[Show abstract][Hide abstract] ABSTRACT: Hepatitis A virus (HAV) epidemiology in Tunisia has changed from high to intermediate endemicity in the last decades. However, several outbreaks continue to occur. The last reported sequences from Tunisian HAV strains date back to 2006. In order to provide an updated overview of the strains currently circulating in Tunisia, a large-scale molecular analysis of samples from hepatitis A cases was performed, the first in Tunisia.
Biological samples were collected from patients with laboratory confirmed hepatitis A: 145 sera samples in Tunis, Monastir, Sousse and Kairouan from 2008 to 2013 and 45 stool samples in Mahdia in 2009. HAV isolates were characterised by nested RT-PCR (VP1/2A region) and sequencing. The sequences finally obtained from 81 samples showed 78 genotype IA and 3 genotype IB isolates.
A Tunisian genotype IA sequence dataset, including both the 78 newly obtained IA sequences and 51 sequences retrieved from GenBank, was used for phylogenetic investigation, including analysis of migration pattern among six towns. Virus gene flow from Sfax and Monastir was directed to all other towns; in contrast, the gene flows from Sousse, Tunis, Mahdia and Kairouan were directed to three, two, one and no towns, respectively.
Several different HAV strains co-circulate in Tunisia, but the predominant genotype still continues to be IA (78/81, 96% isolates). A complex gene flow (migration) of HAV genotype IA was observed, with Sfax and Monastir showing gene flows to all other investigated towns. This approach coupled to a wider sampling can prove useful to investigate the factors underlying the spread of HAV in Tunisia and, thus, to implement appropriate preventing measures.
[Show abstract][Hide abstract] ABSTRACT: Hepatitis E (HEV) is an important public-health concern as a major cause of enterically transmitted hepatitis worldwide. In industrialised countries it is considered rare, and largely confined to travellers returning from endemic areas. However, autochthonous (locally acquired) HEV infection is also emerging in these regions. The infection is caused by different genotypes, depending on whether it is travel-related or autochthonous. Conventional RT-PCR followed by sequencing of PCR products can identify HEV genotype and, depending on the region, the subtype, thus helping in defining the origin of infection and tracing the source of contamination.
We re-analysed a collection of serum samples previously confirmed as hepatitis E positive by anti-HEV IgM and IgG assays as well as by Real-Time PCR, with the aim to compare the performances of five different broad range RT-PCR assays that could be provided for molecular characterisation of HEV. This approach is certainly valuable to investigate the molecular epidemiology of acute hepatitis E in countries where co-circulation of different genotypes occurs, like Italy.
Samples were analyzed by five assays targeting the ORF1, ORF2, and ORF2/3 regions. The sensitivity of these assays varied significantly, depending on the target region. Only 46% of samples tested positive by nested PCR; moreover, no single method was able to detect all positive samples. Most sequences originated from patients who had travelled to endemic areas (genotype 1), while the minority originated from Italian patients with no travel history (genotype 3).
Broad range methods for molecular characterization of HEV still need to be improved to detect all circulating strains.
[Show abstract][Hide abstract] ABSTRACT: Human immunodeficiency virus (HIV-1)-infected patients frequently harbour hepatitis B and C viruses (HBV and HCV, respectively). Possible modifications of the natural history of hepatitis B may occur. The aim of this study was to characterise HBV diversity and evolutionary and mutational viral genome profiles in HIV-1/HBV coinfections.
HIV-1 and HBV markers determinations (Roche, FRG; Abbott, USA) and HBV genome-length retrospective analysis were performed in follow-up isolates from patients who were either stably HBsAg-negative with a low level of HBV DNA (occult hepatitis B infection, OBI) or HBsAg-positive with a high level of HBV DNA. Phylogenetic analysis (maximum likelihood method, MEGA5), statistical analysis and evolutionary rates calculation (d S/d N) were applied.
Positive selection pressures in the PreS/S region and a significantly higher number of mutations in this region including the major hydrophilic region (MHR) and the "a" determinant were shown in HBsAg-negative (possibly OBI) compared to stably HBsAg-positive HIV-1/HBV subgenotypes D3/A2 coinfected patients. Mutants previously described in HIV-1/HBV coinfected patients were found. Known mutants Y100C, P127T and P120A associated to Y134H and S143T and new S mutants, which may potentially affect HBsAg expression and secretion and anti-HBs binding, were detected in baseline sera persisting up to the end of 9 years follow-up. Known mutations of BCP, Pre-C, C and X regions were also characterised. Natural mutants strictly known as being involved in diagnostic failure were not detected; however, numerous corresponding sites showed amino acid variations.
