Detection of herpes simplex virus type 1 shedding in the oral cavity by polymerase chain reaction and enzyme-linked immunosorbent assay at the prodromal stage of recrudescent herpes labialis

The Hippocampal Vulnerability to Herpes Simplex Virus Type I Infection: Relevance to Alzheimer's Disease and Memory Impairment

Herpes simplex virus type 1 (HSV-1) as a possible infectious etiology in Alzheimer’s disease (AD) has been proposed since the 1980s. The accumulating research thus far continues to support the association and a possible causal role of HSV-1 in the development of AD. HSV-1 has been shown to induce neuropathological and behavioral changes of AD, such as amyloid-beta accumulation, tau hyperphosphorylation, as well as memory and learning impairments in experimental settings. However, a neuroanatomical standpoint of HSV-1 tropism in the brain has not been emphasized in detail. In this review, we propose that the hippocampal vulnerability to HSV-1 infection plays a part in the development of AD and amnestic mild cognitive impairment (aMCI). Henceforth, this review draws on human studies to bridge HSV-1 to hippocampal-related brain disorders, namely AD and aMCI/MCI. Next, experimental models and clinical observations supporting the neurotropism or predilection of HSV-1 to infect the hippocampus are examined. Following this, factors and mechanisms predisposing the hippocampus to HSV-1 infection are discussed. In brief, the hippocampus has high levels of viral cellular receptors, neural stem or progenitor cells (NSCs/NPCs), glucocorticoid receptors (GRs) and amyloid precursor protein (APP) that support HSV-1 infectivity, as well as inadequate antiviral immunity against HSV-1. Currently, the established diseases HSV-1 causes are mucocutaneous lesions and encephalitis; however, this review revises that HSV-1 may also induce and/or contribute to hippocampal-related brain disorders, especially AD and aMCI/MCI.

Current status and future of delivery systems for prevention and treatment of infections in the oral cavity

Oral health reflects the general health, and it is fundamental to well-being and quality of life. An infection in the oral cavity can be associated with serious complications in human health. Local therapy of these infections offers many advantages over systemic drug administration, targeting directly to the diseased area while minimizing systemic side effects. Specialized drug delivery systems into the oral cavity have to be designed in such a fashion that they resist to the aqueous environment that is constantly bathed in saliva and subject to mechanical forces. Additionally, a prolonged release of drug should also be provided, which would enhance the efficacy and also decrease the repeated dosing. This review is aimed to summarize the current most relevant findings related to local drug delivery of various drug groups for prevention and treatment of infections (viral, bacterial, fungal) and infection-related manifestations in the oral cavity. Current therapeutic challenges in regard to effective local drug delivery systems will be discussed, and the recent approaches to overcome these obstacles will be reviewed. Finally, future prospects will be overviewed to promote novel strategies that can be implemented in clinical management for prevention and treatment of oral infections.

Herpes Simplex Virus Type 1 Shedding in Tears and Nasal and Oral Mucosa of Healthy Adults

BACKGROUND

Herpes simplex virus type 1 (HSV-1) is prevalent worldwide and causes mucocutaneous infections of the oral area. We aimed to define the frequency and anatomic distribution of HSV-1 reactivation in the facial area in persons with a history of oral herpes.

METHODS

Eight immunocompetent HSV-1 seropositive adults were evaluated for shedding of HSV-1 from 12 separate orofacial sites (8 from oral mucosa, 2 from nose, and 2 from conjunctiva) 5 days a week and from the oral cavity 7 days a week for approximately 5 consecutive weeks by a HSV DNA PCR assay. Symptoms and lesions were recorded by participants.

RESULTS

Herpes simplex virus type 1 was detected at least from 1 site on 77 (26.5%) of 291 days. The most frequent site of shedding was the oral mucosa, with widespread shedding throughout the oral cavity. Lesional shedding rate was 36.4% (4 of 11 days with lesions), and the asymptomatic rate was 27.1% (65 of 240 nonlesional days). In individual participants, the median rate of HSV shedding by HSV PCR was 19.7% of days (range, 11%-63%).

CONCLUSIONS

Reactivation of HSV-1 on the oral mucosa is common and usually asymptomatic. However, HSV-1 is rarely found in tears and nasal mucosa. Frequent oral shedding of HSV-1 may increase the risk for transmitting the virus to both oral and genital mucosa of sexual partners.

Effect of collection material and sample processing on pig oral fluid testing results

The effect of sampling material, sample processing, and collection order on the detection of analytes in pig oral fluid specimens was evaluated. Oral fluid samples were collected from 104 pens of commercial wean-to-finish pigs using ropes made of three different materials. Processed (centrifuged and filtered) and unprocessed oral fluid samples were tested using commercial ELISAs for porcine reproductive and respiratory syndrome virus (PRRSV) antibodies and total IgM, IgA, and IgG. Unprocessed samples were tested for PRRSV nucleic acid and processed samples were assayed for PRRSV neutralizing antibodies. Analysis of the data using repeated measures ANOVA and Tukey-Kramer adjusted t tests found statistically significant, non-uniform, and assay-dependent effects of all three factors. Therefore, when testing oral fluid specimens, swine health specialists, veterinarians, and diagnosticians should be aware of the potential impact of these factors on specific analytes. For monitoring health and welfare parameters, oral fluid samples should be collected using cotton-based materials and undergo minimal post-collection processing.

Primary Maternal Herpes Simplex Virus-1 Gingivostomatitis During Pregnancy and Neonatal Herpes: Case Series and Literature Review

BACKGROUND

Neonatal herpes simplex virus (HSV) is a serious, life-threatening infection that is usually acquired during birth from contact with infected maternal genital secretions. Primary maternal HSV gingivostomatitis is a rare occurrence during pregnancy, and HSV type 1 (HSV-1) neonatal disease after primary maternal HSV gingivostomatitis during pregnancy has not been reported in detail.

METHODS

We reviewed the medical records of neonates (≤28 days of age) with a confirmed diagnosis of neonatal HSV-1 at a single pediatric center from January 1981 to January 2010 to identify cases in which the mother had primary gingivostomatitis during pregnancy or at term.

RESULTS

Seven neonates whose mothers had primary HSV-1 gingivostomatitis during pregnancy were identified from a review of 48 neonates with laboratory-proven HSV-1 neonatal disease. Of the 7 women, 2 presented with symptoms of primary HSV-1 gingivostomatitis during the first trimester and 5 in the third trimester. Three of the neonates developed skin, eye, and mucous membrane disease, 2 developed central nervous system disease, and 2 developed disseminated disease. One of the neonates with disseminated HSV-1 disease died.

CONCLUSIONS

Primary maternal HSV gingivostomatitis during pregnancy may lead to HSV-1 transmission to the neonate. Physicians caring for pregnant women should communicate the diagnosis of HSV gingivostomatitis to the neonate's primary provider to ensure proper surveillance, early evaluation, and prompt treatment.

Predominance of herpes simplex virus type 1 from patients with genital herpes in Nova Scotia

The epidemiology of genital herpes is changing with evidence to suggest an increasing incidence of herpes simplex virus type 1 (HSV-1) infections. The results of 6529 HSV genital cultures taken between April 1998 and December 2001 were reviewed. overall, HSV-1 was recovered more often than HSV-2; 1213 versus 1045. This trend was particularly striking in young women 30 years of age or less, in whom 70.8% of isolates were HSV-1. In men of the same age range, 45% of isolates were HSV-1. The proportion of women with HSV-1 declined from 73.7% in those younger than 31 years of age to 4.5% in those older than 60 years of age.These observations have important implications. The decline in the relative proportion of HSV-1 isolates from young adults may be the result of changing sexual practices, changing susceptibility or increased exposure to HSV-1 during vaginal intercourse. In this setting HSV-2 vaccines may be less likely to produce the desired reduction in the overall prevalence of genital herpes infections.

