What difference does an RNA genetic material make?
A. Oveta Fuller to discuss #Ebola! Keep reading for a part of their interview of Dr. Fuller. Note: if you wish to respond to a question listed here during the twitter chat, use an “A1, A2, A3, …” format so that we know which question you are responding to.
A. Oveta Fuller, PhD is an Associate Professor in the Department of Microbiology Immunology at the University of Michigan. Dr. Fuller’s work focuses on human virus entry, pathogenesis, and infection preventions. interviewed Dr. Fuller about the Ebola Virus Disease.
Q1: What is the origin of the Ebola virus? First discovered in Zaire (now Democratic Republic of the Congo) in 1976 and determined as a new virus check this site.
Q2: How did the current outbreak start? Patient 0 was a 2 year old in Guinea who died on followed by his mother, sister and grandmother in a region close to the boundaries of Guinea, Sierra Leone and Liberia. It was not identified then as Ebola virus. Note that the child’s caregivers are females who fit typically care provided for a sick household member. This trend is frequent for spread of Ebola.
Can follow timeline for the
Q3: How does lack of public works infrastructure, i.e. sewage treatment, potable water, etc increase the spread of infection? The major lack of infrastructure affects health care in facilities and in homes. Conditions mentioned also contribute to more contact between people, body fluids and items touched (fomites). People who are sick with diarrhea, vomiting, bleeding shed fluids full of virus. Virus is highly infectious- contact with a small amount of fluid that has many viruses can infect a new person. Also lack of electricity in many places contributes to spread of infection.
Q4: How does Ebola compare to other viruses in terms of its structure and genome? Ebola is an RNA virus with a complex structure. Other viruses with RNA genetic material are influenza, SARS, the common cold virus, HIV, measles, mumps, West Nile virus, Dengue fever virus, respiratory syncytia virus, hepatitis A virus. RNA is less genetically stable than DNA. Mutations that naturally occur as mistakes in virus replication are not corrected. Human cells have no means for correction of mistakes for RNA as they do for DNA. A change can be amplified into many such viruses. If the mutation has a replicative advantage it brings about a virus that is slightly different than what the immune system may have been primed to attack. Variation occurs faster and is higher in a population of RNA viruses.
Q5: How does Ebola infect host cells? Virus in fluids or on objects touched by those fluids enters into host cells and circulates in the body as it reproduces itself to high numbers. It can reproduce in many different types of cells for a broad tropism in human and animal hosts. What determines cell tropism of a virus? For most viruses, tropism is determined by a cellular molecule at the service or an enzyme that is needed for virus replication. Because Ebola is so deadly, it has to be studied in a Biosafety Level 4 facility. Thus, only a few laboratory investigators have studied it at the molecular biology level. This is also why there are few vaccines or anti-virals that have been developed for Ebola virus.
Q6: How does this compare contrast to other common viruses, e.g., HIV, HSV, influenza and rhino virus, etc.? They are similar and different in several important ways. All except HSV, have RNA genetic material that affects stability and effectiveness of vaccines or anti-virals. Some of these are respiratory transmitted (influenza, rhinovirus) different than Ebola, HSV and HIV that require direct contact. HSV (all herpesviruses like chickenpox, Epstein Barr virus, genital herpes, infectious mono virus) is a DNA virus that can remain dormant long-term in cells. In contrast, Ebola, influenza and rhinovirus are acute viruses. They get into host, replicate and eventually move on to another host as the immune system suppresses their reproduction in an infected host. They cannot remain stored (latent) or hidden away in the host like HIV or HSV.
