Incidence of tuberculous meningitis in France, 2000: a capture-recapture analysis

OBJECTIVE

To estimate the incidence of culture-positive and culture-negative tuberculous meningitis (TBM) in France in 2000.

METHODS

Capture-recapture method using two unrelated sources of data: the tuberculosis (TB) mandatory notification system (MNTB), recording patients treated by anti-tuberculosis drugs, and a survey by the National Reference Centre (NRC) for mycobacterial drug resistance, recording culture-positive TBM.

RESULTS

Of 112 cases of TBM reported to the MNTB, 28 culture-positive and 34 culture-negative meningitis cases were validated (17 duplicates, 3 cases from outside France, 21 false notifications, and 9 lost records were excluded). The NRC recorded 31 culture-positive cases, including 21 known by the MNTB. When the capture-recapture method was applied to the reported culture-positive meningitis cases, the estimated number of meningitis cases was 41 and the incidence was 0.7 cases per million. Sensitivity was 75.6% for the NRC, 68.3% for the MNTB, and 92.7% for both systems together. When sensitivity of the MNTB for culture-positive cases was applied to culture-negative meningitis, the total estimated number of culture-negative meningitis cases was 50 and the incidence was 0.85 cases per million.

CONCLUSION

TBM is underestimated in France. Capture-recapture analysis using different sources to better estimate its incidence is of great interest.

Outbreak of tuberculosis in a migrants' shelter, Paris, France, 2002

SETTING

An overcrowded 362-bed migrants' shelter in Paris, France.

OBJECTIVES

To investigate an outbreak of tuberculosis (TB), to identify a common source of contamination and to prevent further transmission.

METHODS

The outbreak was identified by radiographic screening and an active search for undeclared hospital treated cases, completed by strain phenotyping and a search for contact cases.

RESULTS

Between October 2001 and October 2002, 56 cases of active TB were identified, 30 by radiological screening and 20 by contacting neighbouring hospitals. All cases involved men, with a median age of 30 years. Pulmonary involvement was present in 54% of cases, and nine patients were sputum smear-positive. Thirty-four of the 37 phenotyped strains clustered together.

CONCLUSION

The grouping of the cases in time and place, the large number of cases with early-stage disease and the identical RFLP banding patterns of most of the isolates indicate that this outbreak results from transmission that occurred in France. This report underlines the need for public health departments in industrialised countries to maintain effective anti-tuberculosis control programmes.

Situation épidémiologique de la tuberculose en Ile-de-France en 2001

INTRODUCTION

The incidence of tuberculosis in France is stable at around 10 per 100,000 per year since 1997. However in the Ile-de-France (which includes Paris and its suburbs) high population density, social deprivation and large numbers of immigrants result in the region providing more than half of the total number of cases notified in France.

METHODS

Retrospective analysis using data from the mandatory notification forms of patients diagnosed in 2001.

RESULTS

The incidence of tuberculosis in 2001 was 27.2 cases per 100,000 in the Ile-de-France region and 48.4 per 100,000 in the Paris area. The incidence was particularly high amongst young immigrants, especially those from Sub-Saharian countries. Pulmonary tuberculosis was the most commonly observed disease form (72% of cases). HIV infection was documented in 7.5% of subjects. Local tuberculosis control services were asked to intervene in only 30% of overall cases, and in only 50% of pulmonary cases living in crowded housing.

CONCLUSION

More resource is needed for the surveillance of tuberculosis and the implementation of public health initiatives in the Ile-de-France to strengthen the fight against tuberculosis.

Clusters of travel associated legionnaires' disease in France, September 2001- August 2003

Clusters of travel associated legionnaires' disease warrant urgent attention, and are detected by the French national surveillance system and the European network EWGLINET. Between September 2001 and August 2003, 37 clusters were identified in French tourist accommodation: 27 hotels and 10 campsites. The number of clinical cases per cluster was as follows: 30 clusters of 2 cases (81%), 6 clusters of 3 cases (16%) and one cluster of 4 cases (3%), a total of 82 cases. The local health authorities performed environmental investigations for 36 of the 37 clusters. Among the 36 clusters investigated, water samples were collected for 35. At 16 (46%) sites, Legionella pneumophila was found at a level of more than 103 cfu/litre. In all of the accommodation where risk assessment was found to be inadequate- control measures were implemented immediately. Six hotels were closed immediately following cluster alerts. Comparison of clinical and environmental isolates by pulsed field gel electrophoresis (PFGE) was possible in 3 clusters and identical genomic profiles of the isolates were found in all. During this two year period of surveillance, we found that on many sites there has been a risk of exposure to Legionella. This reinforces the importance of the European surveillance network and the timely notifications of all the cases to EWGLINET.

