Occupational risk for hepatitis C virus infection among New York City dentists

Global prevalence of hepatitis C in general population: A systematic review and meta-analysis

BACKGROUND

According to published reports from the World Health Organization, it is estimated that more than 3% of the world's population is infected with HCV. Given the impact of various factors on the prevalence of HCV in the world's population and the lack of general statistics around the world, this study aims to review the studies conducted in this field and statistical analysis of the results of general statistical studies on the prevalence of HCV in the world population.

METHODS

In this study, systematic review and meta-analysis of information of the studies related to the prevalence of HCV in the world using keywords including: Prevalence, HCV, Hepatitis C, Healthy Population, Healthy subjects, and General Population in SID, MagIran, IranMedex, IranDoc, ScienceDirect, Embase, Scopus, PubMed, Web of Science (WoS) databases and Google Scholar search engine were extracted without time limit until April 2020. In order to perform the analysis of qualified studies, the model of random effects was used, and the inconsistency of studies with I² index was investigated. Data analysis was performed with Comprehensive Meta-Analysis (Version 2).

RESULTS

In a study of 98 studies with a total sample size of 236,964 people in the world, the overall prevalence of HCV was 1.8% (95% CI: 1.4%-2.3%). Also, according to the subgroup analysis in different continents; the highest prevalence of HCV in the African continent was 7.1% (95% CI: 4.4-11.5%).

CONCLUSION

The results of this study show that the prevalence of hepatitis C in the world's population, especially in Africa, is almost high. Therefore, the officials of the World Health Organization should design measures to prevent the spread of this infection.

Prevalence of hepatitis B, C, and HIV among patients attending a teaching dental hospital. A 7-year retrospective study from the United Arab Emirates

Objectives

To determine the seroprevalence and case characteristics of hepatitis B, C and human immunodeficiency virus (HIV), and their transmissibility from patients to dental personnel following percutaneous and mucocutaneous injuries.

Methods

All incidents of sharp and splash injuries reported between January 2010 and January 2017 were retrospectively reviewed and analyzed. Descriptive statistics were calculated using the Statistical Package for the Social Science (SPSS). Prevalence was calculated as percentages, and chi-square test was used to assess categorical variables where a p-value of ≤0.05 was considered significant.

Results

Among the 436 reported incidents, 372 patients underwent serological screening. Fourteen patients (3.8%) had antibodies against hepatitis C virus, and 8 patients (2.2%) were positive for hepatitis B surface antigens. All positive cases were clinically asymptomatic. There were no positive cases for HIV. Three of the 14 hepatitis C positive patients were actively infectious upon polymerase chain reaction (PCR) analysis, but none of the injured dental personnel seroconverted upon a 6-month follow up. Approximately 88% of dental personnel were vaccinated against hepatitis B. Female personnel showed better vaccination rate by comparison to male personnel (p=0.005). Among the 5 different categories of professional status, cleaners showed a significantly low hepatitis B vaccination rate (p<0.000).

Conclusion

The prevalence of hepatitis B and C is higher than that previously reported from the United Arab Emirates, but transmissibility of viral hepatitis seems to be negligible.

Knowledge, attitude and behaviour regarding hepatitis C virus infection amongst Brazilian dental students

AIM

Dental health professionals, including dental students, are at high risk of exposure to infection with the hepatitis C virus (HCV) through occupational percutaneous injuries and eye exposure. Further, fear of HCV infection is associated with discriminatory attitudes. The current study aimed to evaluate the knowledge about HCV infection amongst dental students and their attitudes towards patients infected with HCV.

METHODS

A cross-sectional survey was conducted amongst 340 Brazilian dental students from two public universities using an instrument containing information regarding demographic characteristics, knowledge of HCV and attitudes towards patients with HCV infection. Descriptive statistics, Fisher's exact test, Student's t-tests, Mann-Whitney U-test and multiple logistic regression (MLR) were carried out (P < 0.05 was considered significant).

RESULTS

Response rate was 90% (n = 306), and more than half (54%, n = 165) of participants had high knowledge level (above the mean); 97.7% (n = 299) demonstrated positive attitudes. MLR showed that high knowledge of dental students regarding HCV was substantially influenced by advancement in year of study (last year; P < 0.001) and type of university (federal; P = 0.049). Positive attitude towards HCV-infected patients was mainly influenced by age (P = 0.004) and male gender (P = 0.022).

CONCLUSIONS

These results demonstrated a satisfactory knowledge about HCV infection amongst dental students, but some gaps were observed, suggesting the importance of continuous education about HCV in this population to prevent HCV infection as well as discrimination and prejudice towards patients with hepatitis C.

The prevalence of hepatitis C among healthcare workers: a systematic review and meta-analysis

The aim of this study was to estimate the prevalence of viral hepatitis C (HCV) infection among healthcare workers (HCWs) compared to the general population. A systematic search for the years 1989–2014 was conducted in the Medline, Embase and Cochrane databases. Studies on hepatitis C in HCWs were included if they incorporated either a control group or reference data for the general population. The study quality was classified as high, moderate or low. Pooled effect estimates were calculated to determine the odds of occupational infection. Heterogeneity between studies was analysed using the χ² test (p<0.10) and quantified using the I² test. 57 studies met our criteria for inclusion and 44 were included in the meta-analysis. Analysis of high and moderate quality studies showed a significantly increased OR for HCV infection in HCWs relative to control populations, with a value of 1.6 (95% CI 1.03 to 2.42). Stratification by study region gave an OR of 2.1 in low prevalence countries; while stratification by occupational groups gave an increased prevalence for medical (OR 2.2) and for laboratory staff (OR 2.2). The OR for professionals at high risk of blood contact was 2.7. The pooled analysis indicates that the prevalence of infection is significantly higher in HCWs than in the general population. The highest prevalence was observed among medical and laboratory staff. Prospective studies that focus on HCW-specific activity and personal risk factors for HCV infection are needed.

