Malaria Journal Jaiteh et al. Malar J (2019) 18:39 https://doi.org/10.1186/s12936-019-2672-7 RESEARCH Open Access Community perspectives on treating asymptomatic infections for malaria elimination in The Gambia Fatou Jaiteh1,2,3* , Yoriko Masunaga1,3, Joseph Okebe2, Umberto D’Alessandro2,5, Julie Balen6, John Bradley5, Charlotte Gryseels1, Joan Muela Ribera4 and Koen Peeters Grietens1 Abstract Background: Innovative and cost-effective strategies that clear asymptomatic malaria infections are required to reach malaria elimination goals, but remain a challenge. This mixed methods study explored people’s attitudes towards the reactive treatment of compound contacts of malaria cases with a 3-day course of dihydroartemisinin- piperaquine (DHAP), the socio-cultural representations of asymptomatic infections, and more specifically their treatment. Methods: Prior to the start of the intervention, a sequential mixed method study was carried out. Qualitative data collection involved in-depth interviews and participant observations (including informal conversations) with key informants from the trial communities and the trial staff. Quantitative data were derived from a pre-trial cross- sectional survey on health literacy and health-seeking behaviour among randomly selected members of the study communities. Results: In the pre-trial cross-sectional survey, 73% of respondents reported that malaria could be hidden in the body without symptoms. Whilst this may be interpreted as people’s comprehension of asymptomatic malaria, qualita- tive data indicated that informants had different interpretations of asymptomatic disease than the biomedical model. It was described as: (i) a minor illness that does not prevent people carrying out daily activities; (ii) an illness that oscil- lates between symptomatic and asymptomatic phases; and, (iii) a condition where disease agents are present in the body but remain hidden, without signs and symptoms, until something triggers their manifestation. Furthermore, this form of hidden malaria was reported to be most present in those living in the same compound with a malaria case (71%). Conclusion: Treating asymptomatic malaria with pharmaceuticals was considered acceptable. However, people felt uncertain to take treatment without screening for malaria first, largely due to the lack of symptoms. Knowledge of asymptomatic malaria was not a strong re-inforcement for treatment adherence. In this study, the pre-intervention active engagement of communities existed of having people co-design accurate information messages about their personal risk of malaria, which increased their trust in expert knowledge and thus proved essential for the successful implementation of the community-based intervention. Keywords: Asymptomatic infection, Malaria, Elimination, Community perspectives *Correspondence: fjaiteh@mrc.gm 2 Medical Research Council Unit the Gambia at the London, School of Hygiene and Tropical Medicine, Fajara, The Gambia Full list of author information is available at the end of the article © The Author(s) 2019. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/ publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. Jaiteh et al. Malar J (2019) 18:39 Page 2 of 10 Background and treated if positive, has the limitation of the current As global strides are made towards malaria elimination, diagnostic tools in detecting low density infections [15]. the focus of interventions has shifted to include a group Furthermore, RCD may not be sustainable in the short or of people identified as ‘asymptomatic carriers’ and/or long term in low to moderate transmission settings [16] as the ‘human reservoir of infection’ [1]. The latter are as it may require active commitment of the populations defined as malaria-infected but apparently healthy indi- involved [17]. viduals who may be the source of infection for malaria To overcome these limitations, reactive household- vectors, thereby maintaining transmission [1–4]. In clini- based, self-administered treatment (RHOST) was tested cal malaria studies, ‘apparently healthy’ usually means the through a cluster-randomized trial in a low prevalence absence of fever, the most apparent symptom of malaria setting of The Gambia. The concept and the trial protocol [5, 6]. Although for other vector-borne diseases, such as have been published elsewhere [18]. The trial proposed dengue, the term ‘inapparent symptomatic’ is often used an innovative approach for targeting the human reser- [7–9] to implicate the possibility of asymptomatic carri- voir of infection by combining: i) the passive detection ers to encounter (mild) symptoms, the clinical spectrum of clinical malaria cases; ii) systematic treatment without of experienced asymptomatic malaria has not yet been screening with dihydroartemisinin-piperaquine (DHAP) clearly defined or elaborated on. In contrast to sympto- of all individuals living/sleeping in the index case’s com- matic infections, asymptomatic malaria infections indeed pound; and, iii) an active community participation by tend to generally be described microbiologically. As such, means of involving patients, their households and other an asymptomatic malaria case exhibits a considerably community actors in tackling implementation concerns lower parasite density than a symptomatic case crossing and co-designing solutions according to their knowledge the threshold of what is detectable