Search

Serologic studies for swine influenza viruses (SIVs) in humans with occupational exposure to swine have been reported from the Americas but not from Europe. We compared levels of neutralizing antibodies against 3 influenza viruses--pandemic (H1N1) 2009, an avian-like enzootic subtype H1N1 SIV, and a 2007-08 seasonal subtype H1N1--in 211 persons with swine contact and 224 matched controls in Luxembourg. Persons whose profession involved contact with swine had more neutralizing antibodies against SIV and pandemic (H1N1) 2009 virus than did the controls. Controls also had antibodies against these viruses although exposure to them was unlikely. Antibodies against SIV and pandemic (H1N1) 2009 virus correlated with each other but not with seasonal subtype H1N1 virus. Sequential exposure to variants of seasonal influenza (H1N1) viruses may have increased chances for serologic cross-reactivity with antigenically distinct viruses. Further studies are needed to determine the extent to which serologic responses correlate with infection. [ABSTRACT FROM AUTHOR]

The genetic variability of hepatitis B virus (HBV) represents a challenge for the sensitivity of immunologic and molecular based assays. Based on sequence divergence in the entire genome of >8%, HBV genomes have been classified into nine groups designated A to I. The genotypes of HBV have distinct geographic distributions. Although preliminary clinical studies seem to indicate that there is an association between HBV genotype and the natural history of infection and response to antiviral therapy, further evaluations employing larger cohorts of patients are necessary to provide conclusive evidence. The analytical sensitivity of HBV surface antigen (HBsAg) and antibodies to the HBV surface antigen (anti-HBs) assays may be dependent on HBV genotype or subtype. The influence of genotypic variability on the sensitivity of nucleic acid amplification tests (NATs) has so far been poorly investigated. Preliminary results show that new real-time NATs detect genotypes A to G with equal sensitivity. Different mechanisms intervening at the translational or post-translational level, including conformational changes, hydrophobic changes, insertion of basic residues, and reduced synthesis or secretion of HBsAg may account solely or in combination for escape mutations to the immune response and to detection in HBsAg immunoassays. The clinical significance of S gene mutants needs, similarly to that of HBV genotypes, to be investigated further. HBV mutants are stable over time and can be transmitted horizontally or vertically. The sensitivity of HBsAg assays for mutant detection is being continuously improved. Immunoassays based on polyclonal capture antibodies demonstrate the highest sensitivity for the recognition of recombinant mutants or serum samples harboring mutant forms of HBsAg. However, they do not guarantee full sensitivity. Detection of HBsAg needs to be improved by the introduction of new HBsAg assays able to recognize described S gene mutants and with a lower detection threshold than current immunoassays in order to detect smallest amounts of HBsAg in low level carriers. There is also a need for more complete epidemiological data on the prevalence of HBsAg mutants in Western Europe and assays for the (differential) screening of mutants need to be developed and evaluated. [ABSTRACT FROM AUTHOR]

We conducted a phylogenetic analysis of 19 hepatitis B virus strains from Laos that belonged to 2 subgenotypes of a new genotype I. This emerging new genotype likely developed outside Southeast Asia and is now found in mixed infections and in recombinations with local strains in a geographically confined region. [ABSTRACT FROM AUTHOR]

Digital polymerase chain reaction (dPCR) is an emerging technology that enables accurate and sensitive quantification of nucleic acids. Most available dPCR systems have two channel optics, with ad hoc software limited to the analysis of single and duplex assays. Although multiplexing strategies were developed, variable assay designs, dPCR systems, and the analysis of low DNA input data restricted the ability for a universal automated clustering approach. To overcome these issues, we developed dPCR Cluster Predictor (dPCP), an R package and a Shiny app for automated analysis of up to 4-plex dPCR data. dPCP can analyse and visualize data generated by multiple dPCR systems carrying out accurate and fast clustering not influenced by the amount and integrity of input of nucleic acids. With the companion Shiny app, the functionalities of dPCP can be accessed through a web browser., (© The Author(s) 2023. Published by Oxford University Press.)