Post exposure prophylaxis to occupational injuries for general dentist

Occupational injuries which expose health-care professionals to blood-borne pathogens continue to be an important public health concern. Especially, dentists are at increased risk of exposure to Hepatitis B, Hepatitis C, and HIV. Dentists should remember and apply many precautions to prevent the broad spectrum of sharps and splash injuries that could occur during the delivery of dental care. This article updates and consolidates recommendations for the management of dental health-care personnel who have occupational exposure to blood and other body fluids.

A method of determining the presence of blood in and on a dental needle after the administration of local anesthetic

BACKGROUND

In the study reported in this article, the authors aimed to demonstrate the presence of blood on the surface and in the lumen of two gauges of dental needles after administration of local anesthetic (LA) by using three LA-administering techniques normally used for the extraction of teeth.

METHODS

The authors obtained standardized photographs of 200 urine dipsticks after moistening the dipstick's chemical pads for blood with the first drop of liquid discharged from the needle lumen after LA administration. Using the histogram function of a software program, the authors analyzed differences in gray-scale values of the different blood parameters for the presence of blood. They used luminol spray to expose small quantities of blood on the surface of the needle after LA administration.

RESULTS

Blood was identified at 39 percent in the lumen and at 16 percent on the surface of the needles when analyzed after LA administration.

CONCLUSIONS

With the method used, it was possible to demonstrate and quantify the percentage of blood present in the lumen of needles (39 percent) after the administration of dental LA. Furthermore, the technique was adequately sensitive for demonstrating the quantity of blood in two needles of different diameters.

PRACTICAL IMPLICATIONS

By demonstrating the presence, as well as quantifying the percentage, of blood on two dental needles of different gauges after the administration of LA, dental health care workers can be motivated to report needlestick injuries and to follow the approved protocols recommended by their institutions.

Prevalence of hepatitis C in adult users of the public health service of São José dos Pinhais--Paraná

OBJECTIVES

We aimed to investigate the prevalence of Hepatitis C in adult users of the Public Health Services of São José dos Pinhais - Paraná.

METHODS

We performed an epidemiological survey with a probabilistic sample of 5,017 volunteers who answered a questionnaire and were submitted to an anti-HCV quick test. Data were organized using Epi-info 3.5.1. The association between the presence of the disease and the factors of interest in the study were evaluated by the Chi-square test. We used a Logistic Regression Adjusted Model for risk factor analysis and the Wald test for decision making on the importance of the risk factors.

RESULTS

The absolute frequency of positive anti-HCV was 13, with a prevalence of 0.30%, (IC = 0.12% - 0.40%). A higher probability of the disease was reported in males (p = 0.008) and in single, separated and widowed subjects (p = 0.045); in subjects with prior HCV symptoms (p < 0.001) and a previous blood transfusion (p < 0.001); and with the presence of a tattoo (p = 0.033). Drug abuse, blood transfusion and age > 40 years increased the risk for disease, regardless of sex, age and marital status.

CONCLUSION

We found a low prevalence of Hepatitis C, albeit expected for Southern Brazil. Our results did not differ from other studies as to contamination risks. The study may contribute to highlight the importance of Hepatitis C, the need to implement strategies to cope with it, and stimulate better understanding of Hepatitis C.

[Epidemiology of hepatitis C virus infection]

Hepatitis C is a major cause of chronic liver disease worldwide. There is a significant variation in the prevalence of hepatitis C virus (HCV) infection according to the geographic region studied. These discrepancies reflect not only distinct epidemiological characteristics among the populations, but also differences in the methodologies used for the estimates. Despite scarce data, estimates indicate that Brazil is a country with an intermediate prevalence of HCV infection, ranging from 1% to 2%. The most important risk factors for HCV acquisition include injection drug use, blood product transfusion, organ transplantation, hemodialysis, occupational injury, sexual transmission and vertical transmission. Because there is no vaccine and no post-exposure prophylaxis for HCV, the focus of primary prevention efforts should be identification and removal of the risk factors. In this article we review literature regarding the prevalence of HCV infection, particularly in Brazil. In addition, we discuss the pattern of HCV infection according to the age groups and risk factors for HCV acquisition.

A tailored health surveillance program unveils a case of MALT lymphoma in an HCV-positive health-care worker

Non-Hodgkin lymphoma (NHL) may occur among hepatitis C virus (HCV)-infected individuals. HCV is one of the most common blood-borne pathogens transmitted from patients to health-care workers (HCWs). The development of NHL among HCV-infected HCWs has recently been shown. To investigate this issue further a tailored health surveillance program was applied to 3,138 HCWs from four Medical Institutions. To this aim, all employees were screened for both anti-HCV antibodies and HCV-related extrahepatic manifestations. The HCV prevalence rate, similar among all the HCW subgroups, was 7.3%. The occurrence of a gastric mucosa-associated lymphoma tissue (MALT) lymphoma, diagnosed in a physician following a long history of HCV chronic infection, was observed. Molecular characterization of MALT tissue indicated that immunoglobuline gene combinations were those usually found among HCV-associated lymphomas. Furthermore, B-cell expansion exhibited t(14;18) translocation, as a genetic abnormality associated with the development of MALT lymphomas from HCV-positive patients. Overall, these findings support the hypothesis that HCV viral infection potentially affects the pathway of transformation and progression of lymphoma cells. The occurrence of B-cell NHL, among HCV-positive HCWs, is an additional reason to apply the standard precautions to reduce the risk of blood-borne pathogen transmission.

An 'Academic Detailing' Intervention To Decrease Exposure to HIV Infection among Health-care Workers

This intervention aimed to decrease health-care workers' experience of automatic pilot (mindless functioning) when performing high risk procedures. An academic detailing visit resulted in a significant increase in compliance with safety guidelines and a decreased incidence of other unsafe practices among 80 health care workers of two hospital units. The effects of mindlessness on health behaviour may be far reaching and the model described in this paper can be used to develop appropriate interventions.

