amisurjo83-blog

[amisurjo83-blog]

Abstract

Ebola virus disease (EVD), a fatal viral hemorrhagic illness, is due to infection with the Ebola virus of the Filoviridae family. The disease has evolved as a global public health menace due to a large immigrant population. Initially, the patients present with nonspecific influenza-like symptoms and eventually terminate into shock and multiorgan failure. There exists no specific treatment protocol for EVD and only supportive and symptomatic therapy is the line of treatment. This review article provides a detailed overview of the Ebola virus; it's clinical and oral manifestations, diagnostic aids, differential diagnosis, preventive aspects, and management protocol.

Keywords: Ebola virus, oral manifestations, public health menace, symptomatic therapy

Introduction

Ebola, earlier termed as Ebola hemorrhagic fever (EHF), is a critically lethal ailment which primarily affects the humans and nonhuman primates. Ebola virus disease (EVD) occurs due to a virus infection which belongs to the family Filoviridae and genus Ebolavirus.[1] EVDs has posed diagnostic challenges and has been a universal public health threat since its discovery. While investigating an alleged yellow fever case, Dr. Peter Piot in the year 1976 first detected the disease in Zaire, Africa (presently the Democratic Republic of Congo).[2] The name “Ebola” was termed as the disease was noticed near the Ebola river in Congo.[3]

Fruit bats of Pteropodidae family, such as Hypsignathus monstrous, Epomops franqueti, and Myonycteris torquata serve as the natural hosts of the EBOV in Africa. Nonhuman primates may develop the infection by eating the partly eaten fruits and may also transmit the infection to humans.[4] Indian population is an impending threat to EVD, as India falls in the home range of Pteropodidae family of fruit bats.[5]

Ebola virus transmission primarily takes place through close bodily contact with the infected patient or their fluids, contaminated tissue surfaces, and clothing from alive, infected or deceased individuals. Unsafe traditional burial practices also play a pivotal role in the disease transmission.[6] There is documented evidence regarding the sexual mode of disease transmission, although transmission through the air is unlikely.[7]

EVD present with bizarre and atypical manifestations mimicking other viral diseases, especially in the initial disease phase. Constitutional symptoms, such as fever, myalgia, headache, vomiting, and diarrhea are the early presenting features. Hemorrhagic rash, internal and external bleeding are usually the warning manifestations in the late stages.[8] Bleeding from the body apertures is a distinguishing EVD manifestation.[9] Gum bleeding, odynophagia, and atypical oral manifestations constitute the oral features of EVD.[10]

Till date, there is no precise antiviral management or vaccination for EVD. The management protocol mainly relies on supportive and symptomatic therapy, along with monitoring coagulopathies and multiorgan dysfunction.[2]

The World Health Organization (WHO) affirmed the EVD outbreak as a “Public Health Emergency of International Concern” on August 8th, 2014.[5]

With the enormous immigrant population, India is estimating the likelihood of a probable EVD outbreak. The Ministry of Health and Family Welfare, Government of India, in collaboration with other agencies has appraised the situation and recommended travel instructions by air, land, and sea and health care professionals.[11]

Taxonomy

The virus belongs to the Ebola virus genus, Filoviridae family, and Mononegavirales order.[12] The genus Ebolavirus includes the following species- Zaire ebolavirus (EBOV), Reston ebolavirus (RESTV), Bundibugyo ebolavirus (BDBV), Taï Forest ebolavirus (TAFV), Sudan ebolavirus (SUDV), and the newly identified Bombali ebolavirus (BOMV).[13] Except for exclusive identification of RESTV in the Philippines, all the other species causes endemic West African EVD.[14]

EBOV responsible for the EHF causes the highest human mortality (57%–90%), followed by SUDV (41%–65%) and Bundibugyo virus (40%). TAFV has caused only two nonlethal human infections to date, whereas RESTV causes asymptomatic human infections.[15]

Figure 1 shows the taxonomy of Ebola virus.

Figure 1   

Figure 1

Taxonomy of Ebola virus

Transmission

Based on the Centers for Disease Control and Prevention (CDC) classification, Ebola virus is considered as a biosafety level 4 and category A bioterrorism pathogen with an immense likelihood for massive nationwide transmission.[16]

Source of Infection

Intimate physical contact with the patients in the acute disease stages and contact with the blood/fluids from the dead individuals constitutes the most important modes of transmission.[17]

The long-established funeral ceremonies in the African countries entail direct handling of the dead bodies, thus significantly contributing to the disease dissemination. Unsafe conventional burial procedures accounted for 68% infected cases in 2014 EVD outburst of Guinea.[18]

EBOV RNA may be identified for up to a month in rectal, conjunctival, and vaginal discharges and semen specimens may demonstrate the virus presence up to 3 months, thus signifying the presence of EBOV in recuperating patients.[14] The sexually transmitted case of EVD has been reported between a convalescent patient and close family member. Another study demonstrated a case in a recuperating male patient. The patient's semen specimen tested positive with Ebola viral antigen almost 3 months after the disease onset.[19]

