Species
[edit] Zaïre ebolavirus
Known human cases and deaths during outbreaks of Zaïre Ebolavirus between 1976 and 2003
Known human cases and deaths during outbreaks of Zaïre Ebolavirus between 1976 and 2003
The Zaïre Ebolavirus has the highest mortality rate, up to 90% in some epidemics, with an average of approximately 83% mortality over 27 years. The case-fatality rates were 88% in 1976, 100% in 1977, 59% in 1994, 81% in 1995, 73% in 1996, 80% in 2001-2002 and 90% in 2003. There have been more outbreaks of Zaïre Ebolavirus than any other strain.
The first outbreak took place on August 26, 1976 in Yambuku, a town in the north of Zaïre. The first recorded case was Mabalo Lokela, a 44-year-old schoolteacher returning from a trip around the north of the state. His high fever was diagnosed as possible malaria and he was subsequently given a quinine shot. Lokela returned to the hospital every day. A week later, his symptoms included uncontrolled vomiting, bloody diarrhea, headache, dizziness, and trouble breathing. Later, he began bleeding from his nose, mouth, and anus. Lokela died on September 8, 1976, roughly 14 days after the onset of symptoms.
Soon after, more patients arrived with varying but similar symptoms including fever, headache, muscle and joint aches, fatigue, nausea, and dizziness. These often progressed to bloody diarrhea, severe vomiting, and bleeding from the nose, mouth, and anus. The initial transmission was believed to be due to reuse of the needle for Lokela’s injection without sterilization. Subsequent transmission was also due to care of the sick patients without barrier nursing and the traditional burial preparation method, which involved washing and gastrointestinal tract cleansing.
[edit] Sudan ebolavirus
Known human cases and deaths during outbreaks of Sudan Ebolavirus between 1976 and 2003
Known human cases and deaths during outbreaks of Sudan Ebolavirus between 1976 and 2003
Sudan Ebolavirus was the second strand of Ebola reported in 1976. It apparently originated amongst cotton factory workers in Nzara, Sudan. The first case reported was a worker exposed to a potential natural reservoir at the cotton factory. Scientists tested all animals and insects in response to this, however none tested positive for the virus. The carrier is still unknown.
A second case involved a nightclub owner in Nzara, Sudan. The local hospital, Maridi, tested and attempted to treat the patient; however, nothing was successful, and he died. The nurses did not apply safe and practical procedures in sterilizing and disinfecting the medical tools used on the nightclub owner, facilitating the spread of the virus in the hospital.
The most recent outbreak of Sudan Ebolavirus occurred in May 2004. As of May 2004, 20 cases of Sudan Ebolavirus were reported in Yambio County, Sudan, with 5 deaths resulting. The Centers for Disease Control and Prevention confirmed the virus a few days later. The neighbouring countries of Uganda and the Democratic Republic of Congo have increased surveillance in bordering areas, and other similar measures have been taken to control the outbreak. The average fatality rates for Sudan Ebolavirus were 53% in 1976, 68% in 1979, and 53% in 2000/2001. The average case-fatality rate is 53.76%.
[edit] Reston ebolavirus
Main article: Ebola Reston
First discovered in November of 1989 in a group of 100 Crab-eating monkeys (Macaca fascicularis) imported from the Philippines to Reston, Virginia. A parallel infected shipment was also sent to Philadelphia. This strain was highly lethal in monkeys, but did not cause any fatalities in humans. Six of the Reston primate handlers tested positive for the virus, two due to previous exposure.
Further Reston Ebolavirus infected monkeys were shipped again to Reston, and Alice, Texas in February of 1990. More Reston Ebolavirus infected monkeys were discovered in 1992 in Siena, Italy and in Texas again in March 1996. A high rate of co-infection with Simian Hemorrhagic Fever (SHF) was present in all infected monkeys. No human illness has resulted from these two outbreaks.
[edit] Ivory Coast ebolavirus
This species of Ebola was first discovered amongst chimpanzees of the Tai Forest in Côte d’Ivoire, Africa. On November 1, 1994, the corpses of two chimpanzees were found in the forest. Necropsies showed blood within the heart to be liquid and brown, no obvious marks seen on the organs, and one presented lungs filled with liquid blood. Studies of tissues taken from the chimps showed results similar to human cases during the 1976 Ebola outbreaks in Zaïre and Sudan. Later in 1994, more dead chimpanzees were discovered, with many testing positive to Ebola using molecular techniques. The source of contamination was believed to be the meat of infected Western Red Colobus monkeys, which the chimpanzees preyed upon.[3]
One of the scientists performing the necropsies on the infected chimpanzees contracted Ebola. She developed symptoms similar to dengue fever approximately a week after the necropsy and was transported to Switzerland for treatment. After two weeks she was discharged from hospital, and was fully recovered six weeks after the infection.
