Detection Of Herpes Simplex Virus Research Articles

Detection of HSV and CMV in Pregnant and Miscarriage women by ELISA and real time PCR Assay

Herpes Simplex Viruses (HSV) and Human Cytomegaloviruses (HCMV) are the major cause of serious viral complications in pregnant women. Screening methods that is ELISA for detecting Herpes Simplex virus(HSV) and Human Cytomegalovirus(HCMV) tend to be slow and insensitive. Therefore in this work, a rapid Real Time PCR (qT-PCR) and ELISA based assay was designed to detect HSV and CMV among pregnant women in Iraq from serum samples. Our study revealed that among the ELISA screened 420 sera samples, 81 (19.3%) of CMV and 17(4.05 %) of HSV were positive, while 64 (12.9%) had positive results for CMV DNA and 5(1.2%) had HSV DNA through real-time PCR. Real time PCR was more sensitive and reliable method in diagnosis of CMV and HSV infections in pregnant women in this comparative study.

The Effect of Hormonal Contraception and Menstrual Cycle Timing on Genital Herpes Simplex Virus-2 Shedding and Lesions.

The effect of female sex hormones on herpes simplex virus (HSV)-2 shedding and lesion frequency is poorly understood. Previous studies suggest that hormonal contraception may increase the frequency of HSV-2 shedding. We studied HSV-2 seropositive women who performed daily genital swabbing for HSV DNA and completed diaries for genital lesions and menses. We used Poisson mixed effects models to determine if HSV detection varied throughout the menstrual cycle, or in response to hormonal contraception. We used the Wilcoxon signed-rank test and rank-sum test to determine if lesion frequency differed by cycle phase or hormonal contraceptive use. In 189 women aged 19 to 46 years who collected swabs on 10,715 days and were not using hormonal contraception, HSV-2 DNA was detected on 20.9% of days in the follicular phase and 17.8% of days in the luteal phase (rate ratio, 1.19; 95% confidence interval, 1.03-1.37, P = 0.02). Genital lesions did not differ in the follicular versus luteal phase (12.8% vs. 10.7%, P = 0.07). In analyses of hormonal contraception, including 244 women, HSV-2 DNA was detected on 19.0% of days for women not using hormonal contraception and 18.3% of days for those using hormonal contraception (P = 0.50). Lesions were present on 11.1% of days for women not using hormonal contraception, and 8.7% of days for those using hormonal contraception (P = 0.66). In women with genital HSV-2 infection who are not using hormonal contraception, the follicular phase of the cycle may be associated with a higher frequency of HSV-2 shedding compared to the luteal phase. Lesion frequency is similar during the 2 menstrual phases. Hormonal contraception use was not observed to affect genital HSV-2 DNA detection or lesions.

Deep Learning Enables High-Throughput Analysis of Particle-Aggregation-Based Biosensors Imaged Using Holography

Aggregation-based assays, using micro- and nano-particles have been widely accepted as an efficient and cost-effective bio-sensing tool, particularly in microbiology, where particle clustering events are used as a metric to infer the presence of a specific target analyte and quantify its concentration. Here, we present a sensitive and automated readout method for aggregation-based assays using a wide-field lens-free on-chip microscope, with the ability to rapidly analyze and quantify microscopic particle aggregation events in 3D, using deep learning-based holographic image reconstruction. In this method, the computation time for hologram reconstruction and particle autofocusing steps remains constant, regardless of the number of particles/clusters within the 3D sample volume, which provides a major throughput advantage, brought by deep learning-based image reconstruction. As a proof of concept, we demonstrate rapid detection of herpes simplex virus (HSV) by monitoring the clustering of antibody-coated micro-particles, achieving a detection limit of ~5 viral copies per micro-liter (i.e., ~25 copies per test).

Prevalence of human herpesviruses infections in nonmalignant tonsils: The SPLIT study.

