Human Parainfluenza Virus Type Research Articles

Analysis of hemagglutinin-neuraminidase gene characteristics of human parainfluenza virus type 3 among children with acute respiratory tract infection in Qingdao city

The purpose was to discuss the infection status of human parainfluenza virus type 3 (HPIV-3) in children with acute respiratory tract infection(ARTI) in Qingdao, Shandong province, and to analyze the gene characteristics of HPIV-3 hemagglutinin-neuraminidase protein (HN). This study was a cross-sectional study. A total of 1 674 throat swab samples were collected randomly from children with ARTI, in the three hospitals (Qingdao Women and Children's Hospital, West Coast Branch of Affiliated Hospital of Qingdao University, Laoshan Branch of Affiliated Hospital of Qingdao University) from January 2018 to December 2019. Multiplex real-time fluorescence RT-PCR was performed to screen HPIV-3 positive specimens. For HPIV-3 positive specimens, nested PCR was used to amplify the full-length HN gene of HPIV-3. The HN gene was sequenced and compared with the representative strains of HPIV-3 in GenBank, and the phylogenetic tree was established. As results, this study collected 1 674 samples, in which there were 90 HPIV-3 positive samples showed and the detection rate was 5.37%. Among positive specimens, the number of samples from children under 6 years old was 88, accounting for 97.78%. HPIV-3 positive cases were mainly distributed in spring and summer. The full-length sequences of 44 HPIV-3 HN genes were obtained by nested PCR method. Sequence alignment and evolutionary analysis showed that the HPIV-3HN gene belonged to the C3a and C3b branches of C3 genotype, with 30 strains of subtype C3a and 14 strains of subtype C3b. The nucleotide and amino acid homology of the amplified 44 strains of the HPIV-3 HN gene in Qingdao were 97.0%-100.0% and 98.5%-100.0%, respectively. In conclusion, from 2018 to 2019, the C3a and C3b branches of HPIV-3 C3 genotype were circulating prevalent in Qingdao, Shandong province. HN gene variation rate was low, but showed certain regional characteristics in evolution.

Safety and Immunogenicity of an mRNA-Based Human Metapneumovirus and Parainfluenza Virus Type 3 Combined Vaccine in Healthy Adults.

BackgroundHuman metapneumovirus (hMPV) and parainfluenza virus type 3 (PIV3) cause respiratory tract illness in children and the elderly. No licensed vaccines are available.MethodsIn this phase 1, randomized, dose-ranging, first-in-human study, the safety, reactogenicity, and humoral immunogenicity of an investigational mRNA-based hMPV and PIV3 combination vaccine, mRNA-1653, were evaluated in healthy adults aged 18–49 years. Sentinel participants (n = 20) received 2 doses of mRNA-1653 (25, 75, 150, or 300 μg) in the dose escalation phase, and participants (n = 104) received 2 doses of mRNA-1653 (75, 150, or 300 μg) or placebo in the dose selection phase; injections were 28 days apart.ResultsThe most common solicited reactogenicity events were injection site pain, headache, fatigue, and myalgia, the majority of which were grade 1 or 2. A single mRNA-1653 dose increased neutralization titers against hMPV and PIV3 1 month after vaccination compared with baseline. No notable increases in neutralizing antibody titers were observed with escalating dose levels after mRNA-1653, although no statistical inferences were made; a second mRNA-1653 dose had little observable impact on antibody titers. Neutralizing titers through 1 year remained above baseline for hMPV and returned to baseline for PIV3.ConclusionsmRNA-1653 was well tolerated, with an acceptable safety profile and increased hMPV and PIV3 neutralization titers in healthy adults.

Epidemiological Characteristics of Parainfluenza Virus Type 3 and the Effects of Meteorological Factors in Hospitalized Children With Lower Respiratory Tract Infection.