by currently available and experience. diagnostic methods such as light microscopy or a rapid One of the key challenges for the optimal impact of diagnostic test (RDT) [10, 11]. Research shows that low interventions targeting asymptomatic individuals is their density infections, including sub-microscopic infections, adherence to medication while not being apparently sick could be important contributors to malaria transmission [19]. As a malaria elimination programme in the Solo- in areas with very low transmission intensity [10, 12, 13]. mon Islands showed, despite community engagement In the context of malaria elimination goals, the possibil- and education, people were unwilling to take drugs on ity of continuous transmission maintained by undetected repeated MDA rounds because they were not sick [20]. malaria cases highlights the significance of understand- As other studies have also shown [21–26], understanding ing the ‘human reservoir of infection’ [10, 11, 14]. and consequently adapting intervention strategies to peo- At low malaria prevalence, identifying asympto- ple’s perceptions of asymptomatic infections is crucial for matic carriers becomes increasingly difficult because the effectiveness of such community-based interventions. of the need of screening many individuals to identify a Complex biomedical concepts such as asymptomatic few infected ones. Ultra-sensitive molecular methods infections are difficult to elaborate on with the communi- can maximize the detection of lower densities of para- ties targeted for MDA when using only biomedical lan- sites, but are currently not feasible in routine surveil- guage [22, 23, 27, 28]. lance [11]. A possible approach would be to treat the Perceptions of malaria in sub-Saharan Africa have fre- whole population, regardless of malaria infection status, quently been shown to be different from the biomedical with an efficacious anti-malarial, i.e. mass drug admin- model, consequently influencing the uptake of interven- istration (MDA). However, with the currently available tions [29–32]. Furthermore, concepts from traditional treatments, this approach automatically excludes some and biomedical knowledge sources can syncretize to pro- population groups, such as pregnant women or infants duce hybridized perceptions of malaria [33, 34]. These under 6 months old, while other groups, such as mobile findings have stimulated the development and inspired populations, would be easily missed. Furthermore, both the design of culturally appropriate information, edu- MDA and alternatives such as scheduled screening and cation and communication (IEC) strategies to improve treatment (SST) are difficult to sustain over long periods intervention uptake. However, it is also widely acknowl- of time, particularly when transmission has decreased edged that improving knowledge through well designed to very low levels, due to population fatigue, logisti- IEC strategies does not automatically lead to changed cal challenges and costs. Targeting sub-groups or geo- health behaviour [34]. There is limited understanding on graphical areas may be an alternative approach but has how asymptomatic malaria is understood by recipients of similar shortcomings [1, 5, 6]. Lastly, reactive case detec- MDA, and how these perceptions affect the implemen- tion (RCD), a strategy in which household members of tation and/or the uptake of the intervention. This study, a passively identified clinical malaria case are screened set within the context of a cluster-randomized trial that Jaiteh et al. Malar J (2019) 18:39 Page 3 of 10 included key community participation and engagement Study design component, focused on understanding and contextual- As part of the formative research during the preparatory izing the perceptions of asymptomatic malaria and its phase, a sequential exploratory mixed-methods study treatment. was conducted, in standard annotation (QUAL → quan) [36]. In the first qualitative strand (March–May 2016), ethnographic techniques were used in all intervention Methods villages (n = 17) to understand the general socio-cultural, Study setting political and economic context, including an overview Study population of all health care options in the region. People’s percep- This mixed methods study was carried out in the North tions on asymptomatic malaria were also explored during Bank Region of The Gambia. The main ethnic groups this phase. Based on the qualitative findings, a question- residing in these villages are Fula, Mandinka and Wollof, naire was developed for the cross-sectional survey in the although there are other minority groups: Bambara, Tili- sequential quantitative strand (June 2016). The survey bonka and Turkas, that migrated from neighbouring Mali assessed the representativeness of the qualitative findings and Burkina Faso. Most are Muslims. Each ethnic group in all the study villages (n = 34). speaks their own language, although Mandinka or Fula is the common language for communication and trade. Qualitative strand Farming is the most common occupation, with peanuts Participants and sampling as the main cash crop, while rice, maize, beans, and veg- In the qualitative study, sampling was theoretical mean- etables are grown for own consumption. A significant ing that informants were purposefully and gradually number of families supplement their income through selected based on emerging findings. Access to the