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M Lienard

Publications and source records attributed to M Lienard.

11 recordsLinked to original sources
PubMed2001

Pre-exposure rabies vaccination: strategies and cost-minimization study.

An alternative strategy for pre-exposure rabies vaccination to the institutional recommendations of the World Health Organization and the Centers for Disease Control and Prevention is proposed based on recent long-term follow-up of post-vaccinal seroconversion rates. The alternative strategy uses the same primary series (i.e. vaccination in the deltoid area on D0, D7, and D28), but is completed by a scheduled booster vaccination at D365. The frequency of recommended subsequent booster injections depends on the serological test results obtained by a RFFIT on D379 and 3 years later. The objective of this study was to compare the efficiency of the two pre-exposure strategies. A cost-minimization analysis was carried out to compare the two rabies pre-exposure vaccination and serological test strategies based on the data from two published studies on the long-term evolution of the immunity achieved using the different recommendations. For a theoretically equivalent immunogenicity, the cost of the alternative strategy ranged from 1.7 to 5.2 times lower than that of the institutional recommendations. A sensitivity analysis confirmed the robustness of the results. The alternative strategy should be validated externally under field conditions. This approach would compare its real efficiency to the institutional recommendations.

Antibodies, Viral↗
PubMed2000

Predictive factors for the neutralizing antibody response following pre-exposure rabies immunization: validation of a new booster dose strategy.

A prospective cohort of 312 subjects who received pre-exposure rabies immunization and who were monitored serologically with a 10-year follow-up was assessed using multivariate analysis. The aim was to propose a new booster dose strategy by identifying predictive factors for the durability of the neutralizing antibody response. Evaluation bore on several factors relating to: (1) demographic characteristics: age, gender; (2) vaccines: type of vaccine (HDCV or PVRV), injection regimen (D0-D28-D365 or D0-D7-D28-D365) and vaccine lots' antigenic potency; and (3) resulting antibody titers. Logistic regression analysis enabled the authors to establish a predictive model for immunized subjects' serological status at ten years' follow-up expressed as a P probability for seroreversion (antibody titer <0.5 IU/ml). Highly significant factors were the immunization regimen, the type of vaccine used and the antibody titer at D379. A P value <0.4 identified subjects as "good" responders who were sure to be have satisfactory antibody titers at 10 years and who required a single booster dose every 10 years. A P value >/=0.4 identified subjects as "poor" responders in whom a specific follow-up and booster dose strategy is proposed. This new immunization strategy could at least be applied to subjects with a frequent risk of exposure, as defined by institutional recommendations. This new immunization strategy should nevertheless undergo an external validation and a cost-effectiveness evaluation.

Adolescent↗
PubMed2000

[Prevalence of infection by hepatitis viruses in a rural area. Analysis according to risk factors and alcohol consumption].

OBJECTIVES: To evaluate the prevalence of serum markers of hepatitis A, B and C viruses in a rural area according to risk factors and alcohol consumption. METHODS: Transversal study of unselected subjects living and working in a rural area. Each subject included was asked to fill out an anonymous self-administered questionnaire dealing with his own risk factors, sexual behaviour and alcohol consumption. A blood sample was collected for detection of HBsAg, anti-HBc, anti-HBs, anti-HAV and anti-HCV antibodies. RESULTS: Three hundred three subjects with a mean age of 48 years were included. Main risk factors for viral infection were: blood transfusion (9.4%), intravenous drug addiction (0.73%), acupuncture (17.5%), tattoos (5. 8%), past hospitalizations (71.5%), homosexuality (1.1%), conjugal unfaithfulness (11%), sexual partners >5 (21.3%). Most subjects with at risk sexual behaviour had sexual relations without protection. Anti-HAV prevalence was 87.2% (95% confidence interval 83.4-91.0%). None of the subjects was HBsAg positive and 6.0% (confidence interval 4.7-8.7%) had anti-HBV antibodies. HBV prevalence was correlated to homosexuality only. Two subjects (0.67%, confidence interval 0-1.6%) without any identified risk factor had anti-HCV antibodies. There was no correlation between serum viral marker positivity and an excess alcohol consumption (>80 g of ethanol/d) which was present in 46 subjects. However HBV prevalence was 28.6% in the seven subjects who had been treated for alcoholism; these 7 subjects had a highly at risk sexual behaviour. CONCLUSION: In a rural area, infection by HAV is very frequent. The prevalence of HBV and HCV did not greatly differ from that observed in the general and urban population. The frequent failure to use protection in subjects with at risk sexual behaviour reinforces the need of prevention programs in rural areas.