The epidemiology of seasonal influenza is influenced by age. During the influenza season, the European Influenza Surveillance Network (EISN) reports weekly virological and syndromic surveillance data [mostly influenza-like illness (ILI)] based on national networks of sentinel primary-care providers. Aggregated numbers by age group are available for ILI, but not linked to the virological data. At the end of the influenza season 2012/2013, all EISN laboratories were invited to submit a subset of their virological data for this season, including information on age. The analysis by age group suggests that the overall distribution of circulating (sub)types may mask substantial differences between age groups. Thus, in cases aged 5-14 years, 75% tested positive for influenza B virus whereas all other age groups had an even distribution of influenza A and B viruses. This means that the intepretation of syndromic surveillance data without age group-specific virological data may be misleading. Surveillance at the European level would benefit from the reporting of age-specific influenza data.

In June 2014, a staphylococcal food poisoning outbreak occurred at an international equine sports event in Luxembourg requiring the hospitalisation of 31 persons. We conducted a microbiological investigation of patients and buffet items, a case-control study and a carriage study of catering staff. Isolates of Staphylococcus aureus from patients, food and catering staff were characterised and compared using traditional typing methods and whole genome sequencing. Genotypically identical strains (sequence type ST8, spa-type t024, MLVA-type 4698, enterotoxin A FRI100) were isolated in 10 patients, shiitake mushrooms, cured ham, and in three members of staff. The case-control study strongly suggested pasta salad with pesto as the vehicle of infection (p<0.001), but this food item could not be tested, because there were no leftovers. Additional enterotoxigenic strains genetically unrelated to the outbreak strain were found in four members of staff. Non-enterotoxigenic strains with livestock-associated sequence type ST398 were isolated from three food items and two members of staff. The main cause of the outbreak is likely to have been not maintaining the cold chain after food preparation. Whole genome sequencing resulted in phylogenetic clustering which concurred with traditional typing while simultaneously characterising virulence and resistance traits.

Phylogenetic analysis was performed on hepatitis B virus (HBV) strains obtained from 86 hepatitis B surface antigen (HBsAg) positive donors from Thailand originating throughout the country. Based on the S gene, 87.5% of strains were of genotype C while 10.5% were of genotype B, with all genotype B strains obtained from patients originating from the central or the south Thailand. No genotype B strains were found in the north of Thailand. Surprisingly, one patient was infected with a genotype H strain while another patient was infected with a genotype G strain. Complete genome sequencing and recombination analysis identified the latter as being a genotype G and C2 recombinant with the breakpoint around nucleotide position 700. The origin of the genotype G fragment was not identifiable while the genotype C2 fragment most likely came from strains circulating in Laos or Malaysia. The performance of different HBsAg diagnostic kits and HBV nucleic acid amplification technology (NAT) was evaluated. The genotype H and G/C2 recombination did not interfere with HBV detection., (Copyright © 2012 Wiley Periodicals, Inc.)

To further investigate the genetic diversity of hepatitis B virus (HBV) genotype A in Africa, we analysed 263 HBV strains from Nigeria (n=163) and Cameroon (n=100). Phylogenetic analysis of S fragment sequences attributed 175 strains (66.5%) to genotype E and 88 (33.5%) to genotype A. In Cameroon, genotype A strains were the most prevalent (79/100, 79.0%), whereas, in Nigeria, genotype E was highly dominant (154/163, 94.5%). The genotype A strains grouped with reference strains of subgenotype A3 (n=8), the provisional subgenotype A5 (n=43), a recently reported new variant from Rwanda (n=35), or as outliers (n=2). Ten complete genome sequences obtained from strains that clustered with the new variant from Rwanda formed a separate group supported by a bootstrap value of 96. The between-group distance to other potential or recognized subgenotypes of genotype A was at least 3.81%. Thus, the new group of strains could be considered as a new subgenotype of HBV genotype A, tentatively named 'A7'. Interestingly, the 'A7' strains from Rwanda and Cameroon showed an interspersed clustering, but essentially no other (sub)genotypes were shared between the two countries, suggesting that 'A7' may have evolved in a yet unknown place and may have only relatively recently spread to Rwanda and Western Cameroon. Strains attributed to provisional subgenotype A5 were found for the first time in Cameroon (n=36) and Central Nigeria (n=2), indicating that A5 is more widespread than previously thought., (© 2010 The Authors. Journal Compilation © 2010 European Society of Clinical Microbiology and Infectious Diseases.)

