Ebola Virus: Possible Origin, Transmission, and Future Vaccine - Research Paper Example

Some of the outbreaks are the 2002-2003 outbreak in the Democratic Republic of the Congo and the 1989 outbreak in Philippines (King and Cunha, Medscape). It has also caused several outbreaks in Sudan, England, Uganda, Gabon, South Africa, Liberia, Virginia, Texas, Pennysylvania, Italy and Alice. Another virus of the same family, the Marburg virus has caused outbreaks in Germany. There are 5 different subtypes or species of Ebola virus and they are Zaire ebolavirus (ZEV), Sudanebolavirus (SEV), Restonebolavirus (REV), Ivory Coast ebolavirus (CIEV), and Bundibugyo ebolavirus (BEV) (Gonzalez, 363).

Structure All Filoviruses have a characteristic form that is filamentous with a 80nm uniform diameter. The length however is variable. The filaments are basically staight, but folded. The genome of Ebola virus is RNA, negative stranded and non-segmented. It has 7 regulatory and structural genes. The genome codes for 4 structural proteins and 3 membrane proteins (Gonzalez, 363). Pathogenesis After infection with Ebola virus, rapid multiplication of the virus occurs in the early phase. In some individuals, the immunological response is poor and leads to mortality.

One of the surface protein, the sGP binds to the neutrophils and causes inhibition of early neutrophil activation. The sGP also leads to profound lymphopenia which is very common in Ebola infection. Thus, effective early host immune response is prevented (Takada, 258). Epidemiology Ebola infection is not an endemic disease in the United States. However, several animal care workers has acquired the Restron stain of the virus within the country. This strain does not have pathogenic effects among human beings.

sub-Saharan Africa is endemic to the virus. The most lethal subtype is the Zaire subtype with mortality rate of as high as 89 percent. Sudan subtype has mortality rates of 41-65 percent. There is no sex or racial predilection with the disease (King and Cunha, Medscape). Natural reservoir The actual natural reservoir of Ebola is unknown. Some experts are of the opinion that bats are natural reservoir. The natural reservoirs seem to reside in the tropical forests of Africa which are rainy. Western pacific forests are also considered as natural reservoir sources.

Non-human primates are the most common source of infection to human beings. They however are not considered to be natural reservoir. They get infected from the natural reservoirs. Primates which transmit the infection to human beings are monkeys, chimpanzees, duikers and gorillas. Infact, for each epidemic, a particular primate has been identified, like for example, duikers for the Republic of Congo (WHO, 2008). Clinical presentation There are 2 types of exposure to the virus and they are primary and secondary.

Primary exposure occurs when an individual has traveled to an area endemic to Ebola infection. Bats are considered to be natural reservoirs and travel to African tropical forests is also considered as primary exposure. Secondary exposure occurs when there is primate to human exposure or human-to-human exposure. During outbreaks health care workers and individuals who cared for the infected patients are at risk of secondary exposure. Even animal care workers fall under this category (King and Cunha, Medscape).

Clinical presentation Clinical features depend on the stage of the disease. In the early phases of the