To assess the prevalence of all known human herpesviruses (HHV) in tonsils of an age-stratified large sample of immunocompetent children and adults. Patients undergoing tonsillectomy for benign indications were recruited in 19 French hospitals. After resection, the entire outer surfaces of right and left half tonsils were extensively brushed. A highly sensitive species-specific multiplex assay was used to detect herpes simplex virus 1 (HSV1), HSV2, Epstein-Barr virus (EBV; types 1 and 2), and human cytomegalovirus (CMV) DNA in 688, as well as varicella zoster virus (VZV), HHV6A, HHV6B, HHV7, and Kaposi's sarcoma-associated herpesvirus (KSHV) DNA in a subset of 440 tonsil brushings. Overall 85% of tonsil brushing samples were infected with at least one HHV species. HHV7 and EBV were the most prevalent (≈70%), followed by HHV6B (≈50%), HSV1, CMV, VZV (≈2%), and KSHV and HSV2 (<1%), while HHV6A was not detected. EBV prevalence was significantly higher in adults than in children, whereas it was opposite for HHV6B and VZV. No difference in HHV prevalence was observed by sex. In multivariate analysis, EBV detection was associated with age greater than or equal to 15 years (prevalence ratio [PR] = 1.8; 95% confidence interval [CI]: 1.5-2.3) and marginally with tobacco smoking (PR = 1.2; 95% CI: 1.1-1.3). Differing patterns of HHV infection in tonsils in a large age-stratified population were described. This study is by far the largest available and shows that EBV, HHV6B, and HHV7 are commonly detected in the tonsils in both men and women, in contrast to other HHVs.

Increase in HSV shedding at initiation of antiretroviral therapy and decrease in shedding over time on antiretroviral therapy in HIV and HSV-2 infected persons.

HIV-infected persons with chronic herpesvirus infections may experience paradoxical worsening after initiation of antiretroviral therapy (ART), but the impact of longer term ART is unclear. We evaluated the relationships between genital herpes simplex virus (HSV) shedding and ART initiation and time on therapy in HIV and HSV-2-infected persons. Prospective observational study. Rates of HSV shedding in 45 HIV and HSV-2-infected persons on or off ART were prospectively followed over up to three, noncontiguous, 60-day periods, during which participants performed daily genital swabs for HSV detection by real-time HSV DNA PCR and reported symptoms. Initiation or discontinuation of ART was at the discretion of participants' healthcare providers. In all, 6425 daily genital swabs were obtained from 45 persons (38 men and seven women) during 105 swabbing sessions. During the three sessions, 67, 74, and 92% of persons were on ART. HSV was detected on 26.5% of days in men and 22.3% of days in women. The overall rates of genital HSV shedding were 19.4% of days in persons not on ART, 30.2% in persons within 90 days of ART initiation, and 23.3% in persons on ART for longer than 90 days. After initiation of ART, HSV shedding decreased by 2% per month, or 23% per year (RR 0.98/month on ART; P = 0.0003 in adjusted analysis). This finding was consistent after including consideration of HIV viral load and CD4 cell count. HSV shedding increased significantly shortly after ART initiation, but decreased with time on prolonged ART.

Incidence of Viremia With DNA Viruses in Oncology Patients With Febrile Neutropenia

Although febrile neutropenia (FN) is one of the most common adverse events produced by chemotherapy, its microbiological etiology is determined for only 15% to 30% of cases. We investigated the rate of viremia with common DNA viruses in patients with FN. From June 2012 to April 2014, 72 blood samples from 24 patients receiving chemotherapy, who experienced FN episodes, were examined for the presence of herpes viruses and other DNA viruses. We used real-time polymerase chain reaction assays to detect herpes simplex virus type 1 and 2, varicella zoster virus, Epstein-Barr virus, cytomegalovirus, human herpes virus types 6 and 7, BK virus and human parvovirus B19 (B19). Viruses were identified in 14 of 72 samples (19.4%). The detected etiological agents were BK virus (5 episodes), human herpes virus type 6 (4 episodes), B19 (4 episodes), Epstein-Barr virus (2 episodes), and cytomegalovirus (1 episode). Our results indicate that viral infections are common causes in patients with FN. Therefore, viruses may be responsible for FN in a large proportion of patients in whom a causative microorganism could not be identified, and this viral etiology may explain their poor response to antibiotic therapy.

