Search

Background Viruses and bacteria from the nasopharynx are capable of causing community-acquired pneumonia (CAP), which can be difficult to diagnose. We aimed to investigate whether shifts in the composition of these nasopharyngeal microbial communities can be used as diagnostic biomarkers for CAP in adults. Methods We collected nasopharyngeal swabs from adult CAP patients and controls without infection in a prospective multicenter case-control study design. We generated bacterial and viral profiles using 16S ribosomal RNA gene sequencing and multiplex polymerase chain reaction (PCR), respectively. Bacterial, viral, and clinical data were subsequently used as inputs for extremely randomized trees classification models aiming to distinguish subjects with CAP from healthy controls. Results We enrolled 117 cases and 48 control subjects. Cases displayed significant beta diversity differences in nasopharyngeal microbiota (P = . 016, R 2 =.01) compared to healthy controls. Our extremely randomized trees classification models accurately discriminated CAP caused by bacteria (area under the curve [AUC].83), viruses (AUC.95) or mixed origin (AUC.81) from healthy control subjects. We validated this approach using a dataset of nasopharyngeal samples from 140 influenza patients and 38 controls, which yielded highly accurate (AUC.93) separation between cases and controls. Conclusions Relative proportions of different bacteria and viruses in the nasopharynx can be leveraged to diagnose CAP and identify etiologic agent(s) in adult patients. Such data can inform the development of a microbiota-based diagnostic panel used to identify CAP patients and causative agents from nasopharyngeal samples, potentially improving diagnostic specificity, efficiency, and antimicrobial stewardship practices. [ABSTRACT FROM AUTHOR]

Background Deferral of men who have sex with men (MSM) from blood donation is highly debated. We therefore investigated their suitability to donate blood. Methods We compared the antibody prevalence of 10 sexually and transfusion-transmissible infections (TTIs) among 583 MSM and 583 age-matched repeat male blood donors. MSM were classified as low risk (lr) or medium-to-high risk (hr) based on self-reported sexual behavior and as qualified or unqualified using Dutch donor deferral criteria. Infection pressure (IP) was defined as the number of antibody-reactive infections, with class A infections (human immunodeficiency virus-1/2, hepatitis B virus, hepatitis C virus, human T-cell lymphotropic virus-1/2, syphilis) given double weight compared to class B infections (cytomegalovirus, herpes simplex virus-1/2, human herpesvirus 8, hepatitis E virus, parvovirus B19). Results Donors had a lower median IP than qualified lr-MSM and qualified hr-MSM (2 [interquartile range {IQR}, 1–2] vs 3 [IQR, 2–4]; P <.001). Low IP was found in 76% of donors, 39% of qualified lr-MSM, and 27% of qualified hr-MSM. The prevalence of class A infections did not differ between donors and qualified lr-MSM but was significantly higher in qualified hr-MSM and unqualified MSM. Recently acquired class A infections were detected in hr-MSM only. Compared to blood donors, human herpesviruses were more prevalent in all MSM groups (P <.001). Conclusions IP correlates with self-reported risk behavior among MSM. Although lr-MSM might form a low threat for blood safety with regard to class A infections, the high seroprevalence of human herpesviruses in lr-MSM warrants further investigation. [ABSTRACT FROM AUTHOR]

Background: Treatment of patients with chronic hepatitis B (CHB) with nucleos(t)ide analogues (NAs) suppresses hepatitis B virus (HBV) DNA production but does not affect the synthesis of the RNA pregenome or HBV messenger RNA. Whether HBV RNA-containing particles continue to be secreted into the bloodstream remains controversial.Methods: We developed a sensitive polymerase chain reaction (PCR) assay to quantify the HBV RNA load in a supernatant of NA-treated HepG2-2.2.15 cells and in plasma specimens from 20 patients with CHB who were receiving NA therapy and 86 patients treated with pegylated interferon alfa (Peg-IFN) and adefovir.Results: Treatment of HepG2-2.2.15 cells with NAs for 9 days reduced HBV DNA levels (by 1.98 log10 copies/mL), whereas HBV RNA levels increased (by 0.47 log10 copies/mL; P < .05). During long-term NA treatment of patients with CHB, HBV RNA levels remained higher than HBV DNA levels. Peg-IFN-based treatment induced a stronger decrease in the HBV RNA load than NA monotherapy, and this decline was more pronounced in responders than in nonresponders. In HBV e antigen-negative patients, a lower baseline plasma HBV RNA level was independently associated with response to Peg-IFN and adefovir (odds ratio, 0.44; P = .019). Immunoprecipitation with HBV core antigen-specific antibodies after removal of the HBV surface antigen envelope demonstrated the association of plasma HBV RNA with virions.Conclusions: HBV RNA is present in virions in plasma specimens from patients with CHB. HBV RNA levels vary significantly from those of established viral markers during antiviral treatment, which highlights its potential as an independent marker in the evaluation of patients with CHB. [ABSTRACT FROM AUTHOR]

