GENEDIA Multi Influenza Ag Rapid Test for detection and H1, H3, and H5 subtyping of influenza viruses

Assessment of the spatiotemporal risk of avian influenza between waterfowl and poultry farms during the annual cycle: A spatial prediction study focused on seasonal distribution changes in resident waterfowl in South Korea

Previous studies and efforts to prevent and manage avian influenza (AI) outbreaks have mainly focused on the wintering season. However, outbreaks of AI have been reported in the summer, including the breeding season of waterfowl. Additionally, the spatial distribution of waterfowl can easily change during the annual cycle due to their life-cycle traits and the presence of both migrants and residents in the population. Thus, we assessed the spatiotemporal variation in AI exposure risk in poultry due to spatial distribution changes in three duck species included in both major residents and wintering migrants in South Korea, the mandarin, mallard and spot-billed duck, during wintering (October-March), breeding (April-June) and whole annual seasons. To estimate seasonal ecological niche variations among the three duck species, we applied pairwise ecological niche analysis using the Pianka index. Subsequently, seasonal distribution models were projected by overlaying the monthly ranges estimated by the maximum entropy model. Finally, we overlaid each seasonal distribution range onto a poultry distribution map of South Korea. We found that the mandarin had less niche overlap with the mallard and spot-billed duck during the wintering season than during the breeding season, whereas the mallard had less niche overlap with the mandarin and spot-billed duck during the breeding season than during the wintering season. Breeding and annual distribution ranges of the mandarin and spot-billed duck, but not the mallard, were similar or even wider than their wintering ranges. Similarly, the mandarin and spot-billed duck showed more extensive overlap proportions between poultry and their distributional ranges during both the breeding and annual seasons than during the wintering season. These results suggest that potential AI exposure in poultry can occur more widely in the summer than in winter, depending on sympatry with the host duck species. Future studies considering the population density and variable pathogenicity of AI are required.

Genetic Characterization and Pathogenesis of Avian Influenza Virus H7N3 Isolated from Spot-Billed Ducks in South Korea, Early 2019

Low-pathogenicity avian influenza viruses (LPAIV) introduced by migratory birds circulate in wild birds and can be transmitted to poultry. These viruses can mutate to become highly pathogenic avian influenza viruses causing severe disease and death in poultry. In March 2019, an H7N3 avian influenza virus—A/Spot-billed duck/South Korea/WKU2019-1/2019 (H7N3)—was isolated from spot-billed ducks in South Korea. This study aimed to evaluate the phylogenetic and mutational analysis of this isolate. Molecular analysis revealed that the genes for HA (hemagglutinin) and NA (neuraminidase) of this strain belonged to the Central Asian lineage, whereas genes for other internal proteins such as polymerase basic protein 1 (PB1), PB2, nucleoprotein, polymerase acidic protein, matrix protein, and non-structural protein belonged to that of the Korean lineage. In addition, a monobasic amino acid (PQIEPR/GLF) at the HA cleavage site, and the non-deletion of the stalk region in the NA gene indicated that this isolate was a typical LPAIV. Nucleotide sequence similarity analysis of HA revealed that the highest homology (99.51%) of this isolate is to that of A/common teal/Shanghai/CM1216/2017 (H7N7), and amino acid sequence of NA (99.48%) was closely related to that of A/teal/Egypt/MB-D-487OP/2016 (H7N3). An in vitro propagation of the A/Spot-billed duck/South Korea/WKU2019-1/2019 (H7N3) virus showed highest (7.38 Log₁₀ TCID₅₀/mL) virus titer at 60 h post-infection, and in experimental mouse lungs, the virus was detected at six days’ post-infection. Our study characterizes genetic mutations, as well as pathogenesis in both in vitro and in vivo model of a new Korea H7N3 viruses in 2019, carrying multiple potential mutations to become highly pathogenic and develop an ability to infect humans; thus, emphasizing the need for routine surveillance of avian influenza viruses in wild birds.

Toward practical application of paper-based microfluidics for medical diagnostics: state-of-the-art and challenges

Microfluidic paper-based analytical devices (μPADs) have emerged as a promising diagnostic platform a decade ago. In contrast to highly active academic developments, their entry into real-life applications is still very limited. This discrepancy is attributed to the gap between research developments and their practical utility, particularly in the aspects of operational simplicity, long-term stability of devices, and associated equipment. On the basis of these backgrounds, this review attempts to: 1) identify the reasons for success of paper-based devices already in the market, 2) describe the current status and remaining issues of μPADs in terms of operational complexity, signal interpretation approaches, and storage stability, and 3) discuss the possibility of mass production based on established manufacturing technologies. Finally, the state-of-the-art in commercialisation of μPADs is discussed, and the "upgrades" required from a laboratory-based prototype to an end user device are demonstrated on a specific example.

The use of saliva specimens for detection of influenza A and B viruses by rapid influenza diagnostic tests

BACKGROUND AND OBJECTIVES

Diagnostic tests for influenza infection commonly use nasopharyngeal swabs (NPS) even though these are invasive to obtain. As an alternative specimen, we evaluated the diagnostic usefulness of saliva samples with rapid influenza diagnostic tests (RIDTs).

STUDY DESIGN

Both NPS and saliva samples were collected from 385 influenza suspected patients and analyzed using Sofia Influenza A+B Fluorescence Immunoassay (Quidel Corporation, San Diego, CA, USA), ichroma TRIAS Influenza A+B (Boditech, Chuncheon, Korea), SD Bioline Influenza Ag (Standard Diagnostic, Yonggin, Korea), BinaxNOW Influenza A/B antigen kit (Alere Inc., Waltham, MA, USA), and real-time reverse transcriptase PCR (RT-PCR).

RESULTS

Of the 385 patients, 31.2% (120/385) were positive for influenza A, and 7.5% (29/385) were positive for influenza B virus with saliva or NPS by RT-PCR. The diagnostic sensitivity was slightly higher in NPS than in saliva samples for both influenza A and B by all of the four RIDTs. The diagnostic sensitivities of Sofia and ichroma TRIAS were significantly superior to those of the other conventional influenza RIDTs with both types of sample. The sensitivities of Sofia and ichroma TRIAS with saliva specimens were comparable to the sensitivities of the other two conventional RIDTs with NPS specimens. The simultaneous use of saliva and NPS samples exhibited improved sensitivity from 10.0% to 13.3% for influenza A and from 10.3% to 17.2% for influenza B compared to using NPS alone.

CONCLUSIONS

This study demonstrates that saliva is a useful specimen for influenza detection, and that the combination of saliva and NPS could improve the sensitivities of influenza RIDTs.