Baseline characteristics and clinical symptoms related to respiratory viruses identified among patients presenting with influenza-like illness in primary care.

OBJECTIVES: We aimed to identify patients' clinical characteristics associated with respiratory viruses identified among patients presenting with influenza-like illness (ILI). METHODS: A sample of patients of all ages presenting with ILI was included by physicians of the French Sentinelles network during two seasons (2015/16 and 2016/17). Nasopharyngeal samples were tested for the presence of influenza virus (IV), respiratory syncytial virus (RSV), human rhinovirus (HRV) and human metapneumovirus (HMPV). Patients' characteristics associated with each of the four virus classes were studied using multivariate logistic regressions. RESULTS: A total of 5859 individuals were included in the study: 48.0% tested positive for IV, 7.9% for HRV, 7.5% for RSV and 4.1% for HMPV. Cough was associated with IV (OR 2.14, 95% CI 1.81-2.52) RSV (OR 2.52, 95% CI 1.75-3.74) and HMPV detection (OR 2.15, 95% CI 1.40-3.45). Rhinorrhoea was associated mainly with HRV detection (OR 1.75, 95% CI 1.34-2.32). Headache was associated with IV detection (OR 1.75, 95% CI 1.34-2.32), whereas absence of headache was associated with RSV and HMPV detection. Dyspnoea was associated with RSV detection (OR 2.33, 95% CI 1.73-3.12) and absence of dyspnoea with IV detection. Conjunctivitis was associated with IV detection (OR 1.27, 95% CI 1.08-1.50). Some associations were observed only in children: dyspnoea and cough with RSV detection (age <5 years), conjunctivitis with IV detection (age <15 years). Period of onset of symptoms differed among aetiological diagnoses. Seasonal influenza vaccination decreased the risk of IV detection (OR, 0.67, 95% CI 0.51-0.86). CONCLUSIONS: This study allowed the identification of symptoms associated with several viral aetiologies in patients with ILI. A proper knowledge and understanding of these clinical signs may improve the medical management of patients.

Estimation of seasonal influenza vaccine effectiveness using data collected in primary care in France: comparison of the test-negative design and the screening method.

OBJECTIVES: We discussed which method between the test-negative design (TND) and the screening method (SM) could provide more robust real-time and end-of-season vaccine effectiveness (VE) estimates using data collected from routine influenza surveillance in primary care. METHODS: We used data collected during two influenza seasons, 2014-15 and 2015-16. Using the SM, we estimated end-of-season VE in preventing medically attended influenza-like illness and laboratory-confirmed influenza among the population at risk. Using the TND, we estimated end-of-season VE in preventing influenza among both the general and the at-risk population. We estimated real-time VE using both methods. RESULTS: For the SM, the overall adjusted end-of-season VE was 24% (95% confidence interval (CI), 16 to 32) and 12% (95% CI, -16 to 33) during season 2014-15, and 53% (95% CI, 44 to 60) and 47% (95% CI, 23 to 64) during season 2015-16, in preventing influenza-like illness and laboratory-confirmed influenza, respectively. For the TND, the overall adjusted end-of-season VE was -17% (95% CI, -79 to 24) and -38% (95% CI, -199 to 13) in 2014-15, and 10% (95% CI, -31 to 39) and 18% (95% CI, -33 to 50) in 2015-16, among the general and at-risk population, respectively. Real-time VE estimates obtained through the TND showed more variability across each season and lower precision than those estimated with the SM. CONCLUSIONS: Although the worldwide use of the TND allows for comparison of overall VE estimates among countries, the SM performs better in providing robust real-time VE estimates among the population at risk.

Performances of statistical methods for the detection of seasonal influenza epidemics using a consensus-based gold standard.

Influenza epidemics are monitored using influenza-like illness (ILI) data reported by health-care professionals. Timely detection of the onset of epidemics is often performed by applying a statistical method on weekly ILI incidence estimates with a large range of methods used worldwide. However, performance evaluation and comparison of these algorithms is hindered by: (1) the absence of a gold standard regarding influenza epidemic periods and (2) the absence of consensual evaluation criteria. As of now, performance evaluations metrics are based only on sensitivity, specificity and timeliness of detection, since definitions are not clear for time-repeated measurements such as weekly epidemic detection. We aimed to evaluate several epidemic detection methods by comparing their alerts to a gold standard determined by international expert consensus. We introduced new performance metrics that meet important objective of influenza surveillance in temperate countries: to detect accurately the start of the single epidemic period each year. Evaluations are presented using ILI incidence in France between 1995 and 2011. We found that the two performance metrics defined allowed discrimination between epidemic detection methods. In the context of performance detection evaluation, other metrics used commonly than the standard could better achieve the needs of real-time influenza surveillance.