Background. The kinetics of hepatitis B surface antigen (HBsAg) are predictive in HBV-infected patients treated with pegylated interferon. Knowledge about the value of HBsAg levels in patients coinfected with HBV and human immunodeficiency virus (HIV) is lacking.Methods. We quantified serum HBsAg in a Dutch multicenter cohort of 104 patients coinfected with HIV and HBV who were treated with tenofovir disoproxil fumarate (TDF) as part of highly active antiretroviral therapy. The median duration of therapy was 57 months (interquartile range, 34–72 months).Results. Hepatitis B e antigen (HBeAg)–positive patients achieved a decline of 2.2 log IU/mL in HBsAg, whereas HBeAg-negative patients only achieved a decline of 0.6 log IU/mL during 6 years of TDF therapy. Declines in HBsAg at months 6 and 12 correlated with CD4 cell count for HBeAg-positive patients. Five HBeAg-positive patients (8%) and 3 HBeAg-negative patients (8%) cleared HBsAg. HBeAg-negative patients who cleared HBsAg had lower baseline HBsAg as compared to patients who remained HBsAg positive. The majority of patients who cleared HBsAg achieved this end point within the first year. In HBeAg-positive patients, decline in HBsAg at month 6 was predictive of achieving HBsAg seroclearance.Conclusions. Receipt of TDF therapy by HIV/HBV-coinfected patients for up to 6 years led to a significant decrease in HBsAg in the HBeAg-positive population. HBsAg kinetics early during treatment were predictive of HBsAg seroclearance and correlated with an increased CD4 cell count, underlining the importance of immune restoration in HBV clearance. [ABSTRACT FROM PUBLISHER]

Background. Recent outbreaks in the Netherlands allowed for laboratory follow-up of a large series of patients with acute Q fever and for evaluation of test algorithms to detect chronic Q fever, a condition with considerable morbidity and mortality. Methods. For 686 patients with acute Q fever, IgG antibodies to Coxiella burnetii were determined using an immunofluorescence assay at 3, 6, and 12 months of follow-up. Polymerase chain reaction (PCR) was performed after 12 months and on earlier serum samples with an IgG phase I antibody titer $1:1024. Results. In 43% of patients, the IgG phase II antibody titers remained high ($1:1024) at 3, 6, and 12 months of follow-up. Three months after acute Q fever, 14% of the patients had an IgG phase I titer $1:1024, which became negative later in 81%. IgG phase I antibody titers were rarely higher than phase II titers. Eleven cases of chronic Q fever were identified on the basis of serological profile, PCR results, and clinical presentation. Six of these patients were known to have clinical risk factors at the time of acute Q fever. In a comparison of various serological algorithms, IgG phase I titer$1:1024 at 6 months had the most favorable sensitivity and positive predictive value for the detection of chronic Q fever. Conclusions. The wide variation of serological and PCR results during the follow-up of acute Q fever implies that the diagnosis of chronic Q fever, necessitating long-term antibiotic treatment, must be based primarily on clinical grounds. Different serological follow-up strategies are needed for patients with and without known risk factors for chronic Q fever. [ABSTRACT FROM AUTHOR]

Increasing evidence suggests that hepatitis E virus (HEV) infection may occur in developed countries and that swine may act as a reservoir. We report a cluster of 2 confirmed cases and 1 presumptive case of hepatitis associated with HEV. The typed strain from 1 case was related to HEV strains found in North America and Europe, and it was also related to a cluster of swine HEV strains found in The Netherlands. Our findings indicate that locally acquired HEV infections in industrialized countries may be overlooked. Routine testing for HEV infection in patients with acute hepatitis in The Netherlands should be considered before a diagnosis of autoimmune hepatitis is reached and steroid therapy is initiated. [ABSTRACT FROM AUTHOR]

Background Acute hepatitis B virus infection in adults is generally self-limiting but may lead to chronicity in a minority of patients. Methods We included 9 patients with acute hepatitis B virus (HBV) infection and collected longitudinal follow-up samples. Natural killer (NK) cell characteristics were analyzed by flowcytometry. HBV-specific T-cell function was analyzed by in vitro stimulation with HBV peptide pools and intracellular cytokine staining. Results Median baseline HBV DNA load was 5.12 log IU/mL, and median ALT was 2652 U/mL. Of 9 patients, 8 cleared HBsAg within 6 months whereas 1 patient became chronically infected. Early time points after infection showed increased CD56bright NK cells and an increased proportion of cells expressing activation markers. Most of these had normalized at week 24, while the proportion of TRAIL-positive CD56bright NK cells remained high in the chronically infected patient. In patients who cleared HBV, functional HBV-specific CD8+ and CD4+ responses could be observed, whereas in the patient who developed chronic infection, only low HBV-specific T-cell responses were observed. Conclusions NK cells are activated early in the course of acute HBV infection. Broad and multispecific T-cell responses are observed in patients who clear acute HBV infection, but not in a patient who became chronically infected. [ABSTRACT FROM AUTHOR]