[edit] Zaïre ebolavirus
Known human cases and deaths during outbreaks of Zaïre Ebolavirus between 1976 and 2003
Known human cases and deaths during outbreaks of Zaïre Ebolavirus between 1976 and 2003
The Zaïre Ebolavirus has the highest mortality rate, up to 90% in some epidemics, with an average of approximately 83% mortality over 27 years. The case-fatality rates were 88% in 1976, 100% in 1977, 59% in 1994, 81% in 1995, 73% in 1996, 80% in 2001-2002 and 90% in 2003. There have been more outbreaks of Zaïre Ebolavirus than any other strain.
The first outbreak took place on August 26, 1976 in Yambuku, a town in the north of Zaïre. The first recorded case was Mabalo Lokela, a 44-year-old schoolteacher returning from a trip around the north of the state. His high fever was diagnosed as possible malaria and he was subsequently given a quinine shot. Lokela returned to the hospital every day. A week later, his symptoms included uncontrolled vomiting, bloody diarrhea, headache, dizziness, and trouble breathing. Later, he began bleeding from his nose, mouth, and anus. Lokela died on September 8, 1976, roughly 14 days after the onset of symptoms.
Soon after, more patients arrived with varying but similar symptoms including fever, headache, muscle and joint aches, fatigue, nausea, and dizziness. These often progressed to bloody diarrhea, severe vomiting, and bleeding from the nose, mouth, and anus. The initial transmission was believed to be due to reuse of the needle for Lokela’s injection without sterilization. Subsequent transmission was also due to care of the sick patients without barrier nursing and the traditional burial preparation method, which involved washing and gastrointestinal tract cleansing.
[edit] Sudan ebolavirus
Known human cases and deaths during outbreaks of Sudan Ebolavirus between 1976 and 2003
Known human cases and deaths during outbreaks of Sudan Ebolavirus between 1976 and 2003
Sudan Ebolavirus was the second strand of Ebola reported in 1976. It apparently originated amongst cotton factory workers in Nzara, Sudan. The first case reported was a worker exposed to a potential natural reservoir at the cotton factory. Scientists tested all animals and insects in response to this, however none tested positive for the virus. The carrier is still unknown.
A second case involved a nightclub owner in Nzara, Sudan. The local hospital, Maridi, tested and attempted to treat the patient; however, nothing was successful, and he died. The nurses did not apply safe and practical procedures in sterilizing and disinfecting the medical tools used on the nightclub owner, facilitating the spread of the virus in the hospital.
The most recent outbreak of Sudan Ebolavirus occurred in May 2004. As of May 2004, 20 cases of Sudan Ebolavirus were reported in Yambio County, Sudan, with 5 deaths resulting. The Centers for Disease Control and Prevention confirmed the virus a few days later. The neighbouring countries of Uganda and the Democratic Republic of Congo have increased surveillance in bordering areas, and other similar measures have been taken to control the outbreak. The average fatality rates for Sudan Ebolavirus were 53% in 1976, 68% in 1979, and 53% in 2000/2001. The average case-fatality rate is 53.76%.
[edit] Reston ebolavirus
Main article: Ebola Reston
First discovered in November of 1989 in a group of 100 Crab-eating monkeys (Macaca fascicularis) imported from the Philippines to Reston, Virginia. A parallel infected shipment was also sent to Philadelphia. This strain was highly lethal in monkeys, but did not cause any fatalities in humans. Six of the Reston primate handlers tested positive for the virus, two due to previous exposure.
Further Reston Ebolavirus infected monkeys were shipped again to Reston, and Alice, Texas in February of 1990. More Reston Ebolavirus infected monkeys were discovered in 1992 in Siena, Italy and in Texas again in March 1996. A high rate of co-infection with Simian Hemorrhagic Fever (SHF) was present in all infected monkeys. No human illness has resulted from these two outbreaks.
[edit] Ivory Coast ebolavirus
This species of Ebola was first discovered amongst chimpanzees of the Tai Forest in Côte d’Ivoire, Africa. On November 1, 1994, the corpses of two chimpanzees were found in the forest. Necropsies showed blood within the heart to be liquid and brown, no obvious marks seen on the organs, and one presented lungs filled with liquid blood. Studies of tissues taken from the chimps showed results similar to human cases during the 1976 Ebola outbreaks in Zaïre and Sudan. Later in 1994, more dead chimpanzees were discovered, with many testing positive to Ebola using molecular techniques. The source of contamination was believed to be the meat of infected Western Red Colobus monkeys, which the chimpanzees preyed upon.[3]
One of the scientists performing the necropsies on the infected chimpanzees contracted Ebola. She developed symptoms similar to dengue fever approximately a week after the necropsy and was transported to Switzerland for treatment. After two weeks she was discharged from hospital, and was fully recovered six weeks after the infection.
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