Healthcare-associated viral and bacterial infections in dentistry

Infection prevention in dentistry is an important topic that has gained more interest in recent years and guidelines for the prevention of cross-transmission are common practice in many countries. However, little is known about the real risks of cross-transmission, specifically in the dental healthcare setting. This paper evaluated the literature to determine the risk of cross-transmission and infection of viruses and bacteria that are of particular relevance in the dental practice environment. Facts from the literature on HSV, VZV, HIV, Hepatitis B, C and D viruses, Mycobacterium spp., Pseudomonas spp., Legionella spp. and multi-resistant bacteria are presented. There is evidence that Hepatitis B virus is a real threat for cross-infection in dentistry. Data for the transmission of, and infection with, other viruses or bacteria in dental practice are scarce. However, a number of cases are probably not acknowledged by patients, healthcare workers and authorities. Furthermore, cross-transmission in dentistry is under-reported in the literature. For the above reasons, the real risks of cross-transmission are likely to be higher. There is therefore a need for prospective longitudinal research in this area, to determine the real risks of cross-infection in dentistry. This will assist the adoption of effective hygiene procedures in dental practice.

Hepatitis C virus infection in USA: an estimate of true prevalence

The recent National Health and Nutrition Examination Survey (NHANES) sampled only the civilian, non-institutionalized population of USA and may have underestimated the prevalence of hepatitis C virus (HCV) in this country. We searched the database MEDLINE, the Bureau of Justice Statistics, Center for Medicare and Medicaid and individual states Department of Corrections for all epidemiological studies regarding the prevalence of HCV in populations not sampled by the NHANES survey namely the incarcerated, homeless, nursing home residents, hospitalized and those on active military duty. Because of their relatively low frequency in the NHANES sample, we also expanded our search to include healthcare workers and long-term dialysis patients. Although included in the NHANES sample, we also performed searches on drug users (injection and non-injection) and veterans to confirm the findings of the NHANES study. Based on the prevalence of studies identified meeting our inclusion criteria, our most conservative estimates state that there at least 142,761 homeless persons, 372,754 incarcerated persons and 6805 persons on active military duty unaccounted for in the NHANES survey. While the NHANES estimates of drug users (both injection and non-injection) appear to be reasonable, the survey seems to have underestimated the number of HCV-positive veterans. Our most conservative estimates suggest that there are at least 5.2 million persons living with HCV in USA today, approximately 1.9 million of whom were unaccounted for in the NHANES survey.

A survey of cross-infection control procedures: knowledge and attitudes of Turkish dentists

Objectives:

The objective of this study was to investigate the knowledge, attitudes and behavior of Turkish dentists in Samsun City regarding cross-infection control.

Material and methods:

A questionnaire was designed to obtain information about procedures used for the prevention of cross-infection in dental practices and determine the attitudes and perceptions of respondent dental practitioners to their procedures. The study population included all dentists in the city of Samsun, Turkey, in April 2005 (n=184). The questionnaire collected data on sociodemographic characteristics, knowledge and practice of infection control procedures, sterilization, wearing of gloves, mask, use of rubber dam, method of storing instruments and disposal methods of contaminated material, etc. Questionnaire data was entered into a computer and analyzed by SPSS statistical software.

Results:

From the 184 dentists to whom the questionnaires were submitted, 135 participated in the study (overall response rate of 73.36%). As much as 74.10% dentists expressed concern about the risk of cross-infection from patients to themselves and their dental assistants. Forty-three percent of the participants were able to define "cross-infection" correctly. The greatest majority of the respondents (95.60%) stated that all patients have to be considered as infectious and universal precautions must apply to all of them. The overall responses to the questionnaire showed that the dentists had moderate knowledge of infection control procedures.

Conclusions:

Improved compliance with recommended infection control procedures is required for all dentists evaluated in the present survey. Continuing education programs and short-time courses about cross-infection and infection control procedures are suitable to improve the knowledge of dentists.

Occupational exposures to bloodborne viruses among German dental professionals and students in a clinical setting

PURPOSE

Exposures to bloodborne pathogens pose a serious risk to dental healthcare workers (DHCW). Despite improved methods of preventing exposures like needlestick injuries (NSI), occupational exposures still continue to occur. The purpose of this study was to evaluate the incidence of occupational exposures to patient body fluids among German DHCW, to assess the rate of reporting of such incidents, and to evaluate the association of various factors with these exposures.

METHODS

Data was obtained through an anonymous questionnaire.

RESULTS

Our study confirms that occupational skills are an important factor concerning NSI. It turned out that dental students (0.74 NSI p. a.) had nearly twice the number of NSI compared with dentists with more or less than 10 years working experience (0.42, 0.49 NSI p. a., respectively, P < 0.0001). Overall, 54.3% (n = 144/265) of respondents had sustained at least one NSI in their professional life. Only 28.5% of injured dental students and DHCW reported all of their NSI, the main reason (19.1%) for not reporting NSI was little or no perception of risk on behalf of the respondent. One-fourth of respondents were not wearing a mask and 55.6% were not wearing protective goggles during their last occupational exposures.

CONCLUSIONS

Occupational exposure to blood or body fluids is a common problem among DHCW and dental students. Measures must be adopted by official institutions, public health service, occupational health association and universities in order to reverse this situation.

Antibodies to hepatitis C and other viral markersin multi-transfused patients from Argentina

BACKGROUND

The knowledge of transfusion-transmitted viral infections in Argentina is scarce. A regional study organized by the Pan American Health Organization let us asses the current status.

OBJECTIVES

To estimate the prevalence of HCV, HBV and HIV infection in a population of multi-transfused Argentinean patients.

STUDY DESIGN

Multi-center, cross sectional study of 504 patients from national referral institutions in Buenos Aires, who had received more than ten units of blood products in more than two occasions. Demographic and clinical data were collected using a standardized questionnaire. Blood samples were analyzed for a-HCV, a-HIV, HBsAg and a-HBcore.