Repeat capture-recapture studies as part of the evaluation of the surveillance of Legionnaires' disease in France

We evaluated improvements made to the mandatory notification surveillance system for Legionnaires' disease in France by estimating its sensitivity in 1995 and 1998 using a repeat capture-recapture method. A case of Legionnaires' disease was defined as a person treated for pneumonia in whom legionella had been detected. Patient details were collected from (1) mandatory notifications; (2) the National Reference Centre for Legionella; (3) a postal survey of all hospital laboratories. The three sources were cross-matched and 715 individual cases were identified. A log-linear model, which included an interaction term between mandatory notifications and both the National Reference Centre and Laboratory sources, provided an estimated total of 1124 cases (95% CI 973-1275) in 1998, a twofold increase compared with 1995. The sensitivity of the surveillance system improved from 10% in 1995 to 33% (95% CI 29-38%) in 1998. Capture-recapture methods are important tools in the evaluation of surveillance systems.

Sporadic cases of community acquired legionnaires' disease: an ecological study to identify new sources of contamination

STUDY OBJECTIVE

To explore the relation between incidence of sporadic and community acquired legionnaires' disease and exposure to potentially contaminated industrial aerosols.

DESIGN

Geographical ecological approach using the postcode as the statistical unit. A multivariate Poisson regression model was used to model the relation between exposure to industrial aerosols and legionnaires' disease.

SETTING

Metropolitan France.

MAIN RESULTS

More than 1000 sources of industrial exposure (aerosol and plume of smoke) were identified in 42 French departments. After adjusting for confounding factors, there was a statistically increased incidence of legionnaires' disease in postcodes with plume of smoke in comparison with postcodes without (RR=1.45, 95% CI=1.12 to 1.87), and in postcodes with more than one aerosol in comparison with postcodes without (RR=1.37, 95% CI=1.04 to 1.79).

CONCLUSION

These findings highlight that any industrial systems generating water aerosols should be regarded as potential sources of contamination for legionnaires' disease.

Notified cases of legionnaires disease in France in 2001

In 2001, 807 cases of Legionnaires' disease were reported to the Institut de veille sanitaire (French national public health centre). The incidence of the disease was 1.35 cases per 100,000 inhabitants, compared to a mean European incidence of 0,6 per 100,000. The median age was 59 years [16-97], the group aged more than 80 being the most affected. The sex ratio M/W was 3.1. The outcome of the disease was known in 69% of all cases, the case fatality ratio rating 19.9%. Among the contributing factors found in 558 cases, 11% had a cancer or blood disease, 12% received an immunosuppressant treatment, 10% were diabetic and 40% were smokers. In 2001, 13% (105/807) cases stayed in a hospital or a clinic during the incubation period, compared to 20% in 2000, and 11% were travel-associated.

Surveillance of haemolytic uraemic syndrome in children under 15 years of age in France in 1998

Data from a national network of paediatric nephrology departments in France suggest that the incidence of haemolytic uraemic syndrome (HUS) in 1998 was 0.7 cases per 100 000 children aged under 15 years and that cases occur sporadically. Six out of 85 cas

Haemolytic uraemic syndrome and Shiga toxin-producing Escherichia coli infection in children in France. The Société de Néphrologie Pédiatrique

We conducted a study to determine the incidence of haemolytic uraemic syndrome (HUS) in children in France and to assess the role of Shiga-toxin-producing Escherichia coli (STEC) infection in the aetiology of HUS. In collaboration with the Société de Néphrologie Pédiatrique we undertook a retrospective review of all cases of HUS hospitalized from January 1993 to March 1995 and a 1-year prospective study (April 1995-March 1996) of epidemiological and microbiological features of cases of HUS. The polymerase chain reaction (PCR) procedure was used to detect stx, eae, e-hlyA genes directly from case stool samples. Serum samples from cases were examined for antibodies to lipopolysaccharide (LPS) of 26 major STEC serogroups. Two hundred and eighty-six cases were reported. The average incidence per year was 0.7/10(5) children < 15 years and 1.8/10(5) children < 5 years. During the prospective study, 122/130 cases were examined for evidence of STEC infection using PCR and/or serological assays and 105 (86%) had evidence of STEC infection. Serum antibodies to E. coli O157 LPS were detected in 79 (67%) cases tested. In conclusion, this study showed that STEC infection is an important cause of HUS in children in France, with a high proportion related to the O157 serogroup.

