found in only (6.6%) of samples. (36.6%) CSF samples demonstrated
the mixed viral infection of HSV1 and HSV2. While (23.33%) CSF samples were found negative for any viral etiology. Total cellular DNA quantification revealed
the increased concentration i.e. 802μg/ml in HSV2 infections.
Conclusion: Findings of the present study demonstrated that the detection and diagnosis of neurological infections on the basis of clinical signs are not sufficient.
Therefore, existence of viral etiological agents must be checked subsequent to bacterial culture to avoid the misdiagnosis and wrong treatment of the CNS infections.
... Several researchers proposed PCR-based detection of HSV from patient samples through designing specific primers and found higher sensitive than other conventional methods [5,[20][21][22]. The PCR amplicons can be analyzed which is an agarose gel electrophoresis with or without Southern blotting [23], although Southern blotting increases the sensitivity of a PCR but increase the time taken. Therefore, some researchers replaced it with enzyme-linked inmmunosorbent assay. ...
... The California Encephalitis Project was unable to detect infectious agents in about 71% of their cases from 1998 to 2000 (34). Similarly, even with the increased sensitivity of PCR, HSV was detected in only 6.2% of 6,607 CSF samples at the Mayo Clinic from 1993 to 1997 (35). Cutaneous manifestations of HSV in patients with HSV CNS involvement have been reported to be present in Ͻ10% of cases (36)(37)(38). ...
Herpes simplex virus (HSV) infection of the central nervous system (CNS) is associated with significant morbidity and mortality in children. This study assessed the impact of a direct HSV (dHSV) PCR assay on time to result and duration of acyclovir therapy in children with signs and symptoms of meningitis and encephalitis. A total of 363 patients with HSV PCR on CSF were included in this retrospective analysis, divided into the pre- and post-implementation groups. The pre-implementation arm included CSF testing performed using a laboratory-developed real-time PCR assay and the post-implementation group consisted of CSF samples tested using a direct sample-to-answer assay. All CSF were negative for HSV. Over 60% of patients from both groups were prescribed acyclovir. The average HSV PCR test turnaround time in the post-implementation group was reduced by 14.5 hours (23.6 h vs 9.1 h, p < 0.001). Furthermore, 79 (43.6%) patients in the post-implementation group had dHSV PCR results reported in less than 4 hours from specimen collection. The mean time from specimen collection to acyclovir discontinuation was 17.1 hours (31.1 h v 14 h, p < 0.001) shorter in the post-implementation group. The median duration of acyclovir therapy was also significantly reduced in the post-implementation group, 29.2 vs 14.3 hours, p = 0.01. Our investigation suggests that implementation of rapid HSV PCR can decreased turnaround time and duration of unnecessary acyclovir therapy.