[Cardiovascular pathologies and referrals for hospitalization by general practitioners: factors influencing the choice of a private or public hospital]. / Pathologies cardiovasculaires et recours à l'hospitalisation par le médecin généraliste : facteurs influençant le choix du secteur d'hospitalisation.

OBJECTIVES: When a hospitalisation is required in France, the general practitioner has the choice between public or private hospitals. The reasons for this choice are poorly known. METHODS: All the cases of hospitalisation requirement reported between 1997 and 2001 by the general practitioners involved in the Réseau Sentinelles(®) were included in this study. The cardiovascular reasons were extracted from all these declarations. Factors influencing the general practitioners' choice between public and private sector were assessed by using logistic regression. RESULTS: During the study period, 45,960 cases of hospitalisation requirement were reported. Amongst these cases, 4475 (10.8%) were made for clearly defined cardivoascular diseases (cardiac failure 38.0%, coronary heart disease 24.7%, atrial fibrillation 11.7%, pulmonary embolism 8.4%, hypertension 3.6%, pericarditis 1.6%, cardiovascular check-up 1.5%). Referrals to private sector depended on the reason for hospitalisation, cardiovascular check-up being the reasons the most referred to a private institution (33.8% of patients) and cardiac insufficiency the less referred to private institution (17.2% of patients). Referral to private sector was also associated with physician (patient's usual general practitioner) and consultation (consultation outside of a context of emergency) characteristics. CONCLUSION: Whether patients suffering from cardiovascular diseases are sent to a public or private sector is not completely haphazard. Further analyses are needed in the context of new French health policies.

Physician practices in requesting stool samples for patients with acute gastroenteritis, France, August 2013-July 2014.

A better understanding of physician practices in requesting stool samples for patients with acute gastroenteritis (AG) is needed to more accurately interpret laboratory-based surveillance data. A survey was conducted in General Practitioners (GPs) between August 2013 and July 2014 to estimate the proportion of stool samples requested for patients with AG and to identify factors associated with GP requests for a stool sample. National health insurance (NHI) data together with surveillance data from a French Sentinel GP network were also used to estimate the proportion of stool samples requested. This proportion was estimated at 4·3% in the GP survey and 9·1% (95% confidence interval 8·7-9·6) using NHI data. Multivariate analysis indicated that the ratio of stool samples requested was almost five times higher in patients with bloody diarrhoea and 10-20 times higher in patients with a long duration of illness before consultation. Laboratory-based surveillance data underestimates the actual burden of disease as fewer than one in 10 AG cases consulting their GP will be requested to submit a stool sample for laboratory testing. This underestimation varies by pathogen as stool samples are more frequently requested for severe illness.

Attempted and completed suicide in primary care: not what we expected?

BACKGROUND: General Practitioners (GPs) play a central role in suicide prevention. This study aims to compare the characteristics of individuals who attempt suicide to those who complete suicide in a same primary care setting. METHODS: We compared the characteristics and GP's management of all patients with attempted (N=498, SA) or completed suicide (N=141, SC) reported to the GPs'French Sentinelles surveillance system (2009-2013). RESULTS: Compared to patients who attempted suicide, those who completed suicide were more likely to be male, older and to have used a more lethal method; for men they were less likely to have a history of previous suicide attempt and prior contacts with their GP. In terms of GPs' management, we found no differences between the SA and SC groups in the identification of psychological difficulties and in the care, but GPs were more likely to provide psychological support to the SA group. During the last consultation, the SC group expressed suicidal ideas more frequently than the SA group (26.7% vs. 14.8%, p<0.01), only for women. LIMITATIONS: The network may have missed cases and selected more serious SA. CONCLUSIONS: Individuals who commit suicide differ from those who attempt suicide in terms of demographic characteristics and by sex, of history of suicide attempt, previous contact and expressed suicidal ideas. We show that GPs do not act more intensively with patients who will commit suicide, as if they do not foresee them. Current prevention programs particularly in primary care should be tailored.

Incidence and hospitalisation rates of Lyme borreliosis, France, 2004 to 2012.

