Hepatitis C virus infection: Review and implications for the dentist

Endodontics in Systemically Compromised Patients

A substantial number of people in today’s world are elderly and as the incidence of a number of pathologies increases with age, it is predicted to produce millions of individuals with systemic medical conditions that can affect oral health and subsequent dental treatment. The dental management of these medically compromised patients can be sometimes problematic in terms of oral complications, dental therapy, and emergency care. One of the challenges faced by dental specialists today is the assessment and management of these patients. As mentioned in detail in Chap. 12, geriatric patients are much more likely to be at least partially dentulous having a complex medical history and the use of multiple medications.

Oral Lichen Planus as an Extra-hepatic Manifestation of Viral Hepatitis-Evaluation in Indian Subpopulation

BACKGROUND

Oral Lichen Planus (OLP) is considered to be associated with numerous systemic conditions one of which includes Chronic Liver Disease (CLD). Hepatitis virus B and C (HBV and HCV) have known to be important causative agents of CLD and can be prevalent in asymptomatic carriers that can make them difficult to identify. Off late, the association of viral hepatitis with OLP has been a subject of controversy due to conflicting reports. Indian studies on this regard are sparse to evaluate the same. Association between the hepatitis virus and OLP, if present and established, can be of great help to format a protocol for identifying carrier states of viral hepatitis due to HBV and HCV.

METHODOLOGY

Forty five cases of clinically and histologically confirmed OLP were subjected to a serological screening of hepatitis B and C viruses by detection of hepatitis B surface antigen and anti-hepatitis C virus antibodies.

RESULTS

None of OLP cases were seropositive for the hepatitis viruses.

CONCLUSION

We could not demonstrate any association between OLP and viral hepatitis. This could be attributed to lower prevalence of hepatitis viruses compared to the countries hyper endemic for these viruses or genotypic variation of the viruses or other etiological factors contributing for the present group of patients.

Oral conditions associated with hepatitis C virus infection

Hepatitis C virus (HCV) infection in more than 170 million chronically infected patients with no developed preventive vaccine is a globally important issue. In addition to expected hepatic manifestations, a number of extrahepatic manifestations, such as mixed cryoglobulinemia, glomerulonephritis, polyarteritis nodosa, rashes, renal disease, neuropathy, and lymphoma, have been reported following HCV infection, which are believed to be influenced by the virus or the host immune response. HCV combination therapy with pegylated interferon and ribavirin might be associated with side effects as well. The association of HCV with special oral conditions has also been reported recurrently; the mechanism of most of which remains unclear. This article reviews the association of HCV infection with some of the oral conditions such as oral health, Sjogren's syndrome, lichen planus and oral cancer.

Oral fluid and hepatitis A, B and C: a literature review

BACKGROUND AND AIMS

Viral hepatitis is a significant global health problem that, depending upon the virus, affects individuals of the developing and/or developed world. In recent years, there has been renewed interest in whether oral fluids can be considered as a source of viral hepatitis transmission and whether oral fluid, in particular, whole saliva, may be a useful source for viral detection as part of the diagnosis and monitoring of viral hepatitis. The aim of this article was to review current data concerning the possible carriage of the hepatitis A, B and C viruses within saliva and gingival crevicular fluid. Such knowledge will indicate if (i) oral fluid is a possible source of infection and (ii) whether oral fluid can be used for diagnosis and monitoring of viral hepatitis.

DATA AND SOURCES

A literature search was conducted using PubMed (Medline), EMBASE/Excerpta medica, the Cochrane database and Scopus. The results were limited to published material after 2000. Relevant material was evaluated and reviewed.

CONCLUSION

There is some evidence that hepatitis viruses A, B and C are present in oral fluids, particularly whole saliva and gingival crevicular fluid and may thus be possible sources of viral detection in clinical diagnosis and monitoring. However, the data are inconsistent and warrant the need for well-planned longitudinal studies to explore the precise frequency of oral carriage of such viruses and to determine the virological and host factors that may influence the oral presence of hepatitis A, B and C viruses.

Prion diseases: risks, characteristics, and infection control considerations in dentistry

Prion diseases are a group of fatal neurodegenerative diseases that are rapidly progressive and fatal, with no definite cure. There are no reported cases of prion disease transmission arising from dental procedures. Nevertheless, there is a theoretical but real risk of transmission of prion disease from dental instruments. A review was made of studies up to 2008 to provide an update of the characteristics, risk of transmission, and the infection-control implications of prions in the field of dentistry. As the prions are resistant to conventional sterilization methods, highly-specific, cross-infection control measures are required when managing patients infected with these.

Transmission of hepatitis C virus by saliva?

