Introduction
According to Arata and Johnson (2014), Ebola Haemorrhagic Fever (EHF) is an acute viral illness with a lethality rate that ranges from around 50% to 90%. With the exception of Rabies and HIV/AIDS, no other viral disease has such a high case fatality rate. The Ebola viruses are one of two genera of the family Filoviridae. The symptoms of Ebola infection vary from person to person, but generally involve fever, headache, joint or muscle pains, sore throat, vomiting, diarrhoea, bleeding, shock and other neurological symptoms.
Patients usually die six to nine days after the appearance of the first symptoms. At the time of writing, there exists no cure against the disease, although there are claims of experimental drugs used for the management of cases of Ebola, World Health Organsation (WHO) (2014) stated that Ebola has no cure and all experimental drugs are basically for symptomatic treatment. Transmission of the virus occurs through contact with body fluids or infected blood.
According to WHO (2014), the 2014 West African outbreak which affected Guinea, Sierra Leone, Liberia and Nigeria is the largest and the most challenging outbreak of Ebola in History. WHO (2014) stated that in March 2014, an on outbreak of Ebola occurred in Guinea and by 10th April, 2014, there have been 157 confirmed cases and 101 deaths have been reported in Guinea, 22 suspected cases in Liberia including 14 deaths. 8 suspected cases in Sierra Leone including 6 deaths and 1 suspect in Mali. By late June the death toll had reached 390 deaths and over 600 confirmed cases. In a report of the World Health Organisation in partnership with the ministries of health in Guinea, Sierra Leone, Mali and Nigeria on 4th August, 2014, the epidemic had taken a quantum leap to 3,127 suspected cases with 2,315 confirmed cases of and 1, 845 deaths.
According to the Nigeria minister of Health, Onyebuchi Chukwu in a press statement on 17th August, 2014 the first confirmed case of Ebola was recorded in Nigeria on 16th August, 2014 through Patrick Oliver Sawyer, a Liberian-American lawyer who travelled to Nigeria from Liberia for an unknown reasons though there have been claims that he was in Nigeria to seek medical care.
Conceptual Framework on Ebola
According to Centre for Disease Control and Prevention (CDC) (2014), Ebola haemorrhagic fever (Ebola HF) is a fatal viral infection of public health concern in West Africa.
Gatherer (2014) described Ebola as a disease of humans and other primates, caused by ebolaviruses which typically start between two days and three weeks after contracting the virus, fever, sore throat, muscle pain, and headaches. Then, vomiting, diarrhoea and rashes usually follow, along with decreased function of the liver and kidneys. He therefore added that at this time, some people begin to bleed both internally and externally.
There are five identified subspecies of Ebolavirus, viz. Zaire ebolavirus (EBOV), Bundibugyo ebolavirus (BDBV), Reston ebolavirus (RESTV), Sudan ebolavirus (SUDV) and Tai Forest ebolavirus (TAFV). Except RESTV, all the four subspecies have caused disease in humans. The first Ebolavirus species was discovered in 1976 (88% case fatality) in Zaire (presently Democratic Republic of the Congo (DRC)) near the Ebola river and since then, outbreaks have occurred sporadically. According to (World Health Organisation (WHO), 2014), a total of 1,440 suspected cases (953 laboratory confirmed) and 826 deaths due to Ebola virus disease (EVD) have been reported in Guinea, Sierra Leone, Liberia and Nigeria (CDC, 2014). The symptoms of EVD according to WHO include fever, muscle pain, headache, sore throat, weakness followed by vomiting, diarrhoea, rashes, impaired kidney and liver functions, bleeding inside and outside the body, etc.
The incubation period ranges between 2 and 21 days. The virus is thought to be harboured by fruits bats of the species; Hypsignathus monstrosus, Epomops franqueti and Myonycteris torquata effected by the virus according to West Africa (WHO, 2014). It is hypothesized that the virus might have spread to other animal species and thereby spread to human population through contact between infected animals and humans, or direct contact with infected bats, Human to human transmission of EVD occurs from direct contact through broken skin or mucous membranes with the blood, secretions, organs or other bodily fluids of infected persons Exposure to objects such as needles and syringes contaminated with infected secretions and burial ceremonies contact of mourners with the body of deceased persons also plays a role in the transmission of the virus. It has been reported that men who have recovered from EVD have the potential to transmit the virus through their semen up to seven weeks after recovery (Weyer, 2014).