Adult↗
PubMed1998

Antibody persistence following preexposure regimens of cell-culture rabies vaccines: 10-year follow-up and proposal for a new booster policy.

Subjects (n = 312) received either the human diploid cell rabies vaccine (HDCV) or the purified Vero cell rabies vaccine (PVRV) according to either two-injection (days 0 and 28) or three-injection (days 0, 7, and 28) primary regimens. They received a booster injection at 1 year. Rabies antibody levels were measured after the primary series and the booster and then each year for the next 10 years. The results confirm the superior long-term immunogenicity of the three-injection over the two-injection protocol. HDCV and PVRV in three doses were equally immunogenic. A booster injection at 1 year provides long-term seroconversion (titer > or = 0.5 IU/mL). Antibody titers 2 weeks after the 1-year booster allowed prediction of long-term immunity. Good responders, with titers > or = 30 IU/mL, were protected for at least 10 years. An algorithm for differentiation between good responders and poor responders with respect to vaccine booster strategies is proposed.

Adolescent↗
PubMed1993

[Pre-exposure rabies immunization in occupational exposed milieu. A 5-year prospective and comparative study of immunogenicity].

Pre-exposure rabies immunization has been the object of numerous immunogenicity studies with cultivated cell vaccines. Several primary immunizations and booster injection schedules have been suggested. The purpose of the present study was to compare simultaneously the immunogenicities of two vaccines at 5 years and those of two primary immunization schedules with a booster injection at 1 year. We compared the vaccine prepared from Vero cell cultures (PVRV) versus the reference vaccine prepared from human diploid cell culture (HDCV). We also compared primary immunization with 2 injections (on days 0 and 28) versus 3 injections (on days 0, 7 and 28). This phase IV study was prospective, randomized and conducted on open cohorts, according to a factorial plan defining four modalities (HDCV 2, HDCV 3, PVRV 2, PVRV 3). The study involved 312 volunteers of both sexes, aged from 15 to 65 years and exposed to rabies by their profession. The vaccines were injected intramuscularly in the deltoid region. Immunogenicity was evaluated by staged titering of neutralizing antibodies, using immunofluorescence. Seroprotection levels and mean geometrical means of titers were compared. The 3 injections schedule proved to be significantly superior to the 2 injections schedule. No difference could be clearly elicited between the two vaccines. The worst results were obtained with PVRV 2, with a 68.3 percent seroprotection rate at five years; with the other modalities this rate was 93.1 percent or more. We therefore recommend the following procedure: primary immunization by 3 injections, with a booster dose at 1 year, particularly when PVRV is used. It seems that the seroprotection obtained in this manner would make it possible to envisage a booster injection every 5 years.

Adolescent↗
PubMed1993

[Brucellosis among occupationally exposed people: evaluation of immunological tests after vaccination].

For the evaluation of immunological tests during an epidemiological survey and of vaccination with the PI brucellin vaccine, in an occupationally exposed environment, a sample group of 354 subjects was studied. The vaccinal strategy was based on the outcome of a skin test for hypersensitivity: the PS brucellin test. In this framework, the serological status and evolution of individuals with positive or negative reactions to this test were analysed. Sera were studied using the buffered antigen test, indirect fluorescence immunoassay and Wright's agglutination test, as well as by PACIA and ELISA techniques with assay of IgG, IgA and IgM antibodies. The PS test, which was pivotal in this study, was compared with the lymphoblastic transformation test. One prominent aspect of this evaluation was the establishment of conventional prognostic indices for the PS and serology. The PS is definitely shown to be a convenient, reliable tool for screening. Although it does not generate sensitivity it may modify the serological status of both positive and negative individuals.