Evolutionary and genotypic differences observed, particularly in the PreS/S region, between HBsAg-negative (OBI) and HBsAg-positive HIV-1/HBV coinfected patients, may contribute, in association with mutations of other genomic regions, to the HBsAg-negative phenotype.
[Show abstract][Hide abstract] ABSTRACT: PURPOSE: The prevalence of anti-hepatitis E virus (HEV) and anti-hepatitis A virus (HAV), as well as the possible links with socio-demographic and other viral risks factors, were evaluated in an inmates population. METHODS: The study population consisted of 973 consecutively recruited inmates of eight Italian prisons. RESULTS: The anti-HEV prevalence was 11.6 % (113/973). It increased significantly by age (χ(2) for linear trend: p = 0.001) and was significantly higher among non-Italian compared to Italian inmates (15.3 vs. 10.7 %, respectively). Age >40 years [odds ratio (OR) 2.1; 95 % confidence interval (CI) 1.4-3.1], non-Italian citizenship (OR 1.8; 95 % CI 1.1-2.9) and anti-HIV seropositivity (OR 2.2; 95 % CI 1.2-4.2) were the only factors independently associated to anti-HEV positivity by logistic regression analysis. The overall anti-HAV prevalence was 86.4 %, and was significantly higher in non-Italian compared to Italian prisoners (92.6 vs. 84.9 %, respectively; p = 0.02). Age older than 40 years (OR 3.6; 95 % CI 2.2-5.9), <5 years formal education (OR 2.1; 95 % CI 1.3-3.2) and non-Italian nationality (OR 2.7; 95 % CI 1.5-4.8) were factors independently associated to anti-HAV positivity by the logistic regression analysis. CONCLUSIONS: Compared to the general population, significantly higher anti-HEV and anti-HAV prevalences were observed in an inmates population in Italy. Old age and non-Italian nationality were factors independently related to both HEV and HAV exposures. This data suggest the important role of low socio-economic factors in the transmission of both infections in high-risk populations. The possible epidemiological and/or pathogenetic links between HEV and HIV exposures need to be studied further.
[Show abstract][Hide abstract] ABSTRACT: BACKGROUND: In a 1996 survey, prevalence of hepatitis C virus antibodies (anti-HCV) in a southern Italian town was 12.6%. AIMS: To identify changes in the epidemiology of hepatitis C virus (HCV) infection. METHODS: Anti-HCV, HCV-RNA (PCR, detection limit 15IU/mL), HCV genotype (Innolipa). Were performed in a random 1:4 systematic sample of the general population. Multiple logistic regression analysis was used to estimate factors independently associated with the likelihood of anti-HCV positivity. RESULTS: Of 1012 subjects, 58 (5.7%) were anti-HCV-positive, compared to 12.6% 14 years earlier. Prevalence was 0.4% in individuals <30 years old and 31.8% in those ≥70 years old. Among 139 HCV-negative in 1996 re-sampled in 2010, only one had seroconverted (incidence: 0.05×100 persons/year). Alanine transaminase levels were elevated in 8 (13.8%). HCV-RNA was detected by PCR in 46.5% anti-HCV-positive subjects. In 2010 59% were genotype 2-infected, in 1996 50.7% genotype 1-infected. Previous use of non-disposable glass syringes was a strong independent predictor (OR 3.2; CI 95%=1.4-7.3). CONCLUSION: Epidemiology of HCV infection in an endemic area of south Italy has changed over 14 years, now largely confined to the oldest age group; this seems to be due to the disappearance of its past main mode of transmission, namely the use of glass syringes.