Epidemic cluster of legionnaires disease in Paris, June 1998

From 29 June to July 1998, four cases of legionnaires disease in British citizens were reported to the Reseau National de Sante Publique (RNSP) by the statutory notification system (declaration obligatoire (DO)) and by theEuropean Surveillance Scheme for

Single clonal origin of a high proportion of Legionella pneumophila serogroup 1 isolates from patients and the environment in the area of Paris, France, over a 10-year period

Arbitrarily primed PCR with three primers and pulsed-field gel electrophoresis were used to characterize a set of 75 clinical Legionella pneumophila serogroup 1 isolates, with no apparent epidemiological link, obtained from 24 hospitals in Paris, France, from 1987 to 1997. Unexpectedly, 25 clinical isolates from 15 hospitals had an identical profile (termed type A) by both methods. The same profile was subsequently found in 16 of 64 randomly selected environmental L. pneumophila serogroup 1 isolates from 15 different sites in the Paris area. There was no evidence of geographic clustering or a peak incidence of type A isolation. Type A has not been found in France outside the Paris area, suggesting that a particular type of L. pneumophila serogroup 1 is specifically present in the Paris water distribution network.

Malaria surveillance among the displaced Karen population in Thailand April 1984 to February 1989, Mae Sot, Thailand

Right from the arrival of the displaced Karen people in Thailand, Médecins sans Frontières (MSF) identified malaria as the top priority problem. A program of patient care based on the coupled laboratory/dispensary was set up in April 1984. Immediately a system of surveillance of morbidity and mortality from malaria was set up. This study consisted of analysing data gathered over a period of five years. During this time, the displaced population increased from 9,000 to 20,000. Analysis of the trends shows a hyperendemic situation with an annual incidence rate of 1,067 per thousand in 1984. This figure was 600 per thousand in 1988. 1,500 blood smears were checked each month and the positive predictive value of clinical suspicion was 45% on average. Plasmodium falciparum represented 80% of infections. The malaria case fatality ratio over the course of the last two years of surveillance was 0.3%. Five years observation show that the fight against malaria in this region can be based on the development of curative services and laboratories.

Malaria during pregnancy in an area of unstable endemicity

A prospective study of malaria during pregnancy was conducted between September 1986 and December 1989 in an area of unstable (mesoendemic) malaria transmission on the Thai-Burmese border. Antenatal clinics were set up in camps for displaced persons of the Karen ethnic minority and 1358 pregnant women were enrolled at a mean estimated gestational age of 23 weeks (standard deviation 5.7 weeks) and were followed weekly until delivery. Malaria developed in 505 women (37.2%); 80.2% of infections were Plasmodium falciparum, 17.1% were P. vivax, and 2.7% were mixed. Primigravidae were infected more commonly than multigravidae: 153/322 (47.5%) compared with 318/953 (33.3%) (P less than 0.001). The incidence of malaria declined from the 20th week of gestation (12%) towards term (4.4%). Most infections were detected before symptoms developed, and there were no deaths associated with malaria. Despite this, malaria was associated with an overall 123 g reduction in birthweight (95% confidence interval [CI] 34-212 g). This reduction was largely accounted for by lower birthweights of babies born to infected primigravidae (mean reduction 151 g, 95% CI 21-282 g) and women in their 2nd and 3rd pregnancies (mean reduction 185 g, 95% CI 84-286 g). The incidence of anaemia requiring treatment was higher in women who developed malaria, 149/420 (35.4%) compared with 191/670 (28.5%), and was proportional to the number of parasitaemic episodes. Thus, despite regular antenatal clinic attendance with prompt detection and treatment of malaria (the currently employed antimalarial strategy in areas with multidrug-resistant P. falciparum), malaria still had a significant adverse effect on pregnancy.(ABSTRACT TRUNCATED AT 250 WORDS)