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Tick-borne encephalitis (TBE), a viral infection of the central nervous system, is endemic in many Eurasian

Background Coronaviruses (CoVs) were long thought to only cause mild respiratory and gastrointestinal symptoms in humans but outbreaks of Middle East Respiratory Syndrome (MERS)-CoV, Severe Acute Respiratory Syndrome (SARS)-CoV-1, and the recently identified SARS-CoV-2 have cemented their zoonotic potential and their capacity to cause serious morbidity and mortality, with case fatality rates ranging from 4 to 35%. Currently, no specific prophylaxis or treatment is available for CoV infections. Therefore we investigated the virucidal and antiviral potential of Echinacea purpurea (Echinaforce®) against human coronavirus (HCoV) 229E, highly pathogenic MERS- and SARS-CoVs, as well as the newly identified SARS-CoV-2, in vitro. Methods To evaluate the antiviral potential of the extract, we pre-treated virus particles and cells and evaluated remaining infectivity by limited dilution. Furthermore, we exposed cells to the extract after infection to further evaluate its potential as a prophylaxis and treatment against coronaviruses. We also determined the protective effect of Echinaforce® in re-constituted nasal epithelium. Results In the current study, we found that HCoV-229E was irreversibly inactivated when exposed to Echinaforce® at 3.2 μg/ml IC50. Pre-treatment of cell lines, however, did not inhibit infection with HCoV-229E and post-infection treatment had only a marginal effect on virus propagation at 50 μg/ml. However, we did observe a protective effect in an organotypic respiratory cell culture system by exposing pre-treated respiratory epithelium to droplets of HCoV-229E, imitating a natural infection. The observed virucidal activity of Echinaforce® was not restricted to common cold coronaviruses, as both SARS-CoV-1 and MERS-CoVs were inactivated at comparable concentrations. Finally, the causative agent of COVID-19, SARS-CoV-2 was also inactivated upon treatment with 50μg/ml Echinaforce®. Conclusions These results show that Echinaforce® is virucidal against HCoV-229E, upon direct contact and in an organotypic cell culture model. Furthermore, MERS-CoV and both SARS-CoV-1 and SARS-CoV-2 were inactivated at similar concentrations of the extract. Therefore we hypothesize that Echinacea purpurea preparations, such as Echinaforce®, could be effective as prophylactic treatment for all CoVs due to their structural similarities.

A cross-sectional study was made in a major cattle-breeding area of Switzerland to investigate the prevalence and local distribution of animals antibody positive to bovine viral diarrhoea (BVD) virus and of persistently infected animals. The sample size and statistical analysis took into account the possible clustering of persistently infected animals on individual farms. Of 3440 animals tested on 121 farms, 1982 were found to have antibodies to BVD virus (95 per cent confidence interval for the population prevalence: 57.6+/-4.5 per cent) and 22 were persistently infected (estimate for the population prevalence: 0.64+/-0.34 per cent). The detection of persistent infection in animals less than seven months old was improved either by retesting one year later, by using an antigen-capture ELISA or, in selected cases, by the analysis of original serum samples by reverse-transcription PCR. The results showed that the prevalence of persistent infection may be underestimated by as much as one-third when antigen detection alone is used. None of the 121 farms investigated was free of antibody-positive animals and one in eight herds had at least one animal that was persistently infected. The prevalence of antibodies was lowest in seven- to 12-month-old animals (22.9 per cent) and highest in animals aged five years or over (84.9 per cent).

