Rapid bedside tests for diagnosis, management, and prevention of nosocomial influenza.

Like other respiratory viruses, influenza is responsible for devastating nosocomial epidemics in nursing homes as well as in conventional wards and emergency departments. Patients, healthcare workers, and visitors may be the source of nosocomial influenza. Despite their limited sensitivity, rapid diagnostic tests for influenza can be of real value; they enable early introduction of measures to prevent spread and early specific antiviral treatment of cases. However, these tests cannot detect oseltamivir resistance, susceptibility testing being carried out only in specialist laboratories. Although resistance is rare, it can emerge during treatment, especially of very young children or immunocompromised patients. In the latter, the shedding of resistant influenza virus can last several weeks. Sporadic instances of nosocomial transmission among immunocompromised patients have been reported. The limitations of bedside tests for influenza make them unsuitable for use as stand-alone diagnostic tools. However, their limitations do not preclude their use for detection and subsequent management of nosocomial influenza, for which they are rapid, easy, and cost-effective. Recent developments in these tests look promising, offering prospects of increased sensitivity, increased specificity, and screening for antiviral susceptibility.

Routes of transmission during a nosocomial influenza A(H3N2) outbreak among geriatric patients and healthcare workers.

BACKGROUND: Influenza presents a life-threatening infection for hospitalized geriatric patients, who might be nosocomially infected via healthcare workers (HCWs), other patients or visitors. In the 2011/2012 influenza season an influenza A(H3N2) outbreak occurred in the geriatric department at the Hôpital Edouard Herriot, Lyon. AIM: To clarify the transmission chain for this influenza A(H3N2) outbreak by sequence analysis and to identify preventive measures. METHODS: Laboratory testing of patients with influenza-like illness in the acute care geriatric department revealed 22 cases of influenza between 19th February and 15th March 2012. Incidences for patients and HCWs were calculated and possible epidemiological links were analysed using a questionnaire. Neuraminidase and haemagglutinin genes of culture-positive samples and community influenza samples were sequenced and clustered to detect patients with identical viral strains. FINDINGS: Sixteen patients and six HCWs were affected, resulting in an attack rate of 24% and 11% respectively. Six nosocomial infections were recorded. The sequence analysis confirmed three independent influenza clusters on three different sections of the geriatric ward. For at least two clusters, an HCW source was determined. CONCLUSION: Epidemiological and microbiological results confirm influenza transmission from HCWs to patients. A higher vaccination rate, isolation measures and better hand hygiene are recommended in order to prevent outbreaks in future influenza seasons.

Factors associated with clinical and virological response in patients treated with oseltamivir or zanamivir for influenza A during the 2008-2009 winter.

Oseltamivir or zanamivir are effective in outpatients with seasonal influenza; however, factors associated with response have been incompletely described. During the 2008/2009 epidemic, in a randomized trial for influenza A-infected outpatients, clinical (time to alleviation of flu-related symptoms) and virological (rate of patients with day 2 nasal viral load <200 cgeq/µL) responses to oseltamivir or zanamivir were assessed and associated factors were determined using multivariate analysis. For oseltamivir (141 patients) and zanamivir (149 patients) median times to alleviation of symptoms were 3 and 4 days, respectively; 59% and 34% had virological response. For oseltamivir, a lower clinical response was associated with female gender (HR, 0.53; 95% CI, 0.36-0.79), baseline symptoms score >14 (HR, 0.47; 0.32-0.70), viral load ≥5 log cgeq/µL (HR, 0.63; 0.43-0.93), and initiation of antibiotics (HR, 0.30; 0.12-0.76); a lower virological response was associated with female gender (OR, 0.45; 0.21-0.96), baseline viral load ≥5 log cgeq/µL (OR, 0.40; 0.20-0.84) and days 0-2 incomplete compliance (OR, 0.31; 0.10-0.98). For zanamivir, virological response was associated with age ≥50 years (OR, 0.29; 0.10-0.85) and initiation of antibiotics at baseline (OR, 4.24; 1.07-17.50). Factors associated with lower response to neuraminidase inhibitors in outpatients appeared to be easily identifiable during routine clinical examination and, when appropriate, by nasal sampling at baseline. The unknown association between gender and response to oseltamivir was not explained by compliance.

Pediatric neurological complications associated with the A(H1N1)pdm09 influenza infection.