Agglutination Tests↗
PubMed1992

[Brucella vaccination in professionally exposed subjects. Prospective study].

This prospective phase IV study on cohort concerns a vaccine made of the phenol-insoluble fraction of Brucella abortus biotype 1 (B19 strain). Three hundred and three professionally exposed subjects entered the study; 161 out of 182 subjects (88.5 percent) with negative response to an intradermal test for detection of previous contamination accepted to be vaccinated. Booster injections were given 18 and 36 months after vaccination. Local pain was observed after 45.2 percent of injections and moderate systemic reactions after 5 percent of injections. Seropositivity after primary vaccination reached 80 percent. The booster injection, justified by a major decrease of this rate after 18 months, gave exactly the same response of the thymo-independent type. This vaccinal schedule did not result in detectable hypersensitivity. The clinical effectiveness of the vaccine could not be evaluated accurately because of the insufficient number of subjects. The possibility of subclinical infection in vaccinated subjects calls for wider comparative studies of vaccinated versus non-vaccinated subjects.

Brucella Vaccine↗
PubMed1987

Raynaud's phenomenon in chain saw users. Hot and cold finger systolic pressures and nailfold capillary findings.

To gain insight into the physiopathology of Raynaud's phenomenon of occupational origin, finger systolic pressures under heat and cold, and results of nailfold capillary microscopy, were examined in 29 lumberjacks with Raynaud's phenomenon vibration syndrome (pathological group) and 24 lumberjacks without it (non-pathological group), and compared with the same values in 26 healthy matched manual workers not using a vibrating tool (controls). Vibration syndrome physiopathology seemed multifactorial, combining 5 features: a rise in brachial diastolic and systolic pressures in the pathological group compared with the two other groups. In lumberjacks with Raynaud's phenomenon, these rises seemed to be acquired, since they were not found when the workers were engaged; a reduction in the number of nailfold capillaries (9.4 +/- 2 per mm in the pathological group vs 11 +/- 2.5 in the controls, P less than 0.025); a rise in the brachial digital systolic gradient (P less than 0.025) in the pathological versus the non-pathological lumberjack group abnormal cold vascular tone, since at 15 degrees C finger systolic pressures in the pathological group were lower than pressures in both the control and non-pathological groups (P less than 0.05 and P less than 0.01, respectively), and at 10 degrees C, they were lower in the pathological than in the control group (P less than 0.01); Within the pathological group, individual paired comparisons between the most and least symptomatic finger revealed a rise in the cold vascular tone, and a reduction in the number of nailfold capillaries in the most symptomatic finger compared to the least symptomatic finger.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Pressure↗
PubMed1985

[Raynaud's syndrome in lumberjacks using chain saws. Epidemiology, clinical and capillaroscopic findings].

The overall incidence of Raynaud's syndrome in lumberjacks using a mechanic chain saw in France is at least 45%; workers exposed to the risk for more than 3 years have an incidence of about 60%. Vibrations are probably directly responsible for the disease, while among the other favorizing factors the different winter climatic conditions do not appear to be relevant, and this is the case with conventional vascular risk factors, apart perhaps for hypertension. A history of injury to hands is significantly more frequent in affected subjects possibly related to a relative digital cutaneous hypo-esthesia. Capillaroscopy shows organic microangiopathies with reduction in number of nail-bed capillaries and functional angiopathies of arteries of hand in the form of abnormal spasm induced by cold. Technical progress by the use of chain saws has markedly reduced incidence of this occupational disease, but in France it would appear that only modifications in working conditions of lumberjacks could reduce the incidence of the disease.

Capillaries↗