Author Contributions
K NOWLEDGE AND PROTECTIVE MEASURES ADOPTED BY Q UEBEC RESIDENTS AGAINST MOSQUITOES AND W EST N ILE VIRUS
Valerie Hongoh1*, Pascal Michel1, 2, Pierre Gosselin3, 4, André Ravel1, Céline
Campagna3, 7, Jean-Philippe Waaub6, Karim Samoura1, 5
1Groupe de Recherche en Épidémiologie des Zoonoses et Santé Publique
(GREZOSP), Faculté de médecine vétérinaire, Université de Montréal, 3200 Sicotte, Saint-Hyacinthe, Québec, J2S 7C6, Canada
2National Microbiology Laboratory at Saint-Hyacinthe, Public Health Agency of
Canada, 3200 Sicotte, Saint-Hyacinthe, Québec, J2S 7C6, Canada 3Quebec National Institute of Public Health (INSPQ), 945 avenue Wolfe,
Québec, Québec G1V 5B3 Canada
4Ouranos, Consortium on regional climatology and adaptation to climate
change, 550 Sherbrooke West, Montreal, Quebec H3A 1B9, Canada
5Université Aube Nouvelle, Quartier 1200 Logement, Ouagadougou, Burkina
Faso
6 Group for Research in Decision Analysis (GERAD), 3000 Côte-Sainte-
Catherine, Montréal, H3T 2A7, Québec, Canada
7Department of social and preventive medicine, Université Laval, 2325 rue de
l’Université, Québec, G1V 0A6, Canada
101
Abstract
Recent case numbers of West Nile virus (WNV) have been low in the province of Quebec; however, spikes in incidence have occurred since it first emerged in 2002. While the majority of cases of WNV are asymptomatic, a small number result in more severe complications including death. Recommended preventive measures, including individual behaviours, are thought to be effective at reducing the risk of West Nile virus. Given ongoing concern for WNV here in Canada and global resurgence of mosquito-borne arboviruses such as Zika, there is a need to periodically examine the current state of awareness and adoption of preventive behaviours against mosquito bites in the population. Additionally, given regional differences in recent case occurrence, we examined differences in knowledge, perceptions and behaviours between two at-risk regions in Southern Quebec.
A web-based survey was administered to southern Quebec residents to assess knowledge, perceptions and adoption of recommended preventive measures against mosquitoes and WNV. Overall reported awareness (90%), knowledge of WNV transmission (76%) and practice of recommended preventive measures (85% report habitual use) was good among respondents. However, concern and perceived severity appear to have decreased since a 2004 provincial survey. No significant differences in knowledge and behaviour were found between the two examined risk regions, though some differences in perceived exposure were found. Based on an exploratory multiple correspondence analysis of all sampled respondents, four distinct groups of respondents were found. While a majority (two out of four groups) of respondents report good adoption of preventive measures, a small group were unaware of and had poor knowledge of WNV, though perceive less exposure to mosquitoes. A fourth group was found with good knowledge of WNV yet low concern and low adoption levels of recommended preventive measures compared to the first two groups.
102
These results suggest that while awareness of WNV and adoption of recommended preventive measures is generally good in the study population, motivation to adopt preventive measures is not uniform. Awareness remains paramount in cueing good preventive behaviours. Ongoing vector-borne disease education, including the existence of vector-borne diseases of concern and where disease risk regions exist in the province, will be key to reducing vector-borne and WNV risk in the future. WNV and other vector-borne disease risk regions vary in space and time in the province, therefore, it is important for public health to continue to monitor changing perceptions and behaviours as well as disease incidence in the region so that targeted messages can be sent to target populations and high risk areas at key times. This study offers insights into groups to further study and target for vector- borne disease education and awareness campaigns.
Introduction
Over the last few decades, there has been a global resurgence of mosquito-borne arboviruses such as WNV, dengue, Chikungunya, Zika virus and Yellow fever with the latter two being the most recent to cause epidemics of global concern (1–3). This resurgence of arboviruses serves as a reminder to regularly assess the population level of awareness and adoption of recommended preventive measures (RPM) against mosquitoes and mosquito- borne disease. While dengue, Chikungunya, Zika and Yellow fever do not currently circulate in Canada, WNV has been endemic in the country since 2001 and in southern parts of the province of Quebec since 2002 (4–6).
WNV is a flavivirus whose symptoms are primarily asymptomatic with one quarter exhibiting febrile symptoms and 1% resulting in more severe neurological symptoms or death (7). In Quebec, 37 human cases of WNV were recorded in the first 2 years following the disease’s appearance in the province (8). Fewer than 20 cases were recorded over the next seven years until a resurgence of the virus in 2011 when 42 cases occurred and 134 cases
103
were recorded in 2012 (8). At the time of its emergence in 2002, WNV dominated news headlines and was a Public Health and research priority. Despite the 2012 spike, cases remained relatively low in Quebec following this with only 32, 6, 45 and 30 cases recorded respectively in the province in the four years after the spike, and 9 deaths recorded since 2012 (8).