Objectives: Genotyping of Hepatitis B virus (HBV) strains from patients in Central African Republic and comparison with results obtained in other African countries., Patients and Methods: Sera were collected from patients admitted with symptoms of acute or chronic hepatitis to the "Hôpital de l'Amitié de Bangui", Central African Republic (CAR). The complete sequence of preS2/S gene has been defined for determining genotypes., Results: Hundred and ninety-six sera were collected from 112 men and 84 women. Ninety-two percent of patients had contact with HBV (anti-HBc postitive) and the HBsAg prevalence was about 62%. HBV DNA was detected in 66% of HBsAg positive sera. No HBV-DNA was evidenced among patients with negative HBsAg. Ninety-three percent of the HBV strains belonged to genotype E; one (3.4%) belonged to genotype A1, and one (3.4%) belonged to genotype D., Conclusions: The high prevalence of HBV infection in the studied population is due to their recruitment. The genotype E is predominant in CAR and the intragroup variability of HBV genotype E reached only 1.8%. Genotypes A and D were less common in CAR their presence may be explained by importation.

The Republic of Belarus reports a seroprevalence of 4.8% for hepatitis B virus (HBV) and 1.26% for hepatitis C virus (HCV), but little is known about the molecular characteristics of the circulating viruses. This study analysed 69 HBV surface antigen (HBsAg)-positive and 113 anti-HCV-positive donors attending a national reference hospital in Minsk. Among the HCV patients, 70% were co-infected with human immunodeficiency virus (HIV). Phylogenetic analysis of 12 complete genomes and 31 partial HBV sequences, as well as 78 core/E1 HCV sequences, revealed that multiple genotypes and subtypes of both viruses were circulating in Belarus. Of the HBV strains, 11.6% were genotype A2 and 88.6% were genotype D. The genotype D strains segregated into four recently described subtypes, with D2 being the most prevalent (58.1%), followed by D3 (16.3%), D1 (11.6%) and D4 (2.3%), but with inter-subtypic distances lower than the minimal 4% distance proposed to define subtypes. The 78 HCV strains belonged to subtypes 1b (53.8%), 3a (38.5%), 1a (5.1%), 4a (1.3%) and 4d (1.3%). Subtype 1b was less prevalent (45.1% vs. 70.4%) among HCV/HIV co-infected donors, while subtype 3a was more prevalent (29.6% vs. 43.1%). The relative prevalence of HBV and HCV genotypes in Belarus corresponded to the prevalence in Russia, although with a clear European influence that reflected the socio-political context of the country.

The major neutralizing epitope, the "a" determinant of the hepatitis B virus (HBV) genotype E surface antigen (HBsAg) is most divergent from that of genotype A, which is used for preparing monoclonal antibodies used in commercially available HBV reagents. To evaluate the performance of the latest generation of HBsAg detection assays with respect to genotype E HBsAg. Three commercial assays were evaluated using sera from 200 Nigerian patients compared to the preS/S sequence of DNA positive samples. Out of 200 samples, 61 and 103 gave concordant positive and negative results between the three HBsAg assays. Of 36 samples with discordant results, 35 were confirmed negative by neutralisation. One of the three assays showed significantly high rate of false positives (29 of 35). DNA positive samples with no detectable HBsAg or reduced HBsAg detection signals (<75% of mean signal obtained with HBsAg positive samples) revealed several mutations (V14A, F46S, N48T, L49R, I49T, D51G, A53V, P54L, Q82P, F83C, L127P, A184V, T189I, S204N, V224A), mostly outside the a-determinant. Several of these mutations are found as wild type nucleotides normally in genotype A and only exceptionally in genotype E. All three assays showed comparable sensitivities for genotype E HBsAg detection (98.4-100%) but differed considerably in specificity (84-99%). Failure to detect HBsAg antigen and differences in signal intensity were mainly associated with mutations in the preS/S gene outside the "a" determinant.