Asymptomatic EBOV carriers are not infectious and do not have a major role play in the EVD outburst, and the field practice in Western Africa supported this assumption.[20] However, this presumption was refuted after the documentation of a pioneer asymptomatic carrier case in North Gabon epidemic (1996).[21]

EBOV has been detected from blood, saliva, semen, and breast milk, while RNA has been isolated from sweat, tears, stool, and on the skin, vaginal, and rectal swabs, thus highlighting that exposure to infected blood and bodily secretions constitute the major means of dissemination.[22]

Eating uncooked infected animal meat such as bats or chimpanzees account significantly to oral EVD transmission, especially in the African countries.[23] The demonstration of the Ebola virus in the Filipino pigs in 2008 triggered the likelihood of an extensive range of possible animal hosts.[24]

EVD dissemination has also been reported with hospital-acquired infections, particularly in areas with poor hygiene conditions. The infected needles usage was responsible for the 1976 EVD outbreak in Sudan and Zaire.[25,26] Improper hygiene and sterilization were the crucial factors for the 1967 Yambuku EVD outburst.[27]

EVD dissemination may also occur through the inanimate materials with infected body secretions (fomites).[19] However, disease transmission through the airborne and droplet infection is ambiguous.[10]

Figure 2 shows the primary and secondary transmission of disease.

Figure 2   

Figure 2

Primary and secondary transmission

Table 1 depicts the possible routes of transmission.

Table 1   

Table 1

Possible routes of transmission

Epidemiology

The vast majority of EVD cases and outbursts have been endemic to African continent ever since the disease detection in 1976,[28] and 36 such outbreaks have occurred in six African countries.[29]

Table 2 shows Ebola epidemiological outbreaks between 1976 and 2014.

Table 2   

Table 2

Ebola outbreaks between 1976 and 2014 (Adapted from WHO 2014)

The 2014–2016 EVD started in South East Guinea rural surroundings and eventually became a global public health menace by rapidly disseminating to urban localities and other countries.[28]

Figure 3 depicts the geographical distribution of Ebola virus disease.

Figure 3   

Figure 3

Geographic distribution of Ebola virus disease outbreaks

The conducive environmental surroundings of the African continent facilitate EVD endemicity. However, intermittent imported Ebola cases have also been noticed in United States, United Kingdom, Canada, Spain, and Thailand.[30,31]

Figure 4 depicts the distribution of Ebola virus disease in West African Countries.

Figure 4   

Figure 4

Distribution of Ebola virus disease in West African Countries

Out of the unparalleled globally reported 28,616 cases and 11,310 casualties, Liberia accounted for almost 11,000 cases and over 4,800 deaths.[32]

Table 3 shows the statistics of the 2014–16 West African outbreak.

Table 3   

Table 3

Statistics of 2014-16 West African outbreak

Pathogenesis

Ebola viruses penetrate the human body through mucous membranes, skin lacerations/tear, close contact with infected patients/corpse, or by direct parental dissemination.[33] EBOV has a predilection to infect various cells of immune system (dendritic cells, monocytes, and macrophages), endothelial and epithelial cells, hepatocytes, and fibroblasts where it actively replicates by gene modulation and apoptosis and demonstrate significantly high viremia.[34] The virus reaches the regional lymph nodes causing lymphadenopathy and hematogenous spread to the liver and spleen promote an active inflammatory response.[35] Release of chemical mediators of inflammation (cytokines and chemokines) causes a dysregulated immune response by disrupting the vasculature system harmony, eventually causing disseminated intravascular coagulation and multiple organ dysfunction.[36]

Figure 5 demonstrates the pathogenesis of Ebola virus disease.

Figure 5   

Figure 5

Pathogenesis of Ebola virus disease

Clinical Features

Due to the bizarre and atypical manifestations in the initial phase, mimicking dengue fever, typhoid fever, malaria, meningococcemia, and other bacterial infections, EVD poses diagnostic dilemmas.[37]

The incubation period ranges from 2 to 21 days. However, symptoms usually develop 8–11 days following infection.[38,39]

The initial disease phase is represented by constitutional symptoms.[40] High-grade fever of >38o C is the most frequently reported symptom (85–95%), followed by other vague symptoms such as general malaise (85–95%), headaches (52–74%), dysphagia, sore throat (56–58%), and dry cough.[41,42] The progressively advanced disease is accompanied by abdominal pain (62–68%), myalgia (50–79%), nausea, vomiting, and diarrhea (84–86%).[41]

Variety of hemorrhagic manifestations forms an integral component of the late disease phase.[38] Gastrointestinal tract bleeding manifests as petechiae, hematuria, melena, conjunctival bleeding, contusion, or intraperitoneal bleeding. Mucous membrane and venipuncture site bleeding, along with excess clot formation may also occur. As the features advances with time, the patients experience dehydration, confusion, stupor, hypotension, and multiorgan dysfunction, resulting in fulminant shock and ultimately death.[43,44]

Maculopapular exanthema constitutes a characteristic manifestation of all Filovirus infection, including EVD.[45] The rash usually appears during the 5th to 7th day of disease and occur in 25–52% of patients in the past EVD outbreaks.[46]

Table 4 shows the clinical manifestations of Ebola virus disease.

