Epidemiology of invasive Streptococcus pyogenes infections in France in 2007.

Invasive group A streptococcal (GAS) infections cause significant morbidity and mortality. A national survey was initiated to assess the burden of invasive GAS infections in France, describe their clinical characteristics, and assess the molecular characteristics of GAS strains responsible for these infections. The survey was conducted in 194 hospitals, accounting for 51% of acute care hospital admissions in France. Clinical data, predisposing factors, and demographic data were obtained, and all GAS isolates were emm sequence typed. We identified 664 cases of invasive GAS infections, with an annual incidence of 3.1 per 100,000 population. The case-fatality ratio was 14% and rose to 43% in the case of streptococcal toxic shock syndrome. Bacteremia without identified focus (22%) and skin/soft tissue infections (30%) were the most frequent clinical presentations. Necrotizing fasciitis was frequent in adults (18%) and uncommon in children (3%). The 3 predominant emm types were emm1, emm89, and emm28, accounting for 33%, 16%, and 10% of GAS isolates, respectively. The emm1 type was associated with fatal outcomes and was more frequent in children than in adults. Six clusters of cases were identified, with each cluster involving 2 invasive cases due to GAS strains which shared identical GAS emm sequence types. Four clusters of cases involved eight postpartum infections, one family cluster involved a mother and child, and one cluster involved two patients in a nursing home. Invasive GAS infection is one of the most severe bacterial diseases in France, particularly in persons aged ≥ 50 years or when associated with toxic shock syndrome.

An outbreak of Pneumococcal pneumonia among residents of a retirement home in France during October 2003.

We describe an outbreak of pneumonia due to Streptococcus pneumoniae in a French retirement home. Eleven residents developed pneumonia. Eight patients had positive results of urinary antigen tests. There were no further cases after the implementation of control measures, which involved isolation of and receipt of antibiotic therapy by symptomatic residents. No risk factors for transmission of S. pneumoniae were identified in this population.

Prolonged outbreak of B meningococcal disease in the Seine-Maritime department, France, January 2003 to June 2005.

Between January 2003 and June 2005, an outbreak of meningococcal disease occurred in the department of Seine-Maritime in northern France. Eighty six cases were notified, giving an average annual incidence of 2.7 cases per 100,000 inhabitants, compared with 1.6 in France. An especially affected area was defined as the city of Dieppe and its surrounding area (26 cases, giving an annual incidence of 12 cases per 100,000). This outbreak was due to N. meningitidis phenotype B:14:P1.7,16 belonging to the clonal complex ST-32/ET-5. Over the 31 B14:P1.7,16 cases confirmed by phenotyping methods at the national reference centre for meningococci (CNR, Centre National de Reference des meningocoques) the case-fatality rate (19%) and the proportion of purpura fulminans (42%) were especially high. Teenagers aged between 15 and 19 years and children aged 1 to 9 years were the most affected. In 2003, health authorities put in place enhanced epidemiological surveillance and informed practitioners and population about the disease. In 2004, the national vaccination advisory board studied the opportunity of using a non licensed outer membrane vesicle vaccine developed in Norway which may be effective against the B14:P1.7,16 strain. The Ministry of health decided in 2006 to offer vaccination with this vaccine to people aged 1 to 19 years in Seine-Maritime.

Effectiveness of different policies in preventing meningococcal disease clusters following a single case in day-care and pre-school settings in Europe.

National policies for chemoprophylaxis after single cases of meningococcal disease in day-care or nursery settings vary across Europe. We carried out a multi-national retrospective study to compare the effectiveness of different policies. Countries were divided into those recommending chemoprophylaxis only to close contacts (policy A, close) and those recommending chemoprophylaxis for all children in the same nursery (policy B, mass). Country-specific relative risk (RR) of a cluster was defined as the ratio of the number of clusters observed to the number of clusters expected by chance. In total, 37 clusters were identified between 1 January 1993 and 31 December 2002. After adjusting for marked heterogeneity in RR by country, the ratio of RR between countries suggested possible benefit from mass prophylaxis (RR ratio 3.8, 95% CI 0.7-22.0), although the difference was not statistically significant (P=0.22). The costs of this approach and the low risk of clustering need to be taken into account when deciding national policy.

Prolonged outbreak of B meningococcal disease in the Seine-Maritime department, France, January 2003 to June 2005.