AmpliVue Is a Practical and Timely Test for the Detection of HSV From Keratitis Specimens.

The laboratory diagnostic detection of herpes simplex virus (HSV) from eye samples must be practical, timely, and definitive for appropriate therapy. Although polymerase chain reaction (PCR) and/or cell culture can be definitive, HSV results can be delayed. Enzyme Linked Virus Inducible System (ELVIS) is a test that can provide results within 24 to 48 hr. We evaluated "AmpliVue HSV 1+2 Assay" as a molecular colorimetric test that can detect HSV (1 or 2) DNA within 1 hr. Cornea/conjunctival samples were tested retrospectively with AmpliVue against 53 true-positive and 20 true-negative specimens collected in chlamydial transport medium. All clinical specimens were tested by cell culture isolation, PCR, and ELVIS for routine patient care. The sensitivity of AmpliVue against ocular samples that were both culture-positive and PCR-positive was 84%. The specificity of AmpliVue was 100%. Only one clinical sample was HSV-2 positive, whereas all others tested positive for HSV-1. Based on PCR-positive and cell culture-negative samples, AmpliVue (11 of 17) tested more positive than ELVIS (0 of 17) (P=0.003, Fisher Exact). AmpliVue is moderately sensitive and highly specific as a practical and timely diagnostic test for detecting ocular HSV. Expertise is readily achieved and the test is straightforward with easy interpretation. Negative AmpliVue testing must be confirmed with PCR. AmpliVue has potential as an office-based diagnostic test.

Rapid multiplex nucleic acid amplification test developed using paper chromatography chip and azobenzene-modified oligonucleotides

Although nucleic acid amplification test (NAT) is widely used for pathogen detection, rapid NAT systems that do not require special and expensive instruments must be developed in order to enable point of care (POC)-NATs, which contribute to early initiation of treatment. As a POC-NAT system, Kaneka DNA chromatography chip (KDCC), developed using DNA tag-bound primer through modified substance, was shown to be suitable for POC testing, due to the rapid detection time, simple procedures, and low manufacturing costs. However, owing to some modifications in primer, the detection performance and amplification speed were shown to be reduced when using KDCC, counteracting the increased speed of detection. To solve these issues and improve the speed of this NAT system, we investigated a better modification substance for KDCC. Here, azobenzene-modified primers were shown to have the highest amplification speed and detection performance in KDCC, of all modifications tested in this study, showing 10-100-fold lower detection limit but maintaining the same reaction time. Additionally, rapid herpes simplex virus detection system with azobenzene modified primers was developed. We believed that this breakthrough will contribute toward enabling greater utilization of POC-NATs for medical care, especially in developing countries and clinics.

PREVALENCE AND DIAGNOSIS OF GENITAL HERPES BY IMMUNOLOGICAL AND MOLECULAR STUDY

Genital herpes simplex infection is a viral infection caused by the herpes simplex virus (HSV) type 1 or 2. This disease transmitted during close skin or mucus membranes contact with an infected person who is shedding the virus. Infections that are commonly spread by sex, especially vaginal intercourse, anal sex and oral sex. Objective: For detection of HSV by immunological and molecular methods. Methods: Two hundred (200) samples were collected from females attending the Gynecology Outpatient Department in the Al-Imamein Al-Kadhimein Medical City and Baghdad Teaching Hospital during the period from May 2014 to April 2015. Based on availability of full clinical information about each patient, high vaginal swabs were taken from females at different ages (15-54 years) representing patients group complaining of abnormal vaginal discharge with or without other symptoms. The Statistical Analysis System- SAS program was used to study the effect of difference factors in study parameters. Chi-square test was used to significant comparison between percentages in this study. Results: Each of the vaginal swabs collected were examined, was preserved at -20 °C for DNA extracts were analyzed. In RT-PCR, the rate of infection was in women with HSV, those with age group (25-34) years and (35-44) years were 50%. Conclusion: HSV infections were detected in genital tract infection in women; molecular methods are considered the gold standard for diagnosis, given the excellent sensitivities, specificities, rapid and accurate laboratory diagnosis of HSV.

