Single-step real-time PCR to quantify hepatitis B virus and distinguish genotype D from non-D genotypes

Hepatitis B virus (HBV) viral load and its genotype play important roles in clinical outcome, management of disease and response to antiviral therapy. In many parts of the world such as Europe or the Middle East, distinguishing HBV genotype D from non-D is most relevant for treatment decisions, because genotype D-infected patients respond poorly to interferon-based therapeutic regimens. Here, we developed an in-house real-time PCR to concordantly assess HBV genotype (D vs non-D) based on melt curve analysis and quantify the viral load. Genotype distinction was established with control plasmids of all HBV genotypes and validated with 57 clinical samples from patients infected with six different HBV genotypes. Our in-house real-time PCR assay could discriminate HBV genotype D from non-D using single-step melt curve analysis with a 2 °C difference in the melt curve temperature in all samples tested. Viral load quantification was calibrated with the WHO HBV international standard, demonstrating an excellent correlation with a commercial kit (r = 0.852; P < 0.0001) in a linear range from 3.2 × 10(2) to 3.2 × 10(10) IU/mL. In conclusion, we developed a rapid, simple and cost-effective method to simultaneously quantify and distinguish HBV genotypes D from non-D with a single-step PCR run and melt curve analysis. This assay should be a useful diagnostic alternative to aid clinical decisions about initiation and choice of antiviral therapy, especially in geographical regions with a high prevalence of HBV genotype D.

HBV subgenotype misclassification expands quasi-subgenotype A3

Recently, we proposed a new classification for 'subgenotype A' of hepatitis B virus (HBV), in which the novel 'quasi-subgenotype A3' group comprising HBV 'subgenotype A3', 'tentative A4', and A5 was introduced. Newly 'Tentative subgenotype A7' strains from Cameroon were introduced by Hubschen et al. However, our meticulous phylogenetic analysis demonstrated that these isolates should also be classified into 'quasi-subgenotype A3'. Such misclassification can be avoided by following established principles for HBV subgenotyping. Moreover, their close evolutionary relationship with A3 highlights our hypothesis that geographical origin may be an important factor in further classification of HBV subgenotypes.

Evaluation of the use of a combined HCV antigen/antibody assay in routine laboratory practice

BACKGROUND

Combined hepatitis C virus (HCV) antigen/antibody (Ag/Ab) assays offer the advantage of a shorter window phase compared to traditional anti-HCV antibody assays. These assays have been extensively evaluated for the screening of healthy blood donors, but not in routine laboratory practice.

METHODS

We evaluated the performance of the combined HCV Ag/Ab assay Monolisa Ultra and compared it to Monolisa anti-HCV Plus (which only detects anti-HCV antibodies) in 61 HCV RNA-positive patients (genotypes 1 to 5) and in 276 consecutive AxSYM HCV-reactive patients. Discordant sera were tested with immunoblot and PCR.

RESULTS

All 61 PCR-positive sera were positive with AxSYM, Monolisa Ultra, and Monolisa Plus. Of the 276 consecutive AxSYM-reactive patients, 177 were confirmed as HCV-positive, 78 were HCV-negative and 21 were HCV-indeterminate. There were 4 false-positive results with Monolisa Ultra compared to 1 false-positive result with Monolisa PLus. The signal/cut-off ratio in immunoblot-negative sera was significantly higher with HCV Ultra compared to HCV Plus (p < 0.01). Sensitivity and specificity in AxSYM-reactive sera were 99.4% and 94.9% for Monolisa Ultra and 99.4% and 98.7% for Monolisa Plus.

CONCLUSION

When used as a secondary test, the sensitivity of the combined HCV Ag/Ab assay Monolisa Ultra was excellent, but specificity was reduced in AxSYM-reactive sera compared to Monolisa Plus.

