B. Frider

HCV genomic characterization was performed by nucleotide sequence analysis (n=50) combined with restriction fragment length polymorphism (RFLP) of the 5' UTR region in 82 isolates corresponding to different Argentine groups. Genotype 1 was detected in 70.7% of the samples (58 out of 82), genotype 2 in 21.9% (18 of 82) and genotype 3 in the remaining 6 sera (7.3%). HCV 1b subtype contributed with 35.3% to the whole population studied (29 to 82) and was detected in 6 out of 21 sporadic cases. Besides their epidemiological significance, these results should be taken into account when future vaccines are considered on the basis of geographical HCV genotypic prevalence.

The aim of this study was to evaluate the prevalence of antibodies to hepatitis C virus (anti-HCV) in health-care workers (HCW). Sera from 439 unselected HCW were assessed for anti-HCV by 2nd generation enzyme-linked immunoassay (ELISA) and anti-HBc by ELISA. Anti-HCV (+) sera were evaluated by line immunoassay (LIA) (LiaTeK, Organon). Anti-HCV proved positive by ELISA in 12 (2.73%) subjects, 6 of whom were reactive by LIA, one was indeterminate and 5 non reactive. The prevalence of anti-HCV confirmed by LIA was 1.59% (7 subjects). Positive anti-HCV results with an ELISA ratio greater than 3 were LIA reactive in 6/6 as compared with 5 LIA non reactive with an ELISA ratio less than 2, while in the indeterminate serum the ratio was 2.5. No differences in age, profession, seniority, history of hepatitis or transfusions were found between anti-HCV (+) and (-) subjects, but females predominate significantly. The areas of higher risk were hemodialysis, obstetrics, surgery and intensive ca...

The last 30 years have seen an impressive use of ultrasonography (US) in many fields of veterinary and clinical medicine and the technique is being increasingly applied to a wide variety of parasitic infections including the cestode zoonoses Echinococcus granulosus and E. multilocularis. US provides real-time results which are permanently recordable with a high resolution and diagnostic accuracy. These properties, coupled with the clinical value of the images obtained and the non-invasive nature of the test which is safe, require no special patient preparation time; it is easy to operate and this has resulted in the establishment of US as the diagnostic technique of choice for cystic (CE) and alveolar (AE) echinococcosis. The lack of ionizing radiation and side-effects mean that examination times are not restricted. The hand-held probes facilitate what amounts to a rapid, bloodless non-invasive laparotomy, enabling a search from an infinite number of angles for lesions producing information on their number, size and type of cysts, their location and clinical implications. Such clinical information has facilitated the development of treatment protocols for different cyst types. Less invasive surgical techniques, such as US guidance for PAIR (Puncture, Aspiration, Injection, Re-aspiration), PAIRD (PAIR plus Drainage) or PPDC (Percutaneous Puncture with Drainage and Curettage) are also possible. Longitudinal US studies have facilitated monitoring the effects of the outcome of treatment and chemotherapy. Portable ultrasound scanners which today weigh as little as a few pounds, powered by battery or generators have facilitated the use of the technique in mass community-based screening studies. The majority of these studies have been conducted in remote, low socio-economic areas where there were few, if any, hospitals, veterinary facilities, schools or trained personnel. The surveys led to the discovery of unexpectedly high prevalences of CE and AE in asymptomatic individuals of endemic areas and especially amongst transhumant or nomadic pastoralists living in various parts of the world. Screening for CE and AE is justified as an early diagnosis leads to a better prognosis following treatment. The application of US in field and clinical settings has led to a better understanding of the natural history of CE and AE and to the development of a WHO standardized classification of cyst types for CE. This classification can be used in helping define the treatment options for the different cysts found during the surveys, which in turn can also be used to calculate the public health cost of treating the disease in an endemic community. The case mix revealed can also influence the specificity (particularly proportions of cyst types CE4 and CE5 and cystic lesions--CL) of US as a diagnostic test in a particular setting. Community based US surveys have provided new insights into the public health importance of CE and AE in different endemic settings. By screening whole populations they disclose the true extent of the disease and reveal particular age and sex risk factors. Through the treatment and follow-up of all infected cases found during the mass screening surveys a drastic reduction in the public health impact of the disease in endemic communities can be achieved. Educational impacts of such surveys at the national, community and individual levels for both professional and lay people are beginning to be appreciated. The translation of the information gained into active control programmes remains to be realized. In areas where intermediate hosts, such as sheep and goats, are not slaughtered in large numbers mass US screening surveys to determine the prevalence of CE in livestock has proved possible. Longitudinal studies in such intermediate hosts would reveal changes in prevalence over time, which has been used as a marker for control success in other programmes. Mass US screening surveys in an ongoing control programme in Argentina has demonstrated the early impact of control in the human population and identified breakthroughs in that control programme. Mass US screening surveys must adhere to the highest ethical standards and the outcome of surveys should result in the application of appropriate WHO recommended treatment options for different cyst types. Follow-up strategies have to be in place prior to the implementation of such surveys for all infected individuals who do not require treatment and for all suspected, but not confirmed, cases found during the surveys. The use of US in community screening surveys has revealed the complexity of ethical issues (informed consent, confidentiality, follow-up, detection of lesions that are not the focus of the study etc) and also provided real solutions to providing the most ethical guidelines for the early detection and treatment of CE and AE.

