Question

Create a table of the following Cardiovascular and Systemic Diseases:

7) Dengue fever

8) Infectious Mononucleosis

9) Ebola

10) Lyme disease

11) Cytomegalovirus Disease

Create columns as shown below:

Name of Disease	Causative Agent(s)	Common Mode of Transmission	Pathogenesis and Virulence factors	Epidemiology	Prevention and Treatment

Answer 1

Dengue fever
Causative Agent(s): Mosquito borne flavi-ribo virus

Common Mode of Transmission: through vectors i.e, bite of Aedes aegypti (mosquito)

Pathogenesis and Virulence factors: Dengue virus has 4 serotypes. the 4 serotypes exhibit homology of their surface antigens. In the primary infection when virus enters the body, the immune cells produce antibodies agaisnt the surface antigens and inactivate the virus. During the secondary infection if different serotype of the virus attacks, our immune system attacks in the same way as it did to the first serotype. Due to slight difference in the surface antigens, the viruses do not get inactivated causing severe infection. In addition, the dengue viruses have M proteins that cause apoptosis of their target cell.

Epidemiology: About 2.5 billion people, or 40% of the world’s population, live in areas where there is a risk of dengue transmission. Dengue is endemic in at least 100 countries in Asia, the Pacific, the Americas, Africa, and the Caribbean. The World Health Organization (WHO) estimates that 50 to 100 million infections occur yearly, and is observed mostly among children.

Prevention and Treatment: No vaccine, Mosquitoes and their eggs should be eliminated; Treatment includes bed rest, pushing fluids, and taking an over-the-counter antipyretic, such as Tylenol, for the fever and avoid taking any Aspirin.

Infectious Mononucleosis

Epstein–Barr virus (EBV)

Can spread by saliva, through contaminated items, such as drinking glasses or toothbrushes

The main virulence factor of EBV is its ability to remain latent for years. It replicates and survives in host B cells and evades the immune response. Even if a response is mounted, the virus is never truly eliminated because it injects its DNA into the host cell nucleus.

Occurs worldwide among humans and usually occurs as a subclinical infection in early childhood; Most commonly seen in young adults 15–25 years of age; About 70% of persons in the U.S. are infected with EBV by 30 years of age;The virus is not very contagious, thus takes several exposures to EBV from an infected person to acquire EBV

No vaccines yet, bed rest and analgesics is the primary form of treatment for acute infectious mononucleosis.

Ebola

virus of the family Filoviridae

through close and direct physical contact with infected bodily fluids, the most infectious being blood, faeces and vomit.

There are three to four proteins that exist in association of the envelop and are responsible for the pathogenicity. VP35 and the GP are the major contributors to the onset of disease. Virulence factors reduce the impact of the host immune system. VP24 and VP35 prevent the action of Type I and III interferons. Glycoproteins play a dual role in acting as virulence factors. They both act as decoys to prevent circulating antibodies from performing their functions on virally infected cells and they replace the normal glycoproteins on the surface of the cell. This means that it is harder for ther normal cells, such as those of the immune system, to recognise the infected cell.

The first appearance of Ebola occurred in Sudan and the Democratic Republic of the Congo in 1976. The DRC experienced a mortality rate of 88% while the Sudanese outbreak only had a 53% mortality rate. Sudan experienced a small outbreak in 1979, but for nearly 15 years, no outbreaks of the virus were recorded. However, in 1994 Ebola re-emerged from its unknown dormancy by killing 59% of infected individuals in Gabon. This year marked the start of 3 years of outbreaks. From 1994 to 1996, DRC and Gabon experienced 4 outbreaks with mortality rates ranging from 80%-60%.
The recurrence of outbreaks came back to Africa in 2000. Since the 2000 outbreak of Ebola in Uganda, an outbreak has occurred every year with similar mortality rates of the previous outbreaks. At the start of November, 2003, a developing outbreak of Ebola has been witnessed in Cuvette Oust region of DRC."

vaccines and antivirals are not available, supportive treatment includes replacement of fluids, electrolytes, constant monitoring of blood pressure and oxygen levels, nutrition and comfort.

Lyme disease

bacterium Borrelia burgdorferi

bite of infected blacklegged ticks

Virulence factors of Lyme disease have yet to be proven. It has been proposed, however, that Borrelia burgdorferi experience antigenic variation so that they can avoid permission by the host

Lyme disease is the most common vector-borne illness in the world. Most outbreaks of this disease in the United States occur in the Northeast, usually from Maine to Virginia. Outbreaks have occurred in other states such as Wisconsin, Minnesota, California, and Oregon. Nearly 30,000 cases were confirmed in 2008 in the United States with 60,000 cases occurring worldwide. The most commonly affected age group is 5 to 9 years old.

can be treated successfully with a few weeks of antibiotics;Prevention: using insect repellent, removing ticks promptly, applying pesticides, and reducing tick habitat

Cytomegalovirus Disease

Cytomegalovirus

spread through body fluids including blood, urine, saliva, breast milk, tears, semen and vaginal fluids.

Little is known of the mechanisms underlying the pathogenicity of the virus. Many viral genes are non-essential for replication in vitro which are thus assumed to be important in the pathogenesis of the virus. CMV is physically associated with host ß2 microglobulin, which might have a protective effect against host immunoglobulins.

CMV is transmitted to the neonate transplacentally, by passage through a contaminated birth canal, or by ingestion of infected breast milk; to the adult by heterosexual and homosexual sex with an infected partner; and to the transplant recipient by infected organs. A major unsolved problem in the study of CMV is the nature of viral latency. Knowledge regarding the requirements for activation of latent infection at the molecular, cellular, or host level is incomplete.

Valganciclovir is used for the prevention and treatment of cytomegalovirus disease in immunocompromised hosts