Chapter 12 – Ebola




Abstract




Ebola virus disease (EVD) was first recognised in 1976, when there was an outbreak of viral haemorrhagic fever near the Ebola River in Zaire (now the Democratic Republic of the Congo (DRC)) with multiple subsequent outbreaks confined to sub-Saharan Africa and spread to Europe and the USA by human transportation.


Ebola disease is rare but causes severe viral haemorrhagic disease.


EVD is a filovirus infection, thought to be transmitted to humans from an unknown animal reservoir. Bats or non-human primates are suggested to be the most likely species involved in the occurrence of sporadic human outbreaks.


There are five identified species of EVD. Zaire ebolavirus is the most lethal strain.


Animal-to-human transmission is thought to be through the wild animal meat consumption. Human-to-human transmission is through mucosal contact with infected body fluids.


Incubation period is up to 21 days (median five to nine days).





Chapter 12 Ebola


Adel Elkady , Prabha Sinha and Soad Ali Zaki Hassan


Ebola virus disease (EVD) was first recognised in 1976, when there was an outbreak of viral haemorrhagic fever near the Ebola River in Zaire (now the Democratic Republic of the Congo (DRC)) with multiple subsequent outbreaks confined to sub-Saharan Africa and spread to Europe and the USA by human transportation.1


Ebola disease is rare but causes severe viral haemorrhagic disease.


EVD is a filovirus infection, thought to be transmitted to humans from an unknown animal reservoir. Bats or non-human primates are suggested to be the most likely species involved in the occurrence of sporadic human outbreaks.


There are five identified species of EVD. Zaire ebolavirus is the most lethal strain.


Animal-to-human transmission is thought to be through the wild animal meat consumption. Human-to-human transmission is through mucosal contact with infected body fluids.


Incubation period is up to 21 days (median five to nine days).



EVD and Pregnancy


Maternity services have been particularly vulnerable to nosocomial Ebola infection, therefore it is important to devise a plan for management of pregnant women during an Ebola outbreak.2, 3


Unfortunately, limited evidence does suggest that pregnant women are likely to be at increased risk of severe illness and death when infected with Ebola virus.


Pregnant women with EVD also appear to be at increased risk of fetal loss and pregnancy-associated haemorrhage. Reports of Ebola outbreaks suggest that the incidence of spontaneous miscarriage, prematurity and neonatal death is very high. Neonates do not survive for more than a few days to weeks.4, 5


In a study by Mupapa et al., mortality among pregnant women with Ebola haemorrhagic fever was slightly but not significantly higher than the overall mortality observed during the Ebola epidemic in Kikwit, DRC (77 per cent; 245/316 infected persons). [EL 2]



Effect of Ebola Virus on Pregnancy




  • Ebola viral disease’s interaction with pregnancy is poorly understood and remains a challenge for health care providers.



  • It is not well established whether pregnant women are at higher risk than the general population.



  • However, a small series of case reports does suggest that pregnant women are at risk of severe morbidity and death, perhaps due to decreased immunity during pregnancy itself. There has been no fetal survival in these women; however, the cause of death remains unknown.



  • It is established that Ebola virus does infect the placenta, therefore it is likely that the fetus has placental transmission of the virus. These viruses are detected in the amniotic fluid, meconium, umbilical cord, buccal swab and vaginal secretion.



  • Ebola virus persists in amniotic fluid even after maternal blood is negative for reverse transcription–polymerase chain reaction (RT-PCR) tests. Therefore it is important for health care personnel to take necessary precautions in delivery and avoid contact with body fluid from pregnant women who had been infected and are currently in the convalescent period.7



  • Women with active disease and who survive without pregnancy loss may transmit the virus during delivery and pose a potential risk of transmitting infection.



  • Women who become pregnant after they recover from an Ebola infection pose little risk to the unborn fetus during the new pregnancy, especially if infection occurs at least 20 weeks after negative blood result for RT-PCR tests for Ebola virus in maternal blood.8



  • There is no evidence to show that women who survive EVD and subsequently become pregnant pose a risk for Ebola virus transmission.



Signs and Symptoms during Pregnancy


Health care providers should be aware of the signs and symptoms of Ebola virus, as early signs and symptoms are non-specific and may be confused with malaria, typhoid or influenza.


A history of fever, recent travel to the epidemic zone or any contact with an infected person should raise suspicion of Ebola infection.


Symptoms of EVD include:




  • Fever



  • Severe headache



  • Muscle pain



  • Weakness



  • Fatigue



  • Diarrhoea



  • Vomiting



  • Abdominal (stomach) pain



  • Unexplained haemorrhage (bleeding or bruising)


Symptoms usually appear within 8–10 days of contact and can be confused with influenza (flu) or malaria.



Transmission




  • Initial spread occurs through an Ebola virus-infected animal (bat or non-human primate). After that, the virus spreads from person to person, involving a large number of people (epidemic).



  • The spread is through direct contact and through broken skin or mucous membranes in the eyes, nose or mouth, or direct contact with blood or body fluids (urine, saliva, sweat, faeces, vomit, breastmilk and semen).



  • Proper cleaning and disposal of instruments including needles and syringes are important. Preferably, disposable instruments should be used.10




    • Ebola virus is not usually transmitted by food. However, it may spread through the handling and consumption of meat from wild animals.



    • There is also no evidence that mosquitoes or other insects can transmit Ebola virus.




Fetal Implications of Ebola Virus Infection




  1. 1. Miscarriage



  2. 2. Intrauterine fetal death



  3. 3. Neonatal death



Diagnosis




  1. 1. Clinical


This may be difficult as symptoms are very similar to other diseases (typhoid, malaria, flu). Therefore these symptoms should be combined with history of recent travel to an epidemic country and contact history.


Once suspected the person should be isolated.




  1. 2. Blood test should be carried out to confirm the diagnosis.


Nucleic acid amplification testing (NAAT) is currently the gold standard diagnostic test and is performed in category 4 biosafety facilities. [EL 2]


The low sensitivity of NAAT during the first 72 hours of symptoms may require repeat testing.


As it is a communicable disease, public health should be informed and contact tracing is required.

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Sep 30, 2020 | Posted by in GYNECOLOGY | Comments Off on Chapter 12 – Ebola

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