Ebola virus haemorrhagic fever outbreak – a man-made epidemic?
The first Ebola virus haemorrhaghic fever cases occurred in Zaire in 1976. According to Anonymous (1978. Report of an International Commission: Bull of WHO (56(2): 271-203), “Between 1 September and 24 October 1976, 318 cases of acute haemorrhagic fever occurred in northern Zaire. The outbreak was centred in the one of the Equateur Region and most of the cases were recorded within a radius of 70 km of Yambuku, although a few patients sought medical attention in Bumba, Abumombazi, and the capital city of Kinshasa, where individual secondary and tertiary cases occurred. There were 280 deaths, and only 38 serologically confirmed survivors.
The index case in this outbreak had onset of symptoms on 1 September 1976, five days after receiving an injection of chloroqine for presumptive malaria at the outpatient clinic at Yambuka Mission Hospital (YMH)., He had a clinical remission of his malaria symptoms. Within one week several other persons who had received injections at YMH also suffered from Ebola haemorrhagic fever, and almost all subsequent cases had either received injections at the hospital or had had close contact with another case. Most of these occurred during the first four weeks of the epidemic, after which time the hospital was closed, 11 of the 17 staff members having died of the disease. All, ages and sexes were affected, but women 15 – 29 years of age had the highest incidence of disease, a phenomenon strongly related to the attendance at prenatal and outpatients clinics at the hospital where they received injections. The overall secondary attack rate was about 5%, although it ranged to 20% among close relatives such as spouses, parent or child, and brother and sister.”
There was an interesting reference there as follows “thus it was regarded as quite possible that an infected person had travelled from Sudan to Yambuku and transferred the virus to a needle of the hospital while receiving an injection at the outpatient clinic.” I am particularly in singular tense when referring to a “an injection at the outpatient clinic”. That indicates to me that the hospital very likely used the same (unsterile) needle on many subsequent consecutive patients. Indeed, Baron et al. (1983. Ebola virus disease in southern Sudan: hospital dissemination and intrafamilial spread. Bull of WHO; 61(6): 997-1003) wrote “…while the use of unsterile needles was implicated as a mode of transmission in the Zaire hospital…”).
[The dangerous practice of using unsafe non-disposable unsterile injections in the developing world has been widely researched and publicised in medical journals to this day (Luby et al. 1997. The relationship between therapeutic injections and high prevalence of hepatitis C infection in Hafizabad, Pakistan. Epidemiol Infect; 119: 349-356; Simonsen et al. 1999. Bull WHO; 77 (10): 789-800; Hutin et al. 2003. Use of injections in healthcare settings worldwide, 2000. Literature review and regional estimates. BMJ; 327 (9 November): 1-5)].
Going back to Bull of WHO (1978, as above), “Both the incubation period, and the duration of clinical disease averaged about one week. After 3-4 days of non-specific symptoms and signs, patients typically experienced progressively severe sore throat, developed a maculopapular rash, had an intractable abdominal pain, and began to bleed from multiple sites, principally the gastrointestinal tract. Athough laboratory determinations were limited and not conclusive, it was concluded that pathogenesis of the diseases included non-icteric hepatitis and possibly pancreatitis as well as disseminated intravascular coagulation.”
And, “This syndrome was caused by a virus similar to Marburg virus, but immunologically distinct.. It was named Ebola virus. The agent was isolated from the blood of 8 of 10 suspected cases using vero cell cultures…Ebola virus particles were found in formalin-fixed liver specimens from three cases”.
Importantly, “Virus transmission was interrupted by stopping injections and isolation of patients in their villages. Use of protective clothing and respirators, strict isolation of patients, and careful disposal of potentially contaminated excreta and fomites will almost certainly prevent future major outbreaks. The virus is probably rarely transmitted by infectious aerosols, although infection via large droplets remains a possibility.”
In conclusion, the likelihood of Ebola transmission via unsterile injections is a definite possibility.
