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Y Buisson

Publications and source records attributed to Y Buisson.

At least 37 records · Page 2Linked to original sources
PubMed1999

Baculovirus expression of chimeric hepatitis B virus core particles with hepatitis E virus epitopes and their use in a hepatitis E immunoassay.

Two hepatitis B core proteins bearing the immunodominant region of the hepatitis E virus (HEV) capsid protein, one at the C terminus of hepatitis B virus core antigen (HBcAg) and the other within the HBcAg immunodominant loop, were constructed. Both chimeric proteins exhibited HEV reactivity, but only the first construct retained HBcAg reactivity. The second construct was used to develop an anti-HEV test which is equivalent to a commercial test for the detection of anti-HEV immunoglobulin G (IgG) but is more sensitive for the detection of anti-HEV IgM.

Baculoviridae↗
PubMed1999

[Fall in the seroprevalence of hepatitis A in French youth].

OBJECTIVE: An anti-hepatitis A virus seroprevalence survey was performed in 1997 in 1052 French army recruits (mean age: 21.2 years). To describe epidemiological trends, the current pattern was compared to previous results obtained by similar methods in 1985, 1990 and 1993. RESULTS: In 1997, overall anti-hepatitis A virus seroprevalence was 11.5%. The greatest risk factor of hepatitis A infection was related to travel in intermediate or highly endemic areas for hepatitis A virus: 46% of overseas residents (odds ratio = 10.3), 28% of recruits who had travelled in developing countries (odds ratio = 3.7) and 7.65% of French living in industrialised countries are anti-hepatitis A virus antibody positive. Moreover, seroprevalence was higher in subjects with a history of icteria (adjusted odds ratio = 3.5) and families with at least 3 children (adjusted odds ratio = 3). No association was found with drinking water, socioeconomic status such as baccalaureat degree, or parents profession. The seroepidemiological shift of hepatitis A, as assessed in three previous studies, shows a marked decrease of 20% in 12 years from 30.4% in 1985, to 21.3% in 1990, to 16.3% in 1993, and to 11.5% in 1997. The decrease in the prevalence of anti-hepatitis A virus was more marked in young adults who had never travelled in endemic countries (decrease of 20%) than those who had visited or lived in developing countries (decrease of 10%). CONCLUSION: Although France is not highly endemic for hepatitis A thanks to improved hygiene and housing conditions over the past 20 years, a pattern of intermediate endemicity was seen in French overseas areas in which the risk of outbreaks of hepatitis A was higher. The decrease in anti-hepatitis A virus seroprevalence in French youth can be used to draft a public health policy for hepatitis A control.

Adolescent↗
PubMed1999

[Hepatitis C in tropical areas].

The tropical features of hepatitis C have not yet been fully elucidated due to the scarcity of data. However it has been estimated that two-thirds of the infected population lives in tropics. The most heavily affected regions are Africa, China, and southeast Asia with prevalence rates of 5.3, 3.0, and 2.4 p. 100 respectively. In several countries mostly in Africa, prevalence rates range from 5 to 10 p. 100 or higher. Age is a major risk factor for infection. The classic transmission modes, i.e., blood transfusion and intravenous drug use, do not account for these high prevalence rates. Another mechanism could be parenteral injection under unsafe conditions. The most widespread genotypes in tropical areas are genotypes 1, 2, and 3. Other genotypes can be encountered locally including genotype 4 in black Africa and Egypt, genotype 6 in southeast Asia, and genotypes 1 and 3 in India. The association of hepatitis C with chronic liver disease has been the focus of several studies, mainly in Africa. The seroprevalence of virus C ranges from 2 to 55 p. 100 in cases of chronic hepatitis or cirrhosis and from 0 to 47 p. 100 in cases of hepatocellular cancer. Hepatitis C could be the underlying cause of 33 to 50 p. 100 of chronic liver diseases not linked to virus B. It is observed more often in patients with chronic hepatitis or cirrhosis than cancer in which virus B is dominant. Infection by both virus is rare without liver disease but is more frequent in patients with cancer than chronic non-tumoral liver disease.

