Epidemiology is a key pillar of any public healthcare system. It ensures optimal health for human populations through surveillance, data-driven health promotion, and prevention. Epidemiological tools are used to screen for disease-causing agents, their natural hosts, and means of transmission for effective interventions. This paper applies the concepts of epidemiology and nursing research to describe the epidemiology of Ebola, related determinants of health, the epidemiologic triangle, the role of community health nurse in containing outbreaks, the national agency concerned with this disease, and a global implication of this disease.
Epidemiology of Ebola
Ebola virus disease (EVD) is a severe viral illness that is potentially fatal if an infected person fails to receive timely treatment (World Health Organization [WHO], 2018). It is caused by a virus belonging to the genus Ebolavirus. The specific taxa responsible for outbreaks in Africa are the “Bundibugyo, Zaire, and Sudan” ebolaviruses (WHO, 2018, para. 4). EVD manifests as a viral hemorrhagic fever that is characterized by fever, severe migraines, muscle pain, general body weakness and fatigue, diarrhea, vomiting, abdominal pain, and hemorrhage (Centers for Disease Control and Prevention [CDC], 2018). The period from exposure to symptom onset is 2-21 days (CDC, 2018). During this time, any contact with infected blood or body secretions could cause an infection.
EVD is a zoonotic disease. Animal to human transmission occurs through direct contact with an infected mammal, specifically apes and bats (CDC, 2018). The primary portal of entry is a damaged skin or mucosa. Subsequently, the virus spreads within small local groups or large populations, resulting in an outbreak. Viral transmission between persons occurs through direct contact with blood or body secretions of an infected or dead individual (CDC, 2018). Contaminated objects (syringes), bushmeat, and semen of symptomatic males are the other modes of EVD transmission. A few weeks after contracting the ebola virus, the infected individual experiences bleeding and other complications.
Acute kidney injury is a common complication in people with severe EVD. Monitoring urine output can inform timely interventions. Another frequent complication is septic shock linked to bacterial sepsis or hemorrhagic conditions (Fletcher, Fowler, & Beeching, 2014). Advanced infection predisposes a patient to intravascular coagulation that can be fatal. EVD may cause pregnant women to miscarry. Other complications reported in survivors include abnormal physical weakness, skin desquamation, testicular inflammation, visual impairment, and hepatitis (Fletcher et al., 2014). Adequate supportive care is required to prevent these secondary conditions and increase survival.
The treatment of EVD entails intravenous administration of fluids and electrolytes (dehydration), oxygen therapy, and medication to prevent hypotension, diarrhea, and vomiting (Kaner & Schaak, 2016). Antiviral drugs for treating EVD are currently unavailable. Promising treatments include vaccines and antibody therapy, i.e., blood transfusions from survivors (Kaner & Schaak, 2016). Early detection and management of symptoms in suspected cases (demographic of interest) can help reduce the high death rate in this population.
The average EVID case mortality rate is about 50%; however, it can vary from 25% to 90% depending on the region and responses (WHO, 2018). The aggregate case incidence in the endemic countries – Guinea, Sierra Leone, and Liberia – between 2014 and 2016 was over 3,500, and to date, 11,310 cases (prevalence) have been confirmed worldwide (WHO, 2018). Documenting these statistics is important in the surveillance and control of outbreaks. EVD is a reportable disease. Suspected infections in the US can be reported to the National Notifiable Disease Surveillance System (NNDSS) (CDC, 2018). The required reporting time is within 21 days, i.e., before the person becomes symptomatic.
Determinants of Health
Various factors impact the health of persons and populations. The main determinants of health include the socioeconomic situation, physical environment, and individual characteristics. Social practices, including communal meals during burial ceremonies, ritual hand washing, sharing beds, and caring for an infected family member may result in the development of an EVD outbreak (Kaner & Schaak, 2016). Relatives of EVD patients offer routine nursing practices, increasing the risk of infection. Thus, an awareness of the Ebola transmission can reduce the high case fatality rate.