Hepatitis B virus (HBV) immune escape mutants with point mutations within the S gene may arise during the natural course of HBV infection, due to a positive selection pressure exerted by the host immune response. Mutations within the immunodominant B and T cell epitopes of hepatitis B surface antigen (HBsAg) allow the resulting S-mutants to propagate even in the presence of neutralizing anti-HBs antibodies and the HBV-specific T-cell immune response. To study the antiviral effect of Pegylated-interferon (Peg-IFN) in a patient with chronic hepatitis B carrying unusual S-(and P-) mutants in the presence of anti-HBs antibodies. We report on a 43-year-old male chronically infected with a genotype A HBV strain, with cocirculation of both HBsAg and anti-HBs antibodies, who received treatment with 120 mug of Peg-IFN for 24 weeks. HBeAg seroconversion and clearance of both HBV DNA by polymerase chain reaction and HBsAg were successfully achieved. Improved histology was observed in a biopsy performed 44 weeks after Peg-IFN therapy was completed. It seems plausible that the ascribed genotype A could have contributed to the effective response to Peg-IFN, even though the treatment was provided only throughout a 24-week period. To our knowledge, this is the first report regarding the successful result obtained by using Peg-IFN as a treatment for a chronically HBV-infected patient carrying HBsAg immune escape mutants.

Prevalence rates of hepatocellular carcinoma (HCC)-associated hepatitis B virus (HBV) pre-S mutants among most genotypes are still lacking. In this study, viral (sub)genotypes of 70 Argentine nucleotide sequences (33 newly obtained) were determined by phylogenetic analysis, and the presence of such mutants was assessed in the American continent for the first time. Nucleotide substitutions of the pre-S2 start codon were observed in 10% of the HBV/A2 sequences. Ten per cent of the HBV/A2 and 12.5% of the HBV/F1b - but none of HBV/F4 - exhibited a deletion in the pre-S1/pre-S2 region. The contribution of these variants to liver cirrhosis (LC) and/or HCC development among HBV/F and HBV/A isolates deserves further prospective clinical studies.

Kasabach-Merrit syndrome (KMS) is very rarely observed in adults associated with visceral hemangiomas. Hepatic epithelioid hemangioendothelioma (HEHE) is a very rare clinical entity with an intermediate malignant potential and a mortality rate of 20-30%. We described a case of KMS associated with HEHE in a 70 year old male patient who presented coagulation abnormalities, low platelet count and high fibrin degradation products that were typical features of KMS. Histopathology of the hepatic tissue and a positive immunostaining for endothelial markers confirmed the diagnosis of an HEHE. The first description of KMS was made in children in 1940. It was described as a "consumptive coagulopathy with capillary hemangiomas". However, recent reports have shown that this condition could be associated with kaposiform hemangioendotheliomas, an aggressive form of giant hemangioma. A giant hemangioma in adults as well as an hemangioendothelioma in children could be associated KMS, but an HEHE has been rarely reported in association with this syndrome in adult patients.