Rapid Detection and Identification of Uveitis Pathogens by Qualitative Multiplex Real-Time PCR.

PurposeInfectious uveitis is a serious sight-threatening infection commonly caused by herpesviruses and Toxoplasma gondii. Etiologic diagnosis based on the clinical evaluation is often challenging. We developed and validated a multiplex real-time PCR assay coupled with high-resolution melting (HRM) for rapid detection and identification of herpes simplex viruses 1 and 2 (HSV-1 and HSV-2), varicella-zoster virus (VZV), cytomegalovirus (CMV), and T. gondii.MethodsThe assay was designed to target pathogen genome regions that yield products with distinct melting temperatures. Analytical specificity, sensitivity, and precision of HRM identification were determined. Clinical validation was performed by testing 108 intraocular fluids collected from eyes suffering with infectious uveitis (n = 30) and controls (n = 78).ResultsA nonoverlapping high-precision profile for each pathogen was generated following HRM (coefficient of variation 0%). The assay was highly sensitive, with a limit of detection of 20 genome copies for herpesviruses and 200 genome copies for T. gondii. The intra- and interassay variability of cycle threshold (Ct) measurement was ≤4% and ≤6%, respectively. Thirteen intraocular specimens collected from suspected cases of infectious uveitis were positive (mean Ct values varied from 19.4 to 27.7). Melting profiles of positive cases were consistent with HSV-2 (n = 5), VZV (n = 5), CMV (n = 2), and T. gondii (n = 1). Amplicon identities were confirmed by sequencing. Control intraocular samples from patients without a clinical diagnosis of infectious uveitis were all negative.ConclusionsThis assay allows rapid, sensitive, and reliable detection and identification of the most common known causes of infectious uveitis, making early pathogen information-based intervention possible.

Performance evaluation of the Aptima HSV-1 and 2 assay for the detection of HSV in cutaneous and mucocutaneous lesion specimens

BackgroundTimely and precise laboratory diagnosis of Herpes simplex viruses (HSV) is required to guide clinical management. ObjectivesThe study evaluated limit of detection (LOD) and performance characteristics of the Aptima HSV 1 & 2 assay in comparison to four assays. Study designThe multi-center study compared qualitative detection of HSV-1 and 2 by the Aptima HSV-1 and 2 assay (Hologic) to ELVIS culture, Lyra Direct (Quidel), AmpliVue (Quidel) and a laboratory developed test (LDT). LOD was performed using VTM and STM diluted viral concentrations and clinical performance was evaluated using 505 swab specimens. ResultsThe Aptima LOD studies performed showed a lower detection limit for STM specimens as 1450 copies/mL and 430 copies/mL for HSV1 and HSV-2 respectively; the LOD for VTM specimens was 9370 copies/mL and 8045 copies/mL for HSV-1 and HSV-2 respectively. When the assays were analyzed based on the positive consensus result established the Aptima had 95% of percent positive agreement (PPA) and 100% negative percent agreement (NPA) for the HSV-1. For the HSV-2, the PPA and NPA for Aptima were 96% and 100% respectively. AmpliVue had 1.8% invalid rate, while Lyra had no invalid results but an inhibition rate of 0.8%. Aptima and LDT did not have any invalid or inhibited results. ConclusionThe results indicate that the Aptima HSV-1 & 2 assay is sensitive and the performance characteristics of the Aptima assay is comparable to the assays analyzed for the detection and differentiation of HSV-1 and 2 from cutaneous and mucocutaneous lesions.

