Critical Review Of The Literature On Ebola As A Re-Emerging Communicable Disease Threat

Role of Agent

An emerging disease is referred to an infectious disease whose incidence has increased within a geographical area and threatens to spread and affect a huge proportion of the population. (Morse,2012) states that some of the factors contributing to emerging diseases include civil wars, the breakdown of public health policies, economic changes, increased immunosuppression and change in microorganisms genetic material. (National Institutes of Health,2013) states that a reemerging disease is one which in the past had been dealt with but is now becoming a health concern in a country or certain geographical area. Ebola is a reemerging disease according to the United States center for disease prevention and control. The first outbreak occurred in Zaire and in South Sudan in 1976 both outbreaks caused by different strains of the Ebola virus. In Zaire, there were 280 deaths while in South Sudan there were 151 deaths according to the World Health Organization. In 1977 there was another outbreak in Zaire with one fatality followed by an outbreak in Sudan in 1979 with 22 deaths.1994 was marred with two outbreaks in Gabon and Cote d’Ivoire. Zaire was again hit by the virus in 1995 and consequently Gabon in the year 1996. This continued in the twenty-first century with the worst epidemics occurring in the year 2014 to 2016 in Guinea with 2543 deaths reported representing a case fatality of 67%. At the same time, Liberia had reported 4809 deaths representing a case fatality of 45%. During the same period, Sierra Leone reported 3956 deaths a case fatality of 28%.In 2014 Nigeria reported 8 deaths while Senegal reported one case. The democratic republic of Congo reported 49 deaths in 2014. This virus was also reported in the United States of America, United Kingdom, Spain, and Italy in 2014.

(World Health Organization,2014) declared the 2014 Ebola outbreak as health emergency of warranting international concern since its spread was occurring at a very high rate. The outbreak was heavily attributed to geographical location and migration from the urban to the rural areas. Poor public health systems contributed to the rapid spread of Ebola in 2014 since the countries affected were recovering from war and hence little education among its citizens. The bad roads made it hard to transport the patient, especially in rural areas. Poor telecommunication services led to late emergency response since informing the health agencies was done when it was already too late. (World Health Organization,2015) states that the borders between these countries were porous meaning infected persons would cross to the other country easily transmitting the disease. Also, infected persons would seek health services in the other country while it had started improving causing new infections. Some practices performed such as washing the body of an infected person before burial or even touching it would lead to the spread of this virus since the viral load was still high in the corpse. The 2014 epidemic was manifesting differently compared to the previous outbreaks. This would lead to the slow detection of the virus while its spread continued. Shortage of health workers also led to the spread of the virus as some of them also ended up being infected and dying while there was no use of personal protective equipment at first while attending to the patients.

Host Factors

Ebola is a viral hemorrhagic fever belonging to the family Filoviridae. The virus is known to affect both primates and nonprimates. The agent is a ribonucleotide acid, enveloped and it is negative sense single-stranded. (Cenciarelli et al,2015) states that there are five known Ebola viruses namely Ebola virus which was detected first in Zaire in 1976, Sudan virus discovered in 1976, Reston virus detected in 1989, Tai forest virus in 1994 and Bundibugyo virus in 2007. Reston virus is not pathogenic to humans. (Groseth, Fellmann, and Strong,2012) states that Ebola is zoonotic meaning it affects both humans and animal species. The virus is transmitted via direct contacts such as mucous membranes, body fluids and contaminated objects such as needles, sexual contact, and contact with infected persons or corpses.

Once infected with Ebola virus there is multiple organ dysfunction. According to (Falasca et .al, 2015) the virus replicates in the body, it affects the macrophages and the dendritic cells whose main function is to phagocytose foreign bodies. This is then followed by production of cytokines which causes inflammatory reactions causing damage to the tissues. It also affects the kidneys and the spleen which interferes with the clotting cascade leading to massive hemorrhage. The kidneys are involved in the balance of pH of the blood hence if affected the body is unable to regulate its pH and excrete wastes hence retention. (Bray, Hatfill, Hensley& Hugging, 2013) states that monocytes, macrophages, and dendritic cells are the early replication sites of the Ebola virus infection. These cells are responsible for the spread of the virus in the body after they migrate from the spleen. (Sanchez et.al,2012) also states that during this infection there is the excess production of nitric oxide which causes excessive tissue damage including the blood vessels leading to hemorrhagic shock. Nitric oxide is a vasodilator leading to decreased blood pressure which worsens an already deteriorating condition. Decreased blood volume to vital centers such as the brain and kidneys leads to cell death and consequently organ death hence the high mortality rates.

