Ebola Disease

Ebola Disease

Ebola disease is a deadly disease caused by Ebola virus (Zaire ebolavirus). This zoonotic disease involves people and animals. There are other three strains of ebolaviruses that cause the ebolavirus disease: Sudan virus, Burundibugyo virus, and Tai Forest virus Center for Disease Control, 2023). Reston Ebola virus is not pathogenic to human beings. It infects non-primates. Other species of ebolaviruses are not known to infect people. Ebolavirus disease lethal hemorrhagic fever syndrome that presents with fever, fatigue, headache, abdominal pain, diarrhea, and musculoskeletal pain (CDC, 2023). It takes 2 to 21 days to display symptoms for people infected with Ebola virus. About 30 to 90% of cases result in dead depending on the infection and strain.   

Where is Ebola Disease from?

Ebola disease has been around for four decades. It originated from Africa continent. It first appeared in 1976 in Democratic Republic of Congo and Sudan. It then spread to other African countries such as Gabon, Nigeria, Sierra Leon, Liberia, Guinea, and Mali. While it has been eradicated in other countries, it remains endemic in Sub-Saharan and West Africa. The increased frequency of cases of Ebola virus in these regions can be attributed to power surveillance and monitoring systems, poor health public infrastructure and systems, increased urbanization, and political instability (Rugarabamu et al. 2020).

Virology of Ebola Disease       

Ebola virus belongs to the Filovidae family. The virus is made up of a single-stranded Ribonucleic acid (RNA). When the virus infects cells, they turn into the production factory to make large quantities of new virions. To promote transmitting infections, the virions are released to infect more human cells.

Emergence of Ebola Disease

The first cases of Ebola disease were discovered when two simultaneous outbreaks of lethal hemorrhagic fever occurred in the Democratic Republic of Congo and Sudan in 1976. The first outbreak occurred near the Ebola River valley, DR Congo while the second outbreak happened 850 kilometers away in the present day South Sudan. At first, public health personnel treated these outbreaks as a single event related to an infected individual who visited both locations. Investigations later found the outbreaks unrelated. The discovery showed that viruses that caused the outbreaks came from two different sources (CDC, 2023). Additionally, the two viruses were genetically distinct. This prompted scientists to investigate the origin and host reservoir of these viruses.

            In 1994, outbreaks were recognized again in several remote areas parts of West African countries like. Between 2014 and 2016, the frequency of outbreaks intensified and transmission spread to urban areas (CDC, 2023). The massive outbreaks of Ebola disease happened in Sierra Leon, Guinea, and Liberia in the 2014-2016 period. The period reported more cases and deaths than any other period. Similarly, several countries outside Africa were affected including Spain, UK, U.S., and Italy. Zaire ebolavirus has emerged 30 times since its recognition in 1976 (Jacob, et al., 2020).

The origin of Ebola disease is unknown. However, Ebolaviruses are common in western and central African forests. African rainforests constitute a common habitat for the Ebolavirus emergence, offering abundant animal biodiversity (WHO, 2023). Ebola disease outbreaks occur during wet seasons, characterized by fruit abundance. Experts believe the Ebola virus lives in fruit bats, which are found in Africa. Bats spread Ebola virus to humans or wild animals by a mechanism yet to be known. Scientists noted that Ebola disease could be spread to persons when handling animals infected by the virus. The Ebolaviruses may well have lived long before the 1976 outbreaks. Forest encroachment and consumption of game meat may have led to exchange of ebolaviruses between people and wild animals (CDC, 2023).

How is It Spread?

The Ebola virus is spread by infected blood or body fluids of a person with the virus. Persons can get the ebolavirus from semen, urine, saliva, vomit, diarrhea, stool, and sweat of an infected person. Direct contact implies a person’s broken skin, mouth, eye or nose touch contaminated body fluids of an individual infected by Ebola virus (CDC, 2023). Contaminated objects, bed sheets, and clothing also transmit the infection. Direct contact with deceased or sick person can spread the virus. Deceased persons due Ebola disease are virulent. Certain burial practice also puts a person at risk of infection (WHO, 2023). Pregnant and breastfeeding mothers who recover from acute Ebola disease can still spread the virus in breastmilk.  

Prevention of Ebola Disease

When traveling or living in endemic areas, one can take various measures to protect themselves and prevent the transmission of Ebola disease. One such measure is avoiding contact with body fluids and blood of people infected with the virus. One can also protect themselves by avoiding sexual intercourse with an infected person. In addition, avoid direct contact with contaminated clothing and objects (CDC, 2023). People should avoid burial practices involving touch the deceased who is confirmed or suspected to have died of Ebola disease. More importantly, avoid contact with nonhuman primates, fruit bats, and forest antelopes (CDC, 2023). People returning from an area affected by Ebola disease should observe their health for three weeks for any symptoms. Healthcare providers caring for patients with the virus should observe standard precautions such as respiratory hygiene, hand hygiene, and wear protective equipment (WHO, 2023). Laboratory workers handling biological samples from animals and humans for Ebola infection investigation must take standard precautions by handling the samples in equipped labs (WHO, 2023).   

            Scientists are yet to identify the reservoir host of Ebola virus. Without knowing the natural host it becomes difficult implementing programs to eradicate or control transmissions to people. In addition, there is presently no vaccine or antiviral therapy for treating the disease in people that are infected. It is advisable to isolate the infected person to prevent the spread. People caring for the infected persons need to wear protective equipment to contain the spread. The virus persists in patients who have recovered from Ebola disease for several months (Keita, et al., 2021). This persistence becomes a potential source of viral infection for new outbreaks in the absence of proper management.

References

Center for Disease Control and Prevention. (2023). What is Ebola disease. https://www.cdc.gov/vhf/ebola/about.html

Jacob, S.T. et al. (2020). Ebola virus disease. Nature Reviews Disease Primer, 6(13).

Keita, A.K. et al. (2021). Resurgence of Ebola virus in 2021 in Guinea suggests a new paradigm for outbreaks. Nature, 597:539

Rugarabamu, S., et al. (2020). Forty-two years of responding to Ebola virus outbreaks in Sub-Saharan Africa: a review. BMJ Glob Health, 5(3):e001955. doi: 10.1136/bmjgh-2019-001955

World Health Organization. (2023). Ebola virus disease. https://www.who.int/news-room/fact-sheets/detail/ebola-virus-disease