Africa↗
PubMed1998

Outbreak of enterically-transmitted hepatitis due to hepatitis A and hepatitis E viruses.

BACKGROUND/AIMS: One hundred and eleven patients with acute hepatitis and 61 controls were investigated for hepatitis serological markers in order to determine the viral etiology of cases involved in a waterborne epidemic of hepatitis observed in 1993 in Djibouti, Republic of Djibouti (East Africa). These cases occurred both in indigenous Djiboutians, and in French soldiers and their families in Djibouti. A retrospective study of the viral etiology of acute hepatitis cases observed in French soldiers and relatives living in Djibouti during the 3-year period preceding the epidemic was also undertaken. METHODS: HAV, HBV and HCV infections were investigated using commercial ELISA tests. HEV infections were investigated by testing IgG and IgM-specific antibodies by means of three different ELISA tests using recombinant proteins or synthetic peptides. RESULTS: Hepatitis A was observed in 37 (33%) and hepatitis E in 43 (39%) of the 111 cases of acute hepatitis recorded during this epidemic. Hepatitis B represented only 6% of the indigenous cases and hepatitis C was not observed among the cases investigated. Anti-HEV IgG antibodies were also detected in 19% of the indigenous control group. CONCLUSION: These results suggest that both HAV and HEV were responsible for this waterborne epidemic of acute hepatitis. However, HAV and HEV infections were not equally distributed between French expatriates and Djibouti residents. Whereas HAV infections were mainly observed in French patients, HEV was almost exclusively found in indigenous patients. This study reports for the first time a waterborne outbreak of acute hepatitis simultaneously due to HAV and HEV.

Adolescent↗
PubMed1998

Role of hepatitis E virus in sporadic cases of acute and fulminant hepatitis in an endemic area (Chad).

Forty-one patients with acute or fulminant hepatitis and 86 control patients were entered into a study of sporadic, acute, and fulminant hepatitis in the N'Djamena area of Chad in 1993. Acute hepatitis B was diagnosed in nine (22%) patients and acute hepatitis E in 27 (66%) patients. No acute hepatitis A was observed and 10% of the patients had serologic markers of hepatitis C virus (HCV) infection. Dual acute hepatitis B and E were observed in four patients (10%) and acute HEV infection was associated with chronic hepatitis B surface antigen carriage in 16 (39%). Epidemiologic findings concerning HBV from Chad suggest that these patients had undiagnosed chronic liver disease due to HBV, with acute deterioration caused by superimposed HEV replication. Moreover, it is obvious that in developing countries only the most severe cases of hepatitis are seen in hospital settings and a large proportion of them are related to superinfection with HBV and HEV. Antibody to HEV was observed in 22% of the control patients. This observation and the fact that epidemic and sporadic cases of HEV are observed in Chad indicates that HEV is highly endemic in this country.

Acute Disease↗
PubMed1998

[Viral hepatitis of enteric origin].

Hepatitis viruses of oral-fecal origin are responsible for a high morbidity and mortality throughout the world, even if they never result in chronic hepatitis. Two viruses, the virus of hepatitis A (VHA) and of hepatitis E (VHE) are at present the cause of severe viral hepatitis of enteric origin. Water is the principle vector in the spread of these viruses. However, the epidemiological aspects vary according to the pathogenic agent. VHA is excreted in a highly concentrated form in the feces for a relatively short period of time. Since it resists in an exterior environment, the virus remains infectious for a long time. VHE is excreted for a short period of time and in low concentrations. The viral particles are fragile in vitro and their variability in the environment is little known. The possible reservoir role of certain animals has been envisaged. Epidemics arise especially in countries suffering from poor hygiene and massive water pollution. Hepatitis A should no longer be considered a benign disease of childhood. The progress made in hygiene and economic development in industrialized countries have made contacts with this virus scarce, rendering the populations more receptive to it and epidemics more widespread. When the sickness occurs later in life, infection is more often symptomatic and can be serious, resulting sometimes long-term indisposition. Hepatitis E has a vast distribution throughout the world and manifests itself either in epidemic or endemic-sporadic form in many poor countries. In developed countries, it comes about mostly as a result of imported pathology, even if there exists a "substratum" of infection in these areas. The main clinical aspects, such as we were able to study them in 39 cases of military men from Tchad, Guyana and Somalia, are comparable to those of hepatitis A. The reasons for the particular gravity of symptoms in pregnant women are unknown. These affections have no specific treatment. In the field of prevention, vaccination is at present the best means for hepatitis A prophylaxis. Until a vaccine against hepatitis E is found, prevention depends on hygiene, sanitation measures et distribution of drinking water.

