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.

Prospective evaluation of the Alere i Influenza A&B nucleic acid amplification versus Xpert Flu/RSV.

The rapid and accurate detection of influenza virus in respiratory specimens is required for optimal management of patients with acute respiratory infections. Because of the variability of the symptoms and the numerous other causes of influenza-like illness, the diagnosis of influenza cannot be made on the basis of clinical criteria alone. Thus, rapid influenza diagnostic tests have been developed such as the Alere i Influenza A&B isothermal nucleic acid assay. We prospectively evaluated the performance of the Alere i Influenza A&B assay in comparison with our routine Xpert Flu/RSV assay. Positive samples were subtyped according to the protocol from the National Influenza Center (Paris, France). A total of 96 respiratory nasal swab samples were analyzed: with both methods, 38 were positive and 56 were negative. Samples were prospectively collected from January 20 to April 8, 2015, from patient (86 adult and 10 pediatric patients) presenting with an influenza-like illness through the French influenza season. In comparison with the Xpert Flu/RSV assay, the overall sensitivity and specificity of the Alere i Influenza A&B assay were 95% and 100%, respectively. Our results indicate that the Alere i Influenza A&B assay has a good overall analytical performance and a high degree of concordance with the PCR-based Xpert Flu/RSV assay. The Alere i Influenza A&B isothermal nucleic acid amplification test is a powerful tool for influenza detection due to its high sensitivity and specificity as well as its ability to generate results within 15min.

First cases of Middle East Respiratory Syndrome Coronavirus (MERS-CoV) infections in France, investigations and implications for the prevention of human-to-human transmission, France, May 2013.

In May 2013, Middle East Respiratory Syndrome Coronavirus (MERS-CoV) infection was diagnosed in an adult male in France with severe respiratory illness, who had travelled to the United Arab Emirates before symptom onset. Contact tracing identified a secondary case in a patient hospitalised in the same hospital room. No other cases of MERS-CoV infection were identified among the index case's 123 contacts, nor among 39 contacts of the secondary case, during the 10-day follow-up period.