Study characteristics
Of the 22 studies reviewed, the majority were conducted in Cambodia (n = 10), followed by Vietnam (n = 4), Myanmar (n = 3), Thailand (n = 2), Laos (n = 1), Thai-Burmese border (n = 1), and Vietnamese-Cambodian border (n = 1) (Table
2). Articles were published between 1986 and 2018, with the majority published after 2014 (16/22; 72%) illustrating a growing trend in qualitative studies in recent years. The studies utilized various data collection techniques, including individual interviews (n = 21), participant observations (n = 17), and in-depth group discussions (n = 10). Of the 22 studies, 13 employed a mixed-methods approach combining qualitative and quantitative methods, such as questionnaire-based surveys and focus group discussions. In most studies, forest-goers were not the primary focus, and instead were among other respondents which included community leaders, health providers and malaria patients.
Table 2
Characteristics of the reviewed articles
Adhikari | 2018 | Laos | 11 months (Sep 2015 to Aug 2016) | 12 FGDs with 100 participants | 31 | Yes |
Bannister-Tyrrell | 2018 | Vietnam | 2 months (April to June 2016) | No | 22 in-depth interview, 10 informal conversations | Yes |
Chen | 2017 | Vietnam | 2 months (Dec 2015 to Jan 2016) | | 61 | |
Crawshaw | 2017 | Myanmar | Unspecified | 42 | 5 | |
Grietens | 2010 | Vietnam | 3 months (July 2005 to September 2006) | | 101 | Participated in everyday activities inc. forest activities |
Grietens | 2012 | Vietnam | 3 months (between July 2005 and September 2006) | Yes | Semi-structured | Ethnography |
Grietens | 2015 | Cambodia | Unspecified (during 2012) | | Yes | Yes |
Gryseels | 2013 | Cambodia | 4 months (April to July 2010) | | 126 | Yes |
Gryseels | 2015a | Cambodia | Between 2012 and 2013 | | 320 individual interviews and 759 informal conversations | Smelt household member’s arms for repellent |
Gryseels | 2015b | Cambodia/Vietnam Border | 5 months (between 2008 and 2010) | | 257 | Observed daily life |
Gryseels | 2015c | Cambodia | Unspecified (during 2012) | | 153 | Yes |
Lim | 2017 | Cambodia | 3 days in each village (20) | 1 | 18 | Yes |
Liverani | 2017 | Cambodia | 2013 duration unspecified | | 71 | |
Lyttleton | 2016 | Thailand | 2 weeks in November 2014 | | Yes | Observed daily life, health outreach activity |
Panvisavas | 2001 | Thai Myanmar Border | 8 months in 1999 | 5 | Yes | |
Pell | 2017 | Cambodia | 2015 and 2016 | Yes | 40 | Yes |
Sahan | 2017 | Myanmar | 4 months (March to July 2015) | | 45 | Yes |
Shafique | 2016 | Cambodia | 8 months (August 2010 to March 2011) | 6 | 13 | Yes |
Singhanetra-Renard | 1986 | Thailand | June 1985 to March 1986 | | Yes | Yes |
Taffon | 2018 | Cambodia | 4 months (December 2015 to March 2016) | 86 | 9 | Yes |
Verschuere | 2017 | Cambodia | 4 months (August to November 2013) | 7 (49 participants in total) | 42 | Observed daily life |
Wharton-Smith | 2014 | Myanmar | 2 months (May to June 2014) | Yes | Yes | |
Understanding of malaria
In most of the reviewed sources, respondents demonstrated a basic understanding of malaria and its symptoms. However, in one study along the Thai/Burmese border, malaria was viewed as a symptom rather than a disease [
18]. Mosquito bites were often described as the cause of malaria, and misconceptions regarding the mode of transmission were common: malaria was linked to drinking or bathing in contaminated water, exposure to contaminated wind, tiredness, ill health, poor hygiene, or eating specific foods. In Cambodia, supernatural deities, ghosts, sorcery and forest spirits were reported as causes of malaria [
19‐
23].
Study respondents commonly associated visits to the forest with increased risk of contracting malaria [
22‐
27] and, in Myanmar, malaria was even referred to as forest-sickness [
18]. Despite risking malaria infection, respondents described that visiting forests was essential for sustenance, usually from swidden farming, hunting or logging. In some settings, malaria was perceived as an insignificant risk because mosquitoes in the forest were not seen as malaria vectors [
28] or because only unhealthy individuals could become infected [
29]. In one article, the ease with which malaria could be treated also reduced the perceived danger of malaria infection [
25]. Study respondents referred to fever and chills as the main symptoms of malaria [
18,
21]. However, understanding of asymptomatic malaria was discussed in only one article [
24].