(MacNeil et.al,2010) states that the incubation period of the Ebola virus is between two and twenty-one days. This refers to the period between which one is exposed and when the symptoms first occur. However one is not infectious until the first symptom occurs. The symptoms include muscle pain, diarrhea, blood in the stool, fever, weakness, severe headache, fatigue, hemorrhage such as oozing from the gums. (World Health Organization,2014) states that the laboratory diagnosis is done through enzyme-linked immunosorbent assay, polymerase chain reaction, isolation of the virus from cell culture and recommends whole blood and oral fluids as specimens. The patient presents with low platelet count. There is no known drug used to treat Ebola virus infection neither a vaccine approved by Food and Drug Administration. (World Health Organization,2014) states that the candidate vaccines would require appropriate protocols, a platform that ensures transparency of data and safety monitoring board.

Prompt management of a patient with Ebola is the isolation of the patient to prevent further spread of the virus, providing intravenous fluids and electrolytes, maintaining the blood pressure. The patient has their own items which are not shared and thoroughly disinfected after use. The healthcare workers nurse the patient via barrier nursing while wearing personal protective equipment.

Environmental Factors

Fruit bats are known to be the reservoir hosts of the Ebola virus. The bats spread the virus to the primates. (Rewar and Mirdha,2014) states that in West Africa Ebola emerged as a result of human beings handling bushmeat and coming into contact with infected bats, chimpanzees, and antelopes. Also, the consumption of fruits with infected feces of the bat causes the infection in humans. The people in West Africa have hunted for bushmeat for ages and therefore convincing them otherwise is difficult yet this is the first contact with Ebola from the reservoir hosts. Poverty heavily contributes to this as they lack other sources of proteins except for bushmeat. The preparation of the raw meat increases the chances of transmission since there is contact with blood and feces and organs which have the virus. The meat is eaten raw or not cooked properly the virus is active and therefore transmission.

Another factor closely attributed to the spread of Ebola is caring for a person with Ebola. The culture in most African societies is compassionate care for the sick person and this meant coming into contact with bodily secretions and mucous membranes. As earlier stated Ebola is spread through direct contact and bodily fluids. This means even the healthcare workers who without their knowledge interacted with infected persons were also infected.(Dowell et.al,2012) conducted a study that involved family members infected with Ebola out of 95 members who had direct contact with an infected person 28 members became infected while 78 members who did not have direct contact were not infected.

Sexual contact with an infected person contributes to the spread of Ebola.(Deen et.al,2017) conducted a study on a cohort of male survivors of the Ebola virus on their semen, within different time spans and their semen was positive for RNA virus of Ebola. It advisable to ensure safe sexual practices such as nonpenetrative sex for Ebola survivors and male survivors testing their semen until its negative, use of condoms and abstinence till the semen tests negative.

Breastfeeding is the recommended the mode of feeding for infants under the age of six months. However, in mothers with Ebola, they should not breastfeed as breast milk contains Ebola virus and hence other alternatives should be sought.(Nordensten et.al,2016) conducted a study on a breast milk of an infected mother and found it was positive for Ebola virus hence advising women to stop breastfeeding immediately after a positive symptom of Ebola. This is contentious due to inadequate information and unavailability of alternatives to breast milk, especially in rural communities.

Use of traditional healers propagates the spread of Ebola. Traditional healers are highly sought due to poor access to health facilities. Many cases in Guinea in 2014 were traced back to visiting a traditional healer who had come into contact with an infected person or attending a healer’s burial which involves traditional funeral rites and practices. The epidemic spread the belief that hospitals were the source of Ebola making it even more difficult to seek medical care. (Manguvo and Mafuvadze,2015) states that burial practices such as washing the deceased body contributed to the spread of Ebola; farther encouraging raising awareness among traditional leaders and healers as they draw respect from the majority of the community.

Potential Policy Responses

Changes in weather conditions can cause animal migration such as bats to human settlements causing Ebola virus spread. A fruit bat Eidolon helvum during migration can travel a distance or greater than 2500 kilometers (Richter and Cumming,2010). This bat has tested positive for Ebola virus. The bats migrate in search for food and water and in the process there is human interaction with bats leading to spread of Ebola. According to a study conducted by (Leroy et.al 2012) before the Ebola outbreak in 2007 in the Democratic Republic of Congo, the locals reported a bat migration which settled in Ndongo and Koumelele. These bats were hunted for their meat and there was an Ebola outbreak and when contact tracing was done the first contact had consumed bat meat.