Animals↗
PubMed1997

A plasmid-mediated CMY-2 beta-lactamase from an Algerian clinical isolate of Salmonella senftenberg.

Multiresistance to antibiotics including beta-lactams, e.g. cefoxitin, was transferred by conjugation to Escherichia coli strain C1a from a clinical isolate of Salmonella senftenberg recovered from stools of an Algerian child. The susceptibility pattern to beta-lactams was similar to the profile mediated by an AmpC-type beta-lactamase. By biochemical analysis, typical AmpC-type enzyme substrate and inhibition profiles were obtained. Finally, an ampC plasmid-encoded beta-lactamase gene was cloned and sequenced. Its deduced amino acid sequence confirmed its identity as a class C beta-lactamase. It showed 99.5% sequence identity with the plasmid-mediated beta-lactamase CMY-2. The differences in the amino acid sequences of the two enzymes were located in the signal peptide.

Algeria↗
PubMed1997

Characterization of hepatitis E virus (HEV) from Algeria and Chad by partial genome sequence.

The purpose of this study was to analyze partial nucleotide sequences and derived peptide sequences of hepatitis E virus (HEV) from two outbreaks of hepatitis E in Africa (Chad 1983-1984; Algeria 1978-1980). A portion of ORF3 and the major portion of ORF2 were amplified by Reverse Transcriptase-Polymerase Chain Reaction (RT-PCR). The PCR products were sequenced directly or after cloning into the pCRII vector. Sequences were then compared to the corresponding regions of reported full length HEV sequences. In the ORF2 and ORF3 regions, the homology between the Algerian and the Chad isolates at the nucleic acid level was 92 and 95%, respectively. At the peptide level the homology was 98% in both regions. In these regions, both strains are more related to Asian strains at the nucleic acid level (89 to 95%) and at the amino acid level (95 to 100%) than to the Mexico strain. At the peptide level the differences are less apparent. Both African isolates have amino acid changes in common with some reference strains although the Chad isolate has three unique changes. These African strains of HEV, based on the ORF2 and ORF3 phylogenetic trees, appear to be a distinct phylogenetic group, separate from the Mexican and Asian strains.

Algeria↗
PubMed1997

An outbreak of hepatitis A in a French day-care center and efforts to combat it.

An outbreak of hepatitis A in a French day-care center was identified during a survey of risk factors for such events in a sample of 210 centers. In the period between 29 March and 9 July 1994, 17 cases were diagnosed in the center (anti-HAV IgM serum antibody) including 11 children aged 2-3 (attack rate = 55.5% of class), 2 staff members, 3 parents and 1 educator-parent (secondary attack rate = 27.6%). The source case was probably a classmate of Case 1's older brother, who was diagnosed earlier in the spring. Intensive hygiene measures and the organisational features of the clinic limited all transmission except by direct physical contact with infected children. Vaccination of staff was begun too late to be effective; gamma-globulin prophylaxis might have been administered but was not. This is the first documented outbreak of the disease in a French center.

Adult↗
PubMed1997

Exacerbations of clinical symptoms in human immunodeficiency virus type 1-infected patients with multicentric Castleman's disease are associated with a high increase in Kaposi's sarcoma herpesvirus DNA load in peripheral blood mononuclear cells.