Table 4   

Table 4

Clinical manifestations of Ebola virus disease

Although EVD has a number of similar features with other viral hemorrhagic fevers (e.g. dengue), there are differences that set them apart.

Table 5 depicts the differentiating features of the Ebola virus and dengue virus infection.

Table 5   

Table 5

Differentiating features of Ebola and dengue virus infection

Orofacial features

Gum bleeding, atypical mucosal lesions, and odynophagia comprise the distinctive oral manifestations. Epistaxis (nasal bleed), bleeding from venipuncture sites, conjunctivitis, and cutaneous exanthema are the other manifestations.[9] Bleeding tendencies and gum bleeding is not seen in asymptomatic or initial EBOV patients reporting to the dental hospital.

EVD dissemination in the field of oral and dental health may appear nonsignificant; although, probable situations which may pose a risk to dental health professional have been appraised by Samaranayake et al.[21] and Galvin et al.[10]

Table 6 depicts the various orofacial manifestations of Ebola virus disease

Table 6   

Table 6

Orofacial manifestations of Ebola virus disease

Diagnosis

[amisurjo83-blog]

Why we need to know about this new virus

The concern regarding this rapidly spreading virus is well-deserved. At this writing, statistics on infections and deaths worldwide are truly sobering.

Unfortunately, the numbers are likely to rise as efforts to quickly contain its spread have proven unsuccessful. So, it’s particularly important to get reliable information about what is happening and to find out what you can do to protect yourself.

Beware: Misinformation is rampant

Just as the number of people and countries affected by this new virus have spread, so have conspiracy theories and unfounded claims about it. Social media sites, including Facebook, Twitter, YouTube, and TikTok, have seen a number of false and misleading posts, such as:

“Oregano Oil Proves Effective Against Coronavirus,” an unfounded claim

a hoax stating that the US government had created and patented a vaccine for coronavirus years ago, shared with nearly 5,000 Facebook users

a false claim that “coronavirus is a human-made virus in the laboratory”

sales of unproven “nonmedical immune boosters” to help people ward off 2019-nCoV

unfounded recommendations to prevent infection by taking vitamin C and avoiding spicy foods

dangerous suggestions that drinking bleach and snorting cocaine can cure coronavirus infection

a video with useless advice about preventing infection with the new coronavirus by modifying your diet (for example, by avoiding cold drinks, milkshakes, or ice cream). This video, which demonstrates the removal of a parasitic worm from a person’s lip, is many years old and has nothing to do with the current virus.

Facebook is trying to fact-check postings, label those that are clearly false, and reduce their ranking so they are less prominently displayed. Twitter, YouTube, and TikTok have also taken steps to limit or label misinformation. But it’s nearly impossible to catch them all, especially since some are in private social media groups and are harder to find.

Don’t forget about the flu

While news of a novel and deadly virus spreading across the globe may be terrifying, it’s important to recognize that there’s another, more familiar virus in this country to be concerned about:  it’s the flu. According to the CDC, there have already been up to 51 million cases of the flu this season, leading to hundreds of thousands of hospital admissions and up to 55,000 deaths.

Getting a flu shot is a great first step if you’re worrying about avoiding illness. Other measures to protect yourself from the flu (such as staying away from others who are sick and taking care to not infect others if you’re sick) are basic strategies that can also help you avoid the new coronavirus.

Reliable online sources on the new coronavirus and COVID-19

While no one source of information is perfect, some are undeniably better than others! It’s best to look for sites that:

rely on experts who use well-accepted scientific analyses and publish their results in reputable medical journals

have a mission to inform and protect the public, such as the CDC and the WHO, which recently added a myth busters page to its information on the virus

are not promoting or selling a product related to the information provided.

Other good online sources of information on the virus include:

Medline Plus, from the US National Library of Medicine

the UK’s National Health Service

the US Food and Drug Administration

major news outlets with deep expertise in health reporting, such as The New York Times, The Washington Post, and The Boston Globe’s STAT News.

While gathering information online may be your easiest initial option, isolate yourself and contact your doctor if you have symptoms of an infection, such as fever, cough, or shortness of breath. (If you don’t have a doctor, call the nearest clinic for advice.) If necessary, a doctor may recommend that you see a specialist at an academic medical center (such as a hospital affiliated with a major medical school) who is likely to have the most recent information about a previously unknown infectious illness like this one.

The bottom line

When considering a new infectious disease about which so much is still unknown, it’s important to seek out reliable information and act on it. Be skeptical of implausible conspiracy theories or claims of “fake news” that dismiss recommendations from public health officials. Addressing the concerns surrounding the new coronavirus requires accessible, reliable, and frequently updated information; the best we can do is to look to the experts whose mission it is to protect public health.