RESULTS

Patients belonged to five diagnostic categories: onco-hematology (309; 61.3%); hemophilia (96; 19%); acute blood loss (54; 10.7% ); hemoglobinopathies (35; 6.9%); and hemodialysis (5; 1% ); five patients (1%) had two of the previous conditions. Overall prevalence rates of viral markers were: a-HCV 9.3% (CI(95%): 6.7-12.0); a-HBcore 4.8% (CI(95): 2.8-6.7); a-HIV 1.2% (CI(95%): 0.14-2.2) and HBsAg 0.20%(CI(95%): 0.2-0.59). The highest prevalence rates were found among patients living with hemophilia (PLH). There was a significant statistical association (p < 10(-5), OR =78.8 [29.7-209.7]) between a-HCV infection and having been transfused before 1993, when screening blood donors for a-HCV became mandatory in our country. The subpopulation of patients exposed to transfusion before 1993 was conformed mostly by PLH (70.9%) and hemoglobinopathies (18.6%). In this subpopulation, we found a significant association (p < 10(Dot;), OR -40 [5.68-281.66]) between years of exposure to transfusion and a-HCV among the patients under the median age (21.95 years old); however, there was no association for those above the median age (p=0.111).

CONCLUSION

a-HCV was found to be the most prevalent infection in the multi-transfused patient population under study. Most infected individuals were PLH, transfused before 1993. This study will provide support for further research aimed at improving blood safety in Argentina.

HCV infection: aspects of epidemiology and transmission relevant to oral health care workers

Hepatitis C virus (HCV) infection is a common worldwide problem, giving rise to long-term viral carriage and risk of chronic hepatic disease, hepatic malignancy and a wide spectrum of immunologically mediated disorders. The present report describes relevant data suggesting that nosocomial transmission to oral health care workers is unlikely, but in view of medical and occupational consequences of such infection, and the absence of long-term effective treatment or vaccine, the oral surgery profession must continue to be vigilant and to maintain the highest standards of infection control procedures to minimize the possible acquisition of HCV during dental treatment.

Prevalence of HCV infection among health care workers in a hospital in central Italy

Health care workers are at risk of acquiring transmissible diseases. Controversial results have been reported about HCV. The aims of the present study are to assess the prevalence of HCV in health care workers in Pistoia General Hospital (central Italy) and to compare prevalence with other groups, particularly with a sample of the general population. Serum samples collected from 511 health care employees engaged in direct clinical task and 222 clerical and nurse school attendees have been tested by ELISA and confirmed by RIBA. Total seroprevalence was 3.8%:4.7% in the first group; 1.8% in the second group. The data showed a slight increase in prevalence by age and not by length of stay in the health care workers' group. Comparison of HCV prevalence with blood donors from the province of Pistoia and the general population from Sersale (Catanzaro, southern Italy), restricted to under-40 subjects, indicates an increasing trend in this order: Blood donors, general population, clerical and nursing school attendees, health care workers' group with the highest value (3.4%). A cohort study is needed to evaluate pattern of HCV seroconversion.

A potential hidden source of hepatitis C infection among noninjecting drug users

Hepatitis C virus (HCV) is a major cause of chronic liver disease in the United States and worldwide. It is primarily transmitted through blood-to-blood contact with an infected individual. HCV is hyperendemic among injection drug users (IDUs), who contract the virus through contaminated syringes and drug preparation equipment shared with other IDUs. The prevalence of HCV is also high, to a lesser degree, among noninjection drug users, many of whom report no identifiable HCV risk exposures. This article reviews the epidemiological and virological evidence bearing on a potential hidden source of HCV infection among noninjection drug users: namely, the oral or intranasal transmission of HCV through the sharing of noninjection drug-use implements such as pipes or straws. While there is some epidemiological evidence supporting both oral and intranasal HCV transmission, most studies are hampered by methodological limitations. Thus, there is a need for prospective studies designed specifically to examine these potential routes of transmission. Current biological evidence does not refute either oral or intranasal transmission as possible sources of HCV infection, although more research is needed in the areas of oronasal HCV pathogenesis and the detection of HCV RNA in the nasal mucosa of intranasal drug users.

Occupational exposures to human immunodeficiency virus, hepatitis B virus, and hepatitis C virus: risk, prevention, and management

Current data indicate that the risk for transmitting bloodborne pathogens in dental health care settings is low. Pre-exposure hepatitis B vaccination and the use of standard precautions to prevent exposure to blood are the most effective strategies for preventing DHCP from occupational infection with HIV, HBV or HCV. Each dental health care facility should develop a comprehensive written program for preventing and managing occupational exposures to blood that: (1) describes the types of blood exposures that may place DHCP at risk for infection; (2) outlines procedures for promptly reporting and evaluating such exposures; and (3) identifies a health care professional who is qualified to provide counseling and perform all medical evaluations and procedures in accordance with the most current USPHS recommendations. Finally, resources should be available that permit rapid access to clinical care, testing, counseling, and PEP for exposed DHCP and the testing and counseling of source patients.

Prevalence of transfusion-transmissible viral infections in first-time US blood donors by donation site

BACKGROUND

Understanding the donor base, infectious disease prevalence, and donation loss at various blood donation sites will help maximize blood collection efforts and blood availability.

STUDY DESIGN AND METHODS

Using donation data collected at five US blood centers, the prevalence of HIV, HTLV, HBsAg, and HCV in first-time whole-blood donations at 10 donation sites was evaluated: military, education, religious, professional, industry, services, community, health care, government, and fixed sites. Donation loss from screening test reactivity at each donation site was also evaluated.

RESULTS

During the study, 1.2 million first-time whole-blood donations were collected. Military and education sites had a low prevalence of all viral markers, except for HBsAg, which was highest at education sites. Variations in viral marker prevalence among donation sites were partially explained by donor demographic differences. Donation loss varied by donation site, ranging from 3.3 percent at education sites to 6.4 percent at industry sites, indicating differential efficiency of blood collection efforts.

CONCLUSION

Different rates of positive viral test results and donation loss in first-time whole-blood donors were observed at various types of donation sites. This information may be useful in estimating the yield of usable units from specific blood drives and in allocating resources to meet blood center collection goals.

