Hunting the ebola reservoir host case study

The 2014 Ebola epidemic was the largest in history, with widespread transmission in multiple West African countries. The first case was reported in Guinea in March 2014, and the disease quickly spread into the neighboring countries of Liberia and Sierra Leone. Over the span of a year, the Ebola epidemic caused more than 10 times as many cases of Ebola than the combined total of all previous Ebola outbreaks. As the outbreak spread, travel-associated cases appeared in Nigeria, Mali, Senegal, and places outside Africa, including Europe and the United States. If the virus reservoir is determined, CDC and other international health partners will be able to issue stronger guidance to local groups about the origins of Ebola virus transmission, making such a widespread outbreak less likely to occur in the future.

While the outbreak was declared over by the World Health Organization (WHO) on May 9, 2015, subsequent clusters of disease occurred in June 2015, November 2015, and April 2016.  WHO again declared Liberia Ebola-free in June 2016, but there remained a fear that new cases could emerge.  Researchers believe that Ebola virus is animal-borne (zoonotic) pathogen, and that bats are the most likely natural reservoir. However, the exact reservoir species that harbors the virus has yet to be determined. CDC’s Viral Special Pathogens Branch within the Division of High-Consequence Pathogens and Pathology is conducting studies to determine the virus host in order to develop better risk reduction measures to help prevent future outbreaks.

CDC has partnered with Njala UniversityExternal in Sierra Leone to enhance surveillance for Ebola in wildlife. The main focus is to screen various types of bats, particularly fruit bats, in the area for any signs of Ebola virus. Bats are the current subject of study as Ebola virus is a close cousin of Marburg virus, which causes a similar disease in humans and is consistently found in a specific species of African fruit bat. In total, CDC-trained, local healthcare workers have captured almost 400 fruit bats for testing at Njala University for evidence of  Ebola virus infection.

A disease threat anywhere is a disease threat everywhere, and the Ebola epidemic has shown how easily infectious diseases can cross borders—land, rivers, and even oceans. From the start of the epidemic, porous country borders among West African countries combined with a highly mobile population aided the rapid spread of Ebola virus from its outbreak origin in Guinea. In West Africa, border control measures are mostly nonexistent—getting to another country is often as simple as taking a boat across a river. This makes it easy for a disease like Ebola to spread across countries. Determining the virus reservoir will not only help answer questions about how the virus emerges, but also help local and international public health workers to be more prepared and aware of future epidemic risks.

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Team Number: __3____

Team Members: _Saleana Caraballo, Charla Ward, Brendan Boyd_

CASE STUDY: Hunting the Ebola Reservoir Host:

Part I: The Cycle Starts Again:

1.Given that the initial symptoms of Ebola are very similar to influenza,

how might Dr. Mombutubwa recognize and successfully diagnose

Ebola in his patients? How might the colleagues who assist him

during times of epidemic and who have access to more specialized

equipment be able to diagnose Ebola?

Dr. Mombutubwa might recognize and successfully diagnose Ebola in his

patients by paying closer attention to the symptoms of Ebola that are not

necessarily associated with influenza. Those symptoms would be stomach

pain, vomiting, diarrhea, bruising, and hemorrhaging. The colleagues

who assist him during times of epidemic and who have access to more

specialized equipment may be able to diagnose Ebola by taking samples

from patients and testing those samples to see if the patients have the

RNA virus in them or possess any antibodies to fight off the Ebola virus.

2.What are the possible points of contact that allow the transmission of

Ebola between villagers during the epidemic? You should be able to

list and discuss at least five factors.

There are several possible points of contact that allow the transmission of

Ebola between villagers that exist in their every day lives. One way was

through hunting. The men would go hunting and return with the dead

animal and the animal’s blood all over their clothing and hands; This,

including poor sanitation methods, could contribute to the spread of the

virus through animal body fluids. Another way was through trade; When the

men would catch an ape, they would sell the meat at the market where the

meat could infect others nearby as well as other goods and products. A third

way was through the daily work of the women. The women would get rid of

or scare away rodents, birds, and insects that found the farm crops

appealing and could likely contract the disease from coming into contact

with these organisms or even their feces. The women would then tend to

the house, prepare food, and care/look after the children. All of these

actions when involved with poor sanitation and hygiene practices can

contribute to the transmission of Ebola.

What is the reservoir host of Ebola?

What is the mode of transmission of Ebola?

What is the portal of exit for Ebola?

What is the incubation period for Ebola?