The glucocorticoid (GC) cortisol, the main mediator of the hypothalamic-pituitary-adrenal axis has many implications in metabolism, stress response and the immune system. Its function is mediated via binding to the glucocorticoid receptor (GR), a member of the superfamily of ligand-activated nuclear hormone receptors. The activity of the ligated GR results from its binding as a transcription factor to glucocorticoid response elements (GREs). Two-dimensional gel electrophoresis with DIGE (fluorescence difference gel electrophoresis) technology was applied to study the effects of cortisol on the human THP-1 monocytic cell line. A total of 28 cortisol-modulated proteins were identified belonging to five functional groups: cytoskeleton (8), chaperones (9), immune response (4), metabolism (3) and transcription/translation (4). Their corresponding genes were screened for putative GREs in their + 10 kb/- 0.2 kb promoter regions including all alternative promoters available within the Database for Transcription Start Sites (DBTSS). FKBP51, known to be induced by cortisol, was identified as the strongest differentially expressed protein, and contains the highest number of strict GREs. Genomic analysis of five alternative FKBP5 promoter regions suggests GC inducibility of all transcripts. Additionally, proteomics (2D DIGE and 2D immunoblotting) revealed the existence of several FKBP51 isoforms, which were not previously described. To our knowledge this is the first proteomic study that addresses the effects of cortisol on immune cells. FKBP51 isoforms found on the gel map were linked to alternative promoter usage on the genetic level, successfully correlating both the specific proteomic and genomic findings., (Copyright 2007 John Wiley & Sons, Ltd.)

Background: The measures recommended to reduce TTD include clinical selection of donors, based on a standardized questionnaire which aims to find out antecedents and behaviours predicting transmitted diseases within donors. The effectiveness of this measure is well established in the industrialized countries where the level of education of the population may support a greater receptivity of donors about this procedure. What is happening in developing one?, Aim: This study was carried out to assess knowledge attitude and behaviours among blood donors regarding blood and transfusion safety in Burkina Faso., Methods: A cross sectional study was carried out in the blood bank of the teaching hospital of Ouagadougou. In addition to the routine questionnaire, 544 included blood donors were subjected to additional questions seeking to specify their behaviours, knowledge and attitude towards TTD diseases and screening., Results: Donors were from 16 to 57 years of age (mean age : 28+/-7.9 years). The majority of donors were male (71.2%). Family donors represent 52% and first time donors 55%. About 30.8% were illiterate or of primary school level. A percentage of 14.4 donate to access HIV testing and 30.7% will donate blood immediately to check any contamination in case of exposure. There was no difference between donors having been informed about their HIV status in the past and the other donors regarding HIV, HBs Ag and VHC results., Conclusions: This study suggests that there is some great need for donors' education on transfusion safety. There is also need for staff training in donors' management.

Background: Recent studies have shown that Hepatitis B virus (HBV) genotype E predominates in a vast crescent in West-Africa spanning from Senegal to Angola., Objectives: To determine whether HBV strains in the Central African Republic (CAR) belong predominately to the homogeneous West-African genotype E or whether they are more closely related to genotypes found in East Africa., Study Design: Serum samples were randomly collected from 196 patients admitted with symptoms of acute or chronic hepatitis to the Central Hospital in Bangui. Thirty complete and 36 partial sequences of HBV strains were obtained., Results: Ninety-four percent (62/66) of the strains belonged to genotype E, while genotype A1, most closely related to a strain from Tanzania and genotype D were detected in only one and three samples, respectively. One strain presented a recombination between the S and X gene of a genotype E precursor and a partial PreC/C gene of a genotype D precursor., Conclusions: Genotype E is predominant in CAR with little overlap with genotypes from Eastern Africa, extending the West-African HBV genotype E crescent further to the East.