Saliva can contain a range of infectious agents and, despite several antimicrobial mechanisms, transmission of these can occur. Hepatitis C virus (HCV) is of increasing importance, and HCV is transmitted by unknown routes as well as by the percutaneous route and sexual contact. Contact with blood or other body fluids may be responsible, as may be receipt of unscreened blood or blood product transfusions. HCV-RNA can be detected by the polymerase chain reaction which also shows that HCV may be present in the saliva of HCV-infected patients. This might provide an argument for the possible transmission of HCV via contaminated saliva. Epidemiological studies however, suggest that the infective capacity of HCV viral particles in saliva is low, but it has not been possible to determine their infective potential. Moreover, HCV-specific receptors have not been defined on oral epithelial cells, nor has the role of host defence mechanisms been determined. New experimental animal models and the recently described infectious HCV pseudoparticles, capable of simulating HCV replication in vitro, could be useful in establishing any role of saliva in the transmission of HCV infection.

Prion disease: possible implications for oral health care

BACKGROUND

Prion diseases are a group of rare fatal neurodegenerative disorders in humans and animals that are histopathologically characterized by spongiform change within the central nervous system.

TYPES OF STUDIES REVIEWED

The author reviewed all available case reports and any studies of the oral aspects of prion diseases published in peer-reviewed journals and available via PubMed. He then outlined the risk of nosocomial transmission of prions in dental health care.

RESULTS

Sporadic Creutzfeldt-Jakob disease, or sCJD, is the most common of the acquired human prion disorders, and it typically affects elderly people and leads to rapid death. In contrast, variant CJD, or vCJD, has affected young adults from Europe, giving rise to a slow onset disorder comprising both psychiatric and neurological upset. Oral neurological manifestations are rare and seem to occur only in people with vCJD; there are no oral mucosal or gingival manifestations of prion disease. Prions can be detected in the oral tissues--usually the gingivae and dental pulp--of animals experimentally infected with prions. In contrast, prions have not been detected in the pulpal tissue of people with sCJD, and there are no data of pulpal infection in vCJD. There also are no data suggesting that prions are transmitted easily in the dental setting, but there remains the rare risk of such transmission if appropriate infection control measures are not adhered to.

CLINICAL IMPLICATIONS

Few people in the United States and worldwide have prion disease. Oral manifestations are rare. Evidence suggests that the risk of transmission and acquisition of a prion infection as a result of dental treatment is rare, if appropriate infection control measures are maintained.

An update of the etiology and management of xerostomia

Salivary gland disease gives rise to salivary gland enlargement, pain, and prolonged xerostomia (dry mouth). Xerostomia is the most common long-standing problem for the majority of affected patients. There are many causes of dry mouth, with long-standing xerostomia being a particular problem in Sjögren's syndrome and after radiation to the head and neck region. Xerostomia is usually managed with saliva substitutes, but a large number of potential systemic therapies of long-standing xerostomia now exist. Some-particularly immunosuppressants-are of fundamental interest for the potential reduction of gland damage in Sjögren's syndrome but as yet are of limited clinical usefulness. Others, particularly pilocarpine and cevimeline, are, or have the potential to be, clinically useful in stimulating salivation by virtue of their action on cholinergic receptors.

Position Paper: Oral Features of Mucocutaneous Disorders

Part of periodontology involves the diagnosis and treatment of a variety of non-plaque-related diseases of the periodontium. The International Workshop for a Classification of Periodontal Diseases and Conditions noted that the periodontist may be called upon to manage non-plaque-related mucocutaneous disorders either alone, or as part of a treatment team consisting of physicians, dentists or other allied health care professionals. This informational paper will review the etiology, clinical manifestations, diagnosis, and treatment of the most common chronic mucocutaneous diseases, including those that may present as desquamative gingivitis or intraoral vesiculobullous lesions. This paper is intended for the use of periodontists and other members of the dental profession.

Oral diseases possibly associated with hepatitis C virus

Morbidity associated with hepatitis C virus (HCV) infection can involve a variety of extrahepatic conditions, including lichen planus (LP) and sialadenitis, predominantly or exclusively involving the oral region, conditions which have been largely neglected in reviews. The literature suggests that HCV-infected patients may frequently have Sjögren-like sialadenitis with mild clinical symptoms, whereas oral LP may be significantly associated with HCV infections in Southern Europe and Japan but not in Northern Europe. These geographical differences could be related to immunogenetic factors such as the HLA-DR6 allele, significantly expressed in Italian patients with OLP and HCV. Analysis of experimental data suggests that HCV could be involved in the pathogenesis of both these diseases. Moreover, parotid lymphoma may arise in patients with sialadenitis, mainly with type II cryoglobulinemia. Little attention has been paid to oral health needs in HCV-infected patients and the variable effect of interferon-alpha therapy on oral tissues. Further research is needed, because of the potentially great influence of oral diseases possibly linked to HCV on the quality of life of millions of patients.

Synergism between HIV and other viruses in the mouth

The HIV family replicate in and are shed from the mouth. Oral sexual practices potentially contribute to the overall extent of HIV transmission, particularly if high-risk practices are not restricted. Herpesviruses and papillomaviruses that appear in the oral cavity can determine oral HIV replication. The mechanisms probably include heterologous transactivation, enhanced expression of HIV receptors and co-receptors in target cells, release of cytokines and chemokines, and production of superantigens. Oral diseases peculiar to, or more common in, the HIV-infected patient further predispose to heightened oral HIV replication and trafficking. Defining the mechanisms by which oral viruses interact with HIV in the co-infected host should permit intervention measures against oral HIV transmission to be more precisely targeted.