Background. A unit of the European Mobile Laboratory (EMLab) consortium was deployed to the Ebola virus disease (EVD) treatment unit in Guéckédou, Guinea, from March 2014 through March 2015.Methods. The unit diagnosed EVD and malaria, using the RealStar Filovirus Screen reverse transcription–polymerase chain reaction (RT-PCR) kit and a malaria rapid diagnostic test, respectively.Results. The cleaned EMLab database comprised 4719 samples from 2741 cases of suspected EVD from Guinea. EVD was diagnosed in 1231 of 2178 hospitalized patients (57%) and in 281 of 563 who died in the community (50%). Children aged <15 years had the highest proportion of Ebola virus–malaria parasite coinfections. The case-fatality ratio was high in patients aged <5 years (80%) and those aged >74 years (90%) and low in patients aged 10–19 years (40%). On admission, RT-PCR analysis of blood specimens from patients who died in the hospital yielded a lower median cycle threshold (Ct) than analysis of blood specimens from survivors (18.1 vs 23.2). Individuals who died in the community had a median Ct of 21.5 for throat swabs. Multivariate logistic regression on 1047 data sets revealed that low Ct values, ages of <5 and ≥45 years, and, among children aged 5–14 years, malaria parasite coinfection were independent determinants of a poor EVD outcome.Conclusions. Virus load, age, and malaria parasite coinfection play a role in the outcome of EVD.

Tick-borne encephalitis (TBE) is an endemic disease in Switzerland, with about 110-120 reported human cases each year. Endemic areas are found throughout the country. However, the viruses circulating in Switzerland have not been characterized so far. In this study, the complete envelope (E) protein sequences and phylogenetic classification of 72 TBE viruses found in Ixodes ricinus ticks sampled at 39 foci throughout Switzerland were analyzed. All isolates belonged to the European subtype and were highly related (mean pairwise sequence identity of 97.8% at the nucleotide and 99.6% at the amino acid level of the E protein). Sixty-four isolates were characterized in vitro with respect to their plaque phenotype. More than half (57.8%) of isolates produced a mixture of plaques of different sizes, reflecting a heterogeneous population of virus variants. Isolates consistently forming plaques of small size were associated with recently detected endemic foci with no or only sporadic reports of clinical cases. All of six virus isolates investigated in an in vivo mouse model were highly neurovirulent (100% mortality) but exhibited a relatively low level of neuroinvasiveness, with mouse survival rates ranging from 50% to 100%. Therefore, TBE viruses circulating in Switzerland belong to the European subtype and are closely related. In vitro and in vivo surrogates suggest a high proportion of isolates with a relatively low level of virulence, which is in agreement with a hypothesized high proportion of subclinical or mild TBE infections.

Tomato mosaic virus (ToMV) causes a serious loss of yield and fruit quality in tomato crops. To control ToMV, three resistance genes, Tm-1, Tm-2, and Tm-2(2) from wild tomato species were introduced into commercial tomato cultivars. Soon after, however, single and, rarely, double-resistance-breaking virus strains for Tm-1 and Tm-2 emerged. Sequence analysis of a Tm-1/Tm-2 double-resistance-breaking virus, designated ToMV1-2, revealed 30 nucleotide substitutions compared with wild-type ToMV. Of these, six substitutions result in amino acid exchanges. Two exchanges are in the methyl transferase/helicase domain of the ToMV1-2 130/180-kDa proteins (D-1097 to V, R-1100 to Q), two exchanges are found in the 30-kDa movement protein (MP; E-52 to K, E-133 to K), and two exchanges are in the coat protein (I-22 to V, A-87 to S). Construction of chimeric full-length viral cDNA clones containing the base substitutions resulting in altered amino acids, either in the 130/180 kDa proteins or the MP, revealed that the amino acid exchanges in the 130/180-kDa proteins enable ToMV1-2 to break the Tm-1 resistance, while those in the MP enable ToMV1-2 to overcome the Tm-2 resistance. Furthermore, a novel Tm-1/Tm-2 double-resistance-breaking virus was generated by combining the Tm-1-breaking domain of ToMV1-2 and the MP of a new virus, ToMV2, containing the amino acid exchanges E-133 to K and N-135 to S. Together, the data suggest that double-resistance-breaking ToMV1-2 may have resulted from recombination between Tm-1 and Tm-2 single resistance-breaking virus strains.