ObjectiveTo investigate the relationship between meteorological factors and Human parainfluenza virus type 3 (HPIV-3) infection among hospitalized children.MethodsAll hospitalized children with acute lower respiratory tract infections were tested for viral pathogens and enrolled, at the second affiliated hospital of Wenzhou medical university, between 2008 and 2017. Meteorological data were directly obtained from Wenzhou Meteorology Bureau's nine weather stations and expressed as the mean exposure for each 10-day segment (average daily temperatures, average daily relative humidity, rainfall, rainfall days, and wind speed). The correlation between meteorological factors and the incidence of HPIV-3 was analyzed, with an autoregressive integrated moving average model (ARIMA), generalized additive model (GAM), and least absolute shrinkage and selection operator (LASSO).ResultsA total of 89,898 respiratory specimens were tested with rapid antigen tests, and HPIV-3 was detected in 3,619 children. HPIV-3 was detected year-round, but peak activities occurred most frequently from March to August. The GAM and LASSO-based model had revealed that HPIV-3 activity correlated positively with temperature and rainfall day, but negatively with wind speed. The ARIMA (1,0,0)(0,1,1) model well-matched the observed data, with a steady R2 reaching 0.708 (Ljung-Box Q = 21.178, P = 0.172).ConclusionOur study suggests that temperature, rainfall days, and wind speed have significant impacts on the activity of HPIV-3. GAM, ARIMA, and LASSO-based models can well predict the seasonality of HPIV-3 infection among hospitalized children. Further understanding of its mechanism would help facilitate the monitoring and early warning of HPIV-3 infection.

A single intranasal dose of human parainfluenza virus type 3-vectored vaccine induces effective antibody and memory T cell response in the lungs and protects hamsters against SARS-CoV-2

Respiratory tract vaccination has an advantage of needle-free delivery and induction of mucosal immune response in the portal of SARS-CoV-2 entry. We utilized human parainfluenza virus type 3 vector to generate constructs expressing the full spike (S) protein of SARS-CoV-2, its S1 subunit, or the receptor-binding domain, and tested them in hamsters as single-dose intranasal vaccines. The construct bearing full-length S induced high titers of neutralizing antibodies specific to S protein domains critical to the protein functions. Robust memory T cell responses in the lungs were also induced, which represent an additional barrier to infection and should be less sensitive than the antibody responses to mutations present in SARS-CoV-2 variants. Following SARS-CoV-2 challenge, animals were protected from the disease and detectable viral replication. Vaccination prevented induction of gene pathways associated with inflammation. These results indicate advantages of respiratory vaccination against COVID-19 and inform the design of mucosal SARS-CoV-2 vaccines.

Role of Glycoconjugates and Mammalian Sialidases Involved in Viral Infection and Neural Function

Glycoconjugates are present in various organisms, ranging from animals to viruses. Glycoconjugates are involved in several biologically significant functions, including viral infection and neurotransmission. However, the role of glycoconjugates in virus replication and neural function remains unknown. We discovered that the influenza A virus (IAV) binds to sulfatide, which lacks a sialic acid residue, and that delivering sulfatide combined with newly synthesized IAV hemagglutinin (HA) to the target plasma membrane induces the translocation of viral ribonucleoprotein complexes from the nucleus to the cytoplasm. Molecular species of sialic acid are largely classified as N-acetylneuraminic acid (Neu5Ac) and N-glycolylneuraminic acid (Neu5Gc). We discovered that two amino acids in IAV H3 HA play a critical role in the recognition of Neu5Ac and Neu5Gc. Also, we observed that human parainfluenza virus types 1 (hPIV-1) and 3 (hPIV-3) bind to different forms of gangliosides. These viruses preferentially recognized oligosaccharides containing branched N-acetyllactosaminoglycans with terminal Neu5Acα2-3Gal. Neu5Gcα2-3Gal- and NeuAcα2-6Gal-containing receptors were identified by hPIV-3, but not by hPIV-1. We constructed a novel sialidase fluorescent substrate, 2-benzothiazol-2-yl-phenol derivative-based N-acetylneuraminic acid (BTP3-Neu5Ac), which detects sialidase activity in living mammalian tissues and virus-infected cells expressing viral neuraminidase. We discovered that neural activity-dependent desialylation by sialidase contributes to rat hippocampal memory processing. Using BTP3-Neu5Ac, we developed a rapid and sensitive approach for detecting and isolating drug-resistant influenza viruses. This review summarizes the role of sialylglycoconjugates and sulfatide in virus replication as well as mammalian sialidases involved in neural function and insulin secretion.

Modeling Infection and Tropism of Human Parainfluenza Virus Type 3 in Ferrets.

ABSTRACTHuman parainfluenza virus type 3 (HPIV-3) is a significant cause of lower respiratory tract infections, with the most severe disease in young infants, immunocompromised individuals, and the elderly. HPIV-3 infections are currently untreatable with licensed therapeutics, and prophylactic and therapeutic options are needed for patients at risk. To complement existing human airway models of HPIV-3 infection and develop an animal model to assess novel intervention strategies, we evaluated infection and transmission of HPIV-3 in ferrets. A well-characterized human clinical isolate (CI) of HPIV-3 engineered to express enhanced green fluorescent protein (rHPIV-3 CI-1-EGFP) was passaged on primary human airway epithelial cells (HAE) or airway organoids (AO) to avoid tissue culture adaptations. rHPIV3 CI-1-EGFP infection was assessed in vitro in ferret AO and in ferrets in vivo. Undifferentiated and differentiated ferret AO cultures supported rHPIV-3 CI-1-EGFP replication, but the ferret primary airway cells from AO were less susceptible and permissive than HAE. In vivo rHPIV-3 CI-1-EGFP replicated in the upper and lower airways of ferrets and targeted respiratory epithelial cells, olfactory epithelial cells, type I pneumocytes, and type II pneumocytes. The infection efficiently induced specific antibody responses. Taken together, ferrets are naturally susceptible to HPIV-3 infection; however, limited replication was observed that led to neither overt clinical signs nor ferret-to-ferret transmission. However, in combination with ferret AO, the ferret model of HPIV-3 infection, tissue tropism, and neutralizing antibodies complements human ex vivo lung models and can be used as a platform for prevention and treatment studies for this important respiratory pathogen.

Characterization of Human Parainfluenza Virus Receptor Using Terminal Sialic Acid Linkage-Modified Cells.

Human parainfluenza virus type 1 (hPIV1) and type 3 (hPIV3) are respiratory pathogen viruses that bind to terminal sialic acids of glycoconjugates on the cell surface hemagglutinin-neuraminidase glycoprotein. Sialic acid residues are linked to the galactose residue primarily by α2,3 or α2,6 linkages on the terminal of glycoprotein or glycolipids. One of the major determinants of pathogenicity or tissue tropism is virus binding or infection specificity for each sialyl linkage. Sialic linkage-modified human blood cells or mammalian cells that mainly have α2,3- or α2,6-linked sialic acid residues on the surface can be prepared by treatment with linkage-specific sialidases or sialyltransferases. These linkage-modified cells can be used in hemagglutination assays to estimate virus particles' binding specificity, hemadsorption assays to estimate virus glycoproteins' binding specificity, and virus infectivity assays. These methods contribute to identifying the specificity of sialic acid lineage recognition of the hPIV or other sialic acid-binding viruses.

Solid-Phase Binding Assay for Ganglioside Binding of Human Respiroviruses.

Human parainfluenza virus types 1 (hPIV-1) and 3 (hPIV-3) belong to the family Paramyxoviridae, subfamily Paramyxoviridae, and genus Respirovirus. The viruses enter by utilizing glycoproteins or glycosphingolipids (gangliosides) containing sialic acid on the cell membrane. We developed a solid-phase binding assay to evaluate hPIV-1, hPIV-3, and Sendai virus' abilities to bind to different types of gangliosides. hPIV1 and hPIV3 show strong binding to neolacto-series gangliosides containing a non-reducing terminal sialic acid residue and different specificity regarding the sialic acid linkages. This solid-phase binding assay is suitable to evaluate other orthomyxoviruses and paramyxoviruses' binding specificities utilizing sialic acids.

In Vitro Potential Virucidal Effect Evaluation of Xibornol on Human Adenovirus Type 5, Human Rhinovirus Type 13, Human Coronavirus 229E, Human Parainfluenza Virus Type 1, and Human Respiratory Syncytial Virus.