Evidence for a complex mosaic genome pattern in a full-length hepatitis C virus sequence

The genome of the hepatitis C virus (HCV) exhibits a high genetic variability. This remarkable heterogeneity is mainly attributed to the gradual accumulation of mutational changes, whereas the contribution of recombination events to the evolution of HCV remains controversial so far. While performing phylogenetic analyses including a large number of sequences deposited in the GenBank, we encountered a full-length HCV sequence (AY651061) that showed evidence for inter-subtype recombination and was, therefore, subjected to a detailed analysis of its molecular structure. The obtained results indicated that AY651061 does not represent a "simple" HCV 1c isolate, but a complex 1a/1c mosaic genome, showing five putative breakpoints in the core to NS3 regions. To our knowledge, this is the first report on a mosaic HCV full-length sequence with multiple breakpoints. The molecular structure of AY651061 is reminiscent of complex homologous recombinant variants occurring among other members of the flaviviridae family, e.g. GB virus C, dengue virus, and Japanese encephalitis virus. Our finding of a mosaic HCV sequence may have important implications for many fields of current HCV research which merit careful consideration.

JC viral loads in patients with Crohn's disease treated with immunosuppression: can we screen for elevated risk of progressive multifocal leukoencephalopathy?

BACKGROUND AND AIMS

Anti-alpha4 integrin therapy with natalizumab is efficacious in refractory Crohn's disease and in multiple sclerosis, but carries an estimated 1/1000 risk of progressive multifocal leukoencephalopathy (PML) caused by reactivation of latent JC virus infection. Although anti-alpha4 integrin therapies are likely to be introduced in the clinic, screening for the risk of PML has not been developed.

METHODS

We prospectively collected urine, serum, plasma and buffy coats from 125 patients with Crohn's disease, 100 control subjects with gastrointestinal (GI) disease, and 106 healthy volunteers. Four to eight weeks after this first sample collection, we additionally collected a set of urine, serum, plasma and buffy coat samples from the 125 patients with Crohn's disease, and a next set of samples was collected 12-16 weeks after the first collection. JC viral loads were determined with quantitative real-time polymerase chain reaction (PCR), and JC virus seroprevalence with a specific enzyme-linked immunosorbant assay (ELISA).

RESULTS

The overall JC virus seroprevalence was 65%. JC virus DNA copies were detected in the urine from 29-44% of subjects, both those with Crohn's disease and controls. Median viral loads were significantly higher in patients with Crohn's disease who were immunosuppressed (7.36x10(6) copies/ml) compared to healthy volunteers (2.77x10(5) copies/ml) and compared to GI controls (1.8x10(6) copies/ml). Clearance at any time point occurred in 4/107 (3.7%) subjects only. JC viraemia was found in two patients with Crohn's disease.

CONCLUSIONS

The natural history of JC virus in patients with Crohn's disease is still unknown. Our study results show that JC virus latency and urine viral shedding is frequent in immunosuppressed patients with Crohn's disease. More prospective studies are needed in order to agree on possible recommendations concerning the exclusion of patients with JCV viraemia from anti-alpha4 integrin treatment.

[Primary peritonitis combined with streptococcal toxic shock syndrome following an upper respiratory tract infection caused by Streptococcus pyogenes]

A 52-year-old woman with no previous history of major health problems presented with an acute abdomen and symptoms of shock. Three days earlier she had been diagnosed as having acute laryngitis which was treated with steroids. On admission she was suffering from hypotension, renal failure, liver failure and coagulopathy. Emergency laparotomy revealed purulent fluid spread diffusely throughout the abdominal cavity. Streptococcus pyogenes was grown in culture from this fluid, enabling a diagnosis of streptococcal toxic shock syndrome (STSS) with primary peritonitis to be made. This combination is rare, and has been described only a few times. Only one other patient is known in whom this combination was preceded by respiratory symptoms. The treatment consists of abdominal lavage, intravenous administration of antibiotics and immunoglobulins, and support for renal function, liver function, respiration and coagulation.

