The Hot Zone: The Terrifying True Story of the Origins of the Ebola Virus

Some critics in 1994 accused Preston of being alarmist and of making too much of the dangers of the Reston event in particular and filoviruses in general, but the Ebola virus’s subsequent behavior bears him out. The West African Ebola outbreak of 2014, which infected more than 28,000 people and resulted in 11,000 deaths, highlights the true potential of these viruses to cause widespread disease, including in urban areas (see Centers for Disease Control, “Ebola: Outbreak History." 2023). The Hot Zone raised awareness of this possibility in the public mind 20 years before it arrived.

The medical science of the identification and treatment of filoviruses has advanced since 1994, including the development (using samples of Nurse Mayinga’s virus) of a vaccine effective against Ebola Zaire. Monoclonal antibody treatments are also used when available, and early supportive care including intravenous rehydration can improve survival rates even in their absence. Fatality rates in Ebola outbreaks can still vary from 25-90% depending upon the local circumstances and medical response, meaning that health justice and the relationship of healthcare providers to the communities they serve are crucial. The Hot Zone does make some claims that have not been borne out by subsequent science. Preston argues in favor of the theory that Ebola can in some circumstances be transmitted through the air, but this has not been shown to occur. Meanwhile, the apparent airborne spread of the Reston virus may be explained by the aerosolizing of bodily fluids that can occur when a monkey house worker pressure washes cages, a factor that Preston does not take into account.

The Hot Zone dramatizes the search for the natural animal reservoir of the Ebola virus, beginning with the Kitum Cave expedition of 1988 and closing with Preston’s own visit to the cave. Working during the 2001 and 2003 Ebola outbreaks in Gabon and the Republic of the Congo, a team of researchers led by Eric M. Leroy at Centre International de Recherches Médicales de Franceville in Gabon trapped and examined more than 1000 small mammals, seeking to find the elusive natural host of the virus. They found symptomless Ebola in three species of fruit bats and published their findings in Nature in 2005 (Leroy et. al., “Fruit Bats as Reservoirs of Ebola virus,” Nature, 30 November 2005). While fruit bats are now identified as the natural reservoir of Ebola, it is worth noting that humans can be infected by secondary animal hosts including primates, forest antelope, and porcupines.