The availability of virucidal compounds to reduce the impact of respiratory viruses is a relevant topic for public health, especially during the recent coronavirus disease (COVID-19) pandemic. Antimicrobial properties of Xibornol are known since the 1970s, but its activity on viruses is currently little explored. In this study, Xibornol activity at a fixed concentration of 0.03mg/100ml has been evaluated on five respiratory viruses (Human Adenovirus 5, Human Rhinovirus type 13, Human Coronavirus 229E, Human Parainfluenza Virus type 1, and Human Respiratory Syncytial Virus) through in vitro experiments based on adapted European standard UNI EN 14476-20019. The experiments were carried out under two different environmental conditions, one with the addition of fetal bovine serum to simulate an in vivo condition (dirty condition) and the other without the addition of any organic substances (clean condition). The viral abatement of Xibornol (expressed as Log10 reduction - LR) was statistically significant under both clean and dirty environmental conditions. Namely, in clean condition, LR ranged from 2.67 to 3.84, while in the dirty one the abatement was slightly lower (from 1.75 to 3.03). Parainfluenza Virus and Human Adenovirus were most resistant compared to the other viruses. The obtained data confirmed Xibornol activity and its use as topic substance for viral inactivation to prevent upper respiratory tract disease.

Shift in Clinical Epidemiology of Human Parainfluenza Virus Type 3 and Respiratory Syncytial Virus B Infections in Korean Children Before and During the COVID-19 Pandemic: A Multicenter Retrospective Study.

BackgroundParainfluenza virus type 3 (PIV3) and respiratory syncytial virus (RSV) B epidemics occurred in South Korea in late 2021. We investigated epidemiological changes of PIV3 and RSV B infections in Korean children before and during the coronavirus disease 2019 (COVID-19) pandemic.MethodsIn this multicenter retrospective study, we enrolled patients aged less than 19 years with PIV3 or RSV infection in four university hospitals from January 2018 to January 2022. Demographic and clinical data were extracted from the subject’s medical records and analyzed for each virus.ResultsA total of 652 children with PIV3 were identified including three epidemics: 216 in 2018, 260 in 2019, and 167 in 2021. Among 627 RSV B cases, 169 were identified in 2017/2018, 274 in 2019/2020, and 115 in 2021/2022. The peak circulation of PIV3 and RSV B epidemics were delayed by 6 and 2 months, respectively, in 2021, compared with those in the pre-COVID-19 period. The median age of PIV3 infections increased in 2021 (21.5 months in 2021 vs. 13.0–14.0 in 2018–2019; P < 0.001), whereas that of RSV B infections remained unchanged (3.6–4.0 months). During the COVID-19 pandemic, less frequent hospitalization rates were observed for both PIV3 and RSV B infections, but more children needed respiratory assistance for RSV B infection in 2021/2022 epidemic (32.5%) than before (14.7–19.4%, P = 0.014).ConclusionWe observed changes in the epidemiology and clinical presentation of PIV3 and RSV B infections in Korean children during the COVID-19 pandemic.

SARS-CoV-2 infection mediates differential expression of human endogenous retroviruses and long interspersed nuclear elements.

SARS-CoV-2 promotes an imbalanced host response that underlies the development and severity of COVID-19. Infections with viruses are known to modulate transposable elements (TEs), which can exert downstream effects by modulating host gene expression, innate immune sensing, or activities encoded by their protein products. We investigated the impact of SARS-CoV-2 infection on TE expression using RNA-Seq data from cell lines and from primary patient samples. Using a bioinformatics tool, Telescope, we showed that SARS-CoV-2 infection led to upregulation or downregulation of TE transcripts, a subset of which differed from cells infected with SARS, Middle East respiratory syndrome coronavirus (MERS-CoV or MERS), influenza A virus (IAV), respiratory syncytial virus (RSV), and human parainfluenza virus type 3 (HPIV3). Differential expression of key retroelements specifically identified distinct virus families, such as Coronaviridae, with unique retroelement expression subdividing viral species. Analysis of ChIP-Seq data showed that TEs differentially expressed in SARS-CoV-2 infection were enriched for binding sites for transcription factors involved in immune responses and for pioneer transcription factors. In samples from patients with COVID-19, there was significant TE overexpression in bronchoalveolar lavage fluid and downregulation in PBMCs. Thus, although the host gene transcriptome is altered by infection with SARS-CoV-2, the retrotranscriptome may contain the most distinctive features of the cellular response to SARS-CoV-2 infection.

