From Journal of Viral Hepatitis
09/13/2006

Hepatitis C - Contamination of Toothbrushes: Myth or Reality?


G. Lock; M. Dirscherl; F. Obermeier; C. M. Gelbmann,2 C. Hellerbrand; A. Knöll; J. Schölmerich; W. Jilg

Summary and Introduction

Summary
Chronic hepatitis C patients are advised not to share toothbrushes, razors, nail-scissors or other personal articles that potentially may have been in contact with blood, with others. This study examines the contamination of toothbrushes in patients with chronic hepatitis C as a model for a possible unconventional way of transmission. In 30 patients with chronic hepatitis C, 2 mL of saliva (before and after toothbrushing) and the toothbrush rinsing water after toothbrushing were tested for HCV-RNA. Saliva before and after toothbrushing was positive for HCV-RNA in nine (30%) and 11 patients (36.7%), respectively. Twelve of the toothbrush rinsing water specimens (40%) tested HCV-RNA-positive. In six of these 12 patients, the 'native' saliva had been negative for HCV-RNA. Patients with HCV-RNA-positive toothbrush rinsing water showed no significant differences from those with negative rinsing water with respect to certain clinical, biochemical and virological parameters. In conclusion, our study demonstrates a contamination with HCV-RNA of a considerable portion of toothbrushes used by hepatitis C patients, suggesting at least a theoretical risk of infection by sharing these objects and strengthening the recommendations to take care of a clear separation of these personal care objects between patients and their household members.

Introduction
Although there are certain well-defined risk factors for hepatitis C transmission such as a history of intravenous drug abuse, former transfusions of blood or blood products, or sex with an infected partner, in around 10% of patients with chronic hepatitis C no obvious risk factor for the disease can be found.[1]

Unconventional ways of transmission such as infection by tattooing, piercing or nosocomial infection have been discussed to play a role in the transmission of community-acquired forms of hepatitis C. As sharing of possibly infected household objects has at least a potential risk of infection, patients with hepatitis C are generally advised to take care not to share items such as razors, nail-scissors or toothbrushes with their family and household members.[1] So far, these recommendations have been based more or less on common sense, and there are only scarce data and reports on the actual risk of contamination of personal care objects.[2–4]

In this study, we prospectively examined the contamination of toothbrushes in patients with chronic hepatitis C as a model for a possible unconventional transmission route. Furthermore, we wanted to determine the association of virological contamination to clinical, biochemical and virological parameters.

G. Lock,1,2 M. Dirscherl,2 F. Obermeier,2 C. M. Gelbmann,2 C. Hellerbrand,2 A. Knöll,3 J. Schölmerich2 and W. Jilg3

1Albertinenkrankenhaus Hamburg, 2nd Medical Department, University of Regensburg, Regensburg, Germany; 2Department of Internal Medicine I, University of Regensburg, Regensburg, Germany; and 3Institute for Medical Microbiology and Hygiene, University of Regensburg, Regensburg, Germany



Patients and Methods
Thirty consecutive patients (12 female, 18 male, mean age 39.7 years) with chronic hepatitis C recruited from the hepatitis C outpatient clinic of a university hospital were included in the study. All patients had HCV-RNA-positive serum samples, and no patient was currently under antiviral medication. The study was approved by the ethics committee of the University of Regensburg, and informed consent was obtained from each patient.

Two millilitres of saliva was obtained before and after brushing the teeth under supervised conditions for 2 min with a new, dry toothbrush (without toothpaste). After toothbrushing, the toothbrush was rinsed in 2 mL of 0.9% NaCl. Thus, we examined three specimens of each patient: (a) saliva before toothbrushing; (b) saliva after toothbrushing; and (c) the rinsing solution of the toothbrush (referred to as toothbrush rinsing water hereafter).

RNA was isolated from these specimens with the QIAmp Viral RNA Mini Kit (Qiagen, Hilten, Germany) and hepatitis C virus (HCV) RNA was detected by the Cobas Amplicor HCV Test, v2.0 (Roche, Basel, Switzerland). Results were qualitatively graded as positive (absorption at 660 nm >1, i.e. the absorption of the positive control) or negative (absorption at 660 nm <0.15, i.e. the absorption of the negative control); borderline results (absorption at 660 nm between 0.15 and 1) were classified as negative. The lower detection limit of this assay is stated to be 50 IU HCV-RNA/mL or 100 genome equivalents/mL for plasma.