remittances from relatives living either in the major informants was usually granted through snowball sam- towns or abroad. pling, where initial participants are used to identify and connect the researchers with other theoretically relevant informants. The Alkalo (village head) was a starting point Malaria context to gradually and purposefully select other people from Malaria transmission in the area is seasonal, low (trans- the study villages, including recent malaria cases (individ- mission prevalence of 5%) and occurs mostly between uals diagnosed by rapid diagnostic test (RDT) by a health July and December. The main malaria parasite is Plasmo- worker) and their caretakers, compound heads, VHWs dium falciparum [35]. and marabouts (traditional healers). From the trial team, study nurses and fieldworkers were also included. Sam- pling aimed for maximum variation to ensure that all Trial context relevant groups in relation to the research question were The trial was a cluster-randomized trial designed to included. assess the impact of reactive treatment of contacts of a clinical malaria case living in the same compound on the Data collection prevalence of malaria infection at the end of the trans- In‑depth interviews mission season. It was planned over two transmission Data collection began by carrying out in-depth inter- seasons. In the first season (preparatory phase), study views with the Alkalos who were identified as gatekeep- villages (17 intervention, 17 control) were identified and ers to the communities and knowledgeable on the general approaches to integrate the intervention into the com- socio-cultural, political, economic, and pluralistic medi- munities and health system were tested and adapted by cal context. In their roles as gatekeepers and source of social scientists and health system researchers through reference, they identified households recently affected formative research. During this process, trial implemen- with malaria and/or other key informants, which helped tation concerns were identified and solutions co-devel- to build trust with the interviewees. The focused inquiry oped with relevant stakeholders, including community with key informants involved the in-depth exploration members, health service providers and policy makers. of topics such as the concept of asymptomatic malaria The final health messages for sensitization, including the infection, the processes and metaphors used to describe medicine distribution strategy involving key community asymptomatic conditions, and the acceptability of treat- actors such as village health workers (VHWs) and com- ing asymptomatic individuals with anti-malarials. Inter- pound heads developed for community members to sup- views were conducted by the authors (FJ and JM) with port the intervention, were applied in all intervention the help of two translators. The interviews were recorded villages in the second season (implementation phase). Jaiteh et al. Malar J (2019) 18:39 Page 4 of 10 and transcribed verbatim by the translators. Additionally, frequencies for variables related to asymptomatic carri- during interviews, field notes were written by FJ and JM ers are presented. These are presented stratified by gen- for immediate analysis. der, ethnicity, education level and socio-economic status. Chi squared tests were used to assess whether differences Participant observation were statistically significant. Socio-economic status was During the fieldwork, informal conversations were con- calculated from questions related to education, hous- ducted with community members, trial nurses and field- ing, income and employment using principal component workers. These conversations were useful to confirm or analysis. refute emerging findings and generate new hypotheses for testing. Ethical approval Data analysis Ethical approval was obtained from the joint Gambia Data analysis was a flexible and iterative process. Pre- Government/Medical Research Council Unit The Gam- liminary data from in-depth interviews and participant bia Ethics Committee and the Institutional Review Board observations were jointly analysed by FJ and JM to fur- of the Institute of Tropical Medicine, Antwerp, Belgium. ther adapt the interview guide and process. Additional The interviewers followed the Code of Ethics of the data collection was used to confirm or refute temporary American Anthropological Association. All interviewees findings until the point of saturation (i.e. no new findings were informed before the interview about the topic and emerging). All interviews were systematized and ana- types of questions and their right to decline participation, lysed with NVivo 11 Qualitative analysis software (QSR to interrupt or withdraw from the conversation. Oral International Pty Ltd, Cardigan UK). consent was sought before each interview and was doc- umented by the interviewer. Oral consent was favoured Quantitative strand since the risk was minimal and the act of signing one’s Participants and sampling name on a document was expected to cause mistrust Participants were identified using a bootstrap sampling towards the study team since this is not customary prac- technique with the population stratified by household tice within the local communities. Interviewees confiden- and age (children (< 16 years) and adults). The sampling tiality was assured by assigning unique identifiers to the frame ensured that the number