Elisabeth Lampe

Decline of hepatitis C infection in hemodialysis patients in Central Brazil: a ten years of surveillance

Hepatitis C virus (HCV) has been a significant problem for hemodialysis patients. However this infection has declined in regions where the screening for anti-HCV in blood banks and hemodialysis-specific infection control measures were adopted. In Brazil, these measures were implemented in 1993 and 1996, respectively. In addition, all studied units have implemented isolation of anti-HCV positive patients since 2000. In order to evaluate the impact of these policies in the HCV infection prevalence, accumulated incidence, and risk factors in hemodialysis population of Goiânia City, Central Brazil, all patients were interviewed and serum samples tested for HCV antibodies in 1993, 1996, 1999, and 2002. In the first six years (1993-1999), anti-HCV prevalence increased from 28.2 to 37.2%, however a b decrease in positivity was detected between 1999 and 2002 (37.8 vs 16.5%) when the measures were fully implemented. Also, a decrease of the anti-HCV accumulated incidence in cohorts of susceptible individuals during 1993-2002 (71%), 1996-2002 (34.2%), and 1999-2002 (11.7%) was found. Analysis of risk factors showed that length of time on hemodialysis, blood transfusion before screening for anti-HCV and treatment in multiple units were statistically associated with anti-HCV (p < 0.05). Our study showed a significant decline of hepatitis C infection in hemodialysis patients of Central Brazil, gratifying the importance of public health strategies for control and prevention of hepatitis C in the hemodialysis units.

Molecular detection of hepatitis A virus in urban sewage in Rio de Janeiro, Brazil.

Aims:  A one‐year survey was conducted to examine hepatitis A virus (HAV) prevalence, distribution of genotypes and their relationship to bacterial indicators in raw and treated sewage samples.

Assessment of dried blood spot samples as a simple method for detection of hepatitis B virus markers

Detection of hepatitis B virus (HBV) serological markers in dried blood spot (DBS) samples by enzyme immunoassay (ELISA) has not yet been fully optimized. In this study, the ability to detect three HBV markers (HBsAg, anti‐HBc, and anti‐HBs) was evaluated in DBS samples using a modified commercial ELISA. Matched serum and DBS samples were obtained from individuals with or without a past history of HBV infection. Sera samples were tested according to the manufacturers instructions, but for DBS testing, paper diameters, elution buffer, volume of input sample, and cut‐off values were evaluated to optimize the assay. Stability studies were done on DBS stored at for up to 180 days at different temperatures. The absorbance values that yielded the maximum sensitivity and specificity were determined based on the area under the ROC curve (AUROC) and chosen as the cut‐off value. Using this parameter, sensitivity was 90.5%, 97.6%, and 78% for anti‐HBc, HBsAg, anti‐HBs assays, respectively. Specificity was 92.6%, 96.7%, and 97.3% for anti‐HBc, HBsAg, and anti‐HBs assays, respectively. HBV markers could be detected in DBS samples until 63 days after sample collection at most temperatures, but storage at −20°C yielded more consistent results. These results indicate that modified ELISA can be used to detect HBV markers in DBS samples, particularly if the samples are stored appropriately. J. Med. Virol. 83:1522–1529, 2011.

Hepatitis C virus-associated thrombocytopenia: a controlled prospective, virological study

Chronic hepatitis C virus (HCV) infection has also been associated with the development of several extrahepatic alterations, including thrombocytopenia, and a variety of pathogenic mechanisms are reported to be implicated in this hematological abnormality. Different studies have succeeded in detecting HCV in platelets with discrepant results. Moreover, most of the studies on HCV-associated thrombocytopenia have failed to provide data concerning the infecting genotype, a factor with prognostic implication in chronically HCV-infected patients. To determine whether thrombocytopenia is an extrahepatic alteration dependent on particular HCV genotypes, and to assess the relationship between thrombocytopenia and detection of HCV-RNA (positive strand) in platelets from patients with chronic HCV infection, 106 anti-HCV+/HCV-RNA+ patients (57 thrombocytopenic and 49 non-thrombocytopenic) were prospectively studied. The infecting genotype was analyzed from sera by using direct nucleotide sequencing of the polymerase chain reaction (PCR) products from core region. Genotypes 1a, 1b, and 3a were more prevalent in our patients, and no association between these genotypes and thrombocytopenia was observed (p=0.891). HCV-RNA was detected in platelets by reverse transcriptase (RT)-nested PCR in the 5’ non-coding region with a higher frequency (60%) in thrombocytopenic patients than in non-thrombocytopenic subjects (35%, p=0.017), suggesting that HCV is directly involved in the process that, at least in part, leads to thrombocytopenia.

