Usability of the bivalves Dreissena polymorpha and Anodonta anatina for a biosurvey of the neurotoxin BMAA in freshwater ecosystems

The environmental neurotoxin β-methylamino-L-alanine (BMAA) may represent a risk for human health in case of chronic exposure or after short-term exposure during embryo development. BMAA accumulates in freshwater and marine organisms consumed by humans. It is produced by marine and freshwater phytoplankton species, but the range of producers remains unknown. Therefore, analysing the phytoplankton composition is not sufficient to inform about the risk of freshwater contamination by BMAA. Filter-feeders mussels have accumulation capacities and therefore appear to be relevant to monitor various pollutants in aquatic ecosystems. We investigated the suitability of the freshwater mussels Dreissena polymorpha and Anodonta anatina for monitoring BMAA in water. Both species were exposed to 1, 10, and 50 μg of dissolved BMAA/L daily for 21 days, followed by 42 days of depuration in clean water. On days 0, 1, 7, 14, and 21 of exposure and 1, 7, 14, 21 and 42 of depuration, whole D. polymorpha and digestive glands of A. anatina were sampled, and the total BMAA concentration was measured. D. polymorpha accumulated BMAA earlier (from day 1 at all concentrations) and at higher tissue concentrations than A. anatina, which accumulated BMAA from day 14 when exposed to 10 μg BMAA/L and from day 7 when exposed to 50 μg BMAA/L. As BMAA accumulation by D. polymorpha was time and concentration-dependent, with a significant elimination during the depuration period, this species may be able to reflect the levels and dynamics of water contamination by dissolved BMAA. The species A. anatina could be used for monitoring water concentrations above 10 μg BMAA/L.

Increase of tuberculosis incidence in Ile-de-France region and the role of recent migration

Background

In metropolitan France and in the Ile-de-France region, the incidence of tuberculosis has globally decreased since the year 2000 and has stabilized from 2011 to 2015. This study analysed the evolution of tuberculosis in the Ile-de-France region between 2015 and 2017.

Methods

We analysed tuberculosis cases reported in Ile-de-France from 2015 to 2017; 2015 was considered as the baseline year. Incidence rates of reported tuberculosis cases were estimated using French census data for the corresponding year for the denominator. Age-standardized rates were estimated for each of the 8 departments of the region based on the Ile-de-France region population. Foreigners’ population was based on the 2015 French census data. Differences in incidence and proportions were tested with the CHI2 statistic (STATA® v14.0).

Results

The incidence of tuberculosis increased in the Ile-de-France region from 14.6 to 15.8/100 000 pop. between 2015 and 2017 (+8.2%, p < 0.01). In this region, all department’s incidence were above 10/100 000 pop. in 2017. Sub-regional disparities were observed, with an important increase of the incidence in Paris, from 13,5 to 16.8/100 000 pop. between 2015 and 2017 (p < 0,01). The incidence rates among foreigners increased from 44.6 to 51.7/100 000 pop. (p < 0.01) and the proportion of tuberculosis cases among foreigners who arrived in France less than 2 years ago increased from 23% to 32% (p < 0.01), between 2015 and 2017. The incidence rates of tuberculosis cases increased particularly in men, foreigners, and recent migrants.

Conclusions

The incidence of tuberculosis increased in the Ile-de-France region in 2016 and 2017, particularly in newly arrived migrants. This situation requires actions to better detect and manage tuberculosis in this specific population.

Key messages

The incidence of tuberculosis increased in the Ile-de-France region. The incidence of tuberculosis increased in vulnerable population in relation with recent migration.

Decline in antibiotic resistance and changes in the serotype distribution of Streptococcus pneumoniae isolates from children with acute otitis media; a 2001-2011 survey by the French Pneumococcal Network

Streptococcus pneumoniae is an important cause of acute otitis media (AOM). The aim of this study was to evaluate trends in antibiotic resistance and circulating serotypes of pneumococci isolated from middle ear fluid of French children with AOM during the period 2001-2011, before and after the introduction of the PCV-7 (2003) and PCV-13 (2010) vaccines. Between 2001 and 2011 the French pneumococcal surveillance network analysed the antibiotic susceptibility of 6683 S. pneumoniae isolated from children with AOM, of which 1569 were serotyped. We observed a significant overall increase in antibiotic susceptibility. Respective resistance (I+R) rates in 2001 and 2011 were 76.9% and 57.3% for penicillin, 43.0% and 29.8% for amoxicillin, and 28.6% and 13.0% for cefotaxime. We also found a marked reduction in vaccine serotypes after PCV-7 implementation, from 63.0% in 2001 to 13.2% in 2011, while the incidence of the additional six serotypes included in PCV-13 increased during the same period, with a particularly high proportion of 19A isolates. The proportion of some non-PCV-13 serotypes also increased between 2001 and 2011, especially 15A and 23A. Before PCV-7 implementation, most (70.8%) penicillin non-susceptible pneumococci belonged to PCV-7 serotypes, whereas in 2011, 56.8% of penicillin non-susceptible pneumococci belonged to serotype 19A. Between 2001 and 2011, antibiotic resistance among pneumococci responsible for AOM in France fell markedly, and PCV-7 serotypes were replaced by non-PCV-7 serotypes, especially 19A. We are continuing to assess the impact of PCV-13, introduced in France in 2010, on pneumococcal serotype circulation and antibiotic resistance.