Posttransplant Epstein-Barr virus-associated myogenic tumors: case report and review of the literature

Epstein-Barr virus (EBV) has been implicated in the pathogenesis of different types of malignancies. While nonmelanoma skin cancers, lymphomas and Kaposi sarcomas are the most frequently reported malignancies after solid organ transplantation, EBV-associated smooth muscle tumors (EBV-SMT) after transplantation are rare and thus far only 18 cases in kidney recipients have been reported. A case of a 51-year-old kidney transplant recipient diagnosed with EBV-SMT is reported together with a review of the literature.

Molecular epidemiology of hepatitis C among drug users in Flanders, Belgium: association of genotype with clinical parameters and with sex- and drug-related risk behaviours

The aim of this study was to determine the genotypic variation of hepatitis C among drug users in Flanders and to relate the distribution of genotypes to the characteristics of the population. Hepatitis C virus RNA (HCV-RNA) quantification and genotyping was performed on stored samples from 161 anti-HCV-positive injecting and non-injecting drug users. Information on sociodemographic status, drug-related risk behaviour and sexual risk behaviour was available for each drug user. HCV-RNA was present in 152 of 161 samples (94.4%). Genotype 1 was predominant (48.7%), followed by genotype 3 (41.2%), genotype 4 (8.8%) and genotype 2 (1.4%). In the multivariate analysis, lack of a history of injecting drug use was confirmed as a statistically significant predictor for infection with genotype 1. Predictors for infection with genotype 3 were the presence of anti-HBc antibodies and a history of injecting drug use. Being tattooed emerged as a statistically significant predictor for infection with genotype 4. The 94.4% prevalence of HCV-RNA among anti-HCV-positive drug users was considerably higher than the 54-86% chronicity rate found globally among HCV-infected patients. The results of this study suggest the existence of separate transmission networks for injecting drug users and non-injecting drug users. Finally, the results suggest that tattooing practices play a role in the spread of HCV among drug users.

Bilateral acute retinal necrosis in a 12-year-old girl

Acute retinal necrosis (ARN) is a severe ocular syndrome consisting of a moderate-to-severe anterior uveitis, vasculitis, and vaso-occlusive retinal necrosis. It can occur in healthy individuals at any age, but reports of this condition in children are rare.

An outbreak of nosocomial hepatitis B virus infection in a nursing home for the elderly in Antwerp (Belgium)

After notification of a case of fulminant hepatitis B virus (HBV) infection in a 83-year-old female resident of a nursing home to the Flemish Health Inspectorate, a seroepidemiological study and a retrospective cohort study were conducted among the 94 residents and 47 nursing staff to assess the extent of HBV transmission and to identify risk factors. Susceptible residents were vaccinated against HBV and their serological response to hepatitis B vaccination determined. From December 2002 to April 2003, five residents with acute hepatitis B infection were identified with an attack rate of 5.5% and a case fatality rate of 40%. Three other residents were identified as HBV surface antigen and e-antigen positive carrier. None of the nursing staff tested positive for acute HBV infection or HBV carriage. Diabetic patients who were exposed to a shared finger-stick device for blood sampling were 10.7 times more likely to contract an acute HBV infection (RR 10.7; 95% CI 1.3-91.3). Other potential risk factors were undergoing podiatric care and being exposed to the shared razor blade of the hairdresser. The transmission of the infection could be controlled by restricting the use of finger-stick capillary sampling devices to individual patients, assigning separate glucometers to individual patients and, implementation of standard infection-control recommendations like wearing gloves and performing hand hygiene by the nursing staff, assigning separate podiatric sets to individual patients. HBV vaccination of the residents with three doses of HBV vaccine has not induced a sufficient degree of protection. The outbreak stresses the need for appropriate and generally applied standard procedures in nursing homes to prevent bloodborne pathogens.