Association between vitamin D and hepatitis C virus infection: A meta-analysis

AIM To evaluate the association between 25-hydroxyvitamin D [25(OH)D] and sustained virological response (SVR) in hepatitis C virus (HCV) infected individuals. METHODS Relevant studies were identified by systematically searching MEDLINE databases up to March 2012 and abstracts of the European and American Congress of Hepatology conducted in 2011. Studies must provide information on SVR and the levels of 25(OH)D₃ and/or 25(OH)D₂ [henceforth referred to as 25(OH)D] in sera samples from HCV infected individuals. The inclusion criteria were: clinical studies that included HCV infected patients aged older than 18 years regardless of HCV genotype or ethnic group; provided information on SVR rates; and were reported in the English language as full papers. Due to the heterogeneity of studies in categorizing serum vitamin D levels, a cut-off value of 30 ng/mL of serum 25(OH)D was used. Heterogeneity was assessed using I² statistics. The summary odds ratios with their corresponding 95%CI were calculated based on a random-effects model. RESULTS Overall, 11 studies (8 observational and 3 interventional) involving 1575 individuals were included and 1117 HCV infected individuals (71%) showed low vitamin D levels. Most of the studies included mono-infected HCV individuals with the mean age ranging from 38 to 56 years. Four studies were conducted in human immunodeficiency virus/HCV infected individuals. Regarding vitamin D measurement, most of the studies employed radioimmunoassays (n = 5) followed by chemiluminescence (n = 4) and just one study employed high performance/pressure liquid chromatography (HPLC). Basal vitamin D levels varied from 17 to 43 ng/mL in the studies selected, and most of the HCV infected individuals had genotype 1 (1068/1575) with mean viral load varying from log 4.5-5.9 UI/mL. With regard to HCV treatment, most of the studies (n = 8) included HCV individuals without previous treatment, where the pooled SVR rate was 46.4%. High rates of SVR were observed in HCV individuals with vitamin D levels above 30 ng/mL (OR = 1.57; 95%CI: 1.12-2.2) and those supplemented with vitamin D (OR = 4.59; 95%CI: 1.67-12.63) regardless of genotype. CONCLUSION Our results demonstrated high prevalence of vitamin D deficiency and high SVR in individuals with higher serum vitamin D levels or receiving vitamin D supplementation.

Genetic variability of hepatitis A virus isolates in Rio de Janeiro: implications for the vaccination of school children

The epidemiology of hepatitis A virus (HAV) infection is shifting from high to intermediate endemicity in Brazil, resulting in increased numbers of susceptible individuals and a greater potential for the emergence of outbreaks. Universal vaccination against HAV has been recommended for children, but updated sero-epidemiological data are necessary to analyze the level of natural immunity and to identify candidates for preventive measures. In addition, more molecular studies are necessary to characterize the genotypes involved in HAV infections and outbreaks. Sera from 299 school children (5-15 years old) and 25 school staff members, collected during an outbreak of HAV at a rural public school in June 2000, were tested for IgM and total anti-HAV antibodies (ELISA). Viral RNA was amplified by RT-PCR from anti-HAV IgM-positive sera and from 19 fecal samples. Direct nucleotide sequencing of the VP1/2A region was carried out on 18 PCR-positive samples. Acute HAV infection was detected by anti-HAV IgM in 93/299 children and in 3/25 adult staff members. The prevalence of total anti-HAV antibodies in IgM-negative children under 5 years of age was only 10.5%. HAV-RNA was detected in 46% IgM-positive serum samples and in 16% stool samples. Sequence analysis showed that half the isolates belonged to subgenotype IA and the other half to IB. On the basis of these data, mass vaccination against HAV is recommended without prevaccination screening, especially for children before they enter school, since nearly 90% of the children under 5 years were susceptible. Molecular characterization indicated the endemic circulation of specific HAV strains belonging to subgenotypes IA and IB.

Epidemic history of Hepatitis C virus in Brazil

Hepatitis C virus (HCV) subtypes 1a, 1b and 3a are the most prevalent strains in Brazil, but very little is known about the epidemic history of these subtypes in the country. A total of 231 HCV NS5B gene sequences (subtype 1a=89, subtype 1b=56, and subtype 3a=86) isolated in Brazil between 1995 and 2007 were analyzed in the present study. Sequences (328-pb) were subjected to phylogenetic analyses and statistical tests of phylogenetic mixing by sampling location and risk group. Our results revealed important variations in the pattern of HCV transmission among subtypes. Transmission of subtype 1a was characterized by dissemination of one major Brazilian lineage with a random virus exchange between different geographical regions but not between IDU and non-IDU populations. Transmission of subtype 1b was characterized by concurrent dissemination of multiple HCV lineages with a restricted virus exchange between country regions and risk groups. Transmission of subtype 3a was characterized by simultaneous spreading of multiple HCV lineages and random phylogenetic mixing by risk group and sampling location. Epidemic histories of major subtypes 1a, 1b and 3a Brazilian clades were estimated using a Bayesian coalescent approach. Our results indicate that all major HCV Brazilian clades probably start to circulate in the country during the second half of the 20th century and displayed roughly similar epidemic histories characterized by an initial phase of exponential expansion and by reduction of growth rates since 1980-1995. This suggests that the expansion of HCV may have been effectively controlled in Brazil.