The epidemiologic link between multicentric Castleman's disease (MCD) and Kaposi's sarcoma (KS) and the high frequency of KS herpesvirus (KSHV) detection in both diseases raise the question of a role of this new virus in the pathogenesis of MCD. To explore this hypothesis, the KSHV DNA load was investigated in peripheral blood mononuclear cells of 3 human immunodeficiency virus (HIV)-infected patients with MCD at different points during the clinical course. Clinical parameters, such as fever and the presence of lymphadenopathy, were systematically assessed. Hemogram and C-reactive protein level determinations were performed as standard procedures. KSHV DNA load was investigated by means of semiquantitative polymerase chain reaction assay using peripheral blood mononuclear cells of the patients. A correlation between the variation in clinical and biologic parameters related to MCD and KSHV DNA load was found, suggesting a close relationship between KSHV and MCD in HIV-1-infected patients.

Castleman Disease↗
PubMed1997

[Sensitivity to fosfomycin of multiresistant serotype 012 Pseudomonas aeruginosa. Multicenter study].

In a multicentric study including 214 strains of Pseudomonas aeruginosa, we observed that serotype O12 is more frequently sensitive to fosfomycine than other serotypes strains (72% vs 13.2%, p < 0.000001). Time killing experiments demonstrated that combination of ceftazidime-fosfomycine and amikacine-fosfomycine have usually bactericidal and synergistic activities and could be used for the treatment of multiresistant Pa O12 infections. However, an antagonism between beta-lactams and fosfomycin in disk diffusion needs an adequate concentration of both antibiotics in the site of infection.

Aminoglycosides↗
PubMed1997

[Nephropathy and filariasis from Loa loa. Apropos of 1 case of adverse reaction to a dose of ivermectin].

A patient with a filarial infection due to Loa loa, received single oral dose of ivermectin A few hours after, he has presented a severe renal impairment. Native of the Cameroons, he was also treated for malaria. A renal biopsy has been done, because of chronic proteinuria. It has showed microfilariae in glomeruli, thickening of the basement membrane and a segmental and focal mesangial hyalinosis. By immunofluorescence microscopy there were granular deposits of IgM and C3 along this membrane. Electron microscopy has showed subepithelial electron- dense deposits. This suggests that the renal disease is immunologically induced. During the therapy, adverse reactions seemed to be related with massive liberation of filarial antigens. This is well known with diethylcarbamazine but also now, sometimes with ivermectin.

Adult↗
PubMed1997

[Epidemiologic surveillance in the Army and Public Health: as exemplified by rubella].

Since 1993, several outbreaks of rubella are annually reported from the French military. This trend reveals a transfer of the reservoir of wild virus towards a non-immune population of male adolescents and young adults, as a result of the rubella control programmes. This paradoxical phenomenon should disappear within the next decade, when the new vaccinal schedule including a combined measles, mumps and rubella vaccine for the children of both sexes 11 to 13 years old will have been implemented. Meanwhile, the military system of weekly epidemiological report will be usable as a national observatory for the rubella. Moreover, providing specific data in real time, it will be able to support a strategy of intervention for an early neutralization of epidemics.

Adolescent↗
PubMed1997

[Non-vaccinal prophylaxis for orally transmitted diseases].

Many diseases are transmitted to man by consumption of contaminated food and drinking water. Orally transmitted diseases are among the main risks for travelers in developing and tropical countries. A variety of clinical manifestations can be observed but the diarrhea is the most common. In many cases bacterial gastroenteritis, typho-paratyphoidal fever, brucellosis, viral hepatitis, and various parasitic diseases can develop after various periods of incubation following consumption of contaminated food or drink with no initial reaction. Vaccination can afford protection against only few diseases. Prevention by applying good hygiene and common sense is the best method. By following the standard list of food precautions, travelers can minimize the main risks. Drug prophylaxis is recommended only under special circumstances. Travel medicine providers must have up-to-date information and possess the persuasive powers necessary to convince travelers to apply recommendations despite the major inconveniences.

Communicable Disease Control↗