Lyme borreliosis (LB) has become a major concern recently, as trends in several epidemiological studies indicate that there has been an increase in this disease in Europe and America over the last decade. This work provides estimates of LB incidence and hospitalisation rates in France. LB data was obtained from the Sentinelles general practitioner surveillance network (2009­2012) and from the Programme de Médicalisation des Systèmes d'Information (PMSI) data processing centre for hospital discharges (2004­09). The yearly LB incidence rate averaged 42 per 100,000 inhabitants (95% confidence interval (CI): 37­48), ranging from 0 to 184 per 100,000 depending on the region. The annual hospitalisation rate due to LB averaged 1.55 per 100,000 inhabitants (95% CI: 1.42­1.70). Both rates peaked during the summer and fall and had a bimodal age distribution (5­10 years and 50­70 years). Healthcare providers should continue to invest attention to prompt recognition and early therapy for LB, whereas public health strategies should keep promoting use of repellent, daily checks for ticks and their prompt removal.

Web-based participatory surveillance of infectious diseases: the Influenzanet participatory surveillance experience.

To overcome the limitations of the state-of-the-art influenza surveillance systems in Europe, we established in 2008 a European-wide consortium aimed at introducing an innovative information and communication technology approach for a web-based surveillance system across different European countries, called Influenzanet. The system, based on earlier efforts in The Netherlands and Portugal, works with the participation of the population in each country to collect real-time information on the distribution of influenza-like illness cases through web surveys administered to volunteers reporting their symptoms (or lack of symptoms) every week during the influenza season. Such a large European-wide web-based monitoring infrastructure is intended to rapidly identify public health emergencies, contribute to understanding global trends, inform data-driven forecast models to assess the impact on the population, optimize the allocation of resources, and help in devising mitigation and containment measures. In this article, we describe the scientific and technological issues faced during the development and deployment of a flexible and readily deployable web tool capable of coping with the requirements of different countries for data collection, during either a public health emergency or an ordinary influenza season. Even though the system is based on previous successful experience, the implementation in each new country represented a separate scientific challenge. Only after more than 5 years of development are the existing platforms based on a plug-and-play tool that can be promptly deployed in any country wishing to be part of the Influenzanet network, now composed of The Netherlands, Belgium, Portugal, Italy, the UK, France, Sweden, Spain, Ireland, and Denmark.

Primary-care physicians' patient referral patterns to private versus public hospitals for orthopaedic or trauma surgery-- French Sentinels® database, 1997-2011.

BACKGROUND: In France, primary-care physicians referring patients for admission can choose between public and private hospitals. The factors that govern their choices are unknown. METHODS: Among all patient admissions reported from 1997 to 2011 by primary-care physicians participating in the Sentinels(®) network, we identified those due to orthopaedic conditions or trauma. We then identified the factors associated with referral to a private hospital rather than to a public hospital. RESULTS: Of 45,960 admissions reported to Sentinels(®) in 1997-2011, 2794 (6.1%) were for orthopaedic/trauma care. The main reasons for admission were hip fractures (27.5%), elective orthopaedic surgery (15.5%), fractures of the humerus (5.9%), wrist fractures (5.4%), soft-tissue lesions of the forearm or hand (5.0%), and spinal injuries (4.5%). Private hospitals were chosen more often for orthopaedic/trauma patients than for patients with other conditions (40% vs. 21.6% of cases, P<0.0001). When fracture of the humerus was used as the reference, referral to private hospitals was significantly more common for elective surgery (odds ratio, 3.30 [2.02-5.40]) and hip fracture (odds ratio, 1.50 [1.03-2.18]) and significantly less common for spinal injuries (odds ratio, 0.35 [0.19-0.66]). Other factors associated with referral to private hospitals were patient age, admission decision during an office visit or in a non-emergent setting, and admission decision made by the patient's usual physician. CONCLUSION: Specific factors seem to govern decisions by primary-care physicians to refer orthopaedic/trauma patients to private vs. public hospitals. Identical pricing scales for private and public hospitals will be implemented soon in France, a change that requires further analyses. LEVEL OF EVIDENCE: Level IV.

Mumps: burden of disease in France.