The effect of hormonal contraception and menstrual cycle timing on genital herpes simplex virus-2 shedding and lesions

Background The effect of female sex hormones on herpes simplex virus (HSV)-2 shedding and lesion frequency is poorly understood. Previous studies suggest that hormonal contraception may increase the frequency of HSV-2 shedding. Methods We studied HSV-2 seropositive women who performed daily genital swabbing for HSV DNA and completed diaries for genital lesions and menses. We used Poisson mixed effects models to determine if HSV detection varied throughout the menstrual cycle, or in response to hormonal contraception. We used the Wilcoxon signed-rank test and rank-sum test to determine if lesion frequency differed by cycle phase or hormonal contraceptive use. Results In 189 women aged 19 to 46 years who collected swabs on 10,715 days and were not using hormonal contraception, HSV-2 DNA was detected on 20.9% of days in the follicular phase and 17.8% of days in the luteal phase (rate ratio, 1.19; 95% confidence interval, 1.03-1.37, P = 0.02). Genital lesions did not differ in the follicular versus luteal phase (12.8% vs. 10.7%, P = 0.07). In analyses of hormonal contraception, including 244 women, HSV-2 DNA was detected on 19.0% of days for women not using hormonal contraception and 18.3% of days for those using hormonal contraception (P = 0.50). Lesions were present on 11.1% of days for women not using hormonal contraception, and 8.7% of days for those using hormonal contraception (P = 0.66). Conclusions In women with genital HSV-2 infection who are not using hormonal contraception, the follicular phase of the cycle may be associated with a higher frequency of HSV-2 shedding compared to the luteal phase. Lesion frequency is similar during the 2 menstrual phases. Hormonal contraception use was not observed to affect genital HSV-2 DNA detection or lesions.

Herpes simplex type 1 pneumonitis and acute respiratory distress syndrome in a patient with chronic lymphatic leukemia: a case report

BackgroundPulmonary pathogenicity of herpes simplex virus type 1 in patients in intensive care without classic immunosuppression as well as the necessity of antiviral treatment in the case of herpes simplex virus detection in respiratory specimens in these patients is controversial. We present a case of acute respiratory distress syndrome in a patient with stable chronic lymphatic leukemia not requiring treatment, in whom we diagnosed herpes simplex virus type 1 bronchopneumonitis based on herpes simplex virus type 1 detection in bronchoalveolar lavage fluid and clinical response to antiviral treatment.Case presentationA 72-year-old white man presented with symptoms of lower respiratory tract infection. His medical history was significant for chronic lymphatic leukemia, which had been stable without treatment, arterial hypertension, multiple squamous cell carcinomas of the scalp, and alcohol overuse. Community-acquired pneumonia was suspected and appropriate broad-spectrum antibacterial treatment was initiated. Within a few hours, rapid respiratory deterioration led to cardiac arrest. He was successfully resuscitated, but developed acute respiratory distress syndrome. Furthermore, he remained febrile and inflammation markers remained elevated despite antibacterial treatment. Polymerase chain reaction from bronchoalveolar lavage fluid and viral culture from tracheobronchial secretions tested positive for herpes simplex virus type 1. We initiated antiviral treatment with acyclovir. Concomitantly we further escalated the antibacterial treatment, although no bacterial pathogen had been isolated at any point. Defervescence occurred rapidly and his C-reactive protein and leukocyte levels decreased. He was successfully weaned from mechanical ventilation, transferred to the ward, and eventually discharged to home.ConclusionsHerpes simplex virus should be considered a cause for lower respiratory tract infection in critically ill patients, especially in the setting of an underlying disease.

Etiological mechanism of iridocorneal endothelial (ICE) syndrome may involve infection of herpes simplex virus (HSV) and integration of viral genes into human genome

Iridocorneal (ICE) syndrome is a rare ocular disease characterized by abnormal proliferation of corneal endothelial cells, progressive obstruction of irido-corneal angle and atrophy of iris. ICE syndrome progressed slowly, but can cause serious complications such as secondary glaucoma in late stage. Because the etiology of ICE syndrome is not clear, there is still no effective treatment in clinical practice. Previous studies have detected herpes simplex virus (HSV) DNA inside patient’s aqueous humor. However, no further explanation for HSV-related etiology of ICE syndrome was established. Besides, construction of animal models using HSV all failed, leaving behind a blank space about how HSV infection finally led to ICE syndrome. By summarizing findings from previous studies, we came up with a hypothesis about etiology of ICE syndrome: HSV infection initiated ICE syndrome by integration of viral genetic material into human genome. Infection of HSV changed activity and morphology of endothelial cells, making them regain the ability of mitosis. Proof of such hypothesis will provide a theoretical foundation for construction of animal models and effective intervention of the disease.

