Persistence of coronaviruses on inanimate surfaces and their inactivation with biocidal agents.

Immunology of COVID-19: Current State of the Science.

The Role of Cytokines including Interleukin-6 in COVID-19 induced Pneumonia and Macrophage Activation Syndrome-Like Disease.

General Aspects.- Systematics.- Biology of Mosquitoes.- Medical Importance of Mosquitoes.- Mosquito Research Techniques.- Morphology of Mosquitoes.- Identification Keys Morphology Ecology and Distribution of European Species.- Key to Female Mosquitoes.- Key to Male Mosquitoes.- Key to Mosquito Fourth Instar Larvae.- Subfamily Anophelinae.- Subfamily Culicinae.- Identification Keys, Morphology, Ecology and Distribution of Important Vector and Nuisance Species - Worldwide.- Africa.- Asia.- Australia.- Central and South America.- North America.- Control of Mosquitoes.- Biological Control.- Environmental Management of Mosquitoes.- Chemical Control.- Physical Control.- Genetic Control of Mosquitoes.- Personal Protection.- Implementation and Integration of Mosquito Control Measures.

Mosquitoes and their Control

We undertook a comprehensive phylogenetic study to establish the genetic relationship among the viruses of the genus Flavivirus and to compare the classification based on molecular phylogeny with the existing serologic method. By using a combination of quantitative definitions (bootstrap support level and the pairwise nucleotide sequence identity), the viruses could be classified into clusters, clades, and species. Our phylogenetic study revealed for the first time that from the putative ancestor two branches, non-vector and vector-borne virus clusters, evolved and from the latter cluster emerged tick-borne and mosquito-borne virus clusters. Provided that the theory of arthropod association being an acquired trait was correct, pairwise nucleotide sequence identity among these three clusters provided supporting data for a possibility that the non-vector cluster evolved first, followed by the separation of tick-borne and mosquito-borne virus clusters in that order. Clades established in our study correlated significantly with existing antigenic complexes. We also resolved many of the past taxonomic problems by establishing phylogenetic relationships of the antigenically unclassified viruses with the well-established viruses and by identifying synonymous viruses.

Phylogeny of the genus Flavivirus.

The efficacy of several povidone-iodine (PVP-I) products, a number of other chemical agents and various physical conditions were evaluated for their ability to inactivate the severe acute respiratory syndrome coronavirus (SARS-CoV). Treatment of SARS-CoV with PVP-I products for 2 min reduced the virus infectivity from 1.17 x 10(6) TCID(50)/ml to below the detectable level. The efficacy of 70% ethanol was equivalent to that of PVP-I products. Fixation of SARS-CoV-infected Vero E6 cells with a fixative including formalin, glutaraldehyde, methanol and acetone for 5 min or longer eliminated all infectivity. Heating the virus at 56 degrees C for 60 min or longer reduced the infectivity of the virus from 2.6 x 10(7) to undetectable levels. Irradiation with ultraviolet light at 134 microW/cm(2) for 15 min reduced the infectivity from 3.8 x 10(7) to 180 TCID(50)/ml; however, prolonged irradiation (60 min) failed to eliminate the remaining virus, leaving 18.8 TCID(50)/ml.

Inactivation of SARS Coronavirus by Means of Povidone-Iodine, Physical Conditions and Chemical Reagents

Two New York (NY) strains of the West Nile (WN) virus were plaque-purified and four variants that had different amino acid sequences at the N-linked glycosylation site in the envelope (E) protein sequence were isolated. The E protein was glycosylated in only two of these strain variants. To determine the relationship between E protein glycosylation and pathogenicity of the WN virus, 6-week-old mice were infected subcutaneously with these variants. Mice infected with viruses that carried the glycosylated E protein developed lethal infection, whereas mice infected with viruses that carried the non-glycosylated E protein showed low mortality. In contrast, intracerebral infection of mice with viruses carrying either the glycosylated or non-glycosylated forms of the E protein resulted in lethal infection. These results suggested that E protein glycosylation is a molecular determinant of neuroinvasiveness in the NY strains of WN virus.

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Viral envelope protein glycosylation is a molecular determinant of the neuroinvasiveness of the New York strain of West Nile virus

The pathogenesis of severe acute respiratory syndrome (SARS) is poorly understood and cytokine dysregulation has been suggested as one relevant mechanism to be explored. We compared the cytokine profile in Caco2 cells after infection of SARS coronavirus (SARS-CoV) with other respiratory viruses including respiratory syncytial virus (RSV), influenza A virus (FluAV), and human parainfluenza virus type 2 (hPIV2). Interferon (IFN) system (production and response) was not suppressed by SARS-CoV infection. Therefore, SARS-CoV replication was suppressed by pretreatment with IFN. SARS-CoV and RSV induced high levels of IL-6 and RANTES compared with FluAV and hPIV2. Induction level of suppressor of cytokine signaling-3 (SOCS3) by SARS-CoV was significantly lower than that by RSV in spite of the significant production of IL-6. Toll-like receptors 4 and 9, which correlate with the induction of inflammatory response, were upregulated by SARS-CoV infection. Collectively, overinduction of inflammatory cytokine and dysregulation of cytokine signaling may contribute to the immunopathology associated with "severe" inflammation in SARS.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/jmv.20556

Cytokine regulation in SARS coronavirus infection compared to other respiratory virus infections.

A case of tick-borne encephalitis (TBE) has not been reported for many years in Japan, although a serological survey of sera from domestic animals suggested the presence of TBE foci in Hokkaido, the northern island of Japan. Studies were conducted to prove the presence of an endemic focus of TBE virus in Japan by means of serology and virus isolation. In October 1993 in Hokkaido, a severe case of encephalitis in a dairy farmer's wife was diagnosed as TBE. Serological examination of paired serum specimens showed a rise in the neutralization antibody titer to Russian spring summer encephalitis virus. A seroepizootiological survey of dogs showed that the TBE-related virus was prevalent in the area. Three virus isolates were obtained from the blood of sentinel dogs, and antigenic analysis grouped the isolates into TBE-related viruses. Sequence analysis of the envelope protein gene identified one of the isolates as being of the same subtype as the Russian spring summer encephalitis (Far Eastern TBE) virus. The results provide evidence that TBE is endemic in a certain area of Japan.

A case of tick-borne encephalitis in Japan and isolation of the the virus.

Aedes japonicus (Theobald) was evaluated for competence as a vector of Japanese encephalitis virus and for its ability to transmit the virus vertically to its F1 larvae. Ae. japonicus supported the growth of the virus at 20 and 28 degrees C after feeding on a virus-blood mixture of 10(6.2) plaque forming unit (PFU)/ml. This species was able to transmit the virus to suckling mice after feeding on a virus-blood meal (10(6.2) PFU/ml) or a viremic chick (10(3.7) PFU/ml). Vertical transmission of the virus in Ae. japonicus was demonstrated with a minimum infection rate of 0.7%.

Ikuo Takashima

Papers

Inactivation of SARS Coronavirus by Means of Povidone-Iodine, Physical Conditions and Chemical Reagents

Viral envelope protein glycosylation is a molecular determinant of the neuroinvasiveness of the New York strain of West Nile virus

Cytokine regulation in SARS coronavirus infection compared to other respiratory virus infections.

A case of tick-borne encephalitis in Japan and isolation of the the virus.

Horizontal and vertical transmission of Japanese encephalitis virus by Aedes japonicus (Diptera: Culicidae).