Risky behaviour
Several behaviours that place forest-goers at increased risk of malaria were identified. Socializing during the evenings and delayed sleeping times led to inconsistent bed net usage and increased exposure to mosquito vectors [
30,
33]. In one study, a respondent was aware of this risk and would therefore spend leisure time under a bed net to avoid mosquito bites [
27]. A common misconception among respondents was that alcohol consumption provided protection against mosquito bites and thus malaria [
27,
29,
34]. Blankets were perceived to provide sufficient protection against mosquito bites while sleeping [
27,
31,
34,
37] leading to reduced bed net usage. Respondents in one study reported being bitten by mosquitoes when urinating and defecating at night or in the early morning due to the lack of mosquito-proof latrines in the forest [
33]. The illegal nature of some of the activities carried out in the forest resulted in some respondents resorting to night-time work when mosquito vector densities are higher [
25,
31].
Many forest-goers missed participating in malaria prevention interventions such as MDA [
18,
21,
24], active case detection [
26], bed net distributions [
27], and the dissemination of health information [
22,
27,
29,
34]. Activities that promoted appropriate prevention practices through village drama projects [
20] and positive deviance, a method that encourages preventive behaviours already found in the community [
22], were well received, with respondents reporting behavioural changes and increased uptake of malaria prevention methods. Some respondents therefore requested that they be informed prior to the start of these activities so that they could arrange being back in the village in order to attend [
21] or requested that these activities take place more often [
27].
Treatment-seeking behaviours
With diverse malaria treatment outlets available, treatment seeking was highly heterogeneous among forest-goers and often involved multiple points of care. Treatment choices were influenced by socio-economic factors, local medical traditions, accessibility and quality of service.
Traditional medicine and healing practices such as coining (a traditional dermabrasion therapy used to relieve fevers), fanning and fever baths were commonly reported as ways of alleviating malaria symptoms [
18,
19,
22,
23,
34,
38]. In some cases, traditional medicine was used before seeking biomedical treatment in the public or private sector [
18,
22,
38]. For others, traditional medicine was a last resort if symptoms did not improve after taking anti-malarials [
19,
23]. The perceived cause of the disease also played a role in respondents’ choice of treatment: they were more likely to resort to traditional medicine when they suspected malaria to have a supernatural cause [
19].
Self-treatment (using drugs purchased from pharmacies, groceries and mobile vendors) was frequently reported [
22,
23,
29,
38]. Respondents in two studies described taking drugs with them to the forest in case they fell ill [
19,
29]. A variety of treatment options were available from drug outlets, including artemisinin-based combination therapy (ACT), artemether injections and drug cocktails which consisted of antibiotics, anti-pyretics, artemisinin monotherapies or chloroquine [
19]. In one study, drug cocktails and artemether injections were the preferred choice of treatment because they were considered to be more effective, offered faster relief and had milder side effects when compared to ACTs [
19].
In several articles, study respondents failed to adhere to the full course of treatment because they could either not afford it [
19] or would terminate treatment once symptoms had resolved [
25,
29]. Although the preference for self-treatment often stemmed from convenience and ability to avoid undesired drugs, such as the ACT artesunate-mefloquine, which was perceived to be associated with severe side effects, one Cambodian study demonstrated that health-seeking patterns also depended on the type of malaria diagnosis, with respondents more likely to self-treat if diagnosed with
Plasmodium vivax compared to
Plasmodium falciparum [
23].
Across the GMS, public health facilities provide malaria diagnosis and treatment free of charge. Nevertheless, there was a general preference for the private sector among respondents. This was attributed to the poor accessibility of public health facilities [
22,
24] and long waiting times [
23]. Respondents also preferred the private sector for its superior customer service and flexible opening hours [
19,
23,
29,
38]. In certain settings, such as in Vietnam and Thailand, a national identity card was a requirement for accessing free services provided at health centres [
23,
29] and as a result, many migrants (mostly from neighbouring countries) did not have free access and therefore frequently sought cheaper treatment in the private sector. In one study, respondents were deterred by hidden costs, such as consultation fees, that had to be paid in the public sector [
29].
In four articles, community health workers (CHWs), who support public health coverage in remote and rural villages, were described as the first point of treatment once malaria was suspected [
19,
21,
23,
24]. Nevertheless, CHWs were viewed as unreliable [
19,
22,
38] because they were either unavailable [
38], unwilling to visit patients who lived far away [
38], or ran out of rapid diagnostic tests (RDTs) and treatment [
19]. Some respondents were also disgruntled by CHWs’ limited capacity to treat only malaria [
22,
38] and would therefore seek diagnosis and treatment from alternative health providers if they were unsure whether they had malaria or if they suspected secondary illnesses.