Assessment of the FilmArray ME panel in 4199 consecutively tested cerebrospinal fluid samples.

OBJECTIVES: In central nervous system infections, early and correct management is of utmost importance. Rapid syndromic panel testing can potentially provide valuable guidance. The FilmArray meningitis/encephalitis (ME) panel detects 14 pathogens through multiplex PCR. Our study objectives were to assess its performance compared with established diagnostic procedures, especially real-time quantitative PCR for detection of viruses, and to determine the diagnostic and clinical significance of discrepant results. METHODS: All cerebrospinal fluid samples sent for viral diagnostics to our microbiological laboratory over 34 months were analysed with the ME panel and in-house real-time PCR for herpes simplex virus type 1 (HSV-1), HSV-2, varicella zoster virus and enteroviruses. Other pathogens detected by the panel were confirmed by routine diagnostic procedures. Discrepant results were analysed through interpretation of biological and clinical data, and performance data were calculated for individual pathogens. RESULTS: Altogether, 315 pathogens were detected by the ME panel in 4199 cerebrospinal fluid samples (7.5%) and an additional 21 viral targets were identified using real-time PCR. Thirty-four ME panel detections were not confirmed, totalling 55 discrepant results. After discrepancy analysis, 20 false-positive and 21 false-negative ME panel results remained. Performance varied between pathogens. Sensitivity for HSV-1 was calculated at 82.4% (59.0%-93.8%) with three false-negative results. Also noteworthy were 13 false-negative enterovirus and eight false-positive Streptococcus pneumoniae results. CONCLUSIONS: Our analysis shows good performance for the ME panel in diagnosing central nervous system infection. The risk of false-negative HSV-1 results, however, warrants additional testing when encephalitis is suspected. Uncertainties in interpretation of enterovirus and S. pneumoniae results represent other limitations.

Burden of rotavirus infection in hospitalized elderly individuals prior to the introduction of rotavirus vaccination in Sweden.

BACKGROUND: Rotavirus gastroenteritis (GE) in the elderly has been much less studied than in children. OBJECTIVES: The aim of this study was to determine the morbidity and mortality for elderly hospitalized patients with rotavirus GE prior to the introduction of rotavirus vaccination in Sweden, and to investigate the epidemiology of rotavirus genotypes in these patients. STUDY DESIGN: All patients 60 years or older who were hospitalized at Sahlgrenska University Hospital, Gothenburg, Sweden, and were rotavirus positive in a clinical diagnostic test from 2009 to 2016, were included. Medical records were reviewed and rotavirus genotyping real-time PCR was performed. RESULTS: One hundred and fifty-nine patients were included, corresponding to an annual incidence of hospitalization due to rotavirus GE of 16/100 000 inhabitants aged 60 years or older. G2P[4] was the most common genotype, followed by G1P[8] and G4P[8]. The majority of patients had community-onset of symptoms and no or few pre-existing health disorders. Four patients (2.5%) died within 30 days of sampling. Patients with hospital-onset rotavirus GE had a longer median length of stay following diagnosis compared with patients with community-onset of symptoms (19 vs. 5 days, p = 0.001) and higher 30-day mortality (8.6% (3/35) vs. < 1% (1/124), p = 0.03). CONCLUSIONS: Hospitalization due to rotavirus GE among the elderly seems to mainly affect otherwise healthy individuals and is associated with low 30-day mortality.

Response prediction in chronic hepatitis C by assessment of IP-10 and IL28B-related single nucleotide polymorphisms.

BACKGROUND: High baseline levels of IP-10 predict a slower first phase decline in HCV RNA and a poor outcome following interferon/ribavirin therapy in patients with chronic hepatitis C. Several recent studies report that single nucleotide polymorphisms (SNPs) adjacent to IL28B predict spontaneous resolution of HCV infection and outcome of treatment among HCV genotype 1 infected patients. METHODS AND FINDINGS: In the present study, we correlated the occurrence of variants at three such SNPs (rs12979860, rs12980275, and rs8099917) with pretreatment plasma IP-10 and HCV RNA throughout therapy within a phase III treatment trial (HCV-DITTO) involving 253 Caucasian patients. The favorable SNP variants (CC, AA, and TT, respectively) were associated with lower baseline IP-10 (P = 0.02, P = 0.01, P = 0.04) and were less common among HCV genotype 1 infected patients than genotype 2/3 (P<0.0001, P<0.0001, and P = 0.01). Patients carrying favorable SNP genotypes had higher baseline viral load than those carrying unfavorable variants (P = 0.0013, P = 0.029, P = 0.0004 respectively). Among HCV genotype 1 infected carriers of the favorable C, A, or T alleles, IP-10 below 150 pg/mL significantly predicted a more pronounced reduction of HCV RNA from day 0 to 4 (first phase decline), which translated into increased rates of RVR (62%, 53%, and 39%) and SVR (85%, 76%, and 75% respectively) among homozygous carriers with baseline IP-10 below 150 pg/mL. In multivariate analyses of genotype 1-infected patients, baseline IP-10 and C genotype at rs12979860 independently predicted the first phase viral decline and RVR, which in turn independently predicted SVR. CONCLUSIONS: Concomitant assessment of pretreatment IP-10 and IL28B-related SNPs augments the prediction of the first phase decline in HCV RNA, RVR, and final therapeutic outcome.

Multiplex real-time PCR for detection of respiratory tract infections.

BACKGROUND: Broad diagnostics of respiratory infection by molecular assays has not yet won acceptance due to technical difficulties and high costs. OBJECTIVES: To evaluate clinical applicability of multiplex real-time PCR. STUDY DESIGN: An assay targeting influenza virus A (IfA) and B (IfB), parainfluenza 1-3 (PIV), human metapneumovirus (MPV), respiratory syncytial virus (RSV), rhinovirus (RV), enterovirus (EV), adenovirus (AdV), human coronaviruses (229E, OC43, NL63), M. pneumoniae and Ch. pneumoniae was developed and run daily on consecutive clinical nasopharyngeal swab samples. RESULTS: An etiology was identified in 48% of the 954 samples, with IfA in 25%, RV in 20%, MPV in 10% and M. pneumoniae in 10% of the positive. By a rational procedure costs could be reduced and the customer price set relatively low (euro33 per sample). CONCLUSION: Streamlined testing and cost limitation is achievable and probably critical for implementation of a broad molecular diagnostics of respiratory infections.