This article provides a review of the epidemiological data on mumps in France since 1986. The results of 26 years of monitoring in general practice by the Sentinel network are analysed, such as hospitalisation data between 2004 and 2010, as well as mortality data between 2000 and 2009. The annual incidence rate has plummeted between 1986 and 2011, from 859 cases per 100,000 inhabitants [95% CI: 798-920] to 9 cases per 100,000 inhabitants [95% CI: 4-14]. A change in the age distribution is significant with an increase of Relative Illness Ratio (RIR) for patients over 20 years. Since 2000, vaccine status has also changed, and the majority of recent mumps cases occur among previously vaccinated patients. The average annual hospitalisation rate is 3.2 per 1 million inhabitants. Mumps was identified as the initial cause of death in 1 case every 5 years. This study estimates the burden of mumps disease in France.

[Orientation of patients referred by their general practionner to the public or private hospital sector in France: A prospective epidemiologic study]. / Orientation des patients par leur médecin généraliste vers les secteurs hospitaliers publics ou privés en France : étude épidémiologique prospective du réseau Sentinelles.

PURPOSE: In-patients characteristics generate cost differences between hospitals. In France, there are few data on the characteristics on the patients referred to hospitals by their general practitioners (GPs) and none on the predictors of referral to the public or for-profit hospitals. The aim of this study was to analyze those characteristics and the predictors of referral to the public or for-profit hospitals. METHODS: We collected, prospectively, the request for hospitalizations made by the GPs of the Sentinelles network in France, from 2007 to 2009. Patients' characteristics and also the reasons for that request were analyzed. A logistic regression was used to compare the population between local hospitals. RESULTS: Ten thousand seven hundred and eighteen statements were collected. The median age was 73 years. Patients were women in 51% of the cases, and only 14% of the hospitalizations had been planned. Hospitalization in the public sector was preferred for young children and the elderly (P<0.001). When compared to the patients referred to the private sector, patients addressed to the public sector were more often seen for emergencies (OR: 2.3 [2.0-2.8]), by a doctor different from their referring GP (OR: 1.7 [1.4-2.1]) and out of the GP's office. The reasons for hospital admission were different depending on the sector of hospitalization (P<0.001), patients addressed to the public sector hospitals presented with greater comorbidity or more complex diagnosis (for example: feeling ill, fainting or syncope and fever) or a greater disability (for example: stroke, neurological and psychiatric diseases). CONCLUSION: This study suggests that GPs send their patients to the public or for-profit hospitals according to criteria of severity, comorbidity and disability.

Impact of combination therapy with aminoglycosides on the outcome of ICU-acquired bacteraemias.

Pharmacodynamic studies report on the rapid bactericidal activity of aminoglycosides, conferring them as being of theoretical interest for bacteraemia treatment. We assessed this issue in a retrospective study of patients with intensive care unit (ICU)-acquired bacteraemias. To determine the impact of aminoglycosides in antimicrobial combination on the outcome of patients with bacteraemia, we performed a monovariate analysis and a logistic regression analysis comparing patients treated with or without aminoglycosides. Forty-eight bacteraemias in 48 patients were included. Eighteen patients received aminoglycosides. Baseline characteristics as well as adaptation and adequation of antibiotherapy did not differ in patients who did or did not receive aminoglycosides. Patients who received aminoglycosides had longer time alive away from the ICU (11.3 ± 8.9 (10 [0-20]) vs. 3.2 ± 6.6 (0 [0-2] days; p = 0.002) and free from mechanical ventilation (12.5 ± 9.3 (14 [0-21] vs. 5.5 ± 9.2 (0 [0-10] days; p = 0.02) on day 28. The ICU mortality was 16% in the aminoglycoside group versus 46% (p = 0.03). In the multivariate analysis, patients treated with aminoglycosides were 6 times less likely to die than those treated without aminoglycosides (confidence interval [CI] = [1.3-28.9]; p = 0.02). Our study supports the hypothesis that combination short-term antibiotherapy with an aminoglycoside for ICU-acquired bacteraemias could increase survival.

Pertussis incidence among adolescents and adults surveyed in general practices in the Paris area, France, May 2008 to March 2009.

Since the introduction in 1998 of an adolescent pertussis vaccine booster (for persons aged 11-13 years) in France, the incidence of pertussis in adolescents and adults has been unknown. We therefore undertook a study to estimate the incidence of pertussis in these population groups and to evaluate the feasibility of a real-time electronic surveillance system for pertussis in general practices in France. The general practitioners selected for the study were located in Paris and the surrounding area. Polymerase chain reaction (PCR) or measurement of anti-pertussis toxin IgG levels by enzyme-linked immunosorbent assay (ELISA) was used to confirm the infection. Among the 204 patients enrolled in the study, 46 (23%) were diagnosed as having pertussis: 21 were confirmed cases, 24 were clinical cases and one was an epidemiological case. The median age of the 204 patients was 44 years and 134 (66%) were female. The median duration of the patients' cough at enrolment was 24 days. No clinical difference was observed between those with and without a pertussis diagnosis. The incidence of pertussis was estimated to be 145 (95% confidence interval: 121-168) per 100,000 population based on the results from the 10-month study period (calculated for 12 months). Problems in sample collection were identified: pertussis sentinel surveillance cannot be developed without training the staff of medical laboratories who take the biological samples. French health authorities were alerted and training procedures were developed.

