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H Bourhy

Publications and source records attributed to H Bourhy.

At least 19 recordsLinked to original sources
PubMed2006

Multicenter comparative study of a new ELISA, PLATELIA RABIES II, for the detection and titration of anti-rabies glycoprotein antibodies and comparison with the rapid fluorescent focus inhibition test (RFFIT) on human samples from vaccinated and non-vaccinated people.

The envelope glycoprotein G of rabies virus induces the production of neutralising antibodies, which are important in protection against rabies. Therefore, titration of anti-envelope glycoprotein antibodies is a good indicator of the degree of immunity in people during anti-rabies treatment or after vaccination. According to the World Health Organization (WHO) guidelines, a booster vaccine dose should be given if the rabies antibody titre falls below 0.5 IU/ml. Titration of anti-rabies antibodies is also useful for plasma centers in the preparation and standardization of human anti-rabies gamma-globulins for therapeutic use and to a lesser extent for the diagnosis of rabies in human sera and cerebrospinal fluid (CSF). This paper presents a new enzyme-linked immunosorbent assay (ELISA), PLATELIA RABIES II, developed for rabies envelope glycoprotein antibody detection or titration and its comparison to the current reference method (RFFIT). The data collected during validation of the test in a multicenter study are analysed to give a sound overall knowledge of the capabilities of the PLATELIA RABIES II, for instance specificity, linearity, accuracy, precision, detection limit and quantitation limit. To this aim, human serum samples from a total of 1348 vaccinated or non-vaccinated people were tested in parallel using the new ELISA and the RFFIT for the presence of anti-rabies antibodies. Data generated indicate a linear relationship across the range of titration between the two methods. The sensitivity reaches 98.6% and the specificity 99.4%. This study indicates that this new ELISA test is as sensitive and specific as the current standardized reference method. The method is simple, safe, rapid and can be considered as a useful alternative to the neutralisation test.

Antibodies, Viral↗
PubMed2005

Phylogenetic relationships among rhabdoviruses inferred using the L polymerase gene.

RNA viruses of the family Rhabdoviridae include arthropod-borne agents that infect plants, fish and mammals, and also include a variety of non-vector-borne mammalian viruses. Herein is presented a molecular phylogenetic analysis, the largest undertaken to date, of 56 rhabdoviruses, including 20 viruses which are currently unassigned or assigned as tentative species within the Rhabdoviridae. Degenerate primers targeting a region of block III of the L polymerase gene were defined and used for RT-PCR amplification and sequencing. A maximum-likelihood phylogenetic analysis of a 158-residue L polymerase amino acid sequence produced an evolutionary tree containing the six recognized genera of the Rhabdoviridae and also enabled us to identify four more monophyletic groups of currently unclassified rhabdoviruses that we refer to as the 'Hart Park', 'Almpiwar', 'Le Dantec' and 'Tibrogargan' groups. The broad phylogenetic relationships among these groups and genera also indicate that the evolutionary history of rhabdoviruses was strongly influenced by mode of transmission, host species (plant, fish or mammal) and vector (orthopteran, homopteran or dipteran).

Amino Acid Sequence↗
PubMed2005

[Application of McAbs against rabies nucleocapsid in diagnosis of rabies street virus].

OBJECTIVE: McAbs against rabies nucleocapsid were used to detect rabies street viruses in animal brain specimens with indirect immunofluorescent assay to evaluate the sensitivity and specificity of this assay. METHODS: 62 specimen from rabid animal brains including genotype 1 to 7 and 271 specimens from different normal animal brains collected in Pasteur Institute in 2003 were tested and compared, using indirect immunofluorescent assay. All these specimens were identified and compared using rapid rabies enzyme immunodiagnosis, fluorescent antibody test and rabies virus isolation assay in neuroblastoma cell culture which were all provided by Pasteur Institute. RESULTS: Both sensitivity and the specificity of the indirect immunofluorescent assay were 100%. CONCLUSION: The results showed a positive of rabies virus detection with these methods.

Animals↗
PubMed2005

An imported case of canine rabies in Aquitaine: investigation and management of the contacts at risk, August 2004-March 2005.