Impact of infant pneumococcal vaccination on invasive pneumococcal diseases in France, 2001-2006

Vaccination with the 7-valent pneumococcal conjugate vaccine (PCV) has been recommended in France since 2003 for children under the age of two years who are at risk due to medical or living conditions. From 2006, the recommendation has been extended to all children under two years. The impact of PCV introduction on the incidence of pneumococcal meningitis and bacteraemia and on the serotype distribution in French children and other age-groups was assessed using laboratory surveillance data. The coverage with three doses of PCV was 44% in children aged 6-12 months in 2006. From 2001/2002 to 2006, the incidence of pneumococcal meningitis decreased from 8.0 to 6.0 cases per 100,000, and the incidence of pneumococcal bacteraemia decreased from 21.8 to 17.5 cases per 100,000 in children under the age of two years. For the vaccine strains, the incidence of pneumococcal meningitis and bacteraemia decreased from 20,4 to 6.0 cases per 100,000, while the incidence of pneumococcal meningitis and bacteraemia due to non-vaccine strains increased from 9.4 to 17.5 cases per 100,000 in this time period. The incidence in older children and adults did not decrease. Further expansion of PCV coverage is expected to increase the impact of the vaccination in both children and adults. However, the fact that cases caused by vaccine serotypes have been partially substituted by cases of non-vaccine serotypes is likely to reduce the overall benefit of PCV in France, should this early observation be confirmed in the future.

Critical review of non- or minimally invasive methods (duplex ultrasonography, MR- and CT-angiography) for evaluating stenosis of the proximal internal carotid artery

OBJECTIVE

to assess the performance of non- or minimally invasive methods (duplex ultrasonography, MR- and CT-angiography) in measuring stenosis of the proximal internal carotid prior to endarterectomy without preoperative intra-arterial digital subtraction angiography (DSA).

METHODS

systematic review of the literature (five databases, 1990 to February 2001). The value of each imaging technique was studied through its reproducibility and its sensitivity/specificity compared to DSA.

RESULTS

sensitivity exceeded 80% and specificity 90% in over two-thirds of the methodologically sound studies, regardless of technique, although direct comparisons between results had to be avoided since the findings originated from different populations. The main drawback of duplex ultrasonography is its levels of reproducibility. In contrast, only a few studies have addressed the reproducibility of MR- and CT-angiography. When the results of duplex and MR-angiography agree, the combination use of these two techniques provides a better diagnosis than either technique taken alone.

CONCLUSIONS

all three techniques appear suitable for measuring stenosis of the proximal internal carotid when compared to DSA.

[Endoscopes in urology: disinfection, sterilization, labeling and tracking. Circulars and decrees. Modes of application and commentary. The Committee of Infectious Diseases of the French Association of Urology. Congressional forum UFA--Paris, November 1996. DGS Circular 20 October 1997]

Administrative texts published in 1995, 1996 and 1997, have reinforced materiovigilance and impose disinfection precautions for endoscopes. The steps of disinfection of non-sterilizable endoscopes are: preliminary treatment, rinsing, actual disinfection, final rinsing, storage (see: Progrès en Urologie, 1997, 7, 505-507). Each procedure from collection of the endoscope until storage must be defined by written standard operating procedures validated by CLIN. The risk of transmission of Creutzfeld-Jakob disease requires autoclaving, which is only possible, at the present time, with the most recent rigid endoscopes. Until disinfection has become generalized, the traceability of endoscopes (labelling, utilization files) must be established on the model recommended for haemovigilance (circular of 02/04/96).

Investigations related to the epidemic strain involved in the French listeriosis outbreak in 1992

Two hundred seventy-nine cases of human listeriosis (92 pregnancy-related cases and 187 non-pregnancy-related cases) caused by a serovar 4b and phagovar 2389:2425:3274:2671:47:108:340 strain were identified in France between March and December 1992. Epidemiological investigations included a case-control study (not described here) and microbiological analyses of foods. Results of the case-control study and characterization of food isolates identified pork tongue in jelly, a ready-to-eat meat product, as the major vehicle of this outbreak, and to a lesser extent, delicatessen products contaminated secondarily during handling in food stores. As far as serotyping, phage typing, DNA macrorestriction pattern analysis (obtained by pulsed-field gel electrophoresis [PFGE]), and ribotyping are concerned, this epidemic strain is phenotypically and genomically closely related to strains responsible for major outbreaks of listeriosis previously observed in Europe and North America. The epidemic strain sensu stricto as defined by PFGE (2/1/3) displayed the same serovar, phagovar, ribovar, and ApaI and NotI PFGE patterns as the epidemic strains from outbreaks in Switzerland, California, and Denmark, but it consistently showed differences in the SmaI PFGE profile. This information greatly contributed to the identification of the major food vehicle (pork tongue in jelly) and further allowed exclusion of other foods (cheese) as possible sources of this major listeriosis epidemic.