A Point Mutation in the Human Parainfluenza Virus Type 2 Nucleoprotein Leads to Two Separate Effects on Virus Replication.

Paramyxovirus genomes, like that of human parainfluenza virus type 2 (hPIV2), have lengths of precisely multiples-of-six nucleotides ("rule of six"), where each nucleoprotein subunit (NP) binds exactly six nucleotides. Ten residues of its RNA binding groove contact the genome RNA; but only one, Q202, directly contacts a nucleotide base. The mutation of NPQ202 leads to two phenotypes: the ability of the viral polymerase to replicate minigenomes with defective bipartite promoters where NPwt is inactive, and the inability to rescue rPIV2 carrying this point mutation by standard means. The absence of an rPIV2 NPQ202A prevented further study of the latter phenotype. By extensive and repeated cocultivation of transfected cells, an rPIV2 carrying this mutation was finally recovered, and this virus was apparently viable due to the presence of an additional NP mutation (I35L). Our results suggest that these two phenotypes are due to separate effects of the Q202 mutation, and that the problematic rescue phenotype may be due to the inability of the transfected cell to incorporate viral nucleocapsids during virus budding. IMPORTANCE Paramyxovirus genomes are contained within a noncovalent homopolymer of its nucleoprotein (NP) and form helical nucleocapsids (NC) whose 3' ends contain the promoters for the initiation of viral RNA synthesis. This work suggests that these NC 3' ends may play another role in the virus life cycle via their specific interaction with virus-modified cell membranes needed for the incorporation of viral NCs into budding virions.

In Vitro Anticancer and Antivirus Activities of Cyano- and Bis(Trifluoromethylsulfonyl)imide-Based Ionic Liquids

In the current work, we present a broad analysis of cytotoxicity toward normal (kidney and lung) and cancer (lung, liver, and cervix) cells of ionic liquids (ILs) with imidazolium cations and cyano-based or bis(trifluoromethylsulfonyl)imide anions. Additionally, we verify if ILs might be candidates for new potential virucidal agents. We observed the highest biological activity for 1-methyl-3-octylimidazolium bis(trifluoromethylsulfonyl)imide, whereas the least toxic was 1-ethyl-3-methylimidazolium thiocyanate. We found that all investigated ILs revealed a lack of antiviral activity against viruses: human parainfluenza virus type 3 (HPIV-3), human adenovirus 5 (AdV5), human herpesvirus 1 (HSV-1), and human herpesvirus 5 (HCMV) in nontoxic concentrations.

Non-propagative human parainfluenza virus type 2 nasal vaccine robustly protects the upper and lower airways against SARS-CoV-2

SummaryWe developed an intranasal vaccine against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) using the replication-incompetent human parainfluenza virus type 2 (hPIV2) vector BC-PIV, which can deliver ectopic gene as stable RNA and ectopic protein on the envelope. BC-PIV expressing the full-length prefusion-stabilized spike gene (K986P/V987P) of SARS-CoV-2, S-2PM, possessed a corona-like viral envelope. Intranasal vaccination of mice with BC-PIV/S-2PM induced high levels of neutralizing immunoglobulin G (IgG) and mucosal IgA antibodies against the spike protein. Although BC-PIV showed hemagglutinating activity, BC-PIV/S-2PM lacked such activity, in accordance with the presence of the massive spike protein on the viral surface. Furthermore, single-dose intranasal vaccination of hamsters with BC-PIV/S-2PM completely protected the lungs from SARS-CoV-2 at 11-week post-immunization, and boost vaccination two weeks before the challenge conferred virtually complete protection of the nasal turbinates against SARS-CoV-2. Thus, this chimeric hPIV2/spike intranasal vaccine is a promising vaccine candidate for SARS-CoV-2 to curtail virus transmission.

Changes in influenza and other respiratory virus activity during the COVID-19 pandemic—United States, 2020–2021

The COVID-19 pandemic and subsequent implementation of nonpharmaceutical interventions (e.g., cessation of global travel, mask use, physical distancing, and staying home) reduced the transmission of some viral respiratory pathogens.1 In the United States, influenza activity decreased in March 2020, was historically low through the summer of 2020,2 and remained low during October 2020–May 2021 (<0.4% of respiratory specimens with positive test results for each week of the season). Circulation of other respiratory pathogens, including respiratory syncytial virus (RSV), common human coronaviruses (HCoVs) types OC43, NL63, 229E, and HKU1, and parainfluenza viruses (PIVs) types 1–4 also decreased in early 2020 and did not increase until spring 2021.