In August 2004, a case of rabies was diagnosed in a puppy that had been illegally imported from Morocco to Bordeaux (France). Because a great number of people and animals were thought to have come into contact with the puppy, extensive tracing measures were implemented, and an international alert was launched to trace and treat the contacts at risk. One hundred and eighty seven people received post-exposure treatment, eight of whom also received serovaccination, and 57 animals known to have been exposed to the puppy were tested. Six months after the death of the rabid animal, none of the people treated showed any signs of rabies, nor was any secondary animal case reported. The management of this crisis highlights the importance of the role of a rapid alert system at European level. Strict application of sanitary control regulations is essential for animals introduced into EU countries, and all necessary information must be made available to EU residents travelling to rabies enzootic areas.

Adolescent↗
PubMed2005

Rabies in Europe in 2005.

Rabies is still present in Europe in 2005. Its incidence in humans remains limited (fewer than 5 human cases per year) through the application of strict prophylactic measures (anti-rabies treatment) and by means of veterinary rabies control measures in the domesticated and wild animal populations. The main indigenous animal reservoirs are: the dog in eastern European countries and on the borders with the Middle East; the fox in central and eastern Europe; the racoon dog in northeastern Europe; and the insectivorous bat throughout the entire territory. Finally, each year, cases of animals with rabies imported from enzootic areas are reported, showing the permeability of borders and traveller's lack of consideration of the rabies risk. These importations constantly threaten the rabies-free status of terrestrial animals in western European countries and complicate the therapeutic decisions taken by physicians in the absence of information regarding the biting animal.

Animal Diseases↗
PubMed2004

[Human rabies in France in 2004: update and management].

Twenty people died of rabies in France between 1970 and 2003 (compared to 55,000 yearly worldwide), 80% on returning from Africa. Dogs were the contaminating animals in 90% of the cases and children were the most common victims. The last instance of rabies in a native French animal was reported in 1998. However the illegal importation of animals still poses a risk. The disease is transmitted by saliva, even before the appearance of clinical symptoms, through a bite, scratch, or licks of mucous membranes or broken skin. Person-to-person transmission has only been observed in cases of grafts (cornea). The mean incubation time of 1 to 3 months is long enough to allow passive immunization and vaccination. After its onset, the disease presents as encephalitis or a paralytic syndrome the outcome of which is always fatal. Clinical diagnosis may be difficult in the early stages of the disease. If rabies is suspected, the National Reference Centre is responsible for the sampling and proper transportation of these samples so as to ensure assessment results within 5 days. If stringent hygiene rules are complied to, there is no risk of contamination for those in close contact. Vaccination, which is performed in official rabies centers, is only performed after a diagnosis based on laboratory evidence, and solely for exposed persons or those for whom a reliable history cannot be established (children under 6 years). Prevention is based on information. People traveling abroad, particularly to Africa, are warned not to approach unknown animals (especially dogs) nor to try to import them, and are advised to comply with vaccinal recommendations for travelers, particularly for toddlers.

Adolescent↗
PubMed2002

Presence of European bat lyssavirus RNas in apparently healthy Rousettus aegyptiacus bats.

Apparently healthy Rousettus aegyptiacus bats were randomly chosen from a Dutch colony naturally infected with European bat lyssavirus subgenotype 1a (EBL1a). These bats were euthanised three months after the first evidence of an EBL1a infection in the colony. EBL1a genomic and antigenomic RNAs of the nucleoprotein gene were detected by nested reverse transcriptase PCR in 75% of the examined Rousettus aegyptiacus bats. The EBL1a RNAs of the nucleoprotein gene were detected mainly in brain tissues, but also in other organs. EBL1a messenger RNAs of the nucleoprotein gene and the glycoprotein gene were detected in brain tissues. The standard fluorescent antibody test revealed the presence of lyssavirus antigens in brain tissues from 7 (17.5%) Rousettus aegyptiacus bats. Furthermore, EBL1a could not be detected by virus isolation on murine neuroblastoma cells or by intracerebral inoculation of suckling mice. Neutralising antibodies directed against EBL1 were detected in 11% of the examined bats. This study shows that at least 85% of the apparently healthy Rousettus aegyptiacus bats must have been infected with EBL1a, and that these bats may survive from an EBL1a infection. Furthermore, the study supports the possibility of a long-term maintenance of EBL1a genome in Rousettus aegyptiacus bats.

Animals↗
PubMed2001

Persistent infection of B lymphocytes by bovine respiratory syncytial virus.