A recent study showed that, the current EVD outbreak which first started in March 2014 in Guinea was caused by Zaire ebolavirus with 97% sequence identity to EBOV strains from DRC and Gabon, indicating a parallel evolution of EBOV strains in these regions (Weyer, 2014).
Historical background of Ebola
In 1976, Ebola named after the Ebola River in Zaire first emerged in Sudan and Zaire. The first outbreak of Ebola (Ebola-Sudan) infected over 284 people, with a mortality rate of 53%. A few months later, the second Ebola virus emerged from Yambuku, Zaire, Ebola-Zaire (EBOZ). EBOZ, with the highest mortality rate of any of the Ebola viruses (88%), infected 318 people. According to Feldmann and Geisbert (2011), the third strain of Ebola, Ebola Reston (EBOR), was first identified in 1989 when infected monkeys were imported into Reston, Virginia, from Mindanao in the Philippines. According to Waterman (2009), fortunately, the few people who were infected with EBOR (seroconverted) never developed Ebola hemorrhagic fever (EHF). The last known strain of Ebola, Ebola Cote d’Ivoire (EBO-CI) was discovered in 1994 when a female ethologist performing a necropsy on a dead chimpanzee from the Tai Forest, Cote d’Ivoire, accidentally infected.
The largest outbreak to date is currently occurring in West Africa affecting primarily Guinea, Liberia and Sierra Leone. The 2014 Ebola outbreaks occurred for the first time in Guinea, Liberia and Sierra Leone, and in these countries there has been intense transmission in urban areas. Related to this extensive outbreak, Ebola has been imported into Nigeria, Mali, Senegal, Spain, UK and the USA (Gatherer, 2014).
Signs and symptoms of Ebola
Symptoms usually begin with a sudden influenza-like stage characterized by feeling tired, fever, weakness, decreased appetite, muscle pain, joint pain, headache, and sore throat. The fever is usually higher than 38.3 °C (101 °F). According to WHO (2014), this is often followed by vomiting, diarrhoea and abdominal pain. Next, shortness of breath and chest pain may occur, along with swelling and headaches. In about half of the cases, the skin may develop a maculopapular rash, a flat red area covered with small bumps, 5 to 7 days after symptoms begin (Goeijenbier, 2014).
In some cases, internal and external bleeding may occur. This typically begins five to seven days after the first symptoms. All infected people show some decreased blood clotting. Bleeding from mucous membranes or from sites of needle punctures has been reported in 40–50 percent of cases. This may cause vomiting blood, coughing up of blood, or blood in stool. Bleeding into the skin may create petechiae, purpura, ecchymoses or hematomas especially around needle injection sites. Bleeding of the eyes may also occur. Heavy bleeding is uncommon; if it occurs, it is usually located within the gastrointestinal tract according to (WHO, 2014).
Causes of Ebola
Ebola virus disease in humans is caused by four of five viruses of the genius Ebolavirus. The four are Bundibugyo virus (BDBV), Sudan virus (SUDV), Taï Forest virus (TAFV) and EBOV, Zaire Ebola virus (EBOV) species Zaire ebolavirus, is the most dangerous of the known EVD-causing viruses, and it is responsible for the largest number of outbreaks. The fifth virus, Reston virus (RESTV), is not thought to cause disease in humans, but has caused disease in other primates. All five viruses are closely related to marburgviruses (Hoenen, 2012).
Transmission of Ebola
Between people, Ebola disease spreads only by direct contact with the blood or body fluids of a person who has developed symptoms of the disease. Body fluids that may contain Ebola viruses include saliva, mucus, vomit, faeces, sweat, tears, breast milk, urine and semen CDC (2014). WHO (2014) states that only people who are very sick are able to spread Ebola disease in saliva, and whole virus has not been reported to be transmitted through sweat. Most people spread the virus through blood, faeces and vomit. Entry points for the virus include the nose, mouth, eyes, open wounds, cuts and abrasions. Ebola may be spread through large droplets; however, this is believed to occur only when a person is very sick. This can happen if a person is splashed with droplets. Contact with surfaces or objects contaminated by the virus, particularly needles and syringes, may also transmit the infection (CDC, 2014).