[Show abstract][Hide abstract] ABSTRACT: In 2005, in accordance with recommendations made by the European Medicines Agency, the Italian Drug Agency ordered withdrawal of the hexavalent Hexavac(®) vaccine (Sanofi Pasteur MSD) from the market. Concerns had been raised about the low immunogenicity of the hepatitis B virus component of the vaccine, assessed by measurement of serum antibody levels, and its potential consequences on long-term protection against hepatitis B infection. We evaluated memory T cell response to establish whether there are differences in the protective mechanisms among children who had received either Hexavac(®) or Infanrix-hexa(®) (GlaxoSmithKline) as their primary vaccination. Immunological memory was determined by measuring the ability of T cells to proliferate and secrete IFNγ by ELISA and intracellular cytokines (IFNγ and IL-2) when cultured with hepatitis B surface antigen (HBsAg). The different memory subsets of T cells were also measured. The results indicate that, although they generate different serum antibody levels, both vaccines are efficient in generating T recall responses in vitro five years after the primary vaccination. The less immunogenic Hexavac(®) vaccine induces a strong T antigen response, as indicated by increased blast proliferation and the enhanced presence of memory subsets after HBsAg recall stimulation. These findings suggest that cellular immune response should be considered alongside serological markers as a surrogate of protection.
[Show abstract][Hide abstract] ABSTRACT: The epidemiological pattern of hepatitis B virus infection in Italy has greatly changed over the past decades. The aim of the study was to evaluate during time the epidemiological features of acute hepatitis B cases referred to an Infectious Disease Unit in North-East of Italy between 1978 and 1995.
Stored sera of 183 cases were tested for HBV markers, HBV genotypes, anti-Delta and anti-HCV.
Anti-HBcIgM was positive in all cases. Mean age increased from 30.2 years in 1978 to 37.5 in 1995 (P<0.01). Significant increase was observed in proportion of cases reporting intravenous drug use from 11.5% to 29.6% (P<0.03). Chronicity rate was as low as 1.1%. Mean days of hospitalization significantly decreased. HBV genotype determination showed that majority of cases was infected by genotype D, but its prevalence decreased from 88.2% in 1978 to 75.0% in 1995. Delta coinfection was present in 8.2%. The prevalence of HCV in patients with acute HBV was 35.0%; it fluctuated from 26.2% to 44.2%, mostly related (53.1%) to intravenous drug use. Dual infection did not lead to a more severe course of disease.
From this retrospective study, remarkable fluctuations in the prevalence of dual HBV-HCV infection before the implementation of HBV vaccination were observed. Presence of anti-HCV did not affect the course of acute HBV.
European Journal of Internal Medicine 09/2012; 23(6):e146-9. DOI:10.1016/j.ejim.2012.03.007 · 2.30 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The impact of hepatitis E in developed countries, like Italy, still requires a clear definition. In the present study, we evaluated HEV infection in patients with acute non-A-C hepatitis by an approach comparing data from Real-time PCR and serological assays.
In a first analysis, sera from 52 patients hospitalized with a diagnosis of acute viral non-A-C hepatitis in Italy were tested by in-house Real-Time PCR assay for identification of Hepatitis E Virus (HEV) RNA and by anti-HEV IgM and IgG assays. In a subsequent analysis, selected samples were evaluated by additional IgM tests to confirm diagnosis.
Among the 52 samples, 21 showed positive results for all three markers (IgM, IgG and HEV RNA). One patient showed HEV RNA as single marker. Uncertain results were found in 8 samples while the remaining 22 were negative for all markers. Further analysis of the 8 undefined samples by additional IgM tests confirmed HEV infection in 1 patient. Overall, acute HEV infections were reliably identified in 23 (44.2%) out of 52 patients.
In the present paper, we performed a study evaluating HEV infection in 52 sporadic non-A-C acute hepatitis cases. All samples were collected from 2004 to 2010 in Italy. By a diagnostic strategy based on genomic and serological assays we identified HEV infections in 23 out of 52 patients (44.2%), a percentage higher than previous estimates. Thus, the actual impact of HEV infections in Italy needs to be further evaluated on a national scale by a diagnostic strategy based on multiple and last generation assays.