Between January 2003 and June 2005, an outbreak of meningococcal disease occured in the department of Seine-Maritime in northern France. Eighty six cases were notified, giving an average annual incidence of 2.7 cases per 100 000 inhabitants, compared with 1.6 in France. An especially affected area was defined as the city of Dieppe and its surrounding area (26 cases, giving an annual incidence of 12 cases per 100 000). This outbreak was due to N. meningitidis phenotype B:14:P1.7,16 belonging to the clonal complex ST-32/ET-5. Over the 31 B14:P1.7,16 cases confirmed by phenotyping methods at the national reference centre for meningococci (CNR, Centre National de Référence des méningocoques) the case-fatality rate (19%) and the proportion of purpura fulminans (42%) were especially high. Teenagers aged between 15 and 19 years and children aged 1 to 9 years were the most affected. In 2003, health authorities put in place enhanced epidemiological surveillance and informed practitioners and population about the disease. In 2004, the national vaccination advisory board studied the opportunity of using a non licensed outer membrane vesicle vaccine developed in Norway which may be effective against the B14:P1.7,16 strain. The Ministry of health decided in 2006 to offer vaccination with this vaccine to people aged 1 to 19 years in Seine- Maritime.

Epidemiology of invasive meningococcal disease in France in 2003.

National surveillance of invasive meningococcal disease (IMD) is based on mandatory reporting. The case definition for surveillance notification was changed in mid-2002 to include cases without microbiological confirmation. The IMD alert detection system was enhanced in 2003 with daily reporting and weekly analysis by district, serogroup, and age. Evaluation of the exhaustivity of the surveillance with capture-recapture analysis allowed correcting for underreporting. In 2003, 803 cases were reported. After correction for under-reporting, the estimated incidence was 1.78 / 100,000. After excluding 'new' cases reported with new definition criteria, the 2002-2003 increase was 4%. Incidence decreased with age, with the highest values in infants less than 1 year (20/100,000), children aged between 1 and 2 years (11/100,000) and in teenagers of 17 years old(7/100,000). The overall case fatality rate was 12%. Fifty nine per cent of cases were due to serogroup B, 32% to C, 5% to W135, and 4% to Y and non-groupable meningococci. Patients with purpura fulminans treated with intravenous antibiotics before admission to hospital were shown to have lower fatality rates than those not treated. In 2001-2003, 5 situations required particular attention: two clusters of serogroup B IMD had set off mass prophylaxis, one outbreak due to a specific B IMD clonal complex with high case fatality rate, and two districts crossed the alert threshold for serogroup C IMD, 2/100,000, and mass vaccination was recommended.

Ascertainment of meningococcal disease in Europe.

Meningococcal disease surveillance in most countries is based upon a combination of statutory notification systems and laboratory reporting, both of which are recognised to underestimate the true burden of disease. The incidence of meningococcal disease varies throughout Europe, and although there are many reasons for this, it is important to quantify the degree of under-ascertainment in order to validate international comparisons. Here, we review the literature on the ascertainment of meningococcal disease in Europe and the available methods for estimating the degree of under-reporting. We found that the sensitivity of surveillance varies between countries and over time, with estimates ranging from 40% to 96%. We identified five methods suitable for conducting ascertainment studies, from simple comparative studies to more complicated capture-recapture and regression analyses. Studies of ascertainment may be used to identify weaknesses and biases in surveillance data, and facilitate the improvement of these systems. These findings are relevant to the surveillance of other infectious diseases, particularly those with lower mortality and a lower public profile than meningococcal disease, for which ascertainment may be worse.

Epidemiology of invasive meningococcal disease in France in 2003.

National surveillance of invasive meningococcal disease (IMD) is based on mandatory reporting. The case definition for surveillance notification was changed in mid-2002 to include cases without microbiological confirmation. The IMD alert detection system was enhanced in 2003 with daily reporting and weekly analysis by district, serogroup, and age. Evaluation of the exhaustivity of the surveillance with capture-recapture analysis allowed correcting for underreporting. In 2003, 803 cases were reported. After correction for under-reporting, the estimated incidence was 1.78 / 100 000. After excluding 'new' cases reported with new definition criteria, the 2002-2003 increase was 4%. Incidence decreased with age, with the highest values in infants less than 1 year (20/100 000), children aged between 1 and 2 years (11/100 000) and in teenagers of 17 years old(7/100 000). The overall case fatality rate was 12%. Fifty nine per cent of cases were due to serogroup B, 32% to C, 5% to W135, and 4% to Y and non-groupable meningococci. Patients with purpura fulminans treated with intravenous antibiotics before admission to hospital were shown to have lower fatality rates than those not treated. In 2001-2003, 5 situations required particular attention: two clusters of serogroup B IMD had set off mass prophylaxis, one outbreak due to a specific B IMD clonal complex with high case fatality rate, and two districts crossed the alert threshold for serogroup C IMD, 2/100 000, and mass vaccination was recommended.