A random PCR screening system for the identification of type 1 human herpes simplex virus

Several viral diseases exhibit measles-like symptoms. Differentiation of suspected cases of measles with molecular epidemiological techniques in the laboratory is useful for measles surveillance. In this study, a random PCR screening system was undertaken for the identification of isolates from patients with measles-like symptoms who exhibited cytopathic effects, but who had negative results for measles virus-specific reverse transcription (RT)-PCR and indirect immunofluorescence assays. Sequence analysis of random amplified PCR products showed that they were highly homologous to type 1 human herpes simplex virus (HSV-1). The results were further confirmed by an HSV-1-specific TaqMan real-time PCR assay. The random PCR screening system described in this study provides an efficient procedure for the identification of unknown viral pathogens. Measles-like symptoms can also be caused by HSV-1, suggesting the need to include HSV-1 in differential diagnoses of measles-like diseases.

Herpes Simplex Virus Type 1 infection: overview on relevant clinico-pathological features

Herpes Simplex Virus Type 1 (HSV-1) is a nuclear replicating enveloped virus, usually acquired through direct contact with infected lesions or body fluids (typically saliva). The prevalence of HSV-1 infection increases progressively from childhood, the seroprevalence being inversely related to socioeconomic background. Primary HSV-1 infections in children are either asymptomatic or following an incubation period of about 1 week gives rise to mucocutaneous vesicular eruptions. Herpetic gingivostomatitis typically affects the tongue, lips, gingival, buccal mucosa and the hard and soft palate. Most primary oro-facial HSV infection is caused by HSV-1, infection by HSV-2 is increasingly common. Recurrent infections, which occur at variable intervals, typically give rise to vesiculo-ulcerative lesions at mucocutaneous junctions particularly the lips (herpes labialis). Recurrent HSV-1 infection within the mouth is uncommon in otherwise healthy patients, although in immunocompromised patients, recurrent infection can be more extensive and/or aggressive. The diagnosis of common herpetic infection can usually be based upon the clinical history and presenting features. Confirmatory laboratory diagnosis is, however, required when patients are, or may be, immunocompromised.

Human herpes simplex virus infections: epidemiology, pathogenesis, symptomatology, diagnosis, and management

Eight of the more than 80 known herpesviruses are human pathogens. Human herpes simplex virus (HSV) is a contagious infection with a large reservoir in the general population. It has a potential for significant complications in the immunocompromised host. In addition, psychological distress caused by the negative stigma associated with genital herpes and visible facial lesions in those experiencing frequent outbreaks renders it a challenging clinical dilemma. This article reviews the epidemiology, pathogenesis, and diagnostic features of HSV infections, providing the clinician with an up-to-date understanding of the available management strategies for mucocutaneous HSV-induced disease.

Asymptomatic shedding of HSV-1 in patients undergoing oral surgical procedures and attending for noninvasive treatment

Oral surgery and stress can trigger and/or increase asymptomatic shedding of herpes simplex virus type-1 (HSV-1) into human saliva. In this investigation we examined the frequency of HSV-1 shedding in 32 patients undergoing an oral surgery procedure compared with 40 control patients attending for noninvasive treatment. Control patients comprised 18 migraine patients and 22 patients with temporomandibular (TMD) joint problems. Nested-PCR was carried out on oral rinses collected from each patient prior to treatment and 7 days post-treatment. Fifty-two of sixty-one seropositive patients were positive for HSV-1 DNA in one or both oral rinses. The frequencies of HSV-1 shedding for the oral surgery and control patients were 84.6% and 85.7% respectively. Seropositive patients who started shedding after treatment were significantly higher in oral surgery patients (46.2%) compared to control patients (34.3%). Shedding of HSV-1 in the oral cavity is not only increased by direct surgical trauma, but also appears to be common in migraine and TMD patients attending for general dental treatment. Thus pain or pain-induced stress as well as anxiety associated with dental treatment may also be a risk factor for asymptomatic shedding in specific seropositive patients attending for dental treatment.

Oral shedding of herpes simplex virus type 1 in immunocompetent persons

BACKGROUND

Reactivation of herpes simplex virus-1 (HSV-1) can result in recurrent herpes labialis lesions (RHL) and in oral shedding of virus. This study utilized polymerase chain reaction (PCR) to document the frequency and quantity of such shedding.

METHODS

Thirty adults with greater than three RHL episodes per year were followed through one recurrence. They collected swabs for PCR every 12 h starting at prodrome and for 10 days thereafter. Shedding was analyzed with regard to frequency, timing and quantity.

