The factors that cause prolonged human influenza virus respiratory tract infection and determine its clinical impact and the development of drug-resistant viruses are unclear. During a 3-year period, symptomatic influenza virus excretion for 2 weeks was observed among 8 immunocompromised patients and found to be associated with lymphocytopenia at onset (8 of 8 patients) more often than with granulocytopenia (2 of 8 patients) or monocytopenia (2 of 8 patients). Six (75%) of 8 patients developed influenza lower respiratory tract infection (10 episodes), and receipt of oseltamivir treatment was significantly associated with clinical improvement (8 of 8 episodes vs. 0 of 2 untreated episodes; P = .02). Complete viral clearance was strongly correlated with lymphocyte reconstitution (P = .04) but was never observed during the first 2 weeks after oseltamivir treatment. Neuraminidase inhibitor-resistant influenza viruses emerged in 2 (67%) of 3 patients eligible for resistance analysis. In conclusion, prolonged influenza virus infection was associated with lymphocytopenia, influenza lower respiratory tract infection, and frequent development of drug resistance during antiviral therapy. Clinical improvement in influenza lower respiratory tract infection is observed during oseltamivir treatment, but complete viral clearance is dependent on lymphocyte reconstitution, irrespective of receipt of antiviral medication.

Context The sudden emergence and rapid spread of oseltamivir-resistant influenza A(H1N1) viruses with neuraminidase (NA) gene H274Y amino acid substitution is the hallmark of global seasonal influenza since January 2008. Viruses carrying this mutation are widely presumed to exhibit attenuated pathogenicity, compromised transmission, and reduced lethality. Objective To investigate nosocomial viral transmission in a cluster of patients with influenza A(H1N1) virus infection. Design, Setting, and Patients Descriptive outbreak investigation of 2 hematopoietic stem cell transplant recipients and an elderly patient who developed hospitalacquired influenza A virus infection following exposure to an index patient with community-acquired H274Y-mutated influenza A(H1N1) virus infection in a medical ward at a Dutch university hospital in February 2008. The investigation included a review of the medical records, influenza virus polymerase chain reaction and culture, phenotypic oseltamivir and zanamivir susceptibility determination, and hemagglutinin chain 1 (HA 1) gene and NA gene sequence analysis. Main Outcome Measure Phylogenetic relationship of patient cluster influenza A(H1N1) viruses and other 2007-2008 seasonal influenza A(H1N1) viruses. Results Viral HA 1 and NA gene sequence analysis from the 4 patients revealed indistinguishable nucleotide sequences and phylogenetic clustering of H274Ymutated, oseltamivir-resistant influenza A(H1N1) virus, confirming nosocomial transmission. Influenza virus pneumonia (3 patients) and attributable mortality (2 patients) during active infection was observed in patients with lymphocytopenia at onset. Conclusion Seasonal oseltamivir-resistant influenza A(H1N1) viruses with NA gene H274Y mutation are transmitted and retain significant pathogenicity and lethality in high-risk patients.

The emergence of the plasmid-mediated mcr colistin resistance gene in the community poses a potential threat for treatment of patients, especially when hospitalized. The aim of this study was to determine the prevalence of all currently known mcr mediated colistin resistance gene in fecal samples of patients attending a tertiary care hospital. From November 2014 until July 2015, fecal samples of patients attending the Leiden University Medical Center were collected and screened for presence of mcr using real-time PCR. Two of 576 patients were positive for mcr-1, resulting in a prevalence of 0.35%, whereas no mcr-2 was found. One of these samples was culture negative, the second sample contained a blaCMY-2 and mcr-1 containing E.coli. This strain belonged to Sequence Type 359 and serotype O177:H21. The mcr-1 containing E.coli was phenotypically susceptible to colistin with a MIC of ≤ 0.25mg/l, due to a 1329bp transposon IS10R inserted into the mcr-1 gene as identified by WGS. This prevalence study shows that mcr-1 is present in low levels patients out of the community attending a hospital. Furthermore the study underlines the importance of phenotypical confirmation of molecular detection of a mcr-1 gene.

This study reports the development and evaluation of an internally controlled real-time PCR targeting the ospA gene for detection of Borrelia burgdorferi sensu stricto, Borrelia garinii, Borrelia afzelii and Borrelia valaisiana. DNA was extracted using QIAamp DNA Blood Mini kit columns. DNA from 33 B. burgdorferi sensu lato strains reacted in the assay, whereas no reactivity was observed with DNA from four relapsing fever Borrelia spp., 11 unrelated spirochaetes, and 31 unrelated microorganisms. The quantitative sensitivity of the assay was 1-10 fg of Borrelia DNA and one to five cultured Borrelia spirochaetes. Cerebrospinal fluid (CSF) specimens from 70 patients sent for routine testing for neuroborreliosis, and three CSF specimens containing B. garinii were also tested. Positive PCR results were obtained with all three culture-confirmed neuroborreliosis specimens, five of ten neuroborreliosis specimens with specific antibodies in CSF and pleocytosis, none of nine specimens from possible cases of early neuroborreliosis (antibodies in serum, CSF pleocytosis, no antibodies in CSF), one of 15 specimens from patients with active or past Lyme disease with neurological signs (antibodies in serum, no pleocytosis or antibodies in CSF), and none of 36 specimens from patients without Lyme borreliosis (no antibodies in serum or CSF). Overall, the real-time PCR assay enabled sensitive and specific detection of all B. burgdorferi sensu lato species tested. The PCR had a sensitivity of 50% in patients with neuroborreliosis. The main diagnostic role of the assay could be to confirm neuroborreliosis in patients for whom the diagnosis is doubtful.

No abstract