Ebola Week 2 Assignment

Ebola Week 2 Assignment
1) Infectious Agent
a) Describe the Ebola virus, including what type of virus it is (family, DNA or RNA, envelope or not) and how many genes it has.
The Ebola virus is a highly infectious disease that has killed many worldwide. The virus is part of the Filoviridae family that is a highly infectious agent (Garcia et al., 2012). The Flioviridae family of viruses causes symptoms such as: fever, bleeding, and hypotensive shock to the host in which it enters (Garcia et al., 2012). Ebola virus is a negative RNA virus that is composed of approximately 19kb size of the genome (Garcia et al., 2012). The Flioviridae virus is enveloped and non-segmented virus (Feldmann & Geisbert, 2011). The Ebola virus has seven genes in its genome going from a 3’ to 5’ direction (Feldmann & Geisbert, 2011). This is just some of the information that researchers have found about the Ebola virus.
b) How many different forms (i.e. strains) of the Ebola virus have been discovered, and which one is the main strain killing people in West Africa right now?
Ebola has been studied, investigated and researchers have come to discover multiple strains of the Ebola virus. In 2001 researchers discovered eight different strains of the virus from animal and human outbreaks (Leroy et al., 2004). Later discovery found that between October 2001 and May 2003 eleven different strains were discovered from the outbreak (Leroy et al., 2004). Currently then we are only known to have eleven strains although the rearrangement of the nucleotides is possible to change the possible number of strains of Ebola (Leroy et al., 2004). The Zaire strain of Ebola is what is killing the people in West Africa right now, originating from central Africa (Leroy et al., 2004).
2) Reservoir
a) The reservoir is usually considered the natural environment of the pathogen. Humans, monkeys, and gorillas are actually not considered the reservoir, but instead they are considered “dead-end” hosts. Why do you think humans and non-human primates are NOT the natural reservoir for the virus? Think about the history and previous outbreaks in other parts of Africa. I think that humans and non-human primates are not the natural reservoir for a virus because it is not where it usually originates. For a human to get a virus it must always be transmitted to them. An example is through malaria that is transmitted through Africa. Despite the fact that the malaria virus was discovered in humans it originated from mosquitoes (Kappe, Vaughan, Boddey & Cowman, 2010). As well the mosquitoes transmitted the virus in the beginning to humans and animals through “bitting” (Kappe, Vaughan, Boddey & Cowman, 2010). Since the virus must always be transmitted to humans or animals in some way this is why I believe that humans and non-human primates are not natural reservoirs.
b) What animal species is thought to be the natural reservoir? What kind of evidence supports the theory (cite your sources).
The species that is the natural reservoir has not been yet discovered. The hypothesized natural reservoir for the Ebola virus is believed to be rodents and bats (Feldmann & Geisbert, 2011). It is believed that it is the natural reservoir in bats because of a specific fruit in Africa that has the Zaire virus and the fruit bats eating said fruit (Feldmann & Geisbert, 2011). As well the first set of the Zaire Ebola virus was discovered in bats, through the viral RNA and antibodies in tree bats (Feldmann & Geisbert, 2011). This can not be confirmed yet due to the lack of report of the Ebola virus in Africa (Feldmann & Geisbert, 2011).
c) What does the term zoonosis mean? What genetic mechanism (we talked about this in lecture) allows a zoonosis to occur? The term zoonosis means an infectious disease that is transmitted from animal to human (Cdc.gov, 2014). The genetic mechanisms that allows a zoonosis to occur are: