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V Vaillant

Publications and source records attributed to V Vaillant.

At least 37 records · Page 2Linked to original sources
PubMed2002

[The capture-recapture applied to epidemiology: principles, limits and application].

By matching several sources of information coming from the same population, the capture-recapture method allows, if matches between sources can be identified, to estimate the number of cases not identified by any of the sources, the total number (N) of cases in the population and the sensitivity of each source. Used first in zoology and demography, this technique has been increasingly applied to epidemiology in the last two decades. However, six conditions need to be satisfied: all cases identified by each source are true cases; occurred during the time and the geographical area studied; the study population is closed; all matches are true matches; sources are independent and there is no heterogeneous catchability within sources. It is possible to assess and take into account dependence between sources when 3 or more sources are used, in particular by log linear modelling. However interactions of maximal order cannot be adjusted for. In case of a biased estimation because of the non respect of the conditions, it is recommended to apply a method of correction. The complete application of the methods is illustrated in the study of estimating the number of Salmonella infectious foodborne outbreak. As capture-recapture studies often use data collected for other purposes, this technique should be regarded as exploratory or be used to validate an estimate of a number of cases obtained by another method. It should not replace population sampling methods only because of its low cost. Otherwise it is a very informative approach to evaluate the sensitivity and representativeness of surveillance systems and registries.

Algorithms↗
PubMed2001

Two consecutive nationwide outbreaks of Listeriosis in France, October 1999-February 2000.

In France, listeriosis surveillance is based on mandatory notification of all culture-confirmed cases, with systematic typing of isolates and routine collection of the patient's food history. From October 1999 to March 2000, two outbreaks of listeriosis were detected through this enhanced surveillance system. In outbreak 1, analysis of the food histories of cases suggested brand X "rillettes," a pâté-like meat product, as the vehicle of infection, and the outbreak strain of Listeria monocytogenes was subsequently isolated from the incriminated rillettes. In outbreak 2, a case-control study showed that consumption of jellied pork tongue was strongly associated with infection with the outbreak strain (odds ratio = 75.5, 95% confidence interval: 4.7, 1,216.0). However, trace-back results did not permit incrimination of any particular manufacturer of jellied pork tongue, and the outbreak strain was not isolated from the incriminated food or from any production sites. Consumption of jellied pork tongue was discouraged on epidemiologic evidence alone. The consecutive occurrence of these two outbreaks confirms the epidemic potential of listeriosis, even in a context of decreasing incidence, and underlines the importance of timely case-reporting and systematic typing of human L. monocytogenes strains to allow early detection and separate investigation of different clusters.

Animals↗
PubMed2000

Risk factors for the occurrence of sporadic Salmonella enterica serotype typhimurium infections in children in France: a national case-control study.

To determine risk factors for the occurrence of sporadic Salmonella typhimurium infections among children in France, we conducted a matched case-control study. Cases were identified between 15 June and 30 September 1996. We interviewed 101 pairs of case patients and control subjects, matched for age and place of residence. The risk of illness was greater for children who ate undercooked ground beef than for those who did not (odds ratio [OR], 5.0; 95% confidence interval [CI], 1.9-13.1). Case patients were more likely than control subjects to have taken antibiotics during the month before onset of disease (OR, 2.2; 95% CI, 1.0-4.9). Case patients <5 years of age were more likely to have been in contact with a household member with diarrhea 3-10 days before onset (P=.05). Consumption of undercooked ground beef is a risk factor for the sporadic occurrence of S. typhimurium infection among children, and antibiotics may facilitate the occurrence of illness. The possibility of person-to-person transmission among young children needs to be considered.

Adolescent↗
PubMed2000

How many foodborne outbreaks of Salmonella infection occurred in France in 1995? Application of the capture-recapture method to three surveillance systems.

Despite control measures, foodborne outbreaks of non-typhi Salmonella infection continue to occur in developed countries. The authors aimed to assess the number of foodborne Salmonella outbreaks that occurred in France in 1995 using a capture-recapture approach. Data from three sources--the National Public Health Network (NPHN), the Ministry of Agriculture (MA), which receives mandatory notification, and the National Salmonella and Shigella Reference Center (NRC)-were collected. Matching algorithms permitted identification of matched outbreaks. The total number of outbreaks was estimated by log-linear modeling taking into account source dependencies and the variable catchability. The final estimate was adjusted for the positive predictive value (66%) of the NRC case definition. The dependence between the NPHN and the MA was also evaluated by means of a qualitative survey. A total of 716 foodborne Salmonella outbreaks were reported to the three sources, and 108 matches were identified. The best-fitting model, taking into account a positive dependence between the NPHN and MA sources, gave an estimate of 757 outbreaks. The sensitivity was 15% for the NPHN, 10% for the MA, and 50% for the NRC. In France, routine mandatory reporting of foodborne Salmonella outbreaks is very incomplete, and it is not representative of the serotype and the type of outbreak.