A method for detecting rash and fever illness-associated viruses using multiplex reverse transcription polymerase chain reaction.

In this study, a new multiplex RT-PCR method for detecting various viral genes in patients with rash and fever illnesses (RFIs) was constructed. New primer sets were designed for detection of herpes simplex viruses 1 and 2 (HSV1 and 2), and Epstein-Barr virus (EBV). The newly designed and previously reported primer sets were used to detect 13 types of RFI-associated viruses by multiplex RT-PCR assay systems. Moreover, to eliminate non-specific PCR products, a double-stranded specific DNase was used to digest double-stranded DNA derived from the templates in clinical specimens. RFI-associated viruses were detected in 77.0% of the patients (97/126 cases) by the presented method, multiple viruses being identified in 27.8% of the described cases (35/126 cases). Detected viruses and clinical diagnoses were compatible in 32.5% of the patients (41/126 cases). Sensitivity limits for these viruses were estimated to be 101 -103 copies/assay. Furthermore, non-specific PCR products were eliminated by a double-stranded specific DNase with no influence on sensitivity. These results suggest that this method can detect various RFI-associated viruses in clinical specimens with high sensitivity and specificity.

A high resolution melting (HRM) technology-based assay for cost-efficient clinical detection and genotyping of herpes simplex virus (HSV)-1 and HSV-2

Genital herpes can be caused by two very similar viruses, herpes simplex virus (HSV)-1 or HSV-2. These two HSV types cannot be distinguished clinically, but genotyping is recommended in the first-episodes of genital herpes to guide counselling and management. Quantitative polymerase chain reaction (qPCR) is the preferred diagnostic method for HSV typing. However, commercial qPCR methods use expensive fluorescent labeled probes for detection. Furthermore, most low-cost methods are not able to differentiate between HSV-1 and -2. The aim of this study was to develop a high resolution melting (HRM) technology-based assay for sensitive HSV-1 and HSV-2 detection and genotyping. Using a panel of 46 clinical specimens, the performance of the HRM assay was compared to two commercial HSV tests: the HRM assay detected HSV in all 23 positive samples, with no false positive results (100% concordance with HSV I/II Real-TM assay). Additionally, the HRM assay correctly genotyped both HSV types in a subset of these clinical samples, as determined by the Realstar HSV PCR Kit. The HSV HRM assay provides a cost-effective alternative method to conventional more expensive assays and can be used in routine clinical specimens, in cases where it is particularly necessary to detect and distinguish HSV-1 from -2.

Computational sensing of herpes simplex virus using a cost-effective on-chip microscope

Caused by the herpes simplex virus (HSV), herpes is a viral infection that is one of the most widespread diseases worldwide. Here we present a computational sensing technique for specific detection of HSV using both viral immuno-specificity and the physical size range of the viruses. This label-free approach involves a compact and cost-effective holographic on-chip microscope and a surface-functionalized glass substrate prepared to specifically capture the target viruses. To enhance the optical signatures of individual viruses and increase their signal-to-noise ratio, self-assembled polyethylene glycol based nanolenses are rapidly formed around each virus particle captured on the substrate using a portable interface. Holographic shadows of specifically captured viruses that are surrounded by these self-assembled nanolenses are then reconstructed, and the phase image is used for automated quantification of the size of each particle within our large field-of-view, ~30 mm2. The combination of viral immuno-specificity due to surface functionalization and the physical size measurements enabled by holographic imaging is used to sensitively detect and enumerate HSV particles using our compact and cost-effective platform. This computational sensing technique can find numerous uses in global health related applications in resource-limited environments.

