Evidence Briefs

Provide a synthesis of the best available evidence on a variety of priority topic areas as identified by leading infectious disease experts. We systematically explore the published literature using a comprehensive search strategy to identify relevant research on infection prevention, management, and control. For more information on our search strategy of the published literature, click here.
McMaster University

Knowledge and perception of risk

Mar 28, 2017

Author(s): Stephanie Vendetti-Hastie, RN, CIC, Kristin Read, MPH, & Dr. Maureen Dobbins, PhD, RN
Expert Reviewer(s): Dr. Mark Loeb, MD, MSc, FRCPC & Dr. Dominik Mertz, MD, MSc

The OutbreakHelp Evidence Briefs aim to provide short summaries of the available evidence related to priority topic areas identified by leading infectious disease experts. Content for the Evidence Briefs were developed using a comprehensive and systematic search of the academic literature from inception to December 31st 2015 (more recently published information on this topic may be available here). All results were screened for relevance using pre-defined inclusion and exclusion criteria. Included articles must have met the following criteria: 1) specific to the topic of Ebola Virus Disease (EVD), 2) human research or research with real-world applicability, 3) study in a peer reviewed journal, and 4) published in either English or French. Articles identified as relevant were tagged with priority topic areas and assessed for quality using abbreviated versions of appropriate critical appraisal tools; a 5-star rating scheme was applied to articles as relevant. Relevance screening, category tagging, and critical appraisal were independently conducted by two raters and conflicts were resolved through discussion. A thematic analysis was performed on included articles by charting and then categorizing common concepts and topics discussed in the literature. Results are summarized in a narrative. The following Evidence Brief discusses psychosocial considerations focusing specifically on evidence related to EVD knowledge and risk perceptions among both the general public and healthcare workers.

Main Message

Knowledge about EVD and perception of risk related to the outbreak appears to have an influence on safety behaviours among the general public in both EVD affected areas and abroad. Risk perceptions and adequate information also appears to be related to healthcare workers willingness to provide care to EVD patients. EVD education, information and communication that reflects factual, complete information and focuses on survival messaging may improve public risk perception and help reduce fear based reactions.  This messaging may also assist in healthcare provider recruitment for EVD response.

Knowledge, risk perception and safety behaviours of the general public

Seven studies describe knowledge, risk perceptions and safety behaviours among the general public, including those in countries experiencing EVD outbreaks as well as those in locations around the globe far-removed from outbreak areas.

A 2015 cross sectional online survey conducted in the United States (U.S.) among undergraduate psychology students (n=107) investigated psychological processes associated with EVD related anxiety and safety behaviours during the 2014 outbreak in West Africa. While overall, participants were not highly fearful of EVD on average, some of the participants were moderately fearful. Respondents performed on average a moderate amount of EVD related safety behaviours such as the use of/access to hand sanitizer, checking the internet and avoiding people during the peak of U.S. EVD concerns.  EVD fear and safety behaviours were correlated with general distress, contamination cognitions, disgust sensitivity, body vigilance and anxiety sensitivity related to physical concerns. Fear of the disease was not associated with knowledge about EVD and the outbreak. The tendency to overestimate the severity of contamination emerged as the only significant predictor of both EVD fear and associated safety behaviours (Blakey, Reuman, Jacoby, & Abramowitz, 2015).

In a U.S. internet study of a nationally representative sample (n=1018), 60% of respondents thought EVD could be spread from asymptomatic contacts, 22% thought it could be spread from the air, and 18% thought it could be spread from public door handles, shopping carts or toilet seats.  As such 64% felt that anyone who has been exposed to an EVD patient should be quarantined for 21 days and 57% thought the U.S. should impose a travel ban from affected countries in West Africa.  It is important to note that EVD is transmitted only through direct physical contact with infected body fluids and can only spread when a person is symptomatic. For more information on EVD transmission, please see the OutbreakHelp Evidence Briefs “Transmission: Setting” and “Transmission: Risk factors”.  Furthermore, thirty-nine percent of respondents planned to engage or engaged in the following behaviours: avoiding those who traveled to West Africa (39%), handwashing (35%), avoiding public transport during the holiday season (22%), avoiding health care facilities (13%), purchase of protective supplies (12%), and keeping children home from school or avoiding public places (10%) (Kelly, et al., 2015).