As viral concentration in saliva and toothbrush rinsing water was supposed to increase with gingival inflammation and bleeding, each patient was examined by a dentist (MD) who classified oral hygiene as good, fair or bad according to dental status, dental plaques and the papillary bleeding index (PBI). The PBI (ranging from 0% to 100% with values <10% indicating a normal parodontium) is a convenient parameter of parodontal status originally designed to control the course of inflammatory parodontal diseases.[5]

Furthermore, positive or negative HCV-RNA results in saliva and toothbrush rinsing water were correlated with the following clinical, biochemical and virological parameters: estimated duration of hepatitis C, histology with grading and staging as determined by the score of Desmet and Scheuer,[6] HCV viral load in serum (measured by the Cobas Amplicor HCV Monitor Test, v. 2.0), serum alanine aminotransferase (ALT), bilirubin and prothrombin time. Statistical significance was calculated by a t-test.




Results
In nine patients (30%), the saliva before toothbrushing was positive for HCV-RNA, and in 11 patients (36.7%) HCV-RNA was detected in the saliva after toothbrushing ( Table 1 ). Five of these 11 patients tested negative for saliva samples before toothbrushing. HCV-RNA polymerase chain reaction (PCR) was positive in as many as 12 of 30 specimens (40%) of the toothbrush rinsing water specimens ( Table 1 ). In six of these 12 patients, the saliva before toothbrushing had been negative for HCV-RNA ( Table 2 ).

Patients with HCV-RNA-positive toothbrush rinsing water showed no significant differences from those with HCV-RNA-negative rinsing water with respect to various clinical, biochemical and virological parameters ( Table 3 ). Notably, there were no significant differences in serum HCV-RNA levels between patients with HCV-RNA-positive and -negative toothbrush rinsing water. However, there was a slight (but not significant) association between presence and absence of HCV-RNA in 'native' saliva and serum viral load (serum viral load 5.8 ± 7.2 × 106copies in patients with HCV-RNA-positive saliva compared with a serum viral load of 1.1 ± 1.08 × 106 copies in patients with HCV-RNA-negative saliva).

Discussion
Although initial studies have denied the presence of HCV-RNA in saliva,[7] with the increasing sensitivity of the HCV-RNA assays, the virus has been detected in up to 62% of saliva specimens of patients with chronic hepatitis C.[8,9] Thus, the prevalence of positive saliva specimens in our study is well within this range. As has been demonstrated in previous studies,[9] we found a slight association between presence or absence of HCV-RNA in 'native' saliva and serum viral load. Because of a large standard deviation in serum viral load, however, this association was not significant.

More importantly, this study has demonstrated that with sufficiently sensitive virological methods, a contamination with HCV-RNA can be detected in a large number of toothbrushes used by hepatitis C patients. In our study, the contamination of the toothbrush rinsing water did not show a statistically significant association with serum viral load or parodontal status.

The mere finding of HCV-RNA on the surface of contaminated tools does not prove potential transmission of the virus by these tools, of course, and the low infection risk usually published for household contacts of hepatitis C patients provides good evidence against a significant role of transmission by household objects. Nevertheless, our data prove a possible contamination of personal care objects, suggesting at least a theoretical risk of infection by sharing them. Thus, our study strengthens the recommendations to pay attention to a clear separation of personal care objects between patients and their household members. Considering the great epidemiological importance of hepatitis C, further examinations and maybe even official instructions concerning publically used and possibly contaminated objects such as razors in barbershops are indicated.


CLICK HERE for subscription information about this journal.

Abbreviation Notes

HCV = hepatitis C virus; PBI = papillary bleeding index; ALT = alanine aminotransferase; PCR = polymerase chain reaction.

Reprint Address

Guntram Lock, MD, 2. Medizinische Klinik, Albertinenkrankenhaus, Süntelstr. 11a, D- 22457 Hamburg, Germany. E-mail: guntram.lock@albertinen.de