Bovine respiratory syncytial virus (BRSV) is a major cause of respiratory disease in young cattle. Here we demonstrate BRSV persistence at low levels in tracheobronchial and mediastinal lymph nodes up to 71 days after the experimental infection of calves. Positive results were obtained on viral genomic RNA and messenger RNA coding for the nucleoprotein, glycoprotein (G), and fusion protein (F). G and F proteins were also detected in the pulmonary lymph nodes by immunohistochemistry. Double-staining experiments revealed that viral antigen was present in B-lymphocytes. Coculture experiments with the lymph node cells showed that the virus was still able to infect permissive target cells, even though no cytopathic effect was recorded. In vitro studies indicate that BRSV was still able to replicate in bovine B-lymphocyte cell lines 6 months after infection. These results may also be relevant to the understanding not only of the epidemiology and the peculiarities of the immune response of BRSV infections but also of human respiratory syncytial virus infections.

Animals↗
PubMed2000

Characterisation of a recently isolated lyssavirus in frugivorous zoo bats.

In July 1997 a lyssavirus was isolated in Denmark from a colony of Egyptian flying foxes (Rousettus aegyptiacus) originating from a Dutch zoo. Sequencing of a 400 nucleotides coding region of the nucleoprotein and of a major part of the G-protein ectodomain encoding region of the newly isolated virus, revealed a very high similarity with European Bat Lyssavirus subtype 1a (EBL-1a). For characterisation of the recently isolated lyssavirus in frugivorous zoo bats, 16 frugivorous bats (Rousettus aegyptiacus) of the same colony and 80 mice were experimentally infected with the Rousettus isolate or with a well defined EBL-1a strain isolated from a Dutch insectivorous bat (Eptesicus serotinus). Inoculation viruses were titrated in mice to determine LD50's of both isolates. Clinical signs of inoculated bats were recorded during 6 weeks. After showing neurological signs or at the end of the experimental infection all animals were euthanized. During the experimental infection sera and various tissues of inoculated bats were collected. Immunoassays, mouse inoculation tests (MIT) and polymerase chain reaction (PCR) were employed for detection of lyssavirus specific antibodies, antigen or RNA. Five bats inoculated with the Rousettus isolate and 2 bats inoculated with the Eptesicus isolate showed neurological signs. The remaining 9 bats survived and cleared the virus; at least under the detection limit of the used assays. Despite a much higher pathogenicity of the Rousettus isolate observed in mice, LD25's in bats were quite the same for the 2 isolates. The pathogenicity of both isolates suggested that like many other mammals, Rousettus aegyptiacus bats could be victims of lyssavirus infection besides reservoir hosts of infectious EBL1a. There was no significant difference in detecting the different lyssavirus isolates in Rousettus aegyptiacus bats. An employed immunoperoxidase staining (IP) method was very useful for sensitive detection and localization of lyssavirus antigen in histologic preparates.

Animals↗
PubMed2000

Evolution of bovine respiratory syncytial virus.

Until now, the analysis of the genetic diversity of bovine respiratory syncytial virus (BRSV) has been based on small numbers of field isolates. In this report, we determined the nucleotide and deduced amino acid sequences of regions of the nucleoprotein (N protein), fusion protein (F protein), and glycoprotein (G protein) of 54 European and North American isolates and compared them with the sequences of 33 isolates of BRSV obtained from the databases, together with those of 2 human respiratory syncytial viruses and 1 ovine respiratory syncytial virus. A clustering of BRSV sequences according to geographical origin was observed. We also set out to show that a continuous evolution of the sequences of the N, G, and F proteins of BRSV has been occurring in isolates since 1967 in countries where vaccination was widely used. The exertion of a strong positive selective pressure on the mucin-like region of the G protein and on particular sites of the N and F proteins is also demonstrated. Furthermore, mutations which are located in the conserved central hydrophobic part of the ectodomain of the G protein and which result in the loss of four Cys residues and in the suppression of two disulfide bridges and an alpha helix critical to the three-dimensional structure of the G protein have been detected in some recent French BRSV isolates. This conserved central region, which is immunodominant in BRSV G protein, thus has been modified in recent isolates. This work demonstrates that the evolution of BRSV should be taken into account in the rational development of future vaccines.

Amino Acid Sequence↗
PubMed2000

[Genetic diversity of Lyssavirus].

Rabies is a zoonosis of which the archaeological agents belong to the Lyssavirus species. Seven genotypes are known to exist. The isolates are grouped according to a) their geographical origin, b) historical context, c) type of vector. In parts of the world where several epidemic cycles exist, practical tools have been developed in order to distinguish between them more easily. Vaccine strains--all of which have been elaborated from genotype 1--offer little or no protection against the other genotypes. It is thus necessary to work on extending vaccine coverage.

