Sudan Outbreak 2004
The Lancet Infectious Diseases 2004; 4:388
DOI:10.1016/S1473-3099(04)01071-0Newsdesk
Sudan Ebola outbreak of known strain
Xavier Bosch
Between May 15 and 31, health authorities of Yambio County reported a total of 25 cases, including six deaths, of Ebola haemorrhagic fever in Yambio, in the western equatorial region of Sudan.
The WHO South Sudan Early Warning and Response Network, along with a team from WHO headquarters in Geneva, have been working closely with health authorities and partners in Yambio County to help create a crisis committee to control the outbreak. The committee includes UNICEF, Médecins sans Frontières, and other non-governmental organisations and churches working in public health. The committee has been working actively on social mobilisation, supporting case management in Yambio hospital and organising the follow-up of contacts of people who have been ill with the disease.
Initial tests of blood samples taken by the US Centers for Disease Control and Prevention (CDC; Atlanta, GA, USA) indicated that the outbreak was not linked to the known strains of Ebola viruses. Moreover, scientists at the WHO southern Sudan office initially launched a theory that the outbreak in Yambio was of an unknown Ebola strain, which they suspected was milder than other discovered strains. The main reason for this belief was that the death rate seemed to be lower than in Ebola oubreaks previously registered. Past major outbreaks of Ebola haemorrhagic fever occurred in 1976 (southern Sudan, 117 deaths of 284 people infected), 1995 (Congo, 280 deaths of 318 people infected). 2000 (northern Uganda, 173 deaths) and 2002 (Congo, 100 deaths).
Four strains of Ebola have been discovered so far. (as of 2004 Fla1) Ebola-Zaire, the first-discovered Ebola virus, is the most deadly. At its worst, it has a 90% fatality rate. There have been more outbreaks of Ebola-Zaire than any other type of Ebola virus. The first outbreak was in 1976 in Yambuku, Zaire.
In 1989, crab-eating macaques from the Philippines brought another strain, Ebola-Reston, into quarantine in Virginia, Texas, and Pennsylvania. Although four people developed antibodies from exposure to the virus, none became ill. The Ebola-Reston strain has re-emerged in monkeys several times since but no human beings have contracted it.
Another strain, Ebola-Ivory Coast, infected a scientist in 1994 after he did an autopsy on a wild chimpanzee: it is the only reported case.
Finally, Ebola- Sudan strain is also known to cause outbreaks among people. It usually strikes in east Africa and has a mortality rate of around 50% but is more contagious than Ebola-Zaire.
Click to enlarge image
Ebola virusCDC
On June 4, Abdullahi Ahmed, head of the WHO Office for Southern Sudan, told TLID that both the Kenya Medical Research Institute and CDC confirmed the virus responsible for the Yambio outbreak was the known Ebola-Sudan maleo strain.
The Lancet Infectious Diseases 2004; 4:388
DOI:10.1016/S1473-3099(04)01071-0Newsdesk
Sudan Ebola outbreak of known strain
Xavier Bosch
Between May 15 and 31, health authorities of Yambio County reported a total of 25 cases, including six deaths, of Ebola haemorrhagic fever in Yambio, in the western equatorial region of Sudan.
The WHO South Sudan Early Warning and Response Network, along with a team from WHO headquarters in Geneva, have been working closely with health authorities and partners in Yambio County to help create a crisis committee to control the outbreak. The committee includes UNICEF, Médecins sans Frontières, and other non-governmental organisations and churches working in public health. The committee has been working actively on social mobilisation, supporting case management in Yambio hospital and organising the follow-up of contacts of people who have been ill with the disease.
Initial tests of blood samples taken by the US Centers for Disease Control and Prevention (CDC; Atlanta, GA, USA) indicated that the outbreak was not linked to the known strains of Ebola viruses. Moreover, scientists at the WHO southern Sudan office initially launched a theory that the outbreak in Yambio was of an unknown Ebola strain, which they suspected was milder than other discovered strains. The main reason for this belief was that the death rate seemed to be lower than in Ebola oubreaks previously registered. Past major outbreaks of Ebola haemorrhagic fever occurred in 1976 (southern Sudan, 117 deaths of 284 people infected), 1995 (Congo, 280 deaths of 318 people infected). 2000 (northern Uganda, 173 deaths) and 2002 (Congo, 100 deaths).
Four strains of Ebola have been discovered so far. (as of 2004 Fla1) Ebola-Zaire, the first-discovered Ebola virus, is the most deadly. At its worst, it has a 90% fatality rate. There have been more outbreaks of Ebola-Zaire than any other type of Ebola virus. The first outbreak was in 1976 in Yambuku, Zaire.
In 1989, crab-eating macaques from the Philippines brought another strain, Ebola-Reston, into quarantine in Virginia, Texas, and Pennsylvania. Although four people developed antibodies from exposure to the virus, none became ill. The Ebola-Reston strain has re-emerged in monkeys several times since but no human beings have contracted it.
Another strain, Ebola-Ivory Coast, infected a scientist in 1994 after he did an autopsy on a wild chimpanzee: it is the only reported case.
Finally, Ebola- Sudan strain is also known to cause outbreaks among people. It usually strikes in east Africa and has a mortality rate of around 50% but is more contagious than Ebola-Zaire.
Click to enlarge image
Ebola virusCDC
On June 4, Abdullahi Ahmed, head of the WHO Office for Southern Sudan, told TLID that both the Kenya Medical Research Institute and CDC confirmed the virus responsible for the Yambio outbreak was the known Ebola-Sudan maleo strain.
Comment