Ebola virus disease: A narrative review

(+)-fenchol and (-)-isopinocampheol derivatives targeting the entry process of filoviruses

The increasing frequency of filovirus outbreaks in African countries has led to a pressing need for the development of effective antifilovirus agents. In continuation of our previous research on the antifilovirus activity of monoterpenoid derivatives, we synthesized a series of (+)-fenchol and (-)-isopinocampheol derivatives by varying the type of heterocycle and linker length. Derivatives with an N-alkylpiperazine cycle proved to be the most potent antiviral compounds, with half-maximal inhibitory concentration (IC50) 1.4-20 μМ against Lenti-EboV-GP infection and 11.3-47 μМ against Lenti-MarV-GP infection. Mechanism-of-action experiments revealed that the compounds may exert their action by binding to surface glycoproteins (GPs). It was demonstrated that the binding of the synthesized compounds to the Marburg virus GP is less efficient as compared to the Ebola virus GP. Furthermore, it was shown that the compounds possess lysosomotropic properties. Thus, the antiviral activity may be due to dual effects. This study offers new antiviral agents that are worthy of further exploration.

Identification and Potential Roles of Human MicroRNAs in Ebola Virus Infection and Disease Pathogenesis

Ebola virus (EBOV) is a highly pathogenic virus that causes a severe illness called Ebola virus disease (EVD). EVD has a high mortality rate and remains a significant threat to public health. Research on EVD pathogenesis has traditionally focused on host transcriptional responses. Limited recent studies, however, have revealed some information on the significance of cellular microRNAs (miRNAs) in EBOV infection and pathogenic mechanisms, but further studies are needed. Thus, this study aimed to identify and validate additional known and novel human miRNAs in EBOV-infected adult retinal pigment epithelial (ARPE) cells and predict their potential roles in EBOV infection and pathogenic mechanisms. We analyzed previously available small RNA-Seq data obtained from ARPE cells and identified 23 upregulated and seven downregulated miRNAs in the EBOV-infected cells; these included two novel miRNAs and 17 additional known miRNAs not previously identified in ARPE cells. In addition to pathways previously identified by others, these miRNAs are associated with pathways and biological processes that include WNT, FoxO, and phosphatidylinositol signaling; these pathways were not identified in the original study. This study thus confirms and expands on the previous study using the same datasets and demonstrates further the importance of human miRNAs in the host response and EVD pathogenesis during infection.

Higher local Ebola incidence causes lower child vaccination rates

Ebola is a highly infectious and often fatal zoonotic disease endemic to West and Central Africa. Local outbreaks of the disease are common, but the largest recorded Ebola epidemic originated in Guinea in December 2013, spreading to Liberia, and Sierra Leone in the following year and lasting until April 2016. The epidemic presented a serious challenge to local healthcare systems and foreign aid agencies: it degraded services, caused the loss of healthcare professionals, disrupted the economy, and reduced trust in modern healthcare. This study aims to estimate the extent to which variation in one long-term measure of the quality of local healthcare (the child vaccination rate) is a consequence of local variation in the intensity of the epidemic. Applying a "difference-in-differences" model to household survey data from before and after the epidemic, we show that in 2018-2019, overall rates of vaccination for BCG, DPT, measles, and polio are lower in Guinean and Sierra Leonean districts that had a relatively high incidence of Ebola; statistical analysis indicates that this is a causal effect. The effects of the epidemic on access to healthcare have been local effects, at least in part.

Relationship Between Human FCγRIIA rs1801274 G Allele and Risk of Death Among Different SARS-CoV-2 Variants

Coronavirus disease 2019 (COVID-19), the illness caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), emerged in late 2019 and spread very quickly across the world. Different responses to infections have been related to fragment crystallizable gamma-receptor II alpha (FcγRIIA) polymorphisms. The purpose of this investigation was to determine if FCγRIIA rs1801274 polymorphism was related to COVID-19 mortality among different variants of SARS-CoV-2. The FCγRIIA rs1801274 polymorphism was genotyped using the polymerase chain reaction-restriction fragment length polymorphism technique in 1,734 recovered and 1,450 deceased patients. Deceased patients had significantly higher minor allele frequency of the FCγRIIA rs1801274 G allele than in the recovered cases. The COVID-19 mortality was associated with FCγRIIA rs1801274 GG and AG genotypes in the Delta variant and with FCγRIIA rs1801274 GG genotypes in the Alpha and Omicron BA.5 variants. The reverse transcription-quantitative polymerase chain reaction Ct values revealed statistically significant differences between individuals with a G allele and those with an A allele. In conclusion, among the several SARS-CoV-2 variants, there may be a correlation between the mortality rate of COVID-19 and the G allele of FCγRIIA rs1801274. To confirm our findings, thorough research is still required.

Susceptibility of bovine to SARS-CoV-2 variants of concern: insights from ACE2, AXL, and NRP1 receptors

The possibilities of cross-species transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) between humans and important livestock species are not yet known. Herein, we used the structural and genetic alignment and surface potential analysis of the amino acid (aa) in angiotensin-converting enzyme 2 (ACE2), tyrosine kinase receptor UFO (AXL), and neuropilin 1 (NRP1) in different species with substantial public health importance. The residues interfacing with the N-terminal domain (NTD) or receptor-binding domain (RBD) of S were aligned to screen the critical aa sites that determined the susceptibility of the SARS-CoV-2 to the host. We found that AXL and NRP1 proteins might be used as the receptors of SARS-CoV-2 in bovines. However, ACE2 protein may not be considered to be involved in the cross-species transmission of SARS-CoV-2 VOCs in cattle because the key residues of the ACE2-S-binding interface were different from those in known susceptible species. This study indicated that emerging SARS-CoV-2 variants potentially expand species tropism to bovines through AXL and NRP1 proteins.