How can infection and death from Ebola be contained? In the absence of an effective treatment and a human vaccine, it is by raising awareness about the deadly virus, say experts. OYEYEMI GBENGA-MUSTAPHA and WALE ADEPOJU report.
Ebola haemorrhagic fever (EHF) is one of the most viral diseases known to humankind. There are five distinct species of the genus Ebola virus. They are: Bundibugyo virus, Ebola virus, Reston virus, Sudan virus and Taï Forest virus. Bundibugyo, Sudan and Ebola species have been associated with large outbreaks of Ebola virus disease in Africa, causing deaths in 25 to 90 per cent of all clinically ill cases, while Tai Forest and Reston have not.
The Ebola virus is transmitted by direct contact with the blood, body fluids and tissues of infected persons. Transmission of the Ebola virus can also be by handling sick or dead infected wild animals (chimpanzees, gorillas, monkeys, forest antelope and fruit bats), called bush meat in Nigeria. The predominant treatment is general supportive therapy.
If contracted, the condition is called Ebola hemorrhagic fever and it is often fatal in humans and non-human primates such as monkeys and chimpanzees.
Ebola first appeared in 1976 in two simultaneous outbreaks, in Nzara, Sudan and Yambuku, in the Democratic Republic of Congo (DRC). The latter was in a village situated near the Ebola River, from which the disease takes its name.
The question begging for answer is: Is Nigeria susceptible to Ebola disease outbreak? The answer is yes. Already, neighbouring countries on the West African Coast have been reported as having confirmed cases of infection from the dreaded disease. Is the country proactive in preventing an outbreak? The reply is in the negative.
As the World Health Organisation (WHO) is blowing its whistle on the outbreak and reducing the risks of infection of the Ebola virus, which causes Ebola virus disease (EVD) in humans, with a fatality rate of up to 90 per cent, i.e nine out of 10 people dying, Nigerian government is yet to create awareness for its citizens.
Since the outbreak of the deadly strain of Zaire Ebola in Guinea in February, this year, about 90 people have died as the disease has travelled to neighbouring Sierra Leone, Liberia and Mali. The outbreak has sent shock waves to communities that know little about the disease or how it is transmitted. The cases in Mali have increased the fears that it is spreading through West Africa. Ghana was said to have first suspected the deadly disease, but it was debunked, after the dead was examined.
Reports from the Noguchi Memorial Institute of Medical Research at the University of Ghana showed that there are no cases of Ebola in Ghana. This was as a result of examining a 12-year-old girl, who was admitted at the paediatric unit of the country’s second biggest hospital, Komfo Anokye Teaching Hospital (KATH), in Kumasi. She had symptoms of fever and bleeding. But after a postmortem on her body, it was detected that she had internal bleeding.
Opinions sampled by The Nation revealed that many Nigerians are yet to understand the disease, mode of transmission and its prevention. According to WHO, EVD outbreak is best prevented as there is no cure for it now. It says in the absence of effective treatment and a human vaccine, raising awareness of the risk factors of the disease and the protective measures to be taken would reduce human infection and death.
According to a professor of public health, Prof Akin Osibogun, because of its nature, Ebola causes its victims to bleed from their ears and other orifices because blood vessels are being weakened so they easily burst.
Susceptibility/Unpreparedness
In Nigeria, should there be an outbreak, the reality is that there are little or no effort in place to contain same.
The state of most of the Primary Health Centres (PHCs) and secondary healthcare centres across the country does not support the curtailment of an outbreak. The tertiary hospitals cannot be said to be well equipped for this too.
One of the ways to get ahead of it, is to make sure emergency response teams have the right information as soon as information flow allows. But that is, if citizens can understand the disease and report to health facilities promptly.
If medical staff are not aware of what the disease is, the risk to them and other patients is enormous, which is why the infection rates among medical staff has been so high, even where there are confirmed cases in neigbouring countries.
