Middle East Respiratory Syndrome (MERS)

When we hear the word virus, we usually think of something that makes us sick. A virus is an ultramicroscopic infectious organism that, having no independent metabolic activity, can replicate only within a cell of another host organism. A virus consists of a core of nucleic acid, either RNA or DNA, surrounded by a coating of antigenic protein and sometimes a lipid layer surrounds it as well. The viral genome provides the genetic code for replication, and the host cell provides the necessary energy and raw materials. To fight viruses, we use vaccines. While some may infect a broad range, other viruses can only infect certain kinds of cells. Vaccines are made of inactive, dead or weakened virus cells or protein antigens that can no longer infect

Viruses are microscopic particles that invade and take over both eukaryotic and prokaryotic cells. They consist of two structures, which are the nucleic acid and capsid. The nucleic acid contains all genetic material in the form of DNA or RNA, and is enclosed in the capsid, which is the protein coating that helps the virus attach to and penetrate the host cell. In some cases, certain viruses have a membrane surrounding the capsid, called an envelope. This structure allows viruses to become more stealthy and protected. There are two cycles in which a virus can go into: lytic and lysogenic. The lytic cycle consists of the virus attaching to a cell, injecting its DNA, and creating more viruses, which proceed to destroy the host. On the other hand, the lysogenic cycle includes the virus attaching to the cell, injecting its DNA, which combines with the cell’s DNA in order for it to become provirus. Then, the provirus DNA may eventually switch to the lytic cycle and destroy the host.

The respiratory syncytial pathogen is a non-segmented negative -sense single stranded RNA virus that falls under the paramyxoviridae family. The virus is comprised of 10 genes the encode 11 proteins and is divided into two subtypes A and B, which further divide into multiple genotypes. Genetic studies have tried

Middle East Respiratory Syndrome (MERS) is a severe acute respiratory illness caused by the coronavirus named MERS-CoV. It is believed that the virus is found in camels and passed on to humans who are in contact or around infected animal. These camels are mainly located in Egypt, Oman, Qatar, and Saudi Arabia (WHO, 2015a). Those infected with MERS exhibit fever, cough, and shortness of breath, pneumonia, and diarrhea. Severe cases require patient to be put on mechanical ventilation or in an intensive care unit. It is also known to cause kidney failure and septic shock. The elderly, persons who are immunosuppressed, those who

In September of 2012, beginning in the country of Saudi Arabia, hospitals began seeing increased cases of a respiratory virus never before seen in humans. They named it Middle East Respiratory Syndrome, or MERS. MERS is a viral respiratory illness caused by the coronavirus. It was originally thought to have started there in Saudi Arabia. It was not until later that they were able to trace the origin back to Jordan starting in April of 2012. All outbreaks of MERS have been traced back to originating from the Arabian Peninsula (CDC, 2015a). Unfortunately, it is not known exactly how MERS was contracted in humans, but it is believed to have come from an animal source, probably from camels. Strains of MERS

RSV is the most common cause of LRTI’s leading to morbidity and mortality in children across the world. Most children have acquired an RSV infection by the time they reach 2 years of age. It is typical to see these infections during the winter/early spring seasons in temperate regions, and during the rainy seasons in tropical areas. This is likely due to the increase of indoor crowding related to weather. The transmission of RSV requires close contact by either a large particle aerosol, or by contamination of hands followed by an inoculation into the eye or nose. Secondary infections are seen in in family contacts of an individual with a primary case due to their close contact.

Unlike bacteria, that have everything it needs to reproduce, viruses need to use a living cell's organelles in order to replicate.

SARS is a respiratory infection caused by the coronavirus that was thought to have originated in Guangdong China but was not reported until

The virus fuses with the cell’s plasma membrane. The capsid proteins are removed, releasing the viral proteins and RNA. Reverse transcriptase catalyzes the synthesis of a DNA strand complementary to the viral RNA. Reverse transcriptase catalyzes the synthesis of a second DNA strand complementary to the first. The double-stranded DNA is incorporated as a provirus into the cell’s DNA. Proviral genes are transcribed into RNA molecules, which serve as genomes for the next viral generation and as mRNAs for translation into viral proteins. The viral proteins include capsid proteins and reverse transcriptase (made in the cytosol) and envelope glycoproteins (made in the ER). Vesicles transport the glycoproteins from the ER to the cell’s plasma membrane. Capsids are assembled around viral genomes and reverse transcriptase molecules. New viruses bud off from the host cell.

SARS (Severe Acute Respiratory Syndrome) is a respiratory illness caused by a coronavirus, originally reported in Asia in February 2003 and spread to over two dozen countries before being contained (Centers for Disease Control and Prevention [CDC], 2005). Once infected, individuals with SARS initially develop a high fever and other flu-like symptoms including headache, body aches and “overall feeling of discomfort” before, in most cases, progressing to pneumonia (CDC, 2005).

Viruses can replicate themselves but only within a host cell in which they hijack as they do not own any translational machinery, so it is unable to create new RNA or DNA fragments or create a new set of virions5. In the first stages of viral replication the virus will attach itself onto a host cell via the glycoprotein spikes which eject off the capsid – this is called adorption6. The virion will then transfer its genomic material whether its RNA or DNA into the host cell via penetration of plasma membranes and this occurs through receptors binding to receptor sites and activating a chain of reactions6,7. The virus will the inject its own genomic material into the host cell which causes the host cell to use its replication techniques to replicate the foreign genome meaning its expressed by the host cell – hijacking the cell6. The genomic material that is now in the cell will be replicated as the cell is infected and will express these new characteristics of the virus instead of being able to carry out its own job. The newly produced proteins and enzymes will now mature within the host cell and group together to form new virions and viruses. After these are fully matured the enzymes produced will catalyse the cell membrane of cells and allows the newly produced viruses to be released into the extracellular environment6. This process of replication is also the way in which viruses adapt to their environments another component of being classed ‘alive’ because they

b) Fusion is another way viruses can enter the host cell, however only an enveloped virus can do so in this process. To enter the cell an enveloped virus has a structure known as the spikes, the spikes will than need to attach on the receptor cell to gain entry to the cell. capsid and chromosome are allowed entry in the cell and the spikes are left behind. 1111111

The protective capsid helps the virus escape detection and destruction during the invasion of the host. When the virus reaches the target cell, biochemical reactions between the capsid and cell wall allow the virus to latch on and inject its genome into the cell’s interior. Once inside, the viral genetic material insinuates itself into the host’s DNA or RNA. In an efficient feat of natural bioengineering, the host cell’s genetic machinery now does the rest of the work for the virus. The cell, which had already been making copies of its own genome, now also replicates that of the virus. Coded within the viral material is the blueprint for making more copies of the viral genome. Further instructions command the production of capsids and directions for assembly of new viruses. After the host cell becomes engorged with viruses, it explodes, sending the new

The MERs-CoV pathogen is an enveloped RNA virus that is a genus of the Betacoronavirus which is a subtype of the coronavirinae family.6 The coronavirus gets its name from the spikes on its surface that gives it a crown or halo type

MERS-CoV is a respiratory disease that was first found in Saudi Arabia in 2012. This virus can cause people to get diseases such as the common cold to a Severe Acute Respiratory Syndrome (SARS).