Jean-Claude Desenclos

Epidemiology of pertussis in French hospitals in 1993 and 1994: thirty years after a routine use of vaccination

BACKGROUND Despite widespread vaccination during 30 years, the hypothesis of a resurgence of pertussis in France has been raised by outbreaks and sporadic case reports. No surveillance data were available after 1985. METHODS A survey was undertaken in 1993 and 1994 in a pediatric hospital network able to confirm cases; the network (22 hospitals) represents 19.6% of pediatric admissions in France. Case definition included clinical (> or = 21 days of paroxysmal cough), laboratory-confirmed (culture or serology by immunoblot) or epidemiologically confirmed pertussis (documented contact with a laboratory-confirmed case). The pattern of transmission was studied in the household. Vaccine status was obtained from health records. RESULTS during a 15-month period 560 cases (316 index cases, 244 household contact cases) were reported; 49% of index cases and 20% of contact cases were confirmed by culture and/or serology. Sixty-five percent of index cases were younger than 1 year of age (the incidence in this age group could be estimated to be 95/100000) and 66% were hospitalized for a mean duration of 2 weeks. Infection was acquired from parents (34%) and siblings (46%). Seventy-three percent of index cases were unvaccinated. CONCLUSIONS Although pertussis vaccination coverage is very high in France, the organism is still circulating, affecting, within the pediatric population, mostly non- or incompletely vaccinated infants. These results strongly support the importance of adhering to the immunization schedule and suggest introducing booster dose(s) to prolong vaccine immunity and reduce the exposure to Bordetella pertussis of infants too young to be immunized.

A Community-Wide Outbreak of Legionnaires Disease Linked to Industrial Cooling Towers—How Far Can Contaminated Aerosols Spread?

A community-wide outbreak of legionnaires disease occurred in Pas-de-Calais, France, in November 2003-January 2004. Eighteen (21%) of 86 laboratory-confirmed cases were fatal. A case-control study identified smoking, silicosis, and spending >100 min outdoors daily as risk factors for acquiring the disease. Legionella pneumophila strain Lens was isolated from cooling towers, wastewater, and air samples from plant A. This unique strain matched all 23 clinical isolates, as assessed by pulsed-field gel electrophoresis subtyping. Modeling of atmospheric dispersion of aerosols emitted from plant A cooling towers showed good coverage of the communes where patients lived and showed that the dispersion extended over a distance of at least 6 km from plant A. No other aerosol-producing installation was identified as a plausible source, and no common source of indoor exposure was found. These findings implicate plant A as the most likely outbreak source and suggest that the distance of airborne transmission of L. pneumophila may be greater than previously reported.

Increasing Incidence of Zygomycosis (Mucormycosis), France, 1997–2006

Results were derived from a population-based study using hospital discharge data.

Prevalence of Hepatitis B and Hepatitis C Virus Infections in France in 2004: Social Factors Are Important Predictors After Adjusting for Known Risk Factors

To monitor the prevalence of hepatitis B and hepatitis C a cross‐sectional survey was conducted in 2004 among French metropolitan residents. A complex sampling design was used to enroll 14,416 adult participants aged 18–80 years. Data collected included demographic and social characteristics and risk factors. Sera were tested for anti‐HCV, HCV‐RNA, anti‐HBc and HBsAg. Data were analyzed with SUDAAN® software to provide weighted estimates for the French metropolitan resident population. The overall anti‐HCV prevalence was 0.84% (95% CI: 0.65–1.10). Among anti‐HCV positive individuals, 57.4% (95% CI: 43.2–70.5) knew their status. Factors associated independently with positive anti‐HCV were drug use (intravenous and nasal), blood transfusion before 1992, a history of tattoos, low socioeconomic status, being born in a country where anti‐HCV prevalence >2.5%, and age >29 years. The overall anti‐HBc prevalence was 7.3% (95%: 6.5–8.2). Independent risk factors for anti‐HBc were intravenous drug use, being a man who has sex with men, low socioeconomic status, a stay in a psychiatric facility or facility for the mentally disabled, <12 years of education, being born in a country where HBsAg prevalence >2%, age >29 and male sex. The HCV RNA and HBsAg prevalence were 0.53% (95% CI: 0.40–0.70) and 0.65% (95% CI: 0.45–0.93), respectively. Among HBsAg positive individuals, 44.8% (95% CI: 22.8–69.1) knew their status. Anti‐HCV prevalence was close to the 1990s estimates whereas HBsAg prevalence estimate was greater than expected. Screening of hepatitis B and C should be strengthened and should account for social vulnerability. J. Med. Virol. 82:546–555, 2010.