In another survey of a nationally representative sample of U.S. adults (n=1046) participants answered questions that measured their risk perception, information processing, negative affect and altruistic behavioural intention before and after an experimental risk perception intervention regarding EVD.  The results indicated that participants in the intervention group perceived greater risk than those in the control group (p<0.05). Further analysis regarding emotions experienced as a result of the intervention showed that participants who reported more sadness about the EVD outbreak reported more altruistic behavioural intention. In particular, when risk perception was elevated, participants who viewed the EVD outbreak as an important issue were more likely to support their families and friends to go to West Africa as EVD responders. This study demonstrated that sadness has a statistically significant direct association to altruistic behavioural intention whereas anger was shown to also have a significant but inverse association (Yang, 2015).

A community-based cross sectional study of 5322 participants in Nigeria was conducted in 2015 to assess the public preparedness level to adopt disease preventive behaviour. Knowledge and perception of EVD were assessed. Overall 33% of respondents did not know the cause of EVD. The majority (61%) felt that they could not contract EVD and mentioned spiritual and divine protection and observing appropriate precautions as the reasons for this perception. Some (41%) of respondents had stopped engaging in activities such as shaking hands, hugging, eating bush meat and stopped unnecessary contact with people. Of those who had not stopped these activities 62% reported that they would not shake hands with persons who have recovered from EVD; and 64% would not hug such persons (Gidado, et al., 2015).

In another cross sectional study in three Nigerian states, 1035 study participants were surveyed using a standardized questionnaire regarding EVD knowledge, attitudes and practices (KAP) to inform implementation of effective control measures. Scores for EVD knowledge ranged from 24.35% - 52.56% between the communities. Independent predictors for good knowledge (cut off ≥80%) of EVD were being a healthcare worker (n=42.6%) (OR 2.89, 95% CI 1.41-5.90), reporting moderate to high fear of EVD (OR 2.15, 95% CI 1.47-3.13), and willingness to modify a habit (OR 1.68, 95% CI 1.23-2.30). The proportion of healthcare workers with good attitude (cut off >90%) was 38.3% compared to 68.4% among non-healthcare workers (p=0.0001) (lliyasu, et al., 2015).

In a 2015 online survey of the Israeli public (n=327), respondents were highly (22.65%) or moderately (33.4%) concerned about contracting EVD, though the disease had not spread to Israel. Although 91.3% of respondents reported that anyone could contract infection, 25% reported it was transmitted through air droplets, 12% did not know how it was transmitted, and 30% of respondents believed that a specific EVD treatment or vaccine was available (Gesser-Edelsburg, Shir-Raz, Hayek, & Lev, 2015).

Another study from 2002, conducted in Britain, examined EVD themes in 48 broadsheet and tabloid articles and in-person interviews with 50 members of their readership. Analysis of themes reveals a common picture that EVD is seen as an African disease, associated with African practices and posing little threat to Britain. Issues regarding EVD spread were generalized to include poverty, tribal rituals, poor hospital hygiene and water quality, monkeys and forests. While the newspapers made EVD real by referring to its potential to globalize, some respondents felt detached from it, drawing an analogy between EVD and science fiction (Joffe & Haarhoff, 2002).

Risk perception and willingness to provide care among health care providers

A 2015 cross-sectional descriptive survey in Korea identified factors predicting 179 clinical nurses’ willingness to care for EVD infected patients. A total of 73.2% of participants answered that they were not willing to provide care for EVD patients.  Willingness to provide care for EVD patients was 4.1 times higher when there was a high belief in public services (95% CI: 1.687, 9.953), 0.04 times lower when EVD risk perception was high (95% CI: 0.245, 0.798), and 0.9 times lower with an increase in participants age (95% CI: 0.879, 0.986) (Kim & Choi, 2015).

