Ebola United States

 several cases of Ebola were diagnosed in the United States, due to infected african refugees and travelers from West Africa that had unknowingly harbored and incubated Ebola while en-route to the United States .

By the time a person infected with Ebola virus becomes symptomatic, they are typically starting to shed Ebola  . During an Ebola outbreak, airport workers, passengers,  are often the first to respond and provide care. In this role, they are at a high risk of becoming infected with Ebola as well. Therefore, it is important to understand how we can best prevent Ebola transmission in both clinical and home settings.

Human to human transmission of the Ebola virus occurs primarily through direct contact and exposure to the blood or other bodily fluids of infected patients. However, there have been new infections that occurred without documented contact between a patient and health care provider or family member. While these cases are uncommon, it is possible that a small fraction of the cases of Ebola virus infection may be the result of exposure to small droplets or aerosols containing the virus.

Laboratory studies have shown that the Ebola virus can remain infectious outside of the body for long periods of time. The virus can survive in blood samples on various surfaces for several days, even in hot and humid conditions that would typically kill most other viruses and bacteria. In an aerosolized form, the Ebola virus can survive for over an hour. Additionally, laboratory experiments have demonstrated that inhaling small amounts of Ebola virus can be fatal [1], and there are examples of Ebola virus disease being transmitted between individuals in close proximity, even though they had never been in direct contact with each other [2].

However, assessing the risk of transmission via droplets or aerosols is a complicated process. While the minimum amount of virus required to cause infection is thought to be very low, so far it has not been possible to determine a definitive value. This is because commonly used testing methods are often not sensitive enough to detect or measure the amount of infectious virus in the air. To address these challenges, researchers at the Department of Homeland Security (DHS) Science and Technology Directorate’s (S&T) National Biodefense Analysis and Countermeasures Center (NBACC) designed and conducted a study to optimize methods for collecting and measuring very small amounts of Ebola virus in the air. 

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