By Glynn Cosker
Editor, In Homeland Security
The current Ebola virus outbreak is the worst on record, devastating sections of West Africa at an alarming rate and affecting other countries including the U.S. and Spain. How much do we know about the history of this contagious deadly virus?
There are actually five strains of the virus: Ebola virus (EBOV, formerly Zaire virus);Tai Forest virus (TAFV); Bundibugyo virus (BDBV); Sudan virus (SUDV); and Reston virus (RESTV). They are all named after the areas where cases or outbreaks first occurred. Reston virus (named for a town in Fairfax County, Virginia), is the only strain not found to cause disease in humans—although it has a high mortality rate in primates. In 1989, dozens of imported monkeys at a quarantine facility in Reston died. Four workers developed antibodies but never showed any symptoms.
The very first outbreak of the disease occurred in 1976 in Nzara, South Sudan (part of Sudan at the time). Patient zero was believed to be a cotton factory storekeeper who became ill June 27, 1976 and died a week later. Scientists believe that this victim—and other early victims—contracted the disease through direct or indirect contact with fruit bats, which are natural reservoirs of the Ebola virus. There were 284 cases of the disease with 151 deaths—mostly medical personnel who were caring for patients with the then unnamed virus. Scientists now know that this particular strain was SUDV.
In late August 1976, a second outbreak occurred in Yambuku, Zaire (now the Democratic Republic of Congo). This time, the first person infected was a school principal who had recently visited the Ebola River near Zaire’s border with the Central African Republic. Scientists now know that this strain was EBOV. The highly contagious new disease was named “Ebola virus” after the Ebola River. The subsequent outbreak in Zaire lasted three months and killed 280 of the 318 people infected.
Since 1976, seven more outbreaks with at least 100 cases occurred:
- 1995: EBOV outbreak killed 254 people the Democratic Republic of Congo
- 2000-2001: SUDV outbreak killed 224 people in Uganda
- 2001-2002: EBOV killed 96 people near the border of Gabon and the Republic of Congo
- 2002-2003: EBOV killed 128 people in the Republic of Congo
- 2007: EBOV killed 187 people in the Democratic Republic of Congo
- 2007-2008: BDBV killed 37 people in Uganda
- 2013-2014: The current outbreak of EBOV in Guinea, Liberia, Nigeria, Senegal, and Sierra Leone is by far the most severe with 4,493 deaths as of Oct. 16, 2014.
Except for the current outbreak, each widespread occurrence of the disease was contained with the assistance of The World Health Organization (WHO) by quarantining patients, sterilizing all medical equipment, and ensuring protective clothing for all health care workers. That worked because of the compact areas infected and because officials and medical personnel were dealing with a few hundred cases.
The current outbreak is ominously different. It involves a much bigger infectious area and has the added problem of infected people leaving one area for another or—in the case of Thomas Eric Duncan—embarking on international travel.
WHO predicted Oct. 14 that cases in the current outbreak could skyrocket to 10,000 per week by December. Containment is key to controlling the disease. Without it, the history of the disease might include a global outbreak one day—an extremely frightening scenario.
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