The epidemiology of hepatitis C among injecting drug users in Belgium

In industrialised countries, injecting drug use is currently the most important risk factor for infection with hepatitis C, resulting in high prevalence rates of hepatitis C among injecting drug users. To contain the hepatitis C epidemic major efforts should be done to prevent new infection among injecting drug users. Monitoring infection rates are crucial as it may provide feedback on the effectiveness of interventions. In this article the epidemiology of hepatitis C among injecting drug users in Belgium is briefly reviewed. More specifically the prevalence of anti-HCV antibodies, the prevalence of co-infections, the proportion of chronic HCV carriers, the distribution of genotypes and preventive measures among injecting drug users in Belgium are discussed and compared to the situation elsewhere in Western Europe.

Substance use in Belgium : prevalence and management

Substance use is emerging in Belgium. The 'typical user' starts at a young age. Polydrug use has become very common. Cannabis and alcohol are the most frequently used substances among the school population. Heroin and cocaine are the most frequently injected drugs. Sharing of injecting material and paraphernalia is reported to happen in half of the subjects injecting drugs. Substance use causes a lot of adverse organic, social and psychiatric events. Management of substance use consists of information, drug-free treatment and harm reduction, including substitution and maintenance programs. The management of care in Belgium differs between the regions.

Successful patching of iatrogenic rupture of the fetal membranes

Rupture of the fetal membranes is a common, but potentially serious complication of invasive fetal procedures. Quintero described a technique to seal the fetal membrane defect by means of a bloodpatch, usually called 'amniopatch' in this application. The successful use in two consecutive patients with ruptured membranes after a fetoscopic intervention at respectively 17 and 22 weeks' gestational age is described, together with a literature review of published experience.

Phylogenetic analysis of the full-length SARS-CoV sequences: evidence for phylogenetic discordance in three genomic regions

The origin of the severe acute respiratory syndrome-coronavirus (SARS-CoV) remains unclear. Evidence based on Bayesian scanning plots and phylogenetic analysis using maximum likelihood (ML) and Bayesian methods indicates that SARS-CoV, for the largest part of the genome ( approximately 80%), is more closely related to Group II coronaviruses sequences, whereas in three regions in the ORF1ab gene it shows no apparent similarity to any of the previously characterized groups of coronaviruses. There is discordant phylogenetic clustering of SARS-CoV and coronaviruses sequences, throughout the genome, compatible with either ancient recombination events or altered evolutionary rates in different lineages, or a combination of both.

Viral lower respiratory tract infection in the elderly: a prospective in-hospital study

The objective of this prospective study was to evaluate the clinical and laboratory parameters distinguishing viral from nonviral lower respiratory tract infection in elderly patients and to determine the yield of virological diagnostics in elderly patients with lower respiratory tract infection. The study was conducted in a 184-bed geriatric department in a university hospital during 4 winter months. All consecutive elderly persons admitted with a lower respiratory tract infection were included in the study. Clinical and laboratory parameters, a nasopharyngeal swab, and serological results for respiratory viruses were obtained for all participants. Available blood and sputum cultures were analysed. A total of 165 elderly persons (mean age, 82±6.8 years) were hospitalised with a lower respiratory tract infection. Familial flu-like illness (OR, 4.25; 95%CI, 1.4–13), better functionality (OR, 4; 95%CI, 1.3–14.15), and leucocyte count <10¹⁰/l (OR, 3; 95%CI, 1.3–7.1) were predictive for viral lower respiratory tract infection. Sixty (36.5%) definite diagnoses (positive blood culture, viral culture, or serological test) and seven (4.2%) probable diagnoses (positive sputum culture) were obtained. An early diagnosis (within 72 h) was possible in 38 (23%) and a late diagnosis in 29 (17.6%) participants. A nasopharyngeal swab contributed in 60.5% of the cases to an early diagnosis. Viral culture identified half (22/43) of the lower respiratory tract infections caused by influenza but only one of six lower respiratory tract infections caused by respiratory syncytial virus. In conclusion, a history of flu-like illness in family members and a total leucocyte count within normal limits makes a viral cause more likely in elderly people hospitalised with a lower respiratory tract infection during winter. Viral culture and rapid antigen detection are insensitive in elderly patients hospitalised with a lower respiratory tract infection.