Ascertainment of meningococcal disease in Europe.

Meningococcal disease surveillance in most countries is based upon a combination of statutory notification systems and laboratory reporting, both of which are recognised to underestimate the true burden of disease. The incidence of meningococcal disease varies throughout Europe, and although there are many reasons for this, it is important to quantify the degree of under-ascertainment in order to validate international comparisons. Here, we review the literature on the ascertainment of meningococcal disease in Europe and the available methods for estimating the degree of under-reporting. We found that the sensitivity of surveillance varies between countries and over time, with estimates ranging from 40% to 96%. We identified five methods suitable for conducting ascertainment studies, from simple comparative studies to more complicated capture-recapture and regression analyses. Studies of ascertainment may be used to identify weaknesses and biases in surveillance data, and facilitate the improvement of these systems. These findings are relevant to the surveillance of other infectious diseases, particularly those with lower mortality and a lower public profile than meningococcal disease, for which ascertainment may be worse.

Vaccination campaign following an increase in incidence of serogroup C meningococcal diseases in the department of Puy-de-Dôme (France).

In the department of Puy-de-Dôme, France, 17 cases of invasive meningococcal disease C were notified between March 2001 and the first week of 2002. Among the 15 confirmed cases, 11 (73%) were serogroup C, 2 (13%) serogroup B, and 2 could not be identified. The rapid increase in the number of cases in a period of low endemicity for the rest of the country and the severity of the disease (case fatality ratio 27%, purpura fulminans 64%) led the health authorities to initiate a vaccination campaign targeting children and young adults from 2 months up to 20 years living in a limited area of the department. Around 80,000 people were immunised between 16/01/02 and 09/02/02. More than half of the 1390 immediate side effects were headache and dizziness. As of mid-March, no further case of meningococcal disease has been notified since 6 January.

[Meningococcal W135 infection epidemics associated with pilgrimage to Mecca in 2000]. / Epidémie d'infections à méningocoque W135 liée au pèlerinage de la Mecque de 2000.

OBJECTIVES: On April 3 and 7, 2000, four cases of Neisseria meningitidis serogroup W135 infection were diagnosed in France in Raj pilgrims and their close relatives. Two cases were fatal. Due to the rarity of this strain in France, a strain belonging to a clonal complex implicated in several epidemics in Europe and North America, and it high mortality observed, The French General Direction of Heal issued recommendations on April 8th for rifampicin chemotherapy for all pilgrims and relatives living in their home. The national disease watch (Institut de Veille Sanitaire, InVS) conducted an investigation to describe the epidemic and follow the diffusion of the strain in the population and assess the impact of preventive measures taken as well as need for other specific measures. METHODS: A case was considered to be confirmed when the strain isolated from usually sterile media after March 22 was found to be identical to the epidemic strain (W135, 2a: P1-2.5--clonal complex ET37). A case was considered probable when a pilgrim or in a person in contact with a pilgrim had clinical meningitis (purulent cerebrospinal fluid or purpura fulminans) or when the identified strain was in the W135 serogroup but could not be further identified. A standardized questionnaire developed in collaboration with the European countries concerned by the epidemic was filled out. RESULTS: By November 20, 2000, 25 confirmed and 2 probable cases were identified; 85% of the cases occurred during the first 7 weeks of the epidemic. Mortality was 18%. Patients aged over 50 years accounted for 66% of the cases (6/9) occurring before April 9, 2000 and 17% of the cases (3/18) observed after this data. Four patients had single-joint arthritis. No cluster cases could be identified. Four cases occurred among 19,100 pilgrims (attack rate 21/100,000), 9 among persons living with pilgrims, 7 among subjects in direct contact with pilgrims but not living with them, and 7 among persons who had no identifiable contact with pilgrims. These last 7 cases occurred after the 3rd week of the epidemic. No cases occurred among persons who had taken rifampicin chemoprophylaxis. Eighteen cases occurred after diffusion of the prophylaxis recommendations including 5 in a population directly concerned by the recommendations. CONCLUSIONS: These data suggest that the epidemic strain is not different from other strains in terms of virulence and transmissibility. Eight months after the Raj, the number of cases related to the epidemic remained limited in France. The characteristics of the most recent cases do however suggest an epidemic clone persists in the general population. The Direction of Health recommends vaccination using the quadrivalent A,C,W135,Y vaccine for the 2001 Raj.

