Search

Background: Human Parainfluenza viruses (HPIV) comprise of four members of the genetically distinct genera of Respirovirus (HPIV1&3) and Orthorubulavirus (HPIV2&4), causing significant upper and lower respiratory tract infections worldwide, particularly in children. However, despite frequent molecular diagnosis, they are frequently considered collectively or with HPIV4 overlooked entirely. We therefore investigated clinical and viral epidemiological distinctions of the relatively less prevalent Orthorubulaviruses HPIV2&4 at a regional UK hospital across four autumn/winter epidemic seasons., Methods: A retrospective audit of clinical features of all HPIV2 or HPIV4 RT-PCR-positive patients, diagnosed between 1st September 2013 and 12th April 2017 was undertaken, alongside sequencing of viral genome fragments in a representative subset of samples., Results: Infection was observed across all age groups, but predominantly in children under nine and adults over 40, with almost twice as many HPIV4 as HPIV2 cases. Fever, abnormal haematology, elevated C-reactive protein and hospital admission were more frequently seen in HPIV2 than HPIV4 infection. Each of the four seasonal peaks of either HPIV2, HPIV4 or both, closely matched that of RSV, occurring in November and December and preceding that of Influenza A. A subset of viruses were partially sequenced, indicating co-circulation of multiple subtypes of both HPIV2&4, but with little variation between each epidemic season or from limited global reference sequences., Conclusions: Despite being closest known genetic relatives, our data indicates a potential difference in associated disease between HPIV2 and HPIV4, with more hospitalisation seen in HPIV2 mono-infected individuals, but a greater overall number of HPIV4 cases., (© 2022 The Authors. Influenza and Other Respiratory Viruses published by John Wiley & Sons Ltd.)

Objectives: The aim of the study was to qualitatively and semiquantitatively characterize the expression of the principal HIV co-receptors chemokine (C-C motif) receptor 5 (CCR5) and chemokine (C-X-C motif) receptor 4 (CXCR4) on susceptible CD4 T-helper cell, monocyte/macrophage and Langerhans dendritic cell populations within the cervical epithelia of asymptomatic women attending a genitourinary medicine clinic., Methods: Of 77 asymptomatic women recruited, 35 were excluded: 21 because they were found to have bacterial vaginosis, eight because they were found to have candida and six for other reasons. Cervical cytobrush samples from 11 women with Chlamydia trachomatis infection and 31 women without any detectable genital infection were stained with fluorescently labelled antibodies specific for cell surface CCR5, CXCR4, CD4, CD3, CD1a and CD19 expression, then analysed by flow cytometry., Results: CD4/CD3 T-helper cells (84%), CD1a Langerhans dendritic cells (75%) and CD4/CD14 monocytes/macrophages (59%) were detected in the samples. CCR5 and CXCR4 HIV co-receptor expression was observed on 46-86% of the above subsets. CD1a cells exhibited significantly higher CCR5 and CXCR4 positivity and median fluorescence than CD4 cells and higher CXCR4 positivity and median fluorescence than CD14 cells (P < 0.05 or less). Increased detection of CCR5 over CXCR4 was seen in CD14 cells (P < 0.05). No significant differences in CCR5 or CXCR4 expression were found in samples from asymptomatic women with or without chlamydial infection., Conclusions: Co-receptor expression confirms the potential for CD1a Langerhans cells, monocytes/macrophages and T-helper cells in the cervix as primary targets for HIV infection. Previously observed selective transmission of CCR5-tropic isolates cannot be accounted for by a lack of CXCR4-expressing CD4 cervical immune cells. We were unable to identify any specific impact of chlamydial infection on co-receptor expression in this study., (© 2012 British HIV Association.)