RESULTS

HSV-1 was detectable in 87% of participants for a mean of 4 days. Shedding occurred most frequently during the vesicle/ulcer stage (91% of subjects), but was common in both clinical and subclinical stages (50% vs. 23%, average log DNA copy number/ml(2) 2.6 vs. 1.4).

CONCLUSION

The majority of RHL patients shed viral DNA. Shedding occurred before and after the appearance of clinical lesions. Such findings may be useful in designing methods to reduce viral shedding and prevent transmission.

Oral and perioral herpes simplex virus type 1 (HSV-1) infection: review of its management

Herpes simplex virus type 1 (HSV-1) gives rise to a variety of clinical disorders and is a major cause of morbidity and mortality worldwide. HSV-1 infections are common in oral and perioral area. The aim of the present report was to critically examine the published literature to evaluate the advantages and limitations of therapy of HSV-1 infection in both immunocompetent and immunocompromised patients. Systemic antiviral therapy has been widely accepted as effective for primary herpetic gingivostomatitis. Aciclovir (ACV) 5% cream seems to be the accepted standard topical therapy for herpes labialis, being both effective and well tolerated, although penciclovir 1% cream has been proposed as a potentially useful treatment. Systemic ACV may be effective in reducing the duration of symptoms of recurrent HSV-1 infection, but the optimal timing and dose of the treatment are uncertain. Aciclovir and famciclovir may be of benefit in the acute treatment of severe HSV-1 disease in immunocompromised patients. There is also evidence that prophylactic oral ACV may reduce the frequency and severity of recurrent attack of herpetic infection in immunocompromised patients, but the optimal timing and duration of treatment is uncertain and can vary in different situations.

Polymerase chain reaction for identification of herpes simplex virus (HSV-1), cytomegalovirus (CMV) and human herpes virus-type 6 (HHV-6) in oral swabs

Considering that sensitive and specific methods to detect HSV-1, CMV and HHV-6 on oral mucosa have a great impact on oral diagnosis practice and research, together with the evidence that PCR is a rapid and reliable method, the purpose of the present study was to develop primer sets to detect HSV-1, CMV and HHV-6 in oral swabs by nested polymerase chain reaction (nested PCR). We developed a practical method for sample collection without tissue trauma, and the swabs were stored until used for DNA extraction. After the nested PCR a DNA fragment of 241 bp corresponding to HSV-1 was amplified. DNA fragments of 224 and 369 bp were amplified corresponding to CMV and HHV-6, respectively. DNA sequencing analysis confirmed the expected sequences of each virus. In conclusion, it was demonstrated that these new primer sets are able to identify HSV-1, CMV and HHV-6 in oral swab using nested PCR.

Herpes simplex virus type 1 shedding in the oral cavity of seropositive patients

OBJECTIVE

Investigate the frequency of herpes simplex virus type 1 (HSV-1) reactivation in the oral cavity of seropositive patients with previous history of recurrent herpes labialis (recrudescent group) compared with those without any history of recrudescent lesions (asymptomatic HSV-1 infection). In addition, the relation between recrudescence and the presence of the virus in the saliva was assessed.

MATERIALS AND METHODS

Fourteen individuals with previous history of herpes labialis (recrudescent group) and 11 HSV-1 seropositive asymptomatic volunteers were included in the study. Swabs were performed periodically in all subjects and the presence of HSV-1 DNA was identified by nested PCR.

RESULTS

All the 25 subjects enrolled in the study, revealed at least one positive swab for HSV-1. The frequency of HSV-1 positivity in the group with recrudescent herpes labialis was not statistically different from the other group. Ten subjects of the recrudescent group presented with herpes labialis at least once during the study.

CONCLUSIONS

HSV-1 shedding in the oral cavity occurs independently of herpes labialis recrudescence.

The efficacy of valacyclovir in preventing recurrent herpes simplex virus infections associated with dental procedures

BACKGROUND

Oral herpes simplex virus, or HSV, infections recur after trauma and stress. The prevalence of these infections after dental procedures is not known. Also, it is unclear whether antiviral agents are effective in preventing dental procedure-induced HSV recurrences. This study determined the efficacy and safety of oral valacyclovir in suppressing dentally related cold sore outbreak and HSV shedding.

