scholarly journals Tissue tropism and transmission ecology predict virulence of human RNA viruses

PLoS Biology ◽  
2019 ◽  
Vol 17 (11) ◽  
pp. e3000206 ◽  
Author(s):  
Liam Brierley ◽  
Amy B. Pedersen ◽  
Mark E. J. Woolhouse
Keyword(s):  
Rna Viruses ◽  
Tissue Tropism ◽  
Transmission Ecology

scholarly journals Tissue Tropism and Transmission Ecology Predict Virulence of Human RNA Viruses

2019 ◽  
Author(s):  
Liam Brierley ◽  
Amy B. Pedersen ◽  
Mark E. J. Woolhouse
Keyword(s):  
Public Health ◽  
Machine Learning ◽  
Risk Factors ◽  
Random Forest ◽  
Infectious Diseases ◽  
Rna Viruses ◽  
Rna Virus ◽  
Tissue Tropism ◽  
Virus Species ◽  
Ecological Traits

AbstractNovel infectious diseases continue to emerge within human populations. Predictive studies have begun to identify pathogen traits associated with emergence. However, emerging pathogens vary widely in virulence, a key determinant of their ultimate risk to public health. Here, we use structured literature searches to review the virulence of each of the 214 known human-infective RNA virus species. We then use a machine learning framework to determine whether viral virulence can be predicted by ecological traits including human-to-human transmissibility, transmission routes, tissue tropisms and host range. Using severity of clinical disease as a measurement of virulence, we identified potential risk factors using predictive classification tree and random forest ensemble models. The random forest model predicted literature-assigned disease severity of test data with 90.3% accuracy, compared to a null accuracy of 74.2%. In addition to viral taxonomy, the ability to cause systemic infection, having renal and/or neural tropism, direct contact or respiratory transmission, and limited (0 < R0 ≤ 1) human-to-human transmissibility were the strongest predictors of severe disease. We present a novel, comparative perspective on the virulence of all currently known human RNA virus species. The risk factors identified may provide novel perspectives in understanding the evolution of virulence and elucidating molecular virulence mechanisms. These risk factors could also improve planning and preparedness in public health strategies as part of a predictive framework for novel human infections.Author SummaryNewly emerging infectious diseases present potentially serious threats to global health. Although studies have begun to identify pathogen traits associated with the emergence of new human diseases, these do not address why emerging infections vary in the severity of disease they cause, often termed ‘virulence’. We test whether ecological traits of human viruses can act as predictors of virulence, as suggested by theoretical studies. We conduct the first systematic review of virulence across all currently known human RNA virus species. We adopt a machine learning approach by constructing a random forest, a model that aims to optimally predict an outcome using a specific structure of predictors. Predictions matched literature-assigned ratings for 28 of 31 test set viruses. Our predictive model suggests that higher virulence is associated with infection of multiple organ systems, nervous systems or the renal systems. Higher virulence was also associated with contact-based or airborne transmission, and limited capability to transmit between humans. These risk factors may provide novel starting points for questioning why virulence should evolve and identifying causative mechanisms of virulence. In addition, our work could suggest priority targets for infectious disease surveillance and future public health risk strategies.BlurbComparative analysis using machine learning shows specificity of tissue tropism and transmission biology can act as predictive risk factors for virulence of human RNA viruses.

The genetic basis of viral virulence

1983 ◽  
Vol 303 (1114) ◽  
pp. 209-218 ◽  
Keyword(s):  
High Frequency ◽  
Genetic Basis ◽  
Rna Viruses ◽  
Capsid Proteins ◽  
Tissue Tropism ◽  
Genetic Studies ◽  
Genetic Analyses ◽  
Viral Virulence ◽  
Viral Components ◽  
Outer Capsid

The precise genetic and molecular determ inants of viral virulence are poorly understood. Genetic studies with influenza and reovirus have indicated that virulence is multigenic. The high frequency of m utation of RNA viruses can complicate genetic analyses of virulence, resulting in phenotypes that are difficult to interpret. The ease with which the reoviruses reassort genome segments has made it possible to isolate reassortants from parental viruses causing different patterns of anim al disease. It has thus been feasible to show that each of the three outer capsid proteins plays a m ajor role in the pathogenesis of anim al infection: the viral haem agglutinin determines the specificity of the im mune response and cell and tissue tropism ; the p ic protein plays a central role in determ ining yield at portals of entry as well as in differentiated tissues; the δ3 protein inhibits host m acrom olecular synthesis. Thus virulence is clearly multigenic, with each of the viral components playing distinct roles.

Oncogenesis and the Lucké Virus

1968 ◽  
Vol 26 ◽  
pp. 200-201
Author(s):  
A. E. Vatter ◽  
J. Zambernard
Keyword(s):  
Rna Viruses ◽  
Vegetative State ◽  
Temperature Sensitive ◽  
Structural Level ◽  
Oncogenic Viruses ◽  
Dna Viruses ◽  
Leopard Frogs ◽  
Renal Adenocarcinoma ◽  
Induced Tumors ◽  
Northern Leopard Frogs

Oncogenic viruses, like viruses in general, can be divided into two classes, those that contain deoxyribonucleic acid (DNA) and those that contain ribonucleic acid (RNA). The RNA viruses have been recovered readily from the tumors which they cause whereas, the DNA-virus induced tumors have not yielded the virus. Since DNA viruses cannot be recovered, the bulk of present day investigations have been concerned with RNA viruses.The Lucké renal adenocarcinoma is a spontaneous tumor which occurs in northern leopard frogs (Rana pipiens) and has received increased attention in recent years because of its probable viral etiology. This hypothesis was first advanced by Lucké after he observed intranuclear inclusions in some of the tumor cells. Tumors with inclusions were examined at the fine structural level by Fawcett who showed that they contained immature and mature virus˗like particles.The use of this system in the study of oncogenic tumors offers several unique features, the virus has been shown to contain DNA and it can be recovered from the tumor, also, it is temperature sensitive. This latter feature is of importance because the virus can be transformed from a latent to a vegetative state by lowering or elevating the environmental temperature.

Sign in / Sign up

Export Citation Format

Share Document