Recommended preventive measures (RPMs) in Canada (and the province of Quebec) are targeted at avoiding mosquito bites via the use of long sleeved clothing when outdoors (especially during peak mosquito activity), use of insect repellents (containing DEET, Icaridin or biopesticides), use of mosquito screens on doors and windows, as well as reducing the number of mosquitoes in one’s environment by eliminating stagnant water, and draining, covering or changing water in outdoor containers (9–11). A number of communication campaigns and assessments of population awareness of WNV and mosquito preventive behaviours have been carried out over the years since the disease’s emergence in North America (12–27). The use of personal preventive measures and environmental source reduction measures (e.g. draining or changing standing water) are estimated to be effective means of reducing illness caused by mosquito-borne diseases such as WNV (6,28).
Evaluations of knowledge, beliefs and behaviours (17,23,27,29), at times within explicit health belief model (HBM) frameworks (12,14,21,26,29), have been widely used to help identify factors that relate to the adoption of RPMs. The HBM is a theoretical model that was developed to help understand individuals’ intended adoption of preventive health behaviours based on various perception variables such as the individual’s perceived severity of a disease, perceived susceptibility to the disease, perceived barriers and benefits to adopting preventive behaviours, cues to action, knowledge about the disease and socio-demographic factors (30). Knowledge and awareness about a disease or health condition are deemed important factors in motivating an individual’s intention to adopt appropriate health behaviours,
104
though they have often been found insufficient on their own to explain RPM use (15–17,22,23). Other beliefs present in the HBM framework (31) such as perceived susceptibility and severity of WNV, perceived benefits and barriers to RPM use and sociodemographic factors have also been correlated with intended adoption of RPMs with increased levels of concern generally associated with an increased propensity to adopt an appropriate RPM (12,15,18,21).
Periodic assessments of population awareness and behaviours in Quebec reveal that awareness about WNV has generally increased since the disease first emerged in 2002, and while reported RPM use has also increased compared with evaluations done pre-emergence in the province (31), reported RPM use levels have not changed much in the 15 years since. Early 2003 provincial assessments reported 60% use of either mosquito sprays, long sleeved clothing, screens or source reduction of stagnant water (32). Focus group assessments also held in 2003 revealed that most study participants had heard of the disease but that transmission knowledge was low (27). Concern for WNV was also low. Preventive behaviour was generally motivated by the perceived presence of nuisance mosquitoes around the home with the most common strategy adopted being the avoidance of mosquitoes in the first place. Reported window and door screens use was ubiquitous among participants. A 2004 provincial assessment found that awareness of WNV was generally lower among language minorities in Quebec, low income households (under 15,000$), those with only primary and secondary education and those above 65; however, risk perception of the disease was generally found to be higher among Anglophones (33). Overall study results were found to be similar to other pan-Canadian and American surveys done around that time showing that reported awareness was generally high, knowledge of symptoms was often incomplete and concern about the disease was generally low among compared studies (33). Earlier Canadian surveys had found awareness of WNV to be around 70% and the adoption of at least one
105
preventive measure to be around the same level in assessed populations (24,26). A 2004 regional study in Quebec found a very high awareness of WNV among respondents (96%) accompanied by a high knowledge of its transmission (90% gave an acceptable response) (20). A majority (80%) of participants surveyed perceived the risk of becoming infected with WNV to be low and close to 60% perceived the severity of a potential infection to be high or very high (20). Reported repellent use was 47% and the reported use of protective clothing was 57%. A 2013 assessment in the year following the 2012 outbreak, found that 70% of Montreal metropolitan residents knew that WNV was transmitted by mosquitoes; however, risk perception had reportedly decreased (34). One third of respondents reported using long sleeved clothing and 50% reported the use of insect repellent to protect themselves from mosquito bites.
Given ongoing fluctuations in WNV case numbers in Quebec and anticipated increase in suitable climate for transmission under climate change (35), it is of interest to examine the current state of knowledge, perceptions and behaviours of the population with respect to mosquitoes and WNV in order to make more informed prevention and control decisions. We examined current knowledge and awareness of WNV, perceived exposure to mosquitoes and reported adoption of RPMs by means of an online population survey. We explored the potential relationship between these variables within our sample population by means of a multiple correspondence analysis (MCA). Additionally, given the higher number of cases and deaths from WNV having occurred in the greater Montreal area (Laval and Montérégie regions included), comparisons were made between this region and other targeted regions of the province to see whether knowledge levels, perceptions or behaviours differed between regions of the province that might explain some of the observed differences in cases.
106
Methods
A cross-sectional survey was designed to assess knowledge, perceptions and adoption of recommended preventive measures (RPMs) against mosquitoes, and WNV among English and French speaking residents of southern Quebec (Canada). Based on planned WNV surveillance locations by the province and conscious of budget constraints (36), seven regions were sampled. These regions included Montreal, Montérégie, Laval, Lanaudière, Laurentians, Outaouais, and the Quebec City region (Fig. 4) and represented close to 75% of the Quebec population in 2015 (37).