Transfusion transmitted virus (TTV) in dental patients

Transfusion transmitted virus (TTV) is a new DNA virus found in patients with post-transfusion hepatitis. The prevalence of this virus among dental patients has not been reported, therefore, the prevalence of TTV infection in consecutive dental inpatients was evaluated. TTV DNA was assayed by the polymerase chain reaction (PCR) in 441 dental inpatients with oral cancer (n=192) or oral cysts (n=249). The serum HBs antigen and HCV antibody as well as aspartate transaminase (AST), alanine transaminase (ALT), and gamma glutamyl transpeptidase (gamma-GTP) concentrations were also measured. Of 441 subjects, 137 were infected with TTV (31.1%). This prevalence of TTV was much higher than that of HBV or HCV (HBV 1.2%; HCV 6.0%) in these dental patients. There was no gender or age difference in the prevalence of TTV infection. Of the 192 patients with oral cancer, 57 subjects had TTV in their sera, while 80 of 249 with oral cystic disease had TTV. The prevalence of TTV was similar between the two different disease groups. Neither the serum ALT nor serum AST concentrations were different between the subjects positive and negative for TTV DNA. In hospitalized dental patients, 31.1% were infected with TTV. The prevalence of TTV was much higher than that of HBV or HCV. There was no difference in the prevalence of TTV between subjects with cancer and cysts. Dentists should maintain high standards of infection control when treating any dental patient.

The epidemiology of hepatitis C virus infection

The prevalence of hepatitis C virus (HCV) infection varies in different populations, ranging from as low as 0.6% in volunteer blood donors to as high as 80% in injection drug users. The prevalence of HCV in a population can be predicted by risk factors associated with the transmission of infection. These risk factors include injection drug use, blood product transfusion, organ transplantation, hemodialysis, occupational injury, sexual transmission, and vertical transmission. We review the literature regarding the incidence and prevalence of HCV infection and the evidence supporting various modes of HCV transmission.

Hepatitis C: an epidemiological review

The aim of the study was to analyse the current literature regarding the mode of transmission of HCV and its global prevalence in different groups of people. A systematic review of the literature on the epidemiology of hepatitis C from 1991 to 2000 using computerized bibliographic databases which include Medline, Current Content and Embase. The prevalence of hepatitis C virus (HCV) varies tremendously in different parts of the world, with the highest incidence in the Eastern parts of the globe compared with the Western parts. Furthermore, certain groups of individuals such as intravenous drug users are at increased risk of acquiring this disease irrespective of the geographical location. Although the main route of transmission is via contaminated blood, curiously enough in up to 50% of the cases no recognizable transmission factor/route could be identified. Therefore, a number of other routes of transmission such as sexual or household exposure to infected contacts have been investigated with conflicting results. Hepatitis C infection is an important public health issue globally. Better understanding of routes of transmission will help to combat the spread of disease. In order to prevent a world wide epidemic of this disease, urgent measures are required to (i) develop a strategy to inform and educate the public regarding this disease and (ii) expedite the efforts to develop a vaccine.

High prevalence of HCV infection among the general population in a rural area of central Italy

The hepatitis C virus infection (HCV) is the most frequent cause of hepatic infection in Europe. In Italy, anti-HCV positivity values are extremely variable, depending on the age and geographic location of the population being analysed. The aims of the study were: (1) evaluating positivity for anti-HCV antibodies in various age groups and determining the HBsAg in a mountainous and predominantly farming area in central Italy; (2) assessing some anamnestic and clinical variables through a questionnaire, submitted during the taking of blood samples, in order to determine HCV exposure and risk factors for the target population. 344 subjects selected by random sampling among 3308 people, older than 16, were considered as the target population. A prevalence study was carried out. The sources of data were: blood samples taken to carry out the HCV positivity test; a questionnaire including items about exposures at risk and case-historical and clinical patient data. The risk of infection was evaluated by a multiple logistic regression model. The inferred HCV+ prevalence rate is 22.4/100 (95% confidence interval (CI): 20.8-24.1). An increasing age trend is shown with a higher positive predominance among females (28.99/100 vs. 14.29/100 in males). The positive HBsAg prevalence in the examined survey is 1.2/100. Variables associated with the HCV occurrence are case history of pneumonopathy (OR: 4.9) and exposure to parenteral therapies with glass syringes (OR: 3.3). This study is consistent with literature about the hypothesis of a north-south geographic gradient in the hepatitis C occurrence in Italy. Data clearly show the effects of the inappropriate use of medical or surgery practices on the population, with particular reference to the use of glass syringes. No elements prove that the farming features of the area may be predictive of HCV infection risk. The extent of the recorded prevalence values calls for the implementation of programmes aimed at detecting clusters or population areas at risk.

Hepatitis B prevalence and infection control among dental health care workers in a community in South Korea

OBJECTIVES

The objectives of this study were to investigate the prevalence of hepatitis B vaccine and use of infection control procedures by dental health care workers in Taegu, South Korea.

METHODS

Information was obtained with a mailed questionnaire sent to 300 private dental practices. Surveys were received from 177 dentists, 104 dental hygienists, and 46 dental assistants. All dental health care workers were asked to donate a blood sample for analysis of hepatitis B surface antigen (HBsAg) and antibody (anti-HBs).

RESULTS

Vaccination against hepatitis B virus was reported by 63 percent of the respondents. About 40 percent of all participants answered that they were anti-HBs positive, while another 43 percent did not know their status. About 89 percent of dentists reported that they wore a mask with all patients, while hygienists (13.6%) and assistants (13.0%) were less likely to do so. Reported use of gloves (4.5%) and protective eyewear (14%) with all patients was extremely low in every group. Among the 56 dentists who were tested for HBV markers, 23 did not receive the vaccine against hepatitis B, and 13 percent (3 of 23) were positive for HBsAg as carriers.

CONCLUSIONS

About 37 percent (120 of 327) of dental health care workers surveyed in this study in Korea did not receive the vaccine against HBV infection. Basic barrier techniques to prevent cross-contamination were not being used consistently. Nationwide guidelines for barrier techniques and hepatitis vaccinations should be developed and disseminated to dental personnel.

