An Outbreak of Human Parainfluenza Virus 3 (Phylogenetic Subcluster C5) Infection among Adults at a Residential Care Facility for the Disabled in Croatia, 2018

Controlling a human parainfluenza virus-3 outbreak in a haematology ward in a tertiary hospital: the importance of screening strategy and molecular diagnostics in relation to clinical symptoms

BACKGROUND

Human parainfluenza 3 (HPIV-3) outbreak at the haemato-oncology ward of the Maastricht University Medical Center in the summer of 2016.

AIM

To describe an effective strategy to control the largest reported HPIV-3 outbreak at an adult haematology-oncology ward in the Netherlands by implementing infection control measures and molecular epidemiology investigation.

METHODS

Clinical, patient and diagnostic data were both pro- and retrospectively collected. HPIV-3 real-time-PCR (HPIV-3 RT-PCR) was validated using oropharyngeal rinse samples. Screening of all new and admitted patients was implemented to identify asymptomatic infection or prolonged shedding of HPIV-3 allowing cohort isolation.

FINDINGS

The HPIV-3 outbreak occurred between 9 July and 28 September 2016 and affected 53 patients. HPIV-3 RT-PCR on oropharyngeal rinse samples demonstrated an up to tenfold higher sensitivity compared to pharyngeal swabs. Monitoring showed that at first positive PCR, 20 patients (38%) were asymptomatic (of which 11 remained asymptomatic) and the average duration of shedding was 14 days (range 1-58). Asymptomatic patients had lower viral load, shorter period of viral shedding (≤14 days) and were mostly immune competent oncology patients. The outbreak was under control 5 weeks after implementation of screening of asymptomatic patients.

CONCLUSION

Implementation of a sensitive screening method identified both symptomatic and asymptomatic patients which had lower viral load and allowed early cohort isolation. This is especially important in a ward that combines patients with varying immune status, since both immunocompromised and immune competent patients are likely to spread the HPIV-3 virus, either through prolonged shedding or through asymptomatic course of disease.

Graphene and carbon nanotubes interfaced electrochemical nanobiosensors for the detection of SARS-CoV-2 (COVID-19) and other respiratory viral infections: A review

Recent COVID-19 pandemic has claimed millions of lives due to lack of a rapid diagnostic tool. Global scientific community is now making joint efforts on developing rapid and accurate diagnostic tools for early detection of viral infections to preventing future outbreaks. Conventional diagnostic methods for virus detection are expensive and time consuming. There is an immediate requirement for a sensitive, reliable, rapid and easy-to-use Point-of-Care (PoC) diagnostic technology. Electrochemical biosensors have the potential to fulfill these requirements, but they are less sensitive for sensing viruses/viral infections. However, sensitivity and performance of these electrochemical platforms can be improved by integrating carbon nanostructure, such as graphene and carbon nanotubes (CNTs). These nanostructures offer excellent electrical property, biocompatibility, chemical stability, mechanical strength and, large surface area that are most desired in developing PoC diagnostic tools for detecting viral infections with speed, sensitivity, and cost-effectiveness. This review summarizes recent advancements made toward integrating graphene/CNTs nanostructures and their surface modifications useful for developing new generation of electrochemical nanobiosensors for detecting viral infections. The review also provides prospects and considerations for extending the graphene/CNTs based electrochemical transducers into portable and wearable PoC tools that can be useful in preventing future outbreaks and pandemics.

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

Human 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. IMPORTANCE HPIV-3 is an important cause of pediatric disease and significantly impacts the elderly. Increasing numbers of immunocompromised patients suffer from HPIV-3 infections, often related to problems with viral clearance. There is a need to model HPIV-3 infections in vitro and in vivo to evaluate novel prophylaxis and treatment options. Currently existing animal models lack the potential for studying animal-to-animal transmission or the effect of immunosuppressive therapy. Here, we describe the use of the ferret model in combination with authentic clinical viruses to further complement human ex vivo models, providing a platform to study approaches to prevent and treat HPIV-3 infection. Although we did not detect ferret-to-ferret transmission in our studies, these studies lay the groundwork for further refinement of the ferret model to immunocompromised ferrets, allowing for studies of severe HPIV-3-associated disease. Such models for preclinical evaluation of prophylaxis and antivirals can contribute to reducing the global health burden of HPIV-3.

Identification of the Functional Domain of HPIV3 Matrix Protein Interacting with Nucleocapsid Protein

Human parainfluenza virus type 3 (HPIV3) is the main pathogen that causes respiratory infections in infants, young children, and the elderly. Currently, there are no vaccines and effective anti-infective drugs. Studying the replication and proliferation mechanism of HPIV3 is helpful for exploring the targets of anti-HPIV3 infection. Matrix protein (M) and nucleocapsid protein (N) are two key structural proteins of HPIV3 that exert important functions in HPIV3 proliferation. Herein, we aim to clarify the functional domains of M and N interaction. HPIV3 M and N expression plasmids of pCAGGS-HA-M and pCAGGS-N-Myc/Flag, M C-terminal truncation mutant plasmids of pCAGGSHA-MΔC120, MΔC170, MΔC190, and MΔC210, and M C-terminal plasmid of pCAGGS-HA-MC190 and C-terminal deletion mutant plasmid of pCAGGS-MΔN143-182 were constructed. By using immunoprecipitation, immunofluorescence, and virus-like particle (VLP) germination experiments, we found that N was encapsulated into M-mediated VLP through N and M interaction. Moreover, the C-terminus of the M played a key role in the interaction between M and N. The C-terminus of the M encapsulated the N into the VLP. We finally determined that the 143-182 amino acids in the M were the functional regions that encapsulated the N into the M-mediated VLP. Our findings confirmed the interaction between M and N and for the first time clarified that the 143-182 amino acid region in M was the functional region that interacted with N, which provides a molecular basis for exploring effective anti-HPIV3 targets.