Moreso, many clinics and hospitals in a developing country such as Nigeria, do not have the capacity to safely care for people with disease- they do not have gowns and gloves or disinfectants.
International collaboration is important. This is where the likes of Medecins Sans Frontieres (MSF) and the International Federation of Red Cros come in. They can help identify the disease and ensure the local communities understand it and how it has spread and can further spread.
Explaining the disease and its spread are key in saving lives. It is important that Nigeria learn from other countries where outbreaks have been recorded, by planning on deriving map data, should there be an outbreak. This is because, most international helping hands were working blind, going off of local knowledge and news where outbreaks were recorded.
According to WHO, Ebola is introduced into the human population through close contact with the blood, secretions, organs or other bodily fluids of infected animals. In Africa, infection has been documented through the handling of infected chimpanzees, gorillas, fruit bats, monkeys, forest antelope and porcupines found ill or dead in the rainforest.
Ebola then spreads in the community through human-to-human transmission, with infection resulting from direct contact (through broken skin or mucous membranes) with the blood, secretions, organs or other bodily fluids of infected people and indirect contact with environments contaminated with such fluids. Burial ceremonies in which mourners have direct contact with the body of the deceased person can also play a role in its transmission. Men who have recovered from the disease can still transmit the virus through their semen for up to seven weeks after recovery from illness.
Health-care workers have frequently been infected while treating patients with suspected or confirmed EVD. This has occurred through close contact with patients when infection control precautions are not strictly observed.
Among workers in contact with monkeys or pigs infected with Reston Ebola virus, several infections have been documented in people who are clinically asymptomatic. Thus, RESTV appears less capable of causing disease in humans than other Ebola species.
According to WHO, the only available evidence available comes from healthy adult males. It would be premature to extrapolate the health effects of the virus to all population groups, such as immuno-compromised persons, persons with underlying medical conditions, pregnant women and children. More studies of RESTV are needed before definitive conclusions can be drawn about the pathogenicity and virulence of this virus in humans.
Signs and symptoms
EVD is a severe viral illness often characterised by the sudden onset of fever, intense weakness, muscle pain, headache and sore throat. This is followed by vomiting, diarrhoea, rash, impaired kidney and liver function, while in some cases, it can be through both internal and external bleeding. Laboratory findings include low white blood cell and platelet counts and elevated liver enzymes.
People are infectious as long as their blood and secretions contain the virus. Ebola virus was isolated from semen 61 days after onset of illness in a man, who was infected in a laboratory, stated WHO.
Prof Osibogun said the incubation period, that is, the interval from infection to onset of symptoms, is two to 21 days. And other symptoms according to him, include, “high fever, vomiting and muscle pain. The virus is transmitted through contact with body fluids (blood, saliva and sweat) of infected persons”.
Prevention
The Director-General (DG), National Institute of Medical Research (NIMR), Prof Innocent Ujah has called for more awareness on the disease in order to increase Nigerians’ knowledge about the disease.
He said though the disease is not present in the country, but it could find its way into the country through its borders because Nigerians travel a lot and many people also migrate into the country. “The disease does not exist in the country, but there is the possibility of it finding its way as it be imported by travelers. People should be vigilant and report any case of the disease to the nearest government health facility.
“More awareness is needed to enlighten the people on the disease. Neither anybody who sees people with obvious signs of the disease should keep quiet nor the affected person go to prayer houses or visit herbalists; rather; they should go to a health facility,” he said.
He encouraged people to cook their meat properly to kill any virus that may transmit the disease.
Prof Osibogun advised that since several cases have been reported in Guinea, Liberia and possibly Sierra Leone, there is a need for epidemic vigilance in all West African countries and beyond because of the ease of modern travel.
Diagnosis
Other diseases that should be ruled out before a diagnosis of EVD can be made include: malaria, typhoid fever, shigellosis, cholera, leptospirosis, plague, rickettsiosis, relapsing fever, meningitis, hepatitis and other viral haemorrhagic fevers.