The Ebola virus may be able to persist for up to 8 weeks in the semen after recovery, which could lead to infections via sexual intercourse. Ebola may also occur in the breast milk of women after recovery, and it is not known when it is safe to breastfeed again. Otherwise, people who have recovered are not infectious (CDC, 2014).
Dead bodies remain infectious; thus, people handling human remains in practices such as traditional burial rituals or more modern processes such as embalming are at risk. 69% of the cases of Ebola infections in Guinea during the 2014 outbreak are believed to have been contracted via unprotected (or unsuitably protected) contact with infected corpses during certain Guinean burial rituals (Chan, 2014)
Health-care workers treating people with Ebola are at greatest risk of infection. The risk increases when they do not have appropriate protective clothing such as masks, gowns, gloves and eye protection or do not wear it properly; or handle contaminated clothing incorrectly (CDC, 2014).
Humans may also be infected if they handle infected animals, or come into contact with their bodily fluids or cell cultures, and cases have been documented in people who handled infected chimpanzees, gorillas and forest antelopes, both dead and alive. In Cote d’Ivoire, the Republic of Congo and Gabon, the harvesting of fruits that have contact with migrating bats (CDC, 2014).
Strategies to prevent Ebola virus transmission
According to CDC (2014), people living in Ebola stricken countries or travelling to an area affected by an Ebola outbreak, should ensure the following:
- Practice personal hygiene. For example, washing of hands with soap and water or an alcohol-based hand sanitizer and avoid contact with blood and body fluids.
- Avoid handling items that may have come in contact with an infected person’s blood or body fluids such as clothes, bedding, needles, and medical equipment.
- Avoid funeral or burial rituals that require handling the body of someone who has died from Ebola.
- Avoid contact with bats and primates or blood, fluids, and raw meat prepared from these animals.
- Avoid facilities where Ebola patients are being treated.
Health workers attending to Ebola patients need to avoid contact with the bodily fluids of their infected patients by:
- Wearing of face masks, goggles, gowns and gloves
- Taking extra care when handling blood, secretions and catheters, and when connecting patients to a drip
- Disinfecting non-disposable medical equipment before reusing
- Sterilising and disposing of used needles and all disposable equipment carefully
- Proper disposal of any secretions or bodily waste from the patient
- Carefully and frequently washing of hands with soap and water (or alcohol hand rubs or sanitizers if soap is not available)
- Washing disposable gloves with soap and water after use, disposing of them carefully, then washing of hands.
Global health concern on Ebola
Ebola is such a great concern to global health today because of its high fatality rate. Although its outbreak is relatively not a very common phenomenon, its deadly nature and the rate of its transmission whenever it occurs is certainly a serious concern to global health.
Recently, it has been discovered that there is evidence of Reston Ebola virus in swine population in the Philippines. According to Leroy (2014), this could mean that the virus had been around before 1989, when it was first detected in monkeys. If the disease has the ability to mutate and infect other animals, it needs to be closely monitored so that it does not surprisingly surface in other animals.
The main goals of current attention on Ebola are finding ways of treatment for Ebola haemorrhagic fever and effective vaccines for the virus that can be applied to humans. If an approved vaccine could be developed for Ebola virus, it would save many people from the painful impact of Ebola haemorrhagic fever.
Although it is not a very serious problem right now for most populations outside Africa, Ebola virus has the potential to be dangerous from the point of view of global health in the future. According to Chan (2014), Ebola virus is a class A bioterrorism agent which can cause a very high casualty rate if it can be developed in the laboratory by terrorist groups with the aim of causing havoc to human population.
References
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Leroy, E. M. (2014). Ebola in West Africa: the outbreak able to change many things. Clinical Microbiology and Infection 20(10):597–599
Waterman, T. (2009). Ebola Reston Outbreaks. New York: Stanford University.
Weyer, J. (2014): Nearly 45,000 Indians in Ebola-hit countries, may bring virus home, available at: http://timesofindia.indiatimes. com/India/Nearly-45000-Indians-in-Ebola-hit-countries-may-bring-virus-home/articleshow/39787121.cms; 7 February 2015.
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