Herpes zoster: Burden of disease in France.

This work provides estimates of HZ incidence and HZ-related hospitalization and mortality rates in France, where no immunization programme has been implemented. Herpes zoster data was obtained from the Sentinelles surveillance general practitioners (GPs) network, the PMSI Data processing centre for hospital discharges and from the French National Mortality Database (INSERM CépiDC). The yearly HZ incidence rate averaged 382 cases per 100,000 inhabitants (95% CI 364-405) and exponentially increased with age. The annual rates of hospitalizations and mortality due to HZ varied from 4.14±0.32 to 14.42±0.39 and from 0.11±0.03 to 0.29±0.04 per 100,000 inhabitants, respectively, depending on whether HZ was coded in a 'primary' or 'primary or associated' diagnosis. One or more factors of immunodepression occurred in 43.4% of hospitalized cases and in 21.6% HZ-related deaths.

Early estimates of 2009 pandemic influenza A(H1N1) virus activity in general practice in France: incidence of influenza-like illness and age distribution of reported cases.

In the end of August 2009, an unusually elevated level of influenza-like illness (ILI) activity was reported to the French Sentinel Network. We quantified the observed excess in ILI cases in France during summer 2009 and characterised age patterns in reported cases. An excess of cases has been observed since 5 July, with a time increasing trend. The cumulated estimated excess number of ILI cases was 269,935 [179,585; 316,512], corresponding to 0.5% French population over the period. Compared to the same period in the past years, relative cumulated incidence was greater among young subjects and lower among subjects over 65 years old. Compared to past epidemics, the relative cumulated incidence was greater in children less than 5 years old. This excess of cases may reflect the current spread of the A(H1N1) virus in France, subject to the following limitations: estimates were based on clinical cases consulting a GP; large media coverage may have led to a non specific increase in consultation rates.

[General practitioners' perception of the impact of corticosteroid-induced adverse events]. / Perception par les médecins généralistes de la gêne induite par les effets indésirables d'une corticothérapie systémique prolongée.

BACKGROUND: General practitioners' perception of the discomfort their patients experience because of corticosteroid-induced adverse events is unknown. METHODS: An observational epidemiological study was conducted in September 2007. Eight hundred and sixty general practitioners belonging to the réseau Sentinelles were asked to complete an electronical questionnaire. The questionnaire aimed to assess their perception of discomfort induced by adverse events induced by a long-term (i.e.,>or=3 months) corticosteroid therapy among their patients. Results were compared with the declaration made by 115 long-term corticosteroid treated patients followed in an internal medicine department. RESULTS: Two hundred and ninety-three general practitioners responded to the questionnaire (response rate: 34%). They were predominantly male (87%). Forty-eight percent of them reported 400 to 600 monthly visits. The mean length of corticosteroid therapy for patients was 44+/-38 months and the mean daily dosage was 15+/-14 mg. They suffered mainly from lupus erythematosus (33%) or giant cell arteritis (15%). The adverse events considered to be the most disturbing by patients were lipodystrophy (25%), followed by weight gain (18%) and neuropsychiatric complaints (16%). Physicians widely overestimated the discomfort caused by weight gain cited as the most disturbing adverse event by 59% of them and underestimated that induced by mood disorders cited as the most disturbing by only 3% of them. CONCLUSION: The discomfort caused by corticosteroid-induced neuropsychiatric adverse events are underestimated by general practitioners.

[Internal medicine physicians' perception of frequency and impact of corticosteroid-induced adverse events]. / Perception par les médecins internistes de la fréquence et de la gêne induite par les effets indésirables d'une corticothérapie systémique prolongée.

