Magnus Lindh

Varicella-zoster virus CNS disease - viral load, clinical manifestations and sequels.

BACKGROUND Real-time polymerase chain reaction (PCR) analysis of cerebrospinal fluid (CSF) samples has improved the diagnosis of varicella-zoster virus (VZV) infection of the central nervous system (CNS). The VZV viral load in the CSF obtained from VZV-related neurological syndromes is not known. OBJECTIVES To investigate VZV viral loads associated with VZV-related neurological syndromes, and to describe the clinical manifestations and sequels in patients with VZV DNA in the CSF. STUDY DESIGN Patients in the Western Gotaland region of Sweden with CNS symptoms and VZV DNA in the CSF, during 1995-2006 were retrospectively identified. The diagnoses, laboratory tests (including virus quantity), antiviral treatment, and neurological complications were studied. RESULTS Ninety-seven patients with VZV DNA in the CSF detected by PCR were identified. In 66 patients in whom VZV DNA levels were determined, significantly higher viral loads were found in those with encephalitis and acute aseptic meningitis compared to patients with cranial nerve affection (including Ramsay Hunt syndrome). Fifty patients had a follow-up; 34 (68%) had neurological symptoms 1 month after acute disease and 25 (50%) had neurological complications 3 months after discharge. A minimum yearly incidence of 1.8 per 100,000 of PCR diagnosed VZV CNS infections was estimated. CONCLUSIONS VZV was the most common alpha-herpesvirus detected in CSF samples from patients with CNS symptoms in the Western Gotaland region of Sweden. CSF viral loads were higher in patients with encephalitis and acute aseptic meningitis than in other CNS syndromes caused by VZV. A majority of the patients that were seen in follow-up had neurological symptoms and sequels.

Seasonal variations of 15 respiratory agents illustrated by the application of a multiplex polymerase chain reaction assay

Abstract Background: Nucleic acid amplification tests are increasingly being used to diagnose viral and bacterial respiratory tract infections. The high sensitivity of these tests affects our understanding of the epidemiology of respiratory tract infections. We have assessed the detection rate of a multiplex real-time polymerase chain reaction (PCR) test, with emphasis on epidemiology and seasonal distribution of the most common respiratory tract infections. Methods: Seven thousand eight hundred and fifty-three nasopharyngeal samples from 7220 patients (age range 0–98 y, median 22 y) obtained during 36 consecutive months (November 2006–October 2009), were analyzed with a multiplex PCR panel including influenza A (IfA) and B (IfB) virus, parainfluenza virus (PIV) 1–3, respiratory syncytial virus (RSV), human rhinovirus (HRV), human coronavirus (CoV) OC43, NL63, and 229E, human metapneumovirus (HMPV), adenovirus (AdV), enterovirus (EV), and 2 bacteria – Mycoplasma pneumoniae and Chlamydophila pneumoniae. Results: Of the total samples, 44.5% (n = 3496) were positive for at least 1 agent, with HRV being the most common (n = 1482, 38.0%), followed by RSV (n = 526, 13.5%) and IfA (n = 403, 10.3%). The diagnostic yield was significantly higher during the winter and early spring compared to the summer (n = 2439 of 4458 samples, 54.7% and n = 1057 of 3395 samples, 31.1%, respectively; p < 0.001). Conclusions: The diagnostic yield was highly dependent on the month of sampling and the age of the patient. However, the overall detection rate per month was above 30%, apart for August and September. Our findings support the use of similar tests in routine clinical care all year round. HRV was the most common finding in the respiratory tract, independent of season.

Access to a polymerase chain reaction assay method targeting 13 respiratory viruses can reduce antibiotics: a randomised, controlled trial

BackgroundViral respiratory infections are common worldwide and range from completely benign disease to life-threatening illness. Symptoms can be unspecific, and an etiologic diagnosis is rarely established because of a lack of suitable diagnostic tools. Improper use of antibiotics is common in this setting, which is detrimental in light of the development of bacterial resistance. It has been suggested that the use of diagnostic tests could reduce antibiotic prescription rates. The objective of this study was to evaluate whether access to a multiplex polymerase chain reaction (PCR) assay panel for etiologic diagnosis of acute respiratory tract infections (ARTIs) would have an impact on antibiotic prescription rate in primary care clinical settings.MethodsAdult patients with symptoms of ARTI were prospectively included. Nasopharyngeal and throat swabs were analysed by using a multiplex real-time PCR method targeting thirteen viruses and two bacteria. Patients were recruited at 12 outpatient units from October 2006 through April 2009, and samples were collected on the day of inclusion (initial visit) and after 10 days (follow-up visit). Patients were randomised in an open-label treatment protocol to receive a rapid or delayed result (on the following day or after eight to twelve days). The primary outcome measure was the antibiotic prescription rate at the initial visit, and the secondary outcome was the total antibiotic prescription rate during the study period.ResultsA total sample of 447 patients was randomised. Forty-one were excluded, leaving 406 patients for analysis. In the group of patients randomised for a rapid result, 4.5% (9 of 202) of patients received antibiotics at the initial visit, compared to 12.3% (25 of 204) (P = 0.005) of patients in the delayed result group. At follow-up, there was no significant difference between the groups: 13.9% (28 of 202) in the rapid result group and 17.2% (35 of 204) in the delayed result group (P = 0.359), respectively.ConclusionsAccess to a rapid method for etiologic diagnosis of ARTIs may reduce antibiotic prescription rates at the initial visit in an outpatient setting. To sustain this effect, however, it seems necessary to better define how to follow and manage the patient according to the result of the test, which warrants further investigation.Trial registrationClinicalTrials.gov identifier: NCT01133782.