Nosocomial spread of viral disease

Viruses are important causes of nosocomial infection, but the fact that hospital outbreaks often result from introduction(s) from community-based epidemics, together with the need to initiate specific laboratory testing, means that there are usually insufficient data to allow the monitoring of trends in incidences. The most important defenses against nosocomial transmission of viruses are detailed and continuing education of staff and strict adherence to infection control policies. Protocols must be available to assist in the management of patients with suspected or confirmed viral infection in the health care setting. In this review, we present details on general measures to prevent the spread of viral infection in hospitals and other health care environments. These include principles of accommodation of infected patients and approaches to good hygiene and patient management. They provide detail on individual viral diseases accompanied in each case with specific information on control of the infection and, where appropriate, details of preventive and therapeutic measures. The important areas of nosocomial infection due to blood-borne viruses have been extensively reviewed previously and are summarized here briefly, with citation of selected review articles. Human prion diseases, which present management problems very different from those of viral infection, are not included.

Hepatitis C screening and prevalence among urban public safety workers

This study examines the prevalence of anti-hepatitis C virus by using an enzyme-linked immunoassay test (EIA-2) in 2447 volunteers (including 1560 police, 678 fire, and 209 emergency medical service personnel) and a self-reported questionnaire on potential occupational and non-occupational risk factors. Subjects consisted of 76% men, 54.8% blacks, and 40.3% whites. Twenty-eight individuals (1.1%) tested positive, with prevalence rates of 1.1% and 1.3%, respectively, among blacks and whites. Although firefighters and emergency medical service workers had a higher prevalence (2.3% and 2.8%) than police (0.6%), the overall prevalence was lower than that typical of urban populations. In a multivariate analysis, the most important risk factors were behavioral, with no significant occupational exposure risk observed. Previously reported racial differences were not detected in this study, most likely because the subjects were of similar socioeconomic status.

Hepatitis C virus transmission in a pediatric oncology ward: analysis of an outbreak and review of the literature

Hospital-related hepatitis C virus (HCV) infections continue to occur even after the introduction of blood donor screening. We report an outbreak of HCV in nine patients of a pediatric oncology ward in 1996/1997. Sequencing of the hypervariable genomic region 1 (HVR1) of the E2/NS1 region showed near identity between HCV isolates from these patients as evidence for infection with the same virus. Despite a detailed and careful investigation, the source of infection and the mode of virus transmission could not be established. Based on a review of the current literature about nosocomial HCV infection and HCV infection in children, hypotheses for possible means of transmission in this outbreak are discussed.

Commercial tattooing as a potentially important source of hepatitis C infection. Clinical epidemiology of 626 consecutive patients unaware of their hepatitis C serologic status

Tattooing in commercial tattoo parlors is known to transmit blood-borne viral infections, including hepatitis C virus (HCV), in other countries, but its contribution to the high population prevalence of HCV infection in the United States has been incompletely evaluated. Risk factors for blood-borne infection were assessed by physician's interview of 626 consecutive patients undergoing medical evaluation for spinal problems in 1991 and 1992 while unaware of their HCV status. Later all were screened for HCV infection with enzyme-linked immunosorbent assay (EIA-1 and EIA-2), and positives were confirmed with second-generation recombinant immunoblot assay (RIBA). Forty-three patients were seropositive for HCV (sample prevalence 6.9%, population-standardized prevalence 2.8%). Logistic regression analysis identified 4 independent risk factors for HCV infection: injection-drug use (adjusted prevalence odds ratio [OR] = 23.0; 95% confidence intervals [CI] = 7.5-70.6), ancillary hospital jobs held by men (OR = 9.6; 95% CI = 3.8-24.3), tattoos from commercial tattoo parlors (OR = 6.5; 95% CI = 2.9-14.8), and drinking > or = 3 6-packs of beer per month (OR = 4.0; 95% CI = 1.8-8.7). If causal, these 4 risk factors account for 91% of HCV infections, with tattooing explaining 41%, heavy beer drinking 23%, injection-drug use 17%, and ancillary health care jobs for men 8%. Transfusions, promiscuous sexual activity, bone grafts, acupuncture, perinatal or intimate transmission in families, and other modes were not independently associated with serologic evidence of HCV infection. Unlikely to be explained by confounding or incomplete disclosure of other risk factors, tattooing in commercial tattoo parlors may have been responsible for more HCV infections than injection-drug use.

Detection of hepatitis C virus RNA from gingival crevicular fluid and its relation to virus presence in saliva

BACKGROUND

To search for a possible source of hepatitis C virus (HCV) in saliva, the presence and shedding patterns of HCV in gingival crevicular fluid (GCF) and saliva of HCV viremic patients were assessed based on clinical, biochemical, histological, virological, and oral health parameters.

METHODS

Saliva and GCF samples of 50 HCV viremic patients were collected to detect HCV RNA by a modified commercial polymerase chain reaction (PCR) assay. Clinical oral examination was performed and periodontal status at the collection sites was monitored. The results were correlated to specified parameters.

RESULTS

HCV RNA was detected in 59% (29/49) of the GCF specimens and in 35% (17/48) of the saliva specimens. In saliva specimens, HCV RNA was detected only in cases which also had detectable HCV RNA in the GCF samples (P=0.00002) and was significantly related to the presence of blood in saliva (P=0.03). Higher, but not significant, values of oral clinical parameters at the sites of fluid collection were found in GCF specimens harboring HCV RNA. In GCF specimens with no blood detected, HCV RNA was more often present in cases with higher plasma viral load (P=0.05).

CONCLUSIONS

The results suggest that besides blood, the other most probable source of HCV in saliva is GCF. Unknown endogenous HCV inhibitory mechanisms in the oral cavity may explain the discrepancies in HCV appearance between saliva and GCF. The results provide a biologic basis for further investigation of the role of HCV in the pathogenesis of periodontal disease.

Evaluation of environmental bacterial contamination and procedures to control cross infection in a sample of Italian dental surgeries

OBJECTIVES

To perform a pilot study on bacterial contamination in some dental surgeries (n=51) in a local health unit in Brescia (Lombardy Region, Italy) and to evaluate the procedures to control cross infection used by the personnel to reduce the risk of infection in dental practice.