According to a staff of Medical Laboratory Science Council of Nigeria (MLSCN), Yaba, Lagos, there is a standard procedure for the diagnosis of Ebola virus. The source said: “Ebola virus infections can be diagnosed definitively in a laboratory through several types of tests: enzyme-linked immunosorbent assay (ELISA); antigen detection tests; serum neutralisation test; reverse transcriptase polymerase chain reaction (RT-PCR) assay and virus isolation by cell culture. Samples from patients are an extreme biohazard risk and testing should be conducted under maximum biological containment conditions. But I am afraid Nigeria is not fully prepared for all of the laid down diagnostic procedure.”
A member of West African College of Physicians, who wants her identity protected also said there is the fear that should there be confirmed cases in the country, health workers are at risk because “controlling infection in health-care settings is tasking. Human-to-human transmission of the Ebola virus is primarily associated with direct or indirect contact with blood and body fluids. Its transmission to health-care workers has been reported when appropriate infection control measures were not observed.
“It is not always possible to identify patients with EBV early because initial symptoms may be non-specific. For this reason, it is important that health-care workers apply standard precautions consistently with all patients regardless of their diagnosis in all work practices at all times. These include basic hand hygiene, respiratory hygiene, the use of personal protective equipment (according to the risk of splashes or other contact with infected materials), safe injection practices and safe burial practices,” she said.
She continued: “The WHO recommendation for Health-care workers caring for patients with suspected or confirmed Ebola virus should apply, in addition to standard precautions. Other infection control measures include avoiding exposure to the patient’s blood and body fluids and direct unprotected contact with the possibly contaminated environment.
“When in close contact (within one metre) of patients with EBV, health-care workers should wear face protection (a face shield or a medical mask and goggles), a clean, non-sterile long-sleeved gown, and gloves (sterile gloves for some procedures). But the Federal Ministry of Health is yet to sensitise health workers across the Federation on this. It just took it for granted that the Universal precaution would be observed.”
Laboratory workers are also at risk. Samples taken from suspected human and animal Ebola cases for diagnosis should be handled by trained staff and processed in suitably equipped laboratories.
Prevention and
treatment
According to Assistant Director-General, Health Security and Environment, Dr Keiji Fukuda and Medical Officer, WHO, Dr Stéphane Hugonnet, no vaccine for EVD is available. Several vaccines are being tested, but none are available for clinical use.
“Severely ill patients require intensive supportive care. Patients are frequently dehydrated and require oral rehydration with solutions containing electrolytes or intravenous fluids. No specific treatment is available. New drug therapies are being evaluated,” they said.
Ebola viruses cause severe disease in humans because they can deactivate the innate immune system. Associate Professor of Microbiology at Mount Sinai, Christopher Basler, and his team have studied how Ebola viruses evade the immune system and discovered that a viral protein called VP35 is critical to deactivating the immune system. They found out that when VP35 interacts with an important cellular protein called PACT, it blocks PACT from activating the immune system, allowing the virus to spread.
“Ebola viruses are extremely lethal and are a great threat to human health as a bioweapon,” said Dr. Basler, adding: “Currently, there is no approved vaccine or treatment. Our findings will hopefully pave the way for future antiviral treatments.”
With the help of collaborators at the University of Texas and access to special high containment facilities, Dr. Basler and his team infected healthy cells with Ebola virus cells that had mutated versions of VP35. The mutations disabled VP35’s ability to interact with PACT, therefore, allowing it to activate the immune system and prevent the virus from replicating.
The researchers then overexpressed PACT in healthy cells and infected them with Ebola virus cells. They found that overexpressing PACT also inhibited viral replication.
Armed with this discovery, Dr. Basler and his team hope to develop drugs that will disrupt the interaction of VP35 with PACT, or drugs that overexpress PACT.