Disease Outbreaks↗
PubMed2000

A community--wide outbreak of Salmonella enterica serotype Typhimurium infection associated with eating a raw milk soft cheese in France.

In 1997, a community-wide outbreak of Salmonella enterica serotype Typhimurium (S. typhimurium) infection occurred in France. The investigation included case searching and a case-control study. A case was defined as a resident of the Jura district with fever or diarrhoea between 12 May and 8 July 1997, from whom S. typhimurium was isolated in stool or blood. One hundred and thirteen cases were identified. Thirty-three (83 %) of 40 cases but only 23 (55 %) of 42 community controls, matched for age and area of residence, reported eating Morbier cheese (Odds ratio: 6.5; 95 % Confidence Interval: 1.4-28.8). Morbier cheese samples taken from the refrigerators of two case-patients and one symptom-free neighbour cultured positive for S. typhimurium of the same phage type as the human isolates. The analysis of distribution channels incriminated one batch from a single processing plant. These findings show that an unpasteurized soft cheese is an effective vehicle of S. typhimurium transmission.

Adolescent↗
PubMed2000

[Epidemiology of human Listeria infections in France].

Human listeriosis is a relatively rare but serious disease with case fatality rates between 20 and 30%. The majority of patients who have listeriosis present with meningitis or septicaemia. Listeriosis during pregnancy can lead to a congenital infection, neonatal sepsis and meningitis or foetal death. The main mode of transmission is through contaminated foods. The infection usually occurs sporadically but small outbreaks and even large epidemics have occurred in a large number of industrialised countries. During the last 10 years several Listeria monocytogenes control measures have been introduced and implemented at the retail level and in production for plants or foods potentially contaminated with Listeria monocytogenes. During this period the incidence of listeriosis decreased substantially and is at present estimated at 300-400 cases annually.

Food Contamination↗
PubMed1990

An epidemic of respiratory syncytial virus in elderly people: clinical and serological findings.

In 1984-1985, an outbreak of respiratory syncytial virus (RSV) infection occurred in two geriatric wards. Among 68 patients (mean age +/- SD = 82.5 +/- 12.5 with respiratory signs, 52 had signs caused by RSV infection. Among all patients, the clinical and serological attack rates were 61.2% and 75.0%, respectively. The most frequent clinical presentation was intensive coughing (96.1%) and fever (96.1%) associated with expectorate (63.5%). The duration of the respiratory symptoms was 5 to 7 days. The disease gradually resolved, although in eight (15.4%) patients complications occurred. For periods of up to 1 year after infection, 172 sera were obtained and tested by complement fixation test (CFT), fluorescent assays for titrating specific IgG, IgA, and IgM, and Western blotting. Specific IgM appeared in six (11.5%) of the infected patients and peaked 2 to 6 months after infection, and there was no significant correlation with severity of clinical symptoms. However, higher peak G and A antibody responses were observed in persons with rales (CFT: P = 0.008; IgG: P = 0.042; IgA: P = 0.020), cough (IgG: P = 0.034), sputum (IgG: P = 0.030), dyspnea (CFT: P = 0.024), conjunctivitis (CFT: P = 0.025), and bronchitis (CFT: P = 0.018). The temporal patterns of IgA and CFT results were found to be similar, whereas IgG peaked later, i.e., between 2 and 6 months. The patients with the most severe symptoms had the highest antibody titers obtained by conventional tests and by Western blots. Thus, RSV can be an epidemic pathogen among elderly persons, although this illness is usually mild.

Aged↗
PubMed1990

[Evaluation of ELISA using A60 antigen from Mycobacterium bovis BCG: specific IGG and IGM in mycobacterial infections].

The authors have evaluated an ELISA (A60-Tb, Anda biologicals) allowing the detection of specific IgG and IgM against A60 antigen from Mycobacterium bovis BCG during mycobacterial infections. This study included sera from 110 african subjects and from 71 French subjects distributed in 4 clinical groups: 55 tuberculous patients (I), 41 leprous patients (II), 33 pneumopathies (III) and 52 healthy subjects (IV). Serological results were compared taking as reference for the diagnosis of tuberculosis the positivity of culture and/or that of a direct examination, and for leprosy the positivity of a direct examination associated either with a Mitsuda's reaction or with an histopathological examination. IgG were found to be more discriminative than IgM. Considering together the results of groups I and II, the authors found a sensitivity of 95.8 p. cent and a specificity of 75.3 p. cent with threshold of 200 U/ml for specific IgG. Anti-A60 antigen antibodies obtained for groups I and II were significantly higher (IgG: p less than 0.0001; IgM: p less than 0.001) than those observed in other groups. African subjects presented IgG titers higher than those obtained by French subjects (p less than 0.0001). IgM response was more frequent among group II (97.6 p. cent) than group I (21.8 p. cent). However, IgG (26.9 p. cent) and IgM titers (30.8 p. cent) were detected among group IV. This test would allow a control of therapeutic efficacy with an additional interest for classifying borderline forms of leprosy.

Adult↗