Economically, ill-equipped and poorly resourced health care systems contribute to EVD outbreaks. Risky conditions in local facilities, including inadequate masks or gowns, toughing of cadavers, and unsterilized instruments, lead to a five-fold increase in the risk of infection (Kaner & Schaak, 2016). EVD outbreaks can also be attributed to the physical environment. Exposures during late-stage illness include touching the body secretions of an infected individual and sharing meals, clothes, or a bed. Individual characteristics, including frequent contacts and consumption of bushmeat, also increase the risk of the development of an Ebola outbreak.
Epidemiologic Triangle
This model is designed to study communicable diseases and their transmission. The triangle comprises three vertices: the agent (the cause of the infection), the host (disease reservoir), and the environment (extraneous factors) responsible for transmission (Kaur, Sachdeya, Jha, & Sulania, 2017). These variables play a role in the spread of the virus in human populations.
The agent factors of the ebolavirus virus are virulence proteins encoded by its genetic material (RNA molecule). Five species of this virus are distinguished. They include “Zaire, Sudan, Tai Forest, Bundibugyo, and Reston” ebolaviruses (Kaur et al., 2017, p. 3). Their genomes exhibit wide variability in sequence and alleles. The most virulent species causing outbreaks of hemorrhagic fever in Africa are Zaire, Sudan, and Bundibugyo subtypes.
The hosts of these ebolavirus subtypes are humans and bats (natural reservoirs). People of all ages and both genders have an equal risk of infection. EVD affects the normal functioning of natural immunity. According to Kaur et al. (2017), the microbe’s viral protein diminishes a person’s immune response to infection. As a result, the body cells’ ability to destroy interferons produced by the virus is suppressed. Subsequently, the ebolavirus spreads quickly throughout the host body. The animal-to-human infection is dependent on the environment.
Human ebolavirus outbreaks that have been reported in the past indicate that environmental factors that increase the risk of infection are high humidity and cold temperatures (Kaur et al., 2017). However, some new EVD cases have been reported in dry and wet conditions. These seasons coincide with the migration of fruit bats. Contact with these ebolavirus reservoirs increases the risk of infection and disease outbreak. Bats are immune to these viruses because they maintain high body temperature through rapid flight movements (Kaur et al., 2017). Thus, they can transmit the virus without themselves getting infected. Community awareness of the cause and transmission of Ebola is critical in infection control.
Special considerations for at-risk communities, schools, or the general populations exist in the form of guidelines and control measures. They include safe burial practices, change of dietary practices (avoiding bushmeat), home-protective kits, and hand hygiene to prevent high-risk exposures (Kaur et al., 2017). Health education in schools can also alleviate stigma and misconceptions. Adequate quarantine facilities can help contain outbreaks.
The Role of the Community Health Nurse
Community health nurses provide essential services during EVD outbreaks. They are the primary providers of disease education and prevention to affected populations. Their first role is case finding. When an Ebola case is suspected, an epidemiological investigation is initiated. A team comprising of a community health nurse, an epidemiologist, and other professionals visits the area to confirm or discard a suspected case (WHO, 2018). Its first role includes collecting data from the community and local administrators about the disease.
Subsequently, a case definition is developed and all the cases observed are documented (WHO, 2018). The next step of case finding is explaining to the patient about Ebola to obtain informed consent before taking a blood sample for laboratory diagnosis and confirmation. Key behavioral, cultural, and socioeconomic information is also collected to inform the development of control programs.
The data collected during an epidemiological investigation is used to prepare a preliminary written report that is presented to local health authorities and WHO. Reporting aims to confirm or discard a suspected case. The report should identify the routes of transmission, at-risk populations, and possible causes of the outbreak (WHO, 2018). The community health nurse should relate the outcome of the epidemiologic investigation to known facts in preparing this report.
Data collection from a site follows a confirmed outbreak. A register of all suspected cases is established before the investigation commences. Subsequently, blood samples are collected for confirmatory lab tests. The crucial data collected during an epidemiologic investigation include relevant behavioral, socioeconomic, and cultural information that may promote or reduce the outbreak (WHO, 2018). The information is analyzed to confirm or discard each suspected case and design infection control measures.
