By Jereaghogho Efeturi Ukusare
Ebola Virus Disease (EVD) is a severe hemorrhagic fever that affects humans and other mammals. It is a highly fatal disease. The virus family Filoviridae includes three genera: Cuevavirus, Marburgvirus, and Ebolavirus. Within the genus Ebolavirus, five species have been identified: Zaire, Bundibugyo, Sudan, Reston and Taï Forest. The first three, Bundibugyo ebolavirus, Zaire ebolavirus, and Sudan ebolavirus have been associated with large outbreaks in Africa. The virus which caused the 2014–2016 West African outbreak belongs to the Zaire ebolavirus species according to the World Health Organisation. Fruit bats of the Pteropodidae family are natural Ebola virus hosts.
Ebola is introduced into the human population through close contact with the blood, secretions, organs or other bodily fluids of infected animals such as chimpanzees, gorillas, fruit bats, monkeys, forest antelopes and porcupines found ill or dead or in the rainforest. Ebola spreads through human-to-human transmission by direct contact (through broken skin or mucous membranes) with the blood, secretions, organs or other bodily fluids of infected people and with surfaces and materials (e.g. bedding, clothing) contaminated with these fluids. Burial ceremonies requiring direct contact with the body of the deceased also contribute in the transmission of Ebola. People remain infectious for as long as their blood contains the virus.
Difficulties exists in clinically distinguishing EVD from other infectious diseases such as malaria, typhoid fever and meningitis. The confirmation that symptoms are caused by Ebola virus infection are made using the following diagnostic methods:
antibody-capture enzyme-linked immunosorbent assay (ELISA)
antigen-capture detection tests
serum neutralization test
reverse transcriptase polymerase chain reaction (RT-PCR) assay
virus isolation by cell culture.
The World Health Organisation recommends the following tests for EVD:
1. Automated or semi-automated nucleic acid tests (NAT) for routine diagnostic management.
2. Rapid antigen detection tests for use in remote settings where NATs are not readily available. These tests are recommended for screening purposes as part of surveillance activities, however reactive tests should be confirmed with NATs.
According to the World Health Organisation (WHO), the preferred specimens for diagnosis include:
Whole blood collected in ethylenediaminetetraacetic acid (EDTA) from live patients exhibiting symptoms.
Oral fluid specimen stored in universal transport medium collected from deceased patients or when blood collection is not possible.
Samples collected from patients are an extreme biohazard risk; laboratory testing on non-inactivated samples should be conducted under maximum biological containment conditions. All biological specimens should be packaged using the triple packaging system when transported nationally and internationally.
In treating EVD, supportive care-rehydration with oral or intravenous fluids and treatment of specific symptoms increases survival chances. There is as yet no proven treatment available for EVD. However, a range of potential treatments including blood products, immune therapies and drug therapies are currently being evaluated. According to the World Health Organisation (WHO), an experimental Ebola vaccine proved highly protective against the deadly virus in a major trial in Guinea. The vaccine, called rVSV-ZEBOV was studied in a trial involving 11,841 in 2015. Among the 5,837 people who received the vaccine, no Ebola cases were recorded 10 days or more after vaccination. In comparison, there were 23 cases 10 days or more after vaccination among those who did not receive the vaccine.
The trial was led by WHO, together with Guinea’s Ministry of Health, Médecins sans Frontieres and the Norwegian Institute of Public Health, in collaboration with other international partners. A ring vaccination protocol was chosen for the trial, where some of the rings are vaccinated shortly after a case is detected and other rings are vaccinated after a delay of 3 weeks.
The recommendation for good outbreak control relies on applying a package of interventions, these include case management, surveillance and contact tracing, a good laboratory service, safe burials and social mobilisation. Community engagement is key to successfully controlling EVD outbreaks. Raising awareness of risk factors for Ebola infection and protective measures (including vaccination) that individuals can take is an effective way to reduce human transmission. Risk reduction messaging should focus on several factors.