Rapid Response:
Ebola virus haemorrhagic fever outbreak – a man-made epidemic?
The first Ebola virus haemorrhaghic fever cases occurred in Zaire in 1976. According to Anonymous (1978. Report of an International Commission: Bull of WHO (56(2): 271-203), “Between 1 September and 24 October 1976, 318 cases of acute haemorrhagic fever occurred in northern Zaire. The outbreak was centred in the one of the Equateur Region and most of the cases were recorded within a radius of 70 km of Yambuku, although a few patients sought medical attention in Bumba, Abumombazi, and the capital city of Kinshasa, where individual secondary and tertiary cases occurred. There were 280 deaths, and only 38 serologically confirmed survivors.
The index case in this outbreak had onset of symptoms on 1 September 1976, five days after receiving an injection of chloroqine for presumptive malaria at the outpatient clinic at Yambuka Mission Hospital (YMH)., He had a clinical remission of his malaria symptoms. Within one week several other persons who had received injections at YMH also suffered from Ebola haemorrhagic fever, and almost all subsequent cases had either received injections at the hospital or had had close contact with another case. Most of these occurred during the first four weeks of the epidemic, after which time the hospital was closed, 11 of the 17 staff members having died of the disease. All, ages and sexes were affected, but women 15 – 29 years of age had the highest incidence of disease, a phenomenon strongly related to the attendance at prenatal and outpatients clinics at the hospital where they received injections. The overall secondary attack rate was about 5%, although it ranged to 20% among close relatives such as spouses, parent or child, and brother and sister.”
There was an interesting reference there as follows “thus it was regarded as quite possible that an infected person had travelled from Sudan to Yambuku and transferred the virus to a needle of the hospital while receiving an injection at the outpatient clinic.” I am particularly in singular tense when referring to a “an injection at the outpatient clinic”. That indicates to me that the hospital very likely used the same (unsterile) needle on many subsequent consecutive patients. Indeed, Baron et al. (1983. Ebola virus disease in southern Sudan: hospital dissemination and intrafamilial spread. Bull of WHO; 61(6): 997-1003) wrote “…while the use of unsterile needles was implicated as a mode of transmission in the Zaire hospital…”).
[The dangerous practice of using unsafe non-disposable unsterile injections in the developing world has been widely researched and publicised in medical journals to this day (Luby et al. 1997. The relationship between therapeutic injections and high prevalence of hepatitis C infection in Hafizabad, Pakistan. Epidemiol Infect; 119: 349-356; Simonsen et al. 1999. Bull WHO; 77 (10): 789-800; Hutin et al. 2003. Use of injections in healthcare settings worldwide, 2000. Literature review and regional estimates. BMJ; 327 (9 November): 1-5)].
Going back to Bull of WHO (1978, as above), “Both the incubation period, and the duration of clinical disease averaged about one week. After 3-4 days of non-specific symptoms and signs, patients typically experienced progressively severe sore throat, developed a maculopapular rash, had an intractable abdominal pain, and began to bleed from multiple sites, principally the gastrointestinal tract. Athough laboratory determinations were limited and not conclusive, it was concluded that pathogenesis of the diseases included non-icteric hepatitis and possibly pancreatitis as well as disseminated intravascular coagulation.”
And, “This syndrome was caused by a virus similar to Marburg virus, but immunologically distinct.. It was named Ebola virus. The agent was isolated from the blood of 8 of 10 suspected cases using vero cell cultures…Ebola virus particles were found in formalin-fixed liver specimens from three cases”.
Importantly, “Virus transmission was interrupted by stopping injections and isolation of patients in their villages. Use of protective clothing and respirators, strict isolation of patients, and careful disposal of potentially contaminated excreta and fomites will almost certainly prevent future major outbreaks. The virus is probably rarely transmitted by infectious aerosols, although infection via large droplets remains a possibility.”
In conclusion, the likelihood of Ebola transmission via unsterile injections is a definite possibility.
Competing interests: No competing interests