METHODS

A survey was carried out by interviewing 133 dental personnel with a questionnaire on the procedures used to control infection. The autoclaves, chemical baths (chemiclaves), and ovens present in the surgeries were tested for sterilisation efficiency with a spore test, and already packed and sterilised instruments were randomly sampled and tested for sterility. Microbial contamination of air, surface, and dental unit water samples were also studied.

RESULTS

The dental personnel did not generally follow the principal procedures for infection control: 30% of personnel were not vaccinated against hepatitis B virus, infected instruments were often not decontaminated, periodic checks of autoclave efficiency were lacking, and the knowledge of disinfection mechanisms and procedures was incomplete. High bacteriological contamination of water at dental surgeries was often found and total bacteriological counts in air samples were high. Surface studies showed widespread bacterial contamination.

CONCLUSIONS

On the basis of these results, an educational programme for the prevention of infective hazards has been prepared and carried out. The results of this pilot study will be used for planning a national survey.

Risk and management of blood-borne infections in health care workers

Exposure to blood-borne pathogens poses a serious risk to health care workers (HCWs). We review the risk and management of human immunodeficiency virus (HIV), hepatitis B virus (HBV), and hepatitis C virus (HCV) infections in HCWs and also discuss current methods for preventing exposures and recommendations for postexposure prophylaxis. In the health care setting, blood-borne pathogen transmission occurs predominantly by percutaneous or mucosal exposure of workers to the blood or body fluids of infected patients. Prospective studies of HCWs have estimated that the average risk for HIV transmission after a percutaneous exposure is approximately 0.3%, the risk of HBV transmission is 6 to 30%, and the risk of HCV transmission is approximately 1.8%. To minimize the risk of blood-borne pathogen transmission from HCWs to patients, all HCWs should adhere to standard precautions, including the appropriate use of hand washing, protective barriers, and care in the use and disposal of needles and other sharp instruments. Employers should have in place a system that includes written protocols for prompt reporting, evaluation, counseling, treatment, and follow-up of occupational exposures that may place a worker at risk of blood-borne pathogen infection. A sustained commitment to the occupational health of all HCWs will ensure maximum protection for HCWs and patients and the availability of optimal medical care for all who need it.

Risk and management of blood-borne infections in health care workers

Exposure to blood-borne pathogens poses a serious risk to health care workers (HCWs). We review the risk and management of human immunodeficiency virus (HIV), hepatitis B virus (HBV), and hepatitis C virus (HCV) infections in HCWs and also discuss current methods for preventing exposures and recommendations for postexposure prophylaxis. In the health care setting, blood-borne pathogen transmission occurs predominantly by percutaneous or mucosal exposure of workers to the blood or body fluids of infected patients. Prospective studies of HCWs have estimated that the average risk for HIV transmission after a percutaneous exposure is approximately 0.3%, the risk of HBV transmission is 6 to 30%, and the risk of HCV transmission is approximately 1.8%. To minimize the risk of blood-borne pathogen transmission from HCWs to patients, all HCWs should adhere to standard precautions, including the appropriate use of hand washing, protective barriers, and care in the use and disposal of needles and other sharp instruments. Employers should have in place a system that includes written protocols for prompt reporting, evaluation, counseling, treatment, and follow-up of occupational exposures that may place a worker at risk of blood-borne pathogen infection. A sustained commitment to the occupational health of all HCWs will ensure maximum protection for HCWs and patients and the availability of optimal medical care for all who need it.

Prevalence of hepatitis C antibodies in a large sample of Belgian healthcare workers

OBJECTIVE

To assess the risk of hepatitis C virus (HCV) infection among Belgian (Flemish) healthcare workers.

DESIGN

A seroprevalence survey of HCV IgG antibodies.

SETTING AND PARTICIPANTS

A systematic sample of 5,064 employees from 22 general hospitals in Flanders and Brussels, Belgium, was tested at the annual occupational medical examination. Together with demographic and occupational data, information was collected on the frequency of blood contact, needlestick injuries, and medical and surgical history. The blood samples were tested using the third-generation Abbott Screen Kit test, with confirmation by Matrix, LIA, and an in-house polymerase chain reaction and the Quantiplex-HCV b-DNA test.

RESULTS

21 persons were found to be positive for HCV markers. The overall prevalence was 0.41% (95% confidence interval [CI95], 0.24-0.59). A statistically significant association was found with a history of blood transfusion (odds ratio [OR], 4.14; CI95, 1.67-10.31) and with history of a clinically apparent hepatitis (OR, 3.98; CI95, 1.60-9.90). Although the ORs for the frequency of blood contact were slightly elevated (between 1.17 and 2.73), this association was not significant. Moreover, a history of needlestick injuries showed a nonsignificant OR of 1.28 (CI95, 0.53-3.09), and no statistically significant difference was found with a variety of duties and tasks. The ORs for potential occupational risk factors were adjusted according to age, gender, antecedents, and other confounders using a logistic regression analysis. Based on this procedure, the ORs decreased slightly.

CONCLUSIONS

Flemish healthcare workers showed a lower HCV seropositivity than is seen in the general population; a history of blood transfusion and of clinically apparent hepatitis was most strongly associated with the presence of HCV markers. We concluded that employees in Flemish regional general hospitals are not at an overall increased risk for HCV infection, although occasional transmission through percutaneous injuries is possible, and prevention therefore remains imperative.