BMC Research Notes 06/2012; 5:297. DOI:10.1186/1756-0500-5-297
[Show abstract][Hide abstract] ABSTRACT: The immunogenicity of a vaccine is conventionally measured through the level of serum Abs early after immunization, but to ensure protection specific Abs should be maintained long after primary vaccination. For hepatitis B, protective levels often decline over time, but breakthrough infections do not seem to occur. The aim of this study was to demonstrate whether, after hepatitis B vaccination, B-cell memory persists even when serum Abs decline. We compared the frequency of anti-hepatitis-specific memory B cells that remain in the blood of 99 children five years after priming with Infanrix -hexa (GlaxoSmithKline) (n=34) or with Hexavac (Sanofi Pasteur MSD) (n=65). These two vaccines differ in their ability to generate protective levels of IgG. Children with serum Abs under the protective level, <10 mIU/mL, received a booster dose of hepatitis B vaccine, and memory B cells and serum Abs were measured 2 wk later. We found that specific memory B cells had a similar frequency in all children independently of primary vaccine. Booster injection resulted in the increase of memory B cell frequencies (from 11.3 in 10(6) cells to 28.2 in 10(6) cells, p<0.01) and serum Abs (geometric mean concentration, GMC from 2.9 to 284 mIU/mL), demonstrating that circulating memory B cells effectively respond to Ag challenge even when specific Abs fall under the protective threshold.
European Journal of Immunology 06/2011; 41(6):1800-8. DOI:10.1002/eji.201041187 · 4.52 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The prevalence of viral hepatitis markers and of alcohol intake was evaluated in 106 and 99 Albanian patients with the diagnosis of viral and/or alcoholic chronic liver disease who were consecutively admitted to the University Hospital Center of Tirana, during 1995 and 2005, respectively.
A slight decrease in HBsAg (78 vs. 70%) and HBeAg (18 vs. 12%) prevalences were observed in patients admitted to the hospital during 2005 compared with those admitted during 1995, respectively. In both periods of time, hepatitis B virus (HBV) DNA (genotype D) tested positive in all HBsAg-positive patients and in 36% of HBsAg-negative patients. Anti-hepatitis C virus (HCV) prevalence (mainly observed after 30 years of age) was 14 versus 11%; anti-hepatitis Delta virus (HDV) prevalence (more frequently present in young age group patients) was 9 versus 7% during 1995 and 2005, respectively. Among patients who reported alcohol intake, alcoholic liver disease (HBsAg and anti-HCV negative) was diagnosed in 35 and in 57% of patients admitted during 1995 and 2005, respectively (P = 0.05).
In Albanian patients with chronic liver disease, we have found that: (i) HBV remained the most important aetiologic factor of chronic liver disease; HDV and HCV prevalences were still low, (ii) in HBsAg-positive patients, HBeAg-negative chronic hepatitis prevailed, (iii) in HBsAg-negative patients, HBV DNA prevalence was high, (iv) during the last decade, an increased prevalence of alcohol intake in the aetiology of chronic liver disease was observed.
European journal of gastroenterology & hepatology 10/2009; 22(2):167-71. DOI:10.1097/MEG.0b013e328330d410 · 2.15 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The use of adjuvants capable of improving the deficient immune response to hepatitis B virus (HBV) vaccine in haemodialysis patients is highly needed. Among potential adjuvants, type I interferons deserve a special attention in view of their known effects promoting cellular and humoral immune responses. The aim of the present trial was to evaluate the effects of recombinant interferon-alpha2b (IFN) administered as an adjuvant of HBV vaccine in unvaccinated haemodialysis patients. A significant and early enhancing effect on the antibody response was observed in patients receiving IFN. In addition, a predominance of IgG1 anti-HBs along with a transient normalization of circulating Th1 lymphocytes was only found in patients receiving IFN who achieved an early seroprotection. However, 6 months after the last vaccine dose, no significant differences were observed in the seroprotection rate achieved in patients vaccinated with IFN compared to that in patients receiving HBV vaccine alone. Mild to moderate fever, asthenia, and arthromyalgia were the most common reactions that occurred in vaccinees given IFN. In conclusion, addition of IFN to HBV vaccine, under the conditions used in this trial, is safe and achieves an earlier and higher seroprotection rate improving Th1-dependent immune response in haemodialysis patients.
[Show abstract][Hide abstract] ABSTRACT: To evaluate the presence of HBV-DNA in 22,765 consecutive blood donors, who donated blood in the period from January 2006 to August 2007 at a transfusion centre in Lazio, a region in central Italy with low HBV endemicity.
Each donation was individually tested using immunoenzymatic assays and nucleic acid amplification technologies (NAT). Samples that were reactive to generic NAT, Procleix Ultrio Assay were tested for HBV-DNA, HCV-RNA and HIV1-RNA by Discriminatory Procleix Ultrio NAT Assay. In samples that were reactive to generic NAT and negative for HBsAg, HCV-RNA and HIV1-RNA, HBV-DNA was further tested using Cobas TaqMan and an in-house nested PCR following an ultracentrifugation step. Sequence analysis confirmed HBV-DNA positivity.