According to the WHO, reducing the risk of wildlife-to-human transmission from contact with infected fruit bats or monkeys/apes and the consumption of their raw meat, animals should be handled with gloves and other appropriate protective clothing. Animal products (blood and meat) should be thoroughly cooked before consumption. Reducing the risk of human-to-human transmission from direct or close contact with people with Ebola symptoms, particularly with their bodily fluids, gloves and appropriate personal protective equipment should be worn when taking care of ill patients at home. Regular hand washing is required after visiting patients in hospital, as well as after taking care of patients at home.
Reducing the risk of possible sexual transmission, based on further analysis of ongoing research and consideration by the WHO Advisory Group on the Ebola Virus Disease Response, WHO recommends that male survivors of Ebola virus disease practice safe sex and hygiene for 12 months from onset of symptoms or until their semen tests negative twice for Ebola virus. Contact with body fluids should be avoided and washing with soap and water is recommended. WHO does not recommend isolation of male or female convalescent patients whose blood has been tested negative for Ebola virus.
Outbreak containment measures, include prompt and safe burial of the dead, identifying people who may have been in contact with someone infected with Ebola and monitoring their health for 21 days. The importance of separating the healthy from the sick to prevent further spread and the importance of good hygiene and maintaining a clean environment cannot be overemphasised.
The recent outbreak in the Democratic Republic of Congo (DRC), has seen the influx of international organisations and agencies as International Red Cross and Crescent Societies, Medicines San Frontieres (MSF), World Health Organisation (WHO) and the Institute of Tropical Medicine (ITM). While the MSF has been very actively involved in carrying out awareness campaigns to stop the spread, the WHO has been working very closely with the government of the country ensuring proper measures are put in place to facilitate containment and control as well as putting out situation reports, the ITM is on ground for epidemic surveillance and confirmation of ebola diagnoses, the Red Cross and Crescent Societies have been handling the burial of victims.
The earliest cases are believed to have occurred in early April 2018. The suspected index case was a police officer who died in a health center in the village of Ikoko-Impenge near the market town of Bikoro in Équateur province, according to the International Federation of the Red Cross and Red Crescent Societies. After his funeral, eleven family members took ill and of whom seven died. All of the seven deceased had attended the man’s funeral and or cared for him while he was sick. The identification of this individual as the index case has not yet been confirmed.
Équateur province’s Provincial Health Division reported 21 cases with symptoms consistent with Ebola virus disease of whom 17 had died. Out of this number, eight cases have been shown not to have been Ebola-related. The outbreak was declared on 8 May 2018 after samples from two of five patients in Bikoro tested positive for the Zaire strain of the Ebola virus. On 10 May, 2018, the World Health Organization (WHO) stated that the Democratic Republic of the Congo had a total of 32 cases of EVD and a further two suspected cases were announced the following day, bringing the total cases to 34.
The health care facilities in the area are described by the WHO to have “Limited Functionality”. The remoteness of the areas where bulk of the people have been infected suffer inadequate infrastructure as there is no road to this area (Ikoko-Impenge area of Bikoro) and this is hindering treatment of EVD patients as well as surveillance and vaccination efforts.
This goes to show the much neglect suffered by the people of Democratic Republic of Congo under its current leadership. It is clear that the government of the country has placed no priority on health care provision, neither has it placed priority on the provision of infrastructure as roads and standard hospital buildings that are multifunctional. It is also clear that the government has not invested in education as to reduce the level of illiteracy. No wonder three people infected with the EVD escaped from their solitary confinements, two of these later died. It is also obvious that the government of the DRC is reactive rather than being proactive in its approach to the handling of health care in the country.
Currently, the DRC’s Ministry of Public Health are using recombinant vesicular stomatitis virus –Zaire Ebola virus (rVSV-ZEBOV) vaccine – a recently developed experimental Ebola vaccine, produced by Merck and donated to the government – to try to suppress the outbreak. This live-attenuated vaccine expresses the surface glycoprotein of the Kikwit 1995 strain of Zaire ebolavirus in a recombinant vesicular stomatitis virus vector. This rVSV-ZEBOV was trialed in Guinea and Sierra Leone during the West African epidemic of 2014–2016.