Evaluation of Human Respiratory Syncytial Virus and Human Parainfluenza Virus Type 3 among Hospitalized Children in Northwest of Iran

Background Acute respiratory tract infections (ARTIs) are the leading cause of illnesses in children. Human respiratory syncytial virus (HRSV) and human parainfluenza viruses (HPIVs) are among the most common etiologic agents associated with viral respiratory tract infections in children worldwide. Nevertheless, limited information is available on the spread of infections of these two viruses in northwest Iran. Objective The purpose of the current study is to evaluate the frequency of RSV and HPIV-3 and clinical features among Iranian children with confirmed respiratory infections between April 2019 and March 2020. Methods 100 nasopharyngeal swabs were collected from hospitalized patients (under 5 years old) with ARTI from Tabriz Children's Hospital. Detection of respiratory viruses was performed using the nested RT-PCR method. Results Respiratory syncytial virus and HPIV-3 were recognized in 18% (18/100) and 2% (2/100) of children, respectively. Ten (55.6%) of the RSV-positive samples were male, while 8 (44.4%) were female. HPIV‐3 was found only among 2 male patients (100%). Most patients (61.1%) with RSV infection were less than 12 months old. Additionally, samples that were positive for HPIV-3 were less than 12 months old. RSV infections had occurred mainly during the winter season. Conclusions This study confirms that RSV can be one of the important respiratory pathogens in children in northwestern Iran. However, according to this study, HPIV-3 has a lower prevalence among children in this area than RSV. Therefore, implementing a routine diagnosis for respiratory pathogens can improve the management of respiratory infections in children.

Human parainfluenza virus type 1 regulates cholesterol biosynthesis and establishes quiescent infection in human airway cells

Human parainfluenza virus type 1 (hPIV1) and 3 (hPIV3) cause seasonal epidemics, but little is known about their interaction with human airway cells. In this study, we determined cytopathology, replication, and progeny virion release from human airway cells during long-term infection in vitro. Both viruses readily established persistent infection without causing significant cytopathic effects. However, assembly and release of hPIV1 rapidly declined in sharp contrast to hPIV3 due to impaired viral ribonucleocapsid (vRNP) trafficking and virus assembly. Transcriptomic analysis revealed that both viruses induced similar levels of type I and III IFNs. However, hPIV1 induced specific ISGs stronger than hPIV3, such as MX2, which bound to hPIV1 vRNPs in infected cells. In addition, hPIV1 but not hPIV3 suppressed genes involved in lipid biogenesis and hPIV1 infection resulted in ubiquitination and degradation of 3-hydroxy-3-methylglutaryl-coenzyme A reductase, a rate limiting enzyme in cholesterol biosynthesis. Consequently, formation of cholesterol-rich lipid rafts was impaired in hPIV1 infected cells. These results indicate that hPIV1 is capable of regulating cholesterol biogenesis, which likely together with ISGs contributes to establishment of a quiescent infection.

Inhibitory effect of traditional herbal (kampo) medicines on the replication of human parainfluenza virus type 2 in vitro.