Generic NAT identified 31 (0.13%) reactive sera. HBV-DNA discriminatory NAT identified 15 positive sera; HBsAg was positive in 12 sera. Of the 5 generic NAT-reactive/discriminatory NAT-negative/HBsAg-negative sera and of the 3 HBsAg-negative/HBV-DNA discriminatory NAT-positive sera, 7 were positive to Cobas TaqMan or the in-house PCR after ultracentrifugation. The overall HBV-DNA positivity was 0.083% [19 of 22,765 donors: 12 HBsAg-positive (HBV-DNA range 10(2)-10(4) IU/mL), 7 HBsAg-negative/anti-HBc positive (HBV-DNA< 6 IU/mL)].
For blood transfusion safety, the significance of the finding of very low HBV-DNA levels should be further investigated. Our data indicate that in areas with a low HBV endemicity, single NAT assays may not always identify blood donations with very low HBV-DNA levels.
The Journal of infection 07/2009; 59(2):128-33. DOI:10.1016/j.jinf.2009.06.007 · 4.02 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: We conducted an external quality assessment of the results obtained in Italian transfusion centre laboratories employing nucleic acid testing (NAT) for detection of HCV RNA in donated blood.
Of 110 transfusions centres in Italy, 101 voluntarily participated. Each laboratory received seven separate shipments of samples for HCV RNA testing by NAT. Each shipment contained 8 plasma samples for a total of 23 negative and 33 positive samples with viral loads ranging from 25 to 1000 IU/mL.
Of the 2080 HCV RNA-negative samples, 14 (0.7%) were reported as positive. The highest percent of false-negative results (6.9%) was found on samples from the first shipment with viral loads from 75 to 100 IU/mL. In subsequent shipments, the highest false-negative percentage ranged from 0.6% for samples with viral loads of 170-1000 IU/mL to 3.4% for samples with viral loads of 35-50 IU/mL. A false-negative rate of 4.9% occurred in samples in the sixth shipment with the lowest viral load (25IU/mL). Five (4.9%) centres were identified as having laboratories with low-performance. There were no significant differences among genotypes 1b, 2c and 3a with respect to percent of false-negative results reported.
Overall, the accuracy of NAT observed in this study of Italian transfusion centre laboratories was excellent for all HCV genotypes tested, even for samples with low HCV RNA titres.
[Show abstract][Hide abstract] ABSTRACT: HBV vaccine needs 3 injections over 6 months to induce immunity. Thus, the use of adjuvants capable of inducing earlier immune protection would be highly desirable. Most adjuvants may act by inducing cytokines, and among them, type I interferons (IFNs), deserve a special attention in view of the potent immunomostimulatory activity observed in mouse models and on dendritic cell functions. The aim of the present trial was to evaluate the effects of IFN-alpha administered as an adjuvant of HBV vaccine in healthy unvaccinated individuals. No significant enhancing effect on the antibody response was observed, in spite of an early and transient upregulation of costimulatory molecule expression on peripheral blood mononuclear cells, which may be suggestive of an IFN-mediated activation of antigen presenting cells. We conclude that, under the conditions used in this trial, natural IFN-alpha does not act as an adjuvant of the HBV vaccine in healthy unvaccinated individuals.
[Show abstract][Hide abstract] ABSTRACT: In 2001, two hexavalent vaccines were licensed in Italy (Hexavac, Infanrix Hexa), and since 2002 were extensively used for primary immunization in the first year of life (at 3, 5, 11/12 months of age). In 2005, the market authorization of Hexavac was precautionary suspended by EMEA, because of doubts on long-term protection against hepatitis B virus. The objectives of this study were to evaluate the persistence of antibodies to anti-HBs, in children in the third year of life, and to investigate the response to a booster dose of hepatitis B vaccine.
Participant children were enrolled concomitantly with the offering of anti-polio booster dose, in the third year of life. Anti-HBs titers were determined on capillary blood samples. A booster dose of hepatitis B vaccine was administered to children with anti-HBs titers < 10 mIU/ml, with the monovalent precursor product of the previously received hexavalent vaccine. HBsAb titers were tested again one month after the booster.