Willingness to provide care to EVD patients was also assessed among pediatric health care providers (n=245) in the United States using a standardized questionnaire. Ninety-three percent of respondents reported that they would come to work and 80% would examine an EVD patient. Eighty-six percent of respondents felt that they would be safe at work and claimed a high degree of willingness to care for and perform procedures on EVD-suspected patients, however, overall mean knowledge scores from the survey were 56%. Only 16% of all health care workers felt they had received sufficient information and training to care for an EVD patient. Forty-nine percent felt their family members might avoid them if they cared for a patient with EVD, while 38% felt they might potentially infect their family if they cared for a patient with EVD (Highsmith, Cruz, Guffey, Minard, & Starke, 2015).

In Europe, medical and public health specialists completed an online survey in 2015 about their decisions to apply for EVD response missions. Of the total respondents (n=368), 49 (15%) had applied for recent EVD missions to West Africa. Applicants less often considered a mission to West Africa as very dangerous (11% vs 43%; p<0.001) and less often worried about an EVD infection (23% vs 52%; p<0.001). Applicants were more often trained in the field epidemiology (76%), had experience in international outbreak missions (59%), had confidence in their EVD knowledge (91%), considered themselves qualified (90%), and knew how to protect themselves (94%). Factors hindering applications included family concern (87%), family refusal (62%), and current job requirements (62%). The need to use personal protective equipment (16%), the possibility of quarantine (17%), or stigmatization upon their return (11%) did not seem to be of major concern (Rexroth, et al., 2015).

UK healthcare workers (n=3109) also participated in an online survey regarding workers’ attitudes on volunteering to help with the EVD outbreak in West Africa. The most important factors preventing those from considering volunteering was a lack of information, fear of getting EVD, and a partner’s concerns. Of those who had decided not to go, their partner’s concerns was the most important factor; this was followed by concerns about leaving family and fear of EVD. Of those who had already volunteered, fear of EVD was ranked as most important barrier followed by concerns regarding repatriation (Turtle, et al., 2015).

Among US nurses (n=966) who were surveyed regarding perceptions of caring for EVD patients (suspect, patients under investigation (PUI), confirmed), 48.4% felt prepared in protecting themselves from contracting EVD, 25.2% were concerned they would contract EVD and 46% felt they should be able to opt out of caring for confirmed EVD patients and PUIs (39.2%). More than half (53.5%) of the respondents reported that their family influenced their decision to care for PUI or confirmed EVD patients. Most often nurses reported that their willingness to care for an EVD patient would be negatively affected by the fear of transmitting EVD to loved ones (66.9%), the fear of contracting EVD (52.2%) or an imposed quarantine (32.8%) (Speroni, Seibert, & Mallinson, 2015). These authors further explored the qualitative comments received in this survey (n=618) and found 20.5% of respondents felt unprepared or ready to care for EVD patients due to such factors as lack of support by authorities, inadequate resources/guidelines, staffing concerns, and protective policies, procedures and equipment. Furthermore, 16.2% reported the need for training, education and improved communications and 15.4% reported  fear of EVD transmission including infecting family members, becoming infected, contamination of self/dying and concern for open US borders (Speroni, et al., 2015).

U.S. internists (n=202) also participated in a cross-sectional web-based national survey regarding EVD where 66.3% of respondents either agreed or strongly agreed that they accepted the risk of contracting EVD as part of their job. Nine percent expressed fear of contracting EVD, 15.8% reported that their physician colleagues had this fear, and 37.1% indicated that the fear was present among their non-physician colleagues. Most respondents felt very prepared (45%) or somewhat prepared (52%) to communicate information about or diagnose EVD. While the CDC was the most popular reported source for EVD information (75.2%) 53.5% and 55% used the internet and TV news as sources of information (Ganguli, Chang, Weissman, Armstrong, & Metlay, 2015).

Professional commitment and dedication of self to others were also described as being important factors influencing the willingness of HCWs to provide care (Locsin, Kongsuwan, & Nambozi, 2009).


Evidence suggests that the behavioural and emotional responses to outbreaks may contribute significantly to the perception of the epidemic or disease, its spread, and the effectiveness or failure of preventive and control strategies (Ogoina, 2016). Public health measures employed to prevent and control EVD spread should be evaluated for potential negative unintended psychosocial consequences prior to and during implementation.


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