Population-based HIV-1 incidence in France, 2003–08: a modelling analysis

BACKGROUND Routine national incidence testing with enzyme immunoassay for recent HIV-1 infections (EIA-RI) has been done in France since January, 2003. From the reported number of HIV infections diagnosed as recent, and accounting for testing patterns and under-reporting, we aimed to estimate the incidence of HIV infection in France in 2003-08. METHODS We analysed reports from the French National Institute for Public Health Surveillance for patients who were newly diagnosed with HIV between January, 2003, and December, 2008. Missing data were imputed with multiple imputation. Patients were classified with non-recent or recent infection on the basis of an EIA-RI test, which was calibrated with serial measurements from HIV seroconverters from the French ANRS-PRIMO cohort. We used an adapted stratified extrapolation approach to calculate the number of new HIV infections in men who have sex with men (MSM), injecting drug users (IDUs), and heterosexual men and women by nationality. Population sizes were obtained from the national census and national behavioural studies. FINDINGS After accounting for under-reporting, there were 6480 (95% CI 6190-6780) new diagnoses of HIV infection in France in 2008. We estimate that there were 6940 (6200-7690) new HIV infections in 2008, suggesting an HIV incidence of 17 per 100 000 person-years. In 2008, there were 3550 (3040-4050) new infections in heterosexuals (incidence of 9 per 100 000 person-years), 3320 (2830-3810) in MSM (incidence of 1006 per 100 000 person-years), and 70 (0-190) in IDUs (incidence of 86 per 100 000 person-years). Overall HIV incidence decreased between 2003 and 2008 (p<0·0001), but remained comparatively high and stable in MSM. INTERPRETATION In France, HIV transmission disproportionately affects certain risk groups and seems to be out of control in the MSM population. Incidence should be tracked to monitor transmission dynamics in the various population risk groups and to help to target and assess prevention strategies. FUNDING French National Institute for Public Health Surveillance (InVS) and French National Agency for Research on AIDS and Viral Hepatitis (ANRS).

Antimicrobial Resistance in Commensal Flora of Pig Farmers

We assessed the quantitative contribution of pig farming to antimicrobial resistance in the commensal flora of pig farmers by comparing 113 healthy pig farmers from the major French porcine production areas to 113 nonfarmers, each matched for sex, age, and county of residence. All reported that they had not taken antiimicrobial agents within the previous month. Throat, nasal, and fecal swabs were screened for resistant microorganisms on agar containing selected antimicrobial agents. Nasopharyngeal carriage of Staphylococcus aureus was significantly more frequent in pig farmers, as was macrolide resistance of S. aureus from carriers. Nongroupable streptococci from the throat were more resistant to the penicillins in pig farmers. The intestinal isolation of enterococci resistant to erythromycin or vancomycin was not significantly higher in pig farmers in contrast to that of enterobacteria resistant to nalidixic acid, chloramphenicol, tetracycline, and streptomycin. Prevalence of resistance in predominant fecal enterobacteria was also significantly higher in pig farmers for cotrimoxazole, tetracycline, streptomycin, and nalidixic acid. We determined a significant association between pig farming and isolation of resistant commensal bacteria.

VEB-1 Extended-spectrum beta-lactamase-producing Acinetobacter baumannii, France.

VEB-1 extended-spectrum β-lactamase–producing Acinetobacter baumannii was responsible for an outbreak in hospitals in France. A national alert was triggered in September 2003 when 4 hospitals reported clusters of A. baumannii infection with similar susceptibility profiles. Case definitions and laboratory guidelines were disseminated, and prospective surveillance was implemented; strains were sent to a single laboratory for characterization and typing. From April 2003 through June 2004, 53 hospitals reported 290 cases of A. baumannii infection or colonization; 275 isolates were blaVEB-1-positive and clonally related. Cases were first reported in 5 districts of northern France, then in 10 other districts in 4 regions. Within a region, interhospital spread was associated with patient transfer. In northern France, investigation and control measures led to a reduction of reported cases after January 2004. The national alert enabled early control of new clusters, demonstrating the usefulness of early warning about antimicrobial drug resistance.

Estimated risk of Chikungunya viremic blood donation during an epidemic on Reunion Island in the Indian Ocean, 2005 to 2007

BACKGROUND: Between 2005 and 2007, Chikungunya virus (CHIKV) caused a massive epidemic on Reunion Island with a major peak in the number of cases in February 2006. Blood donation was interrupted on the island in January 2006.

Development and Validation of an Immunoassay for Identification of Recent Human Immunodeficiency Virus Type 1 Infections and Its Use on Dried Serum Spots

ABSTRACT The objective was to develop and to validate an immunossay to identify recent human immunodeficiency virus type 1 (HIV-1) infections that can be used on dried serum spots (DSS). A single, indirect enzyme-linked immunosorbent assay was developed to quantify antibodies toward four HIV-1 antigens: consensus peptides of the immunodominant epitope of gp41 (IDE), consensus V3 peptides, recombinant integrase, and recombinant p24. The parameters of the logistic regression used to classify the samples were estimated on a training sample (210 serum samples) using resampling techniques to get stable estimates and then applied to a validation sample (761 serum samples). The IDE and V3 peptides were the best able to discriminate between the antibodies present in serum from recently (≤6 months) infected individuals and those with long-lasting infection. Combined quantification of antibody binding to these two synthetic antigens allowed us to identify recent infections with an area under the receiver operating characteristic curve of 0.949 and a sensitivity of 88.3%, with a specificity of 97.6% in patients with long-term infection (but not AIDS) and 86.0% in patients suffering from AIDS with a threshold of 0.50 in the validation sample. This simple immunoassay can be used to identify recently HIV-1-infected patients. Its performance is compatible with its use in population-based studies including DSS.

Trends in residual risk of transfusion-transmitted viral infections in France between 1992 and 2000

BACKGROUND : Monitoring trends in residual risks of transfusion‐transmitted viral infections (HIV, HTLV, HBV, and HCV) is important to assess improvements in blood safety. In France, theses trends were analyzed between 1992 and 2000.