Rectal swabs can be used for diagnosis of viral gastroenteritis with a multiple real-time PCR assay

BACKGROUND Viral agents, especially norovirus, are the most common cause of nosocomial spread of epidemic gastroenteritis (GE). Rapid and reliable detection of these agents could reduce the risk of outbreaks. OBJECTIVE To evaluate the diagnostic performance of rectal swab samples compared to standard stool samples for detection of agents causing viral GE by PCR. STUDY DESIGN Complete pairs of rectal swab and stool samples, obtained simultaneously from patients with symptoms of acute onset GE, were analysed with a multiple real-time PCR targeting six different gastroenteritis agents (astro-, adeno-, rota-, sapo- and norovirus GI and II). Cycle threshold (Ct) values were registered for positive samples. A positive PCR result in either sample for any virus was considered gold standard. RESULTS 69 sample pairs were included of which 29 were negative in both sample types and 38 were positive in both sample types. One pair was positive in the stool sample only and another pair was positive in the rectal swab sample only. Sensitivity for both sample types was 97.5% (39/40). CONCLUSION Rectal swab samples are as reliable as stool samples for PCR-based diagnosis of viral gastroenteritis in patients with a short duration of symptoms and may be used as a complement to stool samples, especially when immediate sampling is desirable.

Epstein–Barr virus in bone marrow of rheumatoid arthritis patients predicts response to rituximab treatment

Objectives. Viruses may contribute to RA. This prompted us to monitor viral load and response to anti-CD20 therapy in RA patients. Methods. Blood and bone marrow from 35 RA patients were analysed for CMV, EBV, HSV-1, HSV-2, parvovirus B19 and polyomavirus using real-time PCR before and 3 months after rituximab (RTX) treatment and related to the levels of autoantibodies and B-cell depletion. Clinical response to RTX was defined as decrease in the 28-joint disease activity score (DAS-28) >1.3 at 6 months. Results. Before RTX treatment, EBV was identified in 15 out of 35 patients (EBV-positive group), of which 4 expressed parvovirus. Parvovirus was further detected in eight patients (parvo-positive group). Twelve patients were negative for the analysed viruses. Following RTX, EBV was cleared, whereas parvovirus was unaffected. Eighteen patients were responders, of which 12 were EBV positive. The decrease in the DAS-28 was significantly higher in EBV-positive group compared with parvo-positive group (P = 0.002) and virus-negative patients (P = 0.04). Most of EBV-negative patients that responded to RTX (75%) required retreatment within the following 11 months compared with only 8% of responding EBV-positive patients. A decrease of RF, Ig-producing cells and CD19+ B cells was observed following RTX but did not distinguish between viral infections. However, EBV-infected patients had significantly higher levels of Fas-expressing B cells at baseline as compared with EBV-negative groups. Conclusions. EBV and parvovirus genomes are frequently found in bone marrow of RA patients. The presence of EBV genome was associated with a better clinical response to RTX. Thus, presence of EBV genome may predict clinical response to RTX.

Treatment of chronic hepatitis B infection: An update of Swedish recommendations

The main goal for treatment of chronic hepatitis B is to prevent complications such as liver cirrhosis or hepatocellular carcinoma. Knowledge from population studies of the long-term risk of chronic HBV infection, as well as the recent introduction of pegylated interferon and additional nucleoside analogues has changed the therapeutic situation. Recently, a Swedish expert panel convened to update the national recommendations for treatment. The panel recommends treatment for patients with active HBV infection causing protracted liver inflammation or significant liver fibrosis, verified by liver histology. In general, pegylated interferon alpha-2a is recommended as first-line treatment, in particular for HBeAg-positive patients with HBV genotypes A or B. Among nucleoside analogues, entecavir is the first choice and adefovir or tenofovir can be used as alternatives. Lamivudine monotherapy is not recommended due to the high risk of resistance development. Combinations of nucleoside analogues such as tenofovir and lamivudine or emtricitabine are alternatives for patients with non-response or infection with resistant variants, or as first choice for patients with advanced liver disease. Nucleoside analogue treatment should be monitored to detect primary non-response and virological breakthrough. Special recommendations are given for HBV/HIV coinfected patients, immunosuppressed patients, children, and for treatment before and after liver transplantation. The present guideline is translated from Swedish, where it is published on the MPA and RAV websites (www.mpa.se and www.rav.nu.se) including 7 separate papers based on thorough literature search. The complete reference list can be received from the Medical Products Agency upon request.