METHODS

The authors enrolled 125 otherwise healthy HSV-seropositive adults who reported having recurrent herpes labialis (more than one episode per year and at least one episode in the previous year) in a randomized, double-blind, placebo-controlled study and gave them valacyclovir prophylactically (2 grams taken twice on the day of dental treatment and 1 g taken twice the next day) or a matching placebo. To detect the presence of the virus, the authors used clinical examinations, viral cultures and real-time polymerase chain reaction analysis of saliva.

RESULTS

During the one-week observation period after treatment, there were more clinical lesions (20.6 percent versus 11.3 percent), more HSV-1-positive culture specimens (7.9 percent versus 1.6 percent) and more HSV-1-positive saliva specimens (7.9 percent versus 4.0 percent) in placebo than in valacyclovir-treated patients, respectively. The percentage of patients who developed recurrences and shed HSV-1 in saliva 72 hours after dental procedures was significantly smaller in the valacyclovir group than in the placebo group (11.3 percent versus 27 percent; P = .026). The mean time to pain cessation was significantly less in the valacyclovir group (3.2 days) than in the placebo group (6.2 days) (P = .006).

CONCLUSION

HSV recrudescence after routine dental treatment is suppressed by valacyclovir prophylaxis.

CLINICAL IMPLICATIONS

HSV recrudescence is common after routine dental treatment. Clinicians should consider antiviral therapy for patients at risk of experiencing a recurrence, as well as to minimize transmission of the disease.

Fibroblast growth factors lead to increased Msx2 expression and fusion in calvarial sutures

Craniosynostosis, the premature fusion of the skull bones at the sutures, represents a disruption to the coordinated growth and development of the expanding brain and calvarial vault and is the second most common birth defect that affects the craniofacial complex. Mutations in the human homeobox-containing gene, Msx2, have been shown to cause Boston type craniosynostosis, and we have shown that overexpression of Msx2 leads to craniosynostosis in mice. Activating mutations in fibroblast growth factor (FGF) receptors are thought to cause craniosynostosis in Crouzon, Apert, Jackson-Weiss, Beare-Stevenson, and Muenke syndromes. To mimic activated signaling by mutated FGF receptors, we used heparin acrylic beads to deliver FGF ligands to mouse calvaria and demonstrated increased Msx2, Runx2, Bsp, and Osteocalcin gene expression, decreased cell proliferation, and suture obliteration and fusion. FGF2 elicited the greatest increase in Msx2 expression, and FGF1 was most likely to cause suture obliteration and fusion. Of the three sutures studied, the coronal suture exhibited the greatest increase in Msx2 expression and was the most likely to undergo obliteration and fusion. These results are intriguing because the coronal suture is the most commonly affected suture in syndromic craniosynostosis. These results suggest that Msx2 is a downstream target of FGF receptor signaling and that increased FGF signaling leads to osteogenic differentiation by sutural mesenchyme in mouse calvaria. These results are consistent with the hypotheses that increased Msx2 expression and activated signaling by mutated FGF receptors lead to craniosynostosis.

Hidden scabies: diagnosis by polymerase chain reaction

Diagnosis of scabies infection can be difficult as in many cases only few mites are present on an infected person, and in some cases the skin manifestations can be subtle or atypical. We describe the use of polymerase chain reaction (PCR) to amplify Sarcoptes scabiei DNA in a patient presenting with clinically atypical eczema. Cutaneous scales were PCR positive for S. scabiei DNA before, and negative 2 weeks after, therapy. This method facilitates fast and very sensitive diagnosis of clinically atypical or inapparent scabies infection and therapy control in severely affected patients and may help to identify previously unrecognized scabies cases.