A Novel Method to Titrate Herpes Simplex Virus-1 (HSV-1) Using Laser-Based Scanning of Near-Infrared Fluorophores Conjugated Antibodies.

Among several strategies used for Herpes simplex virus (HSV) detection in biological specimens, standard plaque assay (SPA) remains the most reliable method to evaluate virus infectivity and quantify viral replication. However, it is a manual procedure, thereby affected by operator subjectivity, and it may be particularly laborious for multiple sample analysis. Here we describe an innovative method to perform the titration of HSV type 1 (HSV-1) in different samples, using the “In-Cell WesternTM” Assay (ICW) from LI-COR, a quantitative immunofluorescence assay that exploits laser-based scanning of near infrared (NIR). In particular, we employed NIR-immunodetection of viral proteins to monitor foci of HSV-1 infection in cell monolayers, and exploited an automated detection of their fluorescence intensity to evaluate virus titre. This innovative method produced similar and superimposable values compared to SPA, but it is faster and can be performed in 96 well plate, thus allowing to easily and quickly analyze and quantify many samples in parallel. These features make our method particularly suitable for the screening and characterization of antiviral compounds, as we demonstrated by testing acyclovir (ACV), the main anti-HSV-1 drug. Moreover, we developed a new data analysis system that allowed to overcome potential bias due to unspecific florescence signals, thus improving data reproducibility. Overall, our method may represents a useful tool for both clinical and research purposes.

Simultaneous Detection and Genotype Determination of HSV 1 and 2 by Real-time PCR Using Melting Curve Analysis and a Unique Pair of Primers.

Herpes simplex virus (HSV) is a human pathogen that causes different pathologic manifestations. Rapid and feasible detection and discrimination methods for HSV genotyping is a challenge in clinical laboratories, especially in children suffering from herpetic encephalitis. A quantitative real-time polymerase chain reaction (PCR)-based genotyping assay using SYBR Green I was established. We designed only 1 pair of primer for HSV 1 and 2, targeting thymidine kinase gene conserved region. HSV genotypes were determined by PCR using melting curve analysis with LightCycler. Different HSV genotypes were successfully detected in all clinical samples. The melting temperature for HSV 1 and 2 was 85.5±0.78°C and 89±0.53°C, respectively. These 2 genotypes were completely distinguished by means of the accurate melting assay. Importantly, detection was reliably performed within only 1 hour. The assay had no cross-reactivity across species, an excellent dynamic range from 10 to 10 copies per reaction, a good intra-assay and interassay reproducibility, and a detection limit of a single copy per reaction. Our homebrew designed and validated quantitative real-time PCR followed by a melting curve analysis provided a rapid and convenient screening test for differential identification of HSV genotypes 1 and 2. We recommend the large-scale application of this method for HSV 1 and 2 detection.

A Comparative Analysis of Polymerase Chain Reaction and Direct Fluorescent Antibody Test for Diagnosis of Genital Herpes.

Objective:To compare laboratory tests that can simultaneously detect and type herpes simplex virus (HSV) directly from the genital ulcer specimens in clinically suspected cases of genital herpes.Materials and Methods:A study was conducted over 10 months and 44 adult male and female patients clinically suspected with genital herpes were recruited. Genital ulcer swab specimens were subjected to glycoprotein-G gene-based conventional polymerase chain reaction (PCR) and commercially available direct fluorescent antibody (DFA) test and the results were compared.Results:PCR for HSV was positive in 82% (36/44) cases. DFA was positive in 68.2% (30/44) cases. There was 100% agreement between HSV types detected by DFA and PCR. The strength of agreement between the results was better in primary genital herpes than recurrent cases.Conclusion:PCR was found to be better in the detection of HSV in recurrent genital herpes patients. It is a better modality, especially when genital herpes clinically presents with ulcerative or crusted lesions, and is also a cheaper alternative as compared to DFA.