Infection with GB virus C/hepatitis G virus in Brazilian hemodialysis and hepatitis patients and asymptomatic individuals.

Recently, sequences from a novel human flavivirus, termed GB virus C (GBV‐C) or hepatitis G virus (HGV), have been identified in serum from patients with cryptogenic hepatitis and others. Sera from 116 patients with different clinical backgrounds were tested for the presence of GBV‐C/HGV RNA by a reverse transcription‐polymerase chain reaction with primers from the nonstructural (NS) 5 region. Ten (15%) patients on maintenance hemodialysis and 5 (19%) non A‐C hepatitis patients with GBV‐C/HGV RNA positive, along with one patient with chronic hepatitis B, one patient with chronic hepatitis C, and two asymptomatic individuals. Sequence comparison within 354 base pairs in the NS5 region showed homology rates varying from 87% to 97% among five Brazilian isolates, and from 86% to 93% between Brazilian strains and GBV‐C/HGV isolates from other countries previously sequenced. Homology rates were higher at the amino acid level since most substitutions occurred at the third nucleotide position of codons without changing the codon meaning. J. Med. Virol. 52:61–67, 1997.

Prospective Follow-Up of Patients with Acute Hepatitis C Virus Infection in Brazil

BACKGROUND The natural outcome of infection with hepatitis C virus (HCV) varies substantially among individuals. However, little is known about host and viral factors associated with a self-limiting or chronic evolution of HCV infection. METHODS From 1 January 2001 through 31 December 2008, a consecutive series of 65 patients from Rio de Janeiro, Brazil, with a well-documented diagnosis of acute HCV infection, acquired via various routes, were enrolled in this study. Patients were prospectively followed up for a median of 40 months after the estimated date of HCV infection with serial measurements of serum alanine aminotransferase, HCV RNA, and anti-HCV antibodies. Spontaneous viral clearance (SVC) was defined as undetectable levels of HCV RNA in serum, in the absence of treatment, for 3 consecutive HCV polymerase chain reaction tests within the first 6 months of follow-up. Cox proportional hazards regression was used to identify host and viral predictors of SVC. RESULTS The cumulative rate of SVC was 44.6% (95% confidence interval, 32.3%-57.5%). Compared with chronic HCV evolution, patients with self-limiting disease had significantly lower peak levels of anti-HCV antibodies (median, 109.0 vs 86.7 optical density-to-cutoff ratio [od/co]; P<.02), experienced disease symptoms more frequently (69.4% vs 100%; P<.001), and had lower viral load at first clinical presentation (median, 4.3 vs 0.0 log copies; P=.01). In multivariate analyses, low peak anti-HCV level (<93.5 od/co) was the only independent predictor for SVC; the hazard ratio compared with high anti-HCV levels (> or =93.5 od/co) was 2.62 (95% confidence interval, 1.11-6.19; P=.03). CONCLUSION Our data suggest that low levels of anti-HCV antibodies during the acute phase of HCV infection are independently related to spontaneous viral clearance.

Age-specific prevalence and genetic diversity of GBV-C/hepatitis G virus in Brazil

The recently discovered GBV‐C/hepatitis G virus (GBV‐C/HGV) has been shown to be parenterally transmitted. The occurrence of community‐acquired GBV‐C/HGV infections has also been reported. In order to study the variations with age of the GBV‐C/HGV prevalence, sera from 268 individuals without liver disease, aged 0–80 years, and living in the city of Rio de Janeiro, Brazil, were tested by reverse transcription‐nested polymerase chain reaction for the presence of GBV‐C/HGV RNA. Age‐specific seroprevalence was low (2.3%) among children under the age of 10, reached a maximum of 18% in young adults (21–30 years), and declined in older age groups. Among 170 blood donors aged 18–60, the rate of individuals with antibodies against the viral envelope E2 protein increased with age, from about 6% between the ages of 18 and 24 to about 35% for individuals from the age of 43 to 60. The results suggest that sexual transmission of GBV‐C/HGV might occur and that the virus could be eliminated after a long period of infection. The nucleotide sequences of GBV‐C/HGV genome fragments, 422 base pairs (bp) in the E2 region and 354 bp in the nonstructural 5 region, were determined for 11 and 31 isolates, respectively. Phylogenetic tree based on concatenated E2+NS5 sequences showed that Brazilian strains belonged to three clusters, two of which were previously characterized as genotypes 1 and 2. J. Med. Virol. 56:39–43, 1998.