The nurse has to synthesize and interpret the data obtained through the investigation. Data analysis should be done concerning time, place, and case (Kaur et al., 2017). The routes of transmission should also be analyzed based on the information collected and laboratory tests. Additionally, the likely cause of the outbreak should be determined. A comparison of the results of the analysis with facts about Ebola can help validate or disprove diagnostic hypotheses. An evaluation of the social and cultural practices can help determine the risk of an outbreak. Suspected cases should also be monitored after the epidemiologic investigation as a precautionary measure.
The follow-ups can be made based on the findings of an epidemiological investigation before the lab results are out. The nurse should identify contact individuals for all suspected, likely, or confirmed cases (Kaur et al., 2017). He or she will then follow up on the health status of the patient through these persons and record their progress on the register of cases.
National Agency or Organization
Some agencies have dedicated their efforts to the treatment, prevention, and containment of EVD, particularly in West Africa. One such organization is Doctors without Borders. Through its volunteer health workers and an EVD treatment center in Sierra Leone, it contributed to the containment of the 2014-2016 outbreaks. Doctors without Borders also have six other care facilities, including one in Liberia, dedicated to Ebola treatment. Another organization involved in containing EVD outbreaks in Africa is Project C.U.R.E. Its contribution towards this cause includes medical supplies (protective gear) to Ebola-stricken areas and training of local health workers on safe treatment processes.
Global Implication of Ebola
The 2014 Ebola epidemic had a considerable impact on the economies of the affected countries. A significant implication for healthcare was the heightened screening aimed at containing the outbreak. The epidemic proved that ill-equipped hospitals and inadequate surveillance systems are a barrier to the effective prevention of communicable diseases. In 2014, only a few African countries had equipped diagnostic facilities to isolate and identify the EVD virus. As a result, samples were shipped to European countries for testing (Kaur et al., 2017). This lengthy process hampered timely interventions. Additionally, before 2014, public health surveillance in EVD-endemic nations was weak. As such, quarantine measures were not effective, increasing contact between suspected cases and family members.
The response to this challenge has involved the development of novel diagnostic tools to ensure prompt detection and control of the virus. A portable real-time polymerase chain reaction has been developed for the onsite diagnosis of suspected cases (CDC, 2018). Additionally, serological assays are available for the early detection of outbreaks. Non-invasive diagnostic tools that utilize saliva have been developed for use in communities that object to blood-based tests due to cultural beliefs. In the wake of the 2014 epidemic, the US enhanced the screening of travelers from endemic regions at the airports to identify and quarantine suspected cases.
The same measure was implemented in other countries. Screening can help contain the spread of infectious diseases, including EVD. Ebola is considered to be endemic to West Africa. For example, the 2014 epidemic was localized to Liberia, Guinea, and Sierra Leone (WHO, 2018). However, previous outbreaks have been reported in parts of the Democratic Republic of Congo.
Conclusion
This paper has highlighted the epidemiology of the Ebola virus, identified the determinants of health, described the epidemiological triangle, and explained the nursing role in the containment of an outbreak. It is established that effective health system responses to EVD cases are those that involve community engagement. Additionally, early screening is critical in implementing control measures to curb transmission.
References
Centers for Disease Control and Prevention (CDC). (2018). What is Ebola virus disease? Web.
Fletcher, T., Fowler, R. A., & Beeching, N. J. (2014). Understanding organ dysfunction in Ebola virus disease. Intensive Care Medicine, 40, 1936-1939. Web.
Kaner, J., & Schaak, S. (2016). Understanding Ebola: The 2014 epidemic. Globalization and Health, 12, 53-59. Web.
Kaur, G., Sachdeva, S., Jha, D., & Sulania, A. (2017). Ebola virus disease in the light of epidemiological triad. Tropical Journal of Medical Research, 20(1), 1-9. Web.
World Health Organization (WHO). (2018). Ebola virus disease. Web.