In Africa, highly pathogenic avian influenza H5N1 virus was first detected in northern Nigeria and later also in other regions of the country. Since then, seven other African countries have reported H5N1 infections. This study reports a comparison of full-length genomic sequences of H5N1 isolates from seven chicken farms in Nigeria and chicken and hooded vultures in Burkina Faso with earlier H5N1 outbreaks worldwide. In addition, the antigenicity of Nigerian H5N1 isolates was compared with earlier strains. All African strains clustered within three sublineages denominated A (south-west Nigeria, Niger), B (south-west Nigeria, Egypt, Djibouti) and C (northern Nigeria, Burkina Faso, Sudan, Côte d'Ivoire), with distinct nucleotide and amino acid signatures and distinct geographical distributions within Africa. Probable non-African ancestors within the west Asian/Russian/European lineage distinct from the south-east Asian lineages were identified for each sublineage. All reported human cases in Africa were caused by sublineage B. Substitution rates were calculated on the basis of sequences from 11 strains from a single farm in south-west Nigeria. As H5N1 emerged essentially at the same time in the north and south-west of Nigeria, the substitution rates confirmed that the virus probably did not spread from the north to the south, given the observed sequence diversity, but that it entered the country via three independent introductions. The strains from Burkina Faso seemed to originate from northern Nigeria. At least two of the sublineages also circulated in Europe in 2006 as seen in Germany, further suggesting that the sublineages had already emerged outside of Africa and seemed to have followed the east African/west Asian and Black Sea/Mediterranean flyways of migratory birds.

As the avian influenza virus H5N1 swept from Asia across Russia to Europe, Nigeria was the first country in Africa to report the emergence of this highly pathogenic virus. Here we analyse H5N1 sequences in poultry from two different farms in Lagos state and find that three H5N1 lineages were independently introduced through routes that coincide with the flight paths of migratory birds, although independent trade imports cannot be excluded.

One hundred and twenty-two new hepatitis B virus (HBV) preC/C sequences and three complete genomes from three major countries in West Africa were analysed. The majority of sequences were of genotype E and the only other genotype found was genotype A. Although for genotype E sequences, the genetic diversity of the preC/C gene was about two to three times higher than that of the preS/S gene, it was still considerably lower than that for genotype A sequences. The HBV/E preC/C gene was related most closely to subgenotype D1 and D2 sequences. Evidence of recombination was found in two strains that were of genotype A in the preS/S gene and of genotype E in the preC/C gene. The genotype A strains from Cameroon, Mali and Nigeria could be divided phylogenetically into three subtypes, A3 and two new subtypes, tentatively designated A4 and A5. Each subtype presented a genetic diversity of 2.19-3.85 % and intersubtype distances of 4.47-5.97 %. Interestingly, one sample from Nigeria showed evidence of a triple recombination of genotypes E/D and A, separated by a genotype G-specific insert of 36 bp. Of 110 patients, 19 (17.3 %) showed a coinfection of genotypes A and E, mostly in human immunodeficiency virus-positive children from Cameroon. Thus, in Cameroon, where both genotypes coexist, 37 % of all individuals tested had mixed infections. The low genetic variability in the preC/C gene of genotype E supports our previous speculation about a relatively short evolutionary history of this genotype, in contrast to the subtype-rich African genotype A strains.

A simple genotyping method based on multiplex PCR has been developed to discriminate between all active measles virus (MV) clades and genotypes (A, B3.1, B3.2, C2, D2-D9, G2-G3, and H1-H2). The sequencing reaction was replaced by six multiplex PCRs: one to identify the clade and five to identify the respective genotype. Primers were sensitive to clade- and genotype-specific nucleotides and generated fragments of type-specific sizes that were analyzed by conventional agarose gel electrophoresis. On the basis of all published MV sequences, positive and negative predictive values of 99.2% and 98.6% were calculated. Variability in the primer binding sites, which could potentially reduce sensitivity, was very limited among published sequences. As new genotypes are described, additional specific primers can be included in the multiplex PCR with relative ease. Although sequencing remains the "gold standard," the present method should facilitate MV genotyping especially in developing countries and will therefore contribute to enhanced MV control and elimination strategies as recommended by the World Health Organization.