Comparison of whole-cell versus acellular pertussis vaccine effectiveness in school clusters of pertussis, France, 2013.

OBJECTIVES AND METHOD: We conducted a prospective study in 2013 to compare the whole-cell versus acellular pertussis vaccines effectiveness and duration of protection, following the occurrence of pertussis clusters. RESULTS: During seven school outbreaks, we identified 102 clinical pertussis cases, including 10 cases biologically confirmed by Bordetella pertussis specific PCR, among a cohort of 305 children in 2nd to 6th grade. The risk of pertussis when vaccinated with an acellular vaccine alone was 1.6 (RR=1.6; 95% CI=1.1-2.5) times higher than when vaccinated with a whole-cell vaccine or using a combined schedule. CONCLUSIONS: The limited duration of protection conferred by the acellular vaccine reinforces the 2013 introduction of the pertussis booster at six years old.

Strengthened Ebola surveillance in France during a major outbreak in West Africa: March 2014-January 2016.

Introduction An unprecedented outbreak of Ebola virus diseases (EVD) occurred in West Africa from March 2014 to January 2016. The French Institute for Public Health implemented strengthened surveillance to early identify any imported case and avoid secondary cases. METHODS: Febrile travellers returning from an affected country had to report to the national emergency healthcare hotline. Patients reporting at-risk exposures and fever during the 21st following day from the last at-risk exposure were defined as possible cases, hospitalised in isolation and tested by real-time polymerase chain reaction. Asymptomatic travellers reporting at-risk exposures were considered as contact and included in a follow-up protocol until the 21st day after the last at-risk exposure. RESULTS: From March 2014 to January 2016, 1087 patients were notified: 1053 were immediately excluded because they did not match the notification criteria or did not have at-risk exposures; 34 possible cases were tested and excluded following a reliable negative result. Two confirmed cases diagnosed in West Africa were evacuated to France under stringent isolation conditions. Patients returning from Guinea (n = 531; 49%) and Mali (n = 113; 10%) accounted for the highest number of notifications. CONCLUSION: No imported case of EVD was detected in France. We are confident that our surveillance system was able to classify patients properly during the outbreak period.

Toxigenic Corynebacterium ulcerans in a fatal human case and her feline contacts, France, March 2014.

In March 2014, a person in their eighties who was diagnosed with extensive cellulitis due to toxigenic Corynebacterium ulcerans died from multiple organ failure. Environmental investigation also isolated C. ulcerans in biological samples from two stray cats in contact with the case. This finding provides further evidence that pets can carry toxigenic C. ulcerans and may be a source of the infection in humans.

First estimates of influenza vaccine effectiveness among severe influenza cases, France, 2011/12.

Following a suspected virus-vaccine mismatch, the screening method was used to estimate in almost real time the influenza vaccine effectiveness (VE) against severe cases in high-risk individuals. Data on vaccination status were provided by the influenza severe surveillance system and data on vaccination coverage by the National Social Security Scheme. The analysis showed a decline of the vaccine effectiveness in 2011/12 (VE: 30% (95% CI: 22-39)) compared to 2010/11 (VE: 53% (95% CI: 40-67)).

Diphtheria in the south of France, March 2011.

In March 2011, a 40 year-old French man was diagnosed with diphtheria caused by toxigenic Corynebacterium diphtheriae. Fifty-three close contacts were identified from whom throat samples were analysed. C. diphtheriae was found only in the asymptomatic partner of the index case. The two cases had travelled in Spain during the incubation period of the index case. Investigation around the second case identified 13 new close contacts.None of them was found to be infected.

Psittacosis outbreak after participation in a bird fair, Western France, December 2008.

In December 2008, three hospitalized cases of suspected psittacosis infection were notified by respiratory disease clinicians from a local hospital to the Regional Epidemiology Unit of Pays de la Loire, France. They all had attended a bird fair. A retrospective cohort study was conducted among exhibitors and organizers to identify potential risk factors in relation to this fair. Environmental and veterinary investigations were implemented to trace potential sources of infection. We identified two confirmed, two probable and 44 possible cases among participants. The attack rate in exhibitors and organizers was 38% (33/86). The median incubation period was 11 days (range 6-22 days). Individuals located in two particular sectors of the showroom were found to be at double the risk of developing psittacosis (relative rate 2·1, 95% confidence interval 1·03-4·18) than those in other sectors. Pooled faecal samples of birds belonging to a possible case exhibitor tested positive for Chlamydiaceae by PCR. Ventilation conditions in the showroom were inadequate. This investigation allowed the formulation of recommendations to prevent psittacosis in bird exhibitions which are held weekly in France.