Infectious hepatitis C, hepatitis G, and TT virus: review and implications for dentists

In the past 10 years, hepatitis C and G viruses have been identified, and in the last two years a further parenterally transmitted agent, termed TT virus (TTV), has been discovered. These viruses have a worldwide distribution and frequently cause chronic infection. The purpose of this article was to promote an understanding of these viral agents and their relevance in dental practice. Infected patients may develop a chronic carrier state without clinical disease or may develop liver disease, and may have related oral conditions. Dental providers will see a growing number of patients with HCV/HGV and possibly TTV infection. All of these patients require appropriate infection control measures during dental treatment.

Clinical and pathological characteristics of oral lichen planus in hepatitis C-positive and -negative patients

The reported prevalence rate of anti-hepatitis C virus (HCV) antibodies in patients with oral lichen planus shows wide geographical variation and ranges from 0 to 65%. Certain characteristic clinical features have been attributed to oral lichen planus associated to HCV infection. The purpose of this investigation has been to assess hypothetical clinical differences, as well as differences in the intensity of the subepithelial inflammatory infiltrate between oral lichen planus-HCV +ve patients and oral lichen planus-HCV -ve patients. A total of sixty-two patients entered the study. Their mean age was 63.5 +/- 14.49 years, and 48.4% of them were men and 51.6% women. Patients were classified according to their serum HCV positivity. Age, sex, clinical presentation (reticular or atrophic-erosive), extension of the lesions, location of the lesions, number of locations affected, intensity of the inflammatory infiltrate and Candida albicans colonization were recorded for each patient. Reticular lichen planus was the most frequent clinical presentation in both HCV +ve (57.1%) and HCV -ve patients (63.6%). C. albicans colonization ranged from 42.8% in HCV +ve and 41.7% in HCV -ve patients. HCV + ve patients showed certain oral locations more frequently affected than HCV -ve ones: lip mucosa, 28.6% versus 7.3%; tongue, 57.1% versus 29.1%; and gingiva, 71.4% versus 23.6%. The number of affected intraoral locations was higher in HCV +ve patients (71.4%) than among HCV -ve ones (20.4%; chi2 = 8.34; P < 0.011). No statistically significant differences could be established in terms of density of subepithelial inflammatory infiltrate between the groups. Our results reinforce the need for liver examination in all patients with oral lichen planus, particularly those showing lesions on the gingiva with multiple intraoral locations affected, as no pathological differences could be identified between HCV + ve and HCV -ve patients.

Phylogenetic investigation for the risk of hepatitis C virus transmission to surgical and dental patients

Blood loss during treatment carries a potential risk for the transmission of blood-borne pathogens in hospital patients. To determine whether nosocomial transmission of hepatitis C virus (HCV) occurs in surgical wards and dental hospitals, we tested anti-HCV antibodies and HCV RNA in sera from these patients and analysed the hypervariable region 1 (HVR1) sequence of HCV phylogenetically in the HCV RNA-positive patients. Five of 83 patients from a surgical ward were positive for HCV RNA, and six patients from one dental hospital and nine patients from a second were found to be positive for HCV RNA during the examination period. The HVR1 sequences were amplified from these patients' serum, and after subcloning, multiple clones of the HVR1 sequence from each patient were determined. The phylogenetic analysis of these sequences showed that HVR1 species from each patient could be classified into one to three genetic clusters of HVR1 quasi-species and that these clusters were independent of each other among patients. Thus, there was no evidence of HCV transmission in our study, and unrecognized transmission of HCV may be a rare event in surgical and dental patients at university hospitals.

Hepatitis C virus and oral disease: a critical review

Hepatitis C virus (HCV) infection is widespread with an estimated 3% of the world population being infected. Acute infection is usually mild but chronicity develops in as many as 70% of patients, of whom at least 20% will eventually develop cirrhosis. A further 1-4% of cirrhotic individuals will develop hepatocellular carcinoma. Infection with HCV may have effects on various organs other than the liver. HCV has been causally associated with a remarkable array of extrahepatic manifestations, some of which remain unproven. This review discusses the evidence implicating HCV in the aetiology of two important oral conditions, namely Sjögren's syndrome and lichen planus.

Gastric and gingival localization of mucosa-associated lymphoid tissue (MALT) lymphoma. An immunohistochemical, virological and clinical case report

Non-Hodgkin's lymphomas (NHL) of the mucosa-associated lymphoid tissue (MALT) are characterized by their mucosal and glandular tissue localization. The case described here falls into the European-American classification of a low-grade B-cell lymphoma of the MALT type, with a gingival lesion 2 years after a gastric lesion. The pathogenetic mechanisms of NHL in oral MALT and the diagnosis and treatment are discussed.