INTRODUCTION: Whereas internal medicine physicians frequently prescribe systemic corticosteroids, it is unknown if they assess adequately the frequency and the discomfort caused by corticosteroid-induced adverse events. METHODS: Using an e-mail questionnaire sent to the 813 internal medicine physicians, members of the French National Society of Internal Medicine, we assessed their perception of the frequency and the discomfort induced by the adverse events of long-term (that is, over or at three months) corticosteroid therapy. At the same time, 121 corticosteroid-treated patients, consulting in a department of internal medicine completed an anonymous questionnaire about the frequency and the discomfort caused by the adverse events of their therapy. RESULTS: Three hundred and thirty-six out of 813 internal medicine physicians answered to the questionnaire (response rate: 41%) and 115 of the 121 questionnaires distributed to patients were exploitable. The physicians were predominantly male (71%) working mainly in tertiary centers (53%). The mean length of corticosteroids therapy for patients was 44+/-38 months and the mean daily dosage was 15+/-14mg. Lipodystrophy, trophic skin disorders, neuropsychiatric disorders and insomnia were frequent and reported by more than half of patients. The frequency of neuropsychiatric and skin disorders and of lipodystrophy estimated by practitioners was markedly lower than the frequency reported by patients. If morphological changes (weight-gain and lipodystrophy) were cited by practitioners as the most discomforting adverse event, in agreement with patients' opinion, physicians underestimated the discomfort caused by neuropsychiatric disorders and insomnia. CONCLUSION: Frequency and discomfort caused by corticosteroid-induced neuropsychiatric disorders are underestimated by internal medicine physicians.

[Long-term systemic corticosteroid-therapy associated measures: description of the French internal medicine physicians' practices]. / Mesures adjuvantes à une corticothérapie systémique prolongée : description des pratiques des médecins internistes français.

INTRODUCTION: Except for the prevention of osteoporosis, no consensual recommendations are available regarding the therapeutic measures associated with the prescription of long-term corticosteroid therapy. The aim of this study was to assess the internal medicine physicians' practices regarding the prescription of long-term corticosteroid therapy. METHODS: In September 2007, we sent, by e-mail, a questionnaire to 813 internal medicine physicians, members of the French National Society of Internal Medicine. With this questionnaire, we assessed the frequency of prescription of measures sometimes associated with systemic corticosteroids and for whom no consensual recommendations were available (dietary advices, physical training, potassium supplementation, gastric protection, influenza vaccination and prescription of hydrocortisone). RESULTS: Three hundred and thirty-six out of 813 internal medicine physicians completed the questionnaire (response rate: 41%). The practitioners were predominantly male (71%) and mainly engaged in tertiary centres (53%). Regarding the dietary measures associated with the prescription of corticosteroids, low-sodium diet was recommended by most of the physicians, 69% of them prescribing such dietary regimen in more than 80% of their corticosteroid-treated patients. The concomitant prescription of caloric restriction, low-carbohydrate diet and/or high-protein diet was not consensual. The prescription of muscular physiotherapy was unusual, 74% of physicians prescribing such reeducation in less than 20% of their patients. The frequency of recommendation for daily physical training varied between physicians as well as for potassium supplementation, gastric protection, influenza vaccination or hydrocortisone prescription. CONCLUSION: There is no consensus between French internal medicine physicians regarding most of the measures, which must be prescribed in association with a long-term corticosteroid therapy.

Dual infections by influenza A/H3N2 and B viruses and by influenza A/H3N2 and A/H1N1 viruses during winter 2007, Corsica Island, France.

BACKGROUND: The investigation of dual influenza infection human cases is of major interest specifically for the control of new emerging influenza strains. OBJECTIVES: Using RT-PCR assays, we retrospectively assessed the prevalence of dual influenza virus infections that occurred in patients during the 2006-2007 winter season in Corsica Island (France). STUDY DESIGN: One hundred and thirty-four nasal swabbing samples taken from patients suffering from influenza-like illness between February and March 2007 were analysed using a rapid influenza antigen detection test, cell culture and RT-PCR assays. RESULTS AND CONCLUSION: Influenza viruses were detected in 93 (69.4%) of 134 patients with influenza-like illness using the combination of classical and molecular assays. Dual respiratory infections by influenza viruses were detected in 3 (3.2%) of the 93 influenza positive patients, including two cases of infection by influenza A/H3N2 and B viruses and one case of dual infection by influenza A/H3N2 and A/H1N1 viruses. In the present report, human co-infection cases by two influenza viruses appeared as a rare event in symptomatic patients. However, the virological and epidemiological mechanisms that determine the occurrence of dual influenza infections remain to be fully investigated in further prospective multicentric studies.