of households selected collected forms. was in proportion to the size of the village. The question- naire for children was administered to caregivers and where any of the initially selected persons were unavail- Results able, the next person in the household in the same age Study participants category was approached to complete the questionnaire. Qualitative strand In-depth interviews (n = 88) and informal conversations Data collection (n = 5) were carried out with community members and A paper-based questionnaire containing closed-ended field staff (Table 1). and open-ended questions was used to collect quantita- tive data. Topics included health-seeking behaviour for malaria, health literacy including knowledge on asymp- Table 1 Overview of respondents for in-depth interviews tomatic malaria carriers, adherence to malaria treatment and informal conversations and trust in different health providers. The survey was Participants In-depth Informal piloted by the social science team to ensure clarity and interviews conversations to avoid translation errors in the three main languages. Village heads (Alkalos) 8 Survey data were collected by the social science team and Alkalo’s brother 2 trial fieldworkers previously trained on interview tech- Alkalo’s son 1 niques and administering questionnaires with closed and Alkalo’s wife 1 open-ended questions. Marabout (healer) 2 Malaria case caregiver (women) 2 Data analysis Farmer (men) 42 All completed survey forms were double entered in Excel Farmer (women) 30 by trial data entry clerks, verified by the social science Field staff (men) 5 team and cleaned using Epi Info. Data were analysed Total 88 5 using STATA 15 (Stata Corp, Tx). For this manuscript, Jaiteh et al. Malar J (2019) 18:39 Page 5 of 10 Quantitative strand (i.e. a representation of antibodies provided in health In total, 741 questionnaires were completed; there were messages) are fighting the hidden disease but produce no refusals; 324 adults and 417 children (< 16 years) ques- no apparent symptoms. Symptoms only appear when tionnaires were completed. The questionnaire for chil- the body soldiers are defeated in the presence of exter- dren (< 16 years) was administered to their caretakers nal triggering factors. The elaborated local model of ill- (Table 2). ness progression for asymptomatic conditions therefore presents the following characteristics: (i) everyone is sus- Conceptualization of asymptomatic carriage ceptible to an asymptomatic condition; (ii) the disease There were no local terms in the commonly spoken local can remain hidden for a variable period, depending on languages, i.e. Mandinka, Fula and Wolof, corresponding the fight in the body (body soldiers); (iii) symptoms will directly to ‘asymptomatic disease’. Consequently, asymp- manifest when body soldiers are defeated or when cer- tomatic disease was explained as a health condition tain triggers occur; (iv) disease can be transmitted even where a disease is present, but the affected person does in asymptomatic form; and, (v) asymptomatic conditions not feel any signs and symptoms related to the disease. should be treated when they become symptomatic. Based on this explanation, respondents interpreted the statement to mean a health condition where disease was present in the body but did not affect one’s appetite nor Perceptions of asymptomatic malaria restricted their ability to carry out daily activities. The Several diseases (biomedical) and folk illnesses (illnesses condition, to which everyone was considered susceptible, that do not correspond to any biomedical classifications was understood as covering the following scenarios: (i) of diseases), such as yellow fever, worms, lung tuberculo- a minor illness which mild symptoms does not prevent sis, jinn (spirits) afflictions and malaria, were considered people from carrying out daily activities; (ii) an illness having asymptomatic stages within the local explanatory that oscillates between symptomatic and asymptomatic model of health and illness. However, these distinct bio- phases; and, (iii) a condition where disease agents are medical conditions were not always perceived to be dis- present in the body but remain hidden until something tinct locally and were reported to naturally evolve into triggers their manifestation in apparent symptoms. Dur- one another. ing the asymptomatic phase, the so-called ‘body soldiers’ Malaria was described as one of the conditions that could be asymptomatic. The majority of respondents (73%) thought that malaria can be hidden in the body Table 2 Socio-demographic characteristics respondents without showing symptoms (Table 3). The proportions in quantitative study (N = 741) of those who thought so were similar across gender, ethnicity, educational level and socio-economic status. n % Respondents in the survey considered this form of hid- Gender den malaria most likely to be present in those living in Male 308 41.6 the same household with a malaria case (71%), with no Female 423 57.1 statistically significant differences across the socio- Missing 10 1.3 demographic characteristics (Table 3). Similarly, 78% of Ethnicity respondents stated that living in the same household as Mandinka 385 52.0 someone having malaria increased their personal risk Fula 221 29.8 of getting malaria. This varied by whether the respond- Wolof 50 6.7 ent thought malaria could be asymptomatic, with 80% Tilibonka 34 4.6 