Sera from 113 children previously vaccinated with Hexavac, and from 124 vaccinated with Infanrix Hexa were tested for anti-HBs. Titers were > or = 10 mIU/ml in 69% and 96% (p < 0,0001) respectively. The proportion of children with titers > or = 100 mIU/ml did also significantly differ among groups (27% and 78%; p < 0,0001).Post-booster, 93% of children achieved titers > or = 10 mIU/ml, with no significant difference by vaccine group.
Fifteen months after third dose administration, a significant difference in anti-HBs titers was noted in the two vaccine groups considered. Monovalent hepatitis B vaccine administration in 3-year old children induced a proper booster response, confirming that immunologic memory persists in children with anti-HBs titers < 10 mIU/ml. However, long-term persistence of HBV protection after hexavalent vaccines administration should be further evaluated over time.
[Show abstract][Hide abstract] ABSTRACT: We compared the E2-HVR1 region in HCV-1b positive B-NHL cases from a multicenter study with sequences from studies related to lymphoproliferative disorders and B cell compartmentalisation. We found rare and unique mutations both in B-NHL isolates and in cases with lymphoproliferative disorders and lymphocyte infection. These rare mutations could have an important effect on HVR1 region and, as a consequence, on the binding of E2 on CD81, with a possible implication for both antigenic stimulation and HCV entry. In conclusion, the HCV predominants circulating in B-NHL cases seem to be associated with clonal selection of rare variants.
The New Microbiologica: official journal of the Italian Society for Medical Virology (SIVIM) 08/2007; 30(3):265-70. · 1.60 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Health care workers (HCW) have an elevated risk of acquiring and transmitting parenteral infections. The aim of this study was to evaluate the prevalence of hepatitis B virus (HBV) and hepatitis C virus (HCV) markers with the final goal to encourage HBV vaccination of the non-immune Albanian HCW.
Among 480 HCW enrolled, 92 were physicians, 246 were nurses/techniques, 120 were auxiliary workers and 22 were office workers.
The HBsAg, anti-HBc and anti-HCV prevalence were 8.1%, 70% and 0.6%, respectively. The highest (11.4%) HBsAg prevalence was observed in the youngest age group (20-30 years of age). High HBsAg prevalence (7.2-7.5%) was detected also in age groups above 30 years. The highest HBsAg prevalence (12.6%) was found in the auxiliaries. The anti-HBc prevalence increased significantly with age from 59% in HCWs younger than 39 years to 87% among those older than 50 years. After adjustments for different job categories, age older than 40 years remained independently associated with anti-HBc positivity (OR = 2.9; 95% CI 1.9-4.6) and inversely associated with the lack of HBV immunity or infection markers (OR = 0.4; 95% CI 0.2-0.7). Of 142 HBsAg negative and/or anti-HBc Ab negative sera, 28 (20%) tested positive for anti-HBs. The 114 remaining individuals with no HBV infection or immunity markers were vaccinated against HBV infection.
A high HBV infection rate and low HBV vaccination coverage were found in Albanian HCW. Albania is a Mediterranean country still highly endemic for HBV infection and new strategies to promote HBV vaccination are to be adopted.
[Show abstract][Hide abstract] ABSTRACT: Reported here are details of a simultaneous outbreak of hepatitis B virus (HBV) and hepatitis C virus (HCV) infections that occurred in a hemodialysis centre in northern Italy, with three patients seroconverting for HBsAg and four patients seroconverting for HCV antibodies. Phylogenetic analysis of the E2 region of the isolates from HCV-seroconverted patients showed the sequences were grouped in the same distinct branch as in a chronically HCV-infected patient, suggesting that the chronically infected patient was the index case. For the patients with HBV infection, phylogenetic analysis showed strong clustering among the sequences of the three patients who seroconverted to HBsAg and no relatedness between them and the sequences of patients chronically infected with HBV. For one of the patients who seroconverted to HBsAg, the last test with negative results for HBV markers had been performed 18 months prior to HBsAg seroconversion. This patient may have been previously infected with HBV and is presumed to be the source of the outbreak. This report emphasizes the importance of using universal precaution measures and HBV vaccination to prevent the transmission of viral hepatitis among chronic hemodialysis patients.
European Journal of Clinical Microbiology 09/2006; 25(8):527-31. DOI:10.1007/s10096-006-0162-7 · 2.67 Impact Factor