[Clonal spread of Neisseria meningitidis W135]. / Expansion clonale de Neisseria meningitidis W135.

OBJECTIVES: Efficient surveillance of communicable diseases involves dose collaboration between physicians, epidemiologist and bacteriologists. The characterization of meningococcal infections is a medical emergency due to their lethality and their epidemic behavior. The recent expansion of Neisseria meningitidis of serogroup W135 among pilgrims and their contacts underlines the need of a multidisciplinary procedure of alert. METHODS: Meningococcal strains are usually received by the National Reference Center for Meningococci (CNRM). They are identified and then typed to determine their antigenic formula (serogroup:serotype:serosubtype). For cluster analysis, the CNRM as well as the WHO collaborating center, perform molecular typing of isolated strains. Should an epidemic is suspected, the institut de Veille Sanitaire and the Direction Générale de la Santé are immediately informed. RESULTS: Between the 22th of March and the 20th of November 2000, 27 cases of systemic meningococcal infections due to N. meningitidis of the antigenic formula W135:2a:P1-2.5 were identified. Molecular typing of these strains showed that they were clonal and belonged to the complex ET-37. The dissemination of this clone among pilgrims who were vaccinated against serogroups A and C may suggest the selection of a new variant by an escape alteration in the capsule. However, such strains were detected in France as early as 1994. CONCLUSION: The global spread of N. meningitidis of serogroup W135 belonging to the ET-37 clonal complex should be kept under a close surveillance since epidemics may occur particularly in Africa. New vaccination procedures (quadrivalent vaccines and multivalent conjugate meningococcal vaccines) are therefore needed.

Circumvention of herd immunity during an outbreak of meningococcal disease could be correlated to escape mutation in the porA gene of Neisseria meningitidis.

Meningococcal strains isolated during an outbreak were shown to belong to the ET-5 complex and to harbor a mutation in the VR2 region of the porA gene. They were less susceptible to the bactericidal effect of normal human serum than was the ET-5 wild-type strain. These results are of concern, as PorA is a potential target in vaccine design.

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

Surveillance of tuberculosis in the WHO European region in 1995 : results of the feasibility study.

Efforts to assess the changing epidemiology of tuberculosis (TB) in Europe have been limited by differences in definitions and in the quality of tuberculosis surveillance systems between countries. In order to standardise the surveillance of TB among Euro.

Epidemiology of leptospirosis in New Caledonia (South Pacific): a one-year survey.

We describe a series of 144 cases of leptospirosis diagnosed in 1989 in New Caledonia. The incidence rate was 90 per 100,000 person-years, with a specific mortality rate of 4% patients. Those affected (100 males, 44 females) were mainly aged 20 to 40 years. Incidence in rural areas (112 per 100,000 person-years) was seven times higher than in urban settlements. Two periods with higher incidence were noticed corresponding to highest rainfall. Twenty-nine of the cases occurred in individuals with professions commonly associated with leptospirosis. Contacts with rats, dogs and ditch or river water were the most frequently mentioned. The clinical expression of the disease was polymorphic: 60% of the patients had mild symptoms, 40% were acute forms including Weil's disease. Of 57 hospitalized, 23% were admitted with an initial diagnosis of dengue, and 37% with leptospirosis. Main clinical syndromes were: icterus and/or renal syndrome in 50% of patients, cardiac syndrome in 65%, acute myalgies in 58% and pulmonary syndrome in 50%. Although hemorrhages were uncommon (17%), 40% of the cases demonstrated thrombocytopenia (< 50,000/m3). Pancreatic involvement with hyperamylasemia was evidenced in 50% of cases. Twelve serogroups of Leptospira were implicated, Icterohaemorragiae predominated (41%), but was not associated with severe forms. In New Caledonia, like in all tropics, leptospirosis must be considered as an environmental diseases, professional activities being just an additional risk factor. Use of serology as a reliable tool for confirmation of cases in areas of high environmental contamination is discussed.