Counselling patients with hepatitis C

Hepatitis C virus (HCV) is usually but not exclusively transmitted by the parenteral route. Some precautions are recommended for infected patients as well as his/her close contacts and family members. The risk of sexual transmission and from household contacts is very low. Use of condoms is only recommended in cases of multiple partners and for those at high risk of transmission. Some personal objects should not be shared, i.e. razors, toothbrushes and nail clippers, but it is not necessary to avoid sharing eating utensils. Sexual partners may be tested for anti-HCV HCV-positive individuals should refrain from donating blood, organs and tissue. Clear and evidenced-based information should be provided to patients as to the means of prevention with special attention to individual risk groups such as IV drug abusers. The risk of HCV transmission after needlestick injury, although low, justifies universal precaution measurements for health-care workers. Nosocomial transmission has been described after medical procedures, especially haemodialysis and endoscopy. Thus, disinfection procedures as well as universal precautions are essential for all health-care workers. It is also important for HCV patients to inform health-care workers beforehand about their HCV status. Perinatal transmission is rare and is usually related to the degree of maternal viral load. Pregnancy is not contra-indicated in HCV. infected individuals and breast-feeding is allowed. Finally, HCV patients with active disease should be advised to refrain from alcohol intake, especially during antiviral therapy. After HCV infection it is necessary to consider not only diagnostic and therapeutic steps but also the risk of transmission in the patient's circle and consequences for the patient.

A rapid test for the visual detection of anti-hepatitis C virus antibodies in whole blood

A rapid test for the visual detection of anti-HCV antibodies in whole blood was evaluated in its accuracy when compared with EIA method. The rapid test was performed blind on 50 HCV EIA-positive (adsorbance greater than 3.0) and on 50 HCV EIA-negative samples. Each whole blood sample was 1:20, 1:50 and 1:100 diluted with saline solution for a total of 400 samples. Results showed a sensitivity of 100% when whole blood was tested, 96% when 1:20 diluted blood was tested, 30% when 1:50 diluted blood was tested and 4% when 1:100 diluted blood was tested. The specificity gave also better results and only one false-positive was found in all samples tested. The test took less than 3 min and only a mechanical pipette was required. In conclusion, the HCV Ab rapid test showed a very high accuracy and could be very useful for the detection of HCV-positive subjects in situations where rapid results are required or technical expertise is limited.

Risk and prevention of hepatitis C virus infection. Implications for dentistry

BACKGROUND

The occupational risk of hepatitis C virus, or HCV, infection in dentistry is very low. Nonetheless, the lack of an effective vaccine, the high rates of chronic infection and the limited effectiveness of treatment may cause concern for dental workers who come into contact with blood in their daily practices.

DESCRIPTION OF THE DISORDER

The authors discuss the natural history, diagnosis and treatment, and patterns of transmission of HCV infection, including the Centers for Disease Control and Prevention's recommendations for management and follow-up of health care workers after occupational exposure to HCV.

CLINICAL IMPLICATIONS

In the absence of an effective vaccine or postexposure prophylaxis, prevention of occupational transmission of HCV in dental settings continues to rely on the use of universal precautions, including barrier precautions and the safe handling of sharp instruments.

Risk of hepatitis C virus transmission to surgeons and nurses from infected patients: model-based estimates in France

BACKGROUND/AIM

The aim of this study was to estimate the annual number of cases of hepatitis C virus transmission from infected patients to uninfected surgeons or nurses due to percutaneous injury during invasive procedures.

METHODS

The risk of transmission was estimated using a model involving three probabilities: A, that a health care worker sustains at least one percutaneous injury during a procedure; B, that 1 to 10% of patients are seropositive for hepatitis C virus; and C, that infection by this virus is transmitted to the Health Care Worker after such exposure. Probability A was estimated from the results of 2 French multicentric prospective trials. Probability C was estimated from the results of 9 international prospective studies. A ten-fold decreased risk was assumed for surgeons who wear gloves and use solid-bore suture needles.

RESULTS

During a single procedure, the estimated probability of hepatitis C virus transmission from an infected patient to an uninfected surgeon ranged from 4.2x10(-5)% to 4.2x10(-4)%, and from 2.98x10(-6)% to 2.98x10(-5)% to an uninfected nurse. For surgeons, the estimated annual cumulative risk of occupational infection ranged from 0.01% to 0.1% (1 in 10000 to 1 in 1000), and for nurses from 0.0054% to 0.054% (1 in 18700 to 1 in 1900).

CONCLUSIONS

Between 2 and 21 surgeons out of a total 20000 are estimated to acquire occupationally-related hepatitis C virus infection, and between 16 and 167 nurses out of a total 300000. These estimates strongly justify introducing preventive measures to protect health care workers from bloodborne infection.

Hepatitis G virus infection in a high-risk subgroup of hospitalized dental patients

OBJECTIVE

The prevalence of hepatitis G virus infection was evaluated in dental patients whose clinical laboratory test results were positive for hepatitis C virus antibody, hepatitis B virus surface antigen, or elevated serum alanine transaminase concentrations.

STUDY DESIGN

Frozen serum samples from patients with hepatitis C virus antibody (n = 63), hepatitis B virus surface antigen (n = 20), or alanine transaminase concentrations greater than 100 IU (n = 14) were assessed for GB virus C (GBV-C)/hepatitis G virus RNA by a reverse transcriptase-polymerase chain reaction.

RESULTS

Six of 63 patients with hepatitis C virus antibodies had serum hepatitis G virus RNA (9.5%), and 2 of 20 subjects with hepatitis B virus surface antigen had hepatitis G virus RNA (10.0%). None of 14 patients whose alanine transaminase concentration was greater than 100 IU/L had hepatitis G virus RNA. Of 4 subjects with both hepatitis C virus antibody and hepatitis B virus surface antigen, 2 had hepatitis G virus RNA (50%). In the total study population (N = 92), 6 subjects (6.5%) had hepatitis G virus RNA. All hepatitis G virus-infected patients also had hepatitis C virus antibody. Neither serum alanine transaminase nor aspartate transaminase concentrations were different between subjects with and subjects without hepatitis G virus RNA. The lack of a relationship between hepatitis G virus infection and elevation of alanine transaminase and aspartate transaminase might suggest that this virus is not truly a hepatitis virus.

CONCLUSIONS

Hospitalized dental patients are infected with hepatitis G virus at a prevalence similar to or slightly higher than that seen in the general population. Dentists should pay close attention to infection control with respect to the potential new hepatitis virus known as hepatitis G virus.