BACKGROUND: Influenza-related neurological complications (INC) have been reported during seasonal flu in children. OBJECTIVES: To investigate the types, outcomes and incidence of INC occurring during the 2009 A(H1N1) pandemic, a retrospective analyze was conducted in the single French pediatric hospital of Lyon from October 2009 to February 2010. STUDY DESIGN: All children presenting with fever, influenza-like illness, respiratory distress or neurological symptoms were tested for influenza A(H1N1)pdm09 infection from respiratory specimens using real time RT-PCR. RESULTS: INC occurred in 14 A(H1N1)pdm09 positive children (7.7% of A(H1N1)pdm09 positive children admitted to hospital) with a median age of 5.1 years. Admission to the intensive care unit (ICU) was required for nine children (64.3%). Half of the children with INC had comorbidity and three had coinfection, both characteristics mainly found in children requiring the ICU. All children received oral oseltamivir treatment. Febrile seizures were observed in eight children, half of them having a chronic comorbidity (2 epilepsy, 1 nonketotic hyperglycinemia, 1 anoxic encephalopathy). Other INC, less commonly reported, included 2 cases of encephalitis, 1 encephalopathy, 1 basilar artery thrombosis, 1 myasthenic crisis and 1 coma. Eleven of the 14 children (78.6%) recovered, one had a minor disability, one child developed a locked-in syndrome and one died from complications of an acute necrotizing encephalopathy. DISCUSSION: INC can be observed even in children with no underlying disorder. It may lead to dramatic issue in a significant number of cases.

S-OtrH3N2 viruses: use of sequence data for description of the molecular characteristics of the viruses and their relatedness to previously circulating H3N2 human viruses.

Emergence of influenza viruses from the animal reservoir is a permanent challenge. The rapid description and immediate sharing of information on these viruses is invaluable for influenza surveillance networks and for pandemic preparedness. With the help of data generated from the World Health Organization Collaborating Centre for Reference and Research on Influenza at the United States Centers for Disease Control and Prevention, we provide here information on the swine­origin triple reassortant influenza A(H3N2) viruses detected in human cases in the north-east of the United States.

[First cases of secondary transmission of a novel swine-origin influenza A (H1N1) virus in France]. / Premiers cas de transmission secondaire en France du nouveau virus grippal d'origine porcine A(H1N1)v.

On April 2009, a new swine-origin A(H1N1) influenza virus, A(H1N1)v, was identified in the United States. Today (June 12, 2009), more than 29,000 cases have been reported in the world, and 73 in France. This is the first report of secondary transmission in France. The three patients presented with common influenza signs including cough, fever, and sore throat. The incubation period could last from two to four days; it should be kept in mind that the first international data mentioned one to seven days. The buildup and maintenance of an infectious focus involve secondary transmissions.

[A fatal case of Herpes simplex virus meningoencephalitis in an immunocompetent adult]. / Un cas mortel de méningoencéphalite à Herpes simplex virus chez un adulte immunocompétent.

Management of herpes simplex virus encephalitis (HSE) has been considerably improved by the development of rapid polymerase chain reaction (PCR) assays and by the use of intravenous acyclovir. However, an absence of early antiviral treatment has been associated to a poor outcome in patients with HSE. In the present report, we described the case of a 53 years-old adult immunompetent patient who was admitted to the emergency department of university medical center of Reims (France). At the time of hospitalisation, he was suffering from a febrile encephalitis syndrome evolving for more than 24 hours. A cerebrospinal fluid (CSF) puncture was performed demonstrating the presence of a lymphocytic meningitidis (42 leukocytes/mm3 which 90% of mononuclear cells; CSF protein = 1650 mg/L) associated with high levels of interferon alpha (75 UI/mL). Specific herpesvirus PCR and hybridisation assays (Herpes Consensus Hybridowell, Argene, France) were positive for the detection of HSV-1 genome on this CSF sample. Despite the intravenous acyclovir treatment (15 mg/kg/8 hours) delivered at the time of hospitalisation, this immunocompetent adult patient will dead 15 days later by a cardiorespiratory failure that was related to extensive HSE lesions. The time delay between the beginning of the clinical syndrome and the instauration of intravenous acyclovir treatment (more than 24 hours) was the only point susceptible to explain the presence of extensive CNS lesions in this patient. Specific Herpesvirus PCR detection assays are powerful tools that are actually used to establish a rapid etiological diagnosis of viral meningo-encephalitis. However, in patients demonstrating clinical signs of encephalitis associated with an aseptic CSF, it remains essential to urgently initiate a presumptive intravenous acyclovir treatment (10-15 mg/kg/8 hours). Actually, this medical practice is the only one susceptible to reduce the morbi-mortality rates linked to HSE.