Genetic Variation↗
PubMed1999

Dynamics of rabies virus quasispecies during serial passages in heterologous hosts.

To understand the mutations and genetic rearrangements that allow rabies virus infections of new hosts and adaptation in nature, the quasispecies structure of the nucleoprotein and glycoprotein genes as well as two noncoding sequences of a rabies virus genome were determined. Gene sequences were obtained from the brain and from the salivary glands of the original host, a naturally infected European fox, and after serial passages in mice, dogs, cats and cell culture. A relative genetic stasis of the consensus sequences confirmed previous results about the stability of rabies virus. At the quasispecies level, the mutation frequency varies, in the following order: glycoprotein region (21.9 x 10(-4) mutations per bp), noncoding sequence nucleoprotein-phosphoprotein region (7.2-7.9 x 10(-4) mutations per bp) and nucleoprotein gene region (2.9-3.7 x 10(-4) mutations per bp). These frequencies varied according to the number, type of heterologous passages and the genomic region considered. The shape of the quasispecies structure was dramatically modified by passages in mice, in which the mutation frequencies increased by 12-31 x 10(-4) mutations per bp, depending on the region considered. Non-synonymous mutations were preponderant particularly in the glycoprotein gene, stressing the importance of positive selection in the maintenance and fixation of substitutions. Two mechanisms of genomic evolution of the rabies virus quasispecies, while adapting to environmental changes, have been identified: a limited accumulation of mutations with no replacement of the original master sequence and a less frequent but rapid selective overgrowth of favoured variants.

Animals↗
PubMed1999

Evaluation of a nested reverse transcription-PCR assay based on the nucleoprotein gene for diagnosis of spontaneous and experimental bovine respiratory syncytial virus infections.

The first nested reverse transcription (RT)-PCR based on the nucleoprotein gene (n RT-PCR-N) of the bovine respiratory syncytial virus (BRSV) has been developed and optimized for the detection of BRSV in bronchoalveolar lavage fluid cells of calves. This test is characterized by a low threshold of detection (0.17 PFU/ml), which is 506 times lower than that obtained by an enzyme immunosorbent assay (EIA) test (RSV TESTPACK ABBOTT). During an experimental infection of 17 immunocompetent calves less than 3 months old, BRSV RNA could be detected up to 13 days after the onset of symptoms whereas isolation in cell culture was possible only up to 5 days. Compiling results obtained by conventional techniques (serology, antigen detection, and culture isolation) for 132 field samples collected from calves with acute respiratory signs revealed that n RT-PCR-N showed the highest diagnostic sensitivity and very good specificity. This n RT-PCR-N with its long period of detection during BRSV infection thus provides a valuable tool for diagnostic and epidemiological purposes.

Animals↗
PubMed1998

Molecular variation in the nucleoprotein gene (ORF7) of the porcine reproductive and respiratory syndrome virus (PRRSV).

The nucleoprotein gene (ORF7) of 15 European isolates of porcine reproductive and respiratory syndrome virus (PRRSV) was sequenced and compared with corresponding sequences of other PRRSV isolates (2 European and 13 American) and one isolate each of other arteriviruses (the lactate dehydrogenase elevating virus (LDV), the simian haemorrhagic fever virus (SHFV) and the equine arteritis virus (EAV)). Their phylogenetic relationships were established using neighbour-joining and parsimony methods. Four lineages (PRRSV, LDV, SHFV and EAV) were discriminated. Two genotypes of PRRSV, European and American, could be further identified. The European genotype of PRRSV was highly conserved. Analysis of the nucleotide and amino acid substitutions in PRRSV ORF7 revealed four stable regions, probably conserved because of their requirement for nucleocapsid function and/or structure. No constant mutations accumulation in the ORF7 could be determined precisely when either synonymous or non-synonymous mutations were studied. Passage of the European PRRSV in vivo had little influence on the ORF7 sequence: only a small number of synonymous substitutions in ORF7 was detectable, confirming its low variability.

Amino Acid Sequence↗
PubMed1998

Intravitam diagnosis of human rabies by PCR using saliva and cerebrospinal fluid.

An optimized reverse transcription (RT)-PCR protocol for the intravitam detection of rabies virus genomic RNA was tested with clinical samples obtained from 28 patients suspected of having rabies, 9 of whom were confirmed to have had rabies by postmortem examination. RT-PCR using saliva combined with an immunofluorescence assay performed with skin biopsy samples allowed detection of rabies in the nine patients.

Cerebrospinal Fluid↗