Subclinical reactivation of herpes simplex virus type 1 in the oral cavity

Reactivation in the oral cavity either symptomatically (recrudescence) or without symptoms (recurrence) may contribute to the transmission of herpes simplex virus type 1 (HSV-1), especially in critical areas of exposure such as dentistry. In order to measure the frequency of HSV-1 reactivation, nested polymerase chain reaction (PCR) was performed on oral swabs collected from 30 healthy people over a period of 58-161 days. In total 19 of 25 (76%) seropositive people were PCR-positive at least once, 6 of these 19 (32%) had recrudescence and 13 (68%) had only asymptomatic reactivation. Frequencies of additional recurrences were higher in people showing symptomatic reactivation than in those who had only recurrences. Recrudescence is a risk factor for elevated levels of asymptomatic HSV-shedding. In most cases HSV-1 was detected only by nested PCR investigated by early onset of therapy or time span before sampling.

Development of a high-throughput quantitative assay for detecting herpes simplex virus DNA in clinical samples

We have developed a high-throughput, semiautomated, quantitative fluorescence-based PCR assay to detect and type herpes simplex virus (HSV) DNA in clinical samples. The detection assay, which uses primers to the type-common region of HSV glycoprotein B (gB), was linear from <10 to 10(8) copies of HSV DNA/20 microl of sample. Among duplicate samples in reproducibility runs, the assay showed less than 5% variability. We compared the fluorescence-based PCR assay with culture and gel-based liquid hybridization system with 335 genital tract specimens from HSV type 2 (HSV-2)-seropositive persons attending a research clinic and 380 consecutive cerebrospinal fluid (CSF) samples submitted to a diagnostic virology laboratory. Among the 162 culture-positive genital tract specimens, TaqMan PCR was positive for 157 (97%) specimens, whereas the quantitative-competitive PCR was positive for 144 (89%) specimens. Comparisons of the mean titer of HSV DNA detected by the two assays revealed that the mean titer detected by the gel-based system was slightly higher (median, 1 log). These differences in titers were in part related to the fivefold difference in the amount of HSV DNA used in the amplicon standards with the two assays. Among the 380 CSF samples, 42 were positive by both assays, 13 were positive only by the assay with the agarose gel, and 3 were positive only by the assay with the fluorescent probe. To define the subtype of HSV DNA detected in the screening assay, we also designed one set of primers which amplifies the gG regions of both types of HSV and probes which are specific to either HSV-1 (gG1) or HSV-2 (gG2). These probes were labeled with different fluorescent dyes (6-carboxyfluorescein for gG2 and 6-hexachlorofluorescein for gG1) to enable detection in a single PCR. In mixing experiments the probes discriminated the correct subtype in mixtures with up to a 7-log-higher concentration of the opposite subtype. The PCR typing results showed 100% concordance with the results obtained by assays with monoclonal antibodies against HSV-1 or HSV-2. Thus, while the real-time PCR is slightly less sensitive than the gel-based liquid hybridization system, the high throughput, the lack of contamination during processing, the better reproducibility, and the better ability to type the isolates rapidly make the real-time PCR a valuable tool for clinical investigation and diagnosis of HSV infection.

Recrudescent herpes simplex infection mimicking primary herpetic gingivostomatitis

We report six cases of recrudescent intraoral herpes simplex infection clinically indistinguishable from primary herpetic gingivostomatitis. All infections occurred in healthy children or young adults. Serological analysis demonstrated herpes simplex virus (HSV)-specific IgG at initial presentation, indicating that the infection was not a primary infection. Convalescent sera exhibited HSV-specific IgM and a rising HSV-specific IgG titre. These findings demonstrate that the initial clinical diagnosis of primary herpetic gingivostomatitis was erroneous and that what was actually being observed was widespread recrudescent intraoral herpes simplex infection.

Oral shedding of herpes simplex virus type 1: a review

Herpes simplex virus type 1 (HSV-1) and, to a lesser extent, type 2 (HSV-2) are the aetiological agents of recrudescent herpes labialis (RHL). The available literature on patterns of HSV-1 shedding into the oral cavity at the prodromal stage of disease, during recrudescences and also during asymptomatic periods, is reviewed, as are the potential sources of virus and the known trigger factors leading to viral reactivation. Attention is given to the methodologies in use for the detection of HSV-1 and the relevance to the risk of cross-infection in surgery. This review also discusses the increase in incidence of HSV-1 genital infections and the significance of salivary inhibitors of the herpes simplex type 1 virus.