During dry seasons animals will migrate in search of water and during the process infection to humans. The risks of outbreaks are higher during dry seasons which occur after a rainy season. This is because animals migrate in search of food while humans also go into the forest in search of food. Dry seasons have since been associated with Ebola outbreaks and can be used to avert Ebola epidemics.

Human-wildlife conflict in West Africa has been largely faulted for Ebola outbreaks. Deforestation occurring massively to accommodate the ever-increasing population and displacing wild animals increasing contact. (Norris et.al 2010) states that in Sierra Leone the forests are home to 25% of the mammals found in Africa. Continuous deforestation increases the chance of human beings interacting with a wide variety of animals posing a great risk and increasing chances of spread of Ebola from infected animals to humans. Furthermore, if the animals are destroying crops on the farmers land they are at risk of being hunted down and eaten as bushmeat.

The movement of bats into farms in search of fruits poses a huge risk since they are densely populated and therefore the spread of Ebola by infected bats. They mainly feed on fruits and crops (Mickleburgh, Hutson and Racey, 2015).

This refers to the plan of action set and implemented by various health organizations to cease the spread of Ebola. The Australian government recognizes Ebola as a biologic agent that could be used in bioterrorism (Australia Institute of Health, 2015). The department of health in Australia has set several guidelines, for example, clinicians should inform public health reference laboratory for advice on the collection and transport of specimen. Confirmatory testing of Ebola should be done at National High-Security Quarantine Laboratory. The patient should be isolated and nursed via barrier nursing. The healthcare workers should use a P2/N95 mask and must ensure all skin is covered. There should be the use of disposable gown, gloves and shoe coverings. The visitors to the patients should be limited and adults only and they should also don personal protective equipment. A log in the entry for visitors should be maintained. Hospital staff should be trained on how to don the personal protective equipment, how to ensure the mask fits them, how to take off the personal protective equipment while ensuring no cross contamination.

The World Health Organization is the international agency concerned with public health all over the globe. It came up with policy measures during the 2014 West Africa Ebola epidemic. (WHO,2015) involved formation of Ebola treatment units with medical teams which work together with teams from infection prevention. Ebola community care centers were formed to involve the community. There was the formation of teams to conduct safe dignified burials while observing the set protocols in conjunction with faith-based organizations.WHO has been on the frontline in providing protective personal equipment to healthcare workers while at the same providing training on the use of the equipment, how to safely discard the equipment and safe burial practices. Formation of infection prevention guidelines in performing clinical procedures, laboratory investigations and discarding waste. Promotion of surveillance in conjunction with the center for disease control and prevention to collect data, case finding, contact tracing and data analysis which promotes prompt discovery of new cases. There has been involvement of the community by demystifying Ebola and education on signs to monitor for by use of posters and social media.

The Center for Disease Control and prevention is also involved in policy making of emerging and reemerging diseases. According to (Marston et .al, 2017) the CDC on the frontline of formation of national laboratories in the Liberia, Guinea and Sierra Leone with new technologies such as Gene expert to perform polymerase chain reaction test. Rapid antigen tests were used to perform tests on deceased patients to allow prompt internment. Sierra Leone has used Integrated Disease Surveillance and response to monitoring priority diseases and conditions. The Ebola epidemic has seen the rise of personnel involved in surveillance and teaching the community on Ebola. These personnel have engaged themselves in public health courses. This has foreseen formation of field epidemiology training programs which allow individuals to train on surveillance of various diseases and leadership during such outbreaks.

Conclusion

Ebola is regarded as a weapon of warfare and bioterrorism agent which can be used to cause biological warfare. It also causes so much anguish considering that the 2014 epidemic caused 11310 deaths in some cases wiping out the whole family. This is worsened by its biologic aspects of causing hemorrhage within a short time. This calls for prompt surveillance of Ebola while considering various strains of how it can manifest. It also requires the improvement of health systems especially in African countries to handle and contain this hemorrhagic fever. Strong communication and alert systems would go a long way in ensuring prompt response of outbreaks. The factor that culture is involved means that education about harmful practices such as some burial rites should be conducted by the traditional leaders or the community members who are conversant with such sensitive matters. The governments of all countries should also set policies regarding Ebola and educate its citizens on signs to look out for and hotlines to reach out to. The role of research should not be underestimated since Ebola virus has the ability to produce various strains which may manifest in different ways. Continued research on vaccines to provide immunity would be a stepping stone in the health sector. Curbing Ebola requires sustained efforts from international organizations, governments, healthcare workforce, and the community members.

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