Thirteen herbal medicines, Kakkonto (TJ-001), Kakkontokasenkyushin'i (TJ-002), Hangekobokuto (TJ-016), Shoseiryuto (TJ-019), Maoto (TJ-027), Bakumondoto (TJ-029), Hochuekkito (TJ-041), Goshakusan (TJ-063), Kososan (TJ-070), Chikujountanto (TJ-091), Gokoto (TJ-095), Saibokuto (TJ-096), and Ryokankyomishingeninto (TJ-119) were tested for human parainfluenza virus type 2 (hPIV-2) replication. Eight (TJ-001, TJ-002, TJ-019, TJ-029, TJ-041, TJ-063, TJ-095 and TJ-119) out of the thirteen medicines had virus growth inhibitory activity. TJ-001 and TJ-002 inhibited virus release, and largely inhibited genome, mRNA and protein syntheses. TJ-019 slightly inhibited virus release, inhibited gene and mRNA syntheses, and largely inhibited protein synthesis. TJ-029 slightly inhibited virus release, largely inhibited protein synthesis, but gene and mRNA syntheses were unaffected. TJ-041 only slightly inhibited virus release, the gene and mRNA syntheses, but largely inhibited protein synthesis. TJ-091 largely inhibited gene, mRNA and protein syntheses. TJ-095 largely inhibited gene synthesis, but NP and HN mRNAs were slightly detected, and protein syntheses were observed. TJ-119 inhibited gene, mRNA and protein syntheses. TJ-001, TJ-002, TJ-091, TJ-095 and TJ-119 inhibited multinucleated giant cell formation derived from cell-to-cell spreading of virus. However, in TJ-019, TJ-029 and TJ-041 treated infected cells, only small sized fused cells with some nuclei were found. TJ-019 and TJ-041 slightly disrupted actin microfilaments, and TJ-001 and TJ-002 destroyed them. TJ-041 slightly disrupted microtubules, and TJ-001 and TJ-002 disrupted them. In general, the medicines effective on common cold and bronchitis inhibited hPIV-2 replication.

Human parainfluenza virus type 3 infections in a haemato-oncology unit: social distancing measures needed in outpatient clinics

Human parainfluenza virus type 3 (HPIV3) infections are associated with high mortality in immunocompromised settings, especially in bone marrow transplant recipients. Asymptomatic infection and lack of effective antiviral treatment makes HPIV3 prevention and treatment a real challenge. To retrospectively investigate the epidemiological characteristics, clinical characteristics and outcomes of 51 haematology patients with confirmed HPIV3 infections, detected between February and May 2019 in the haematology unit at King's College Hospital, London. Between February and May 2019, HPIV3 RNA was detected in combined nose and throat swab samples collected from 51 symptomatic haematology patients, 41 of whom attended the haematology outpatient unit. Clinical data were reviewed retrospectively and a timeline of patients' appointments drawn up to investigate transmission. Sequencing analysis was performed on 14 stored samples. Fifty-one patients were identified with HPIV3 infection. Mean age was 54 years (SD: 12; range: 19-72) and 60% (31/51) were male. There were 41 (80%) bone marrow transplant recipients, 24 had an allograft, and 17 an autograft. Thirty-day and 3-month mortality post HPIV3 was 6% and 14%, respectively. Lower respiratory tract infection and inpatient acquisition were associated with higher mortality (6/7 vs 1/7, P= 0.010; and 5/7 vs 2/7, P= 0.031). Onset of HPIV3 infection in patients within 6 days of attending the clinic was associated with the clusters identified in phylogenetic analysis (64% (9/14) vs 21% (8/37); odds ratio: 6.5 (confidence interval: 95% 1.7-25); P= 0.006). Timelines suggested community transmission, but also possible transmission patterns within the outpatients and subsequent nosocomial transmission within the same ward. Early recognition of HPIV3 infection and the use of polymerase chain reaction and sequence analysis is fundamental in identifying respiratory virus outbreaks and person-to-person transmission. Careful planning of outpatient clinic attendance is required to minimize contact and prevent respiratory virus transmission in immunosuppressed patients.

Curcumin Inhibits Replication of Human Parainfluenza Virus Type 3 by Affecting Viral Inclusion Body Formation

Human Parainfluenza Virus Type 3 (HPIV3) is one of the main pathogens that cause acute lower respiratory tract infections in infants and young children. However, there are currently no effective antiviral drugs and vaccines. Herein, we found that a natural compound, curcumin, inhibits HPIV3 infection and has antiviral effects on entry and replication of the virus life cycle. Immunofluorescence and western blotting experiments revealed that curcumin disrupts F-actin and inhibits viral inclusion body (IB) formation, thus inhibiting virus replication. Curcumin can also downregulate cellular PI4KB and interrupt its colocalization in viral IBs. This study verified the antiviral ability of curcumin on HPIV3 infection and preliminarily elucidated its influence on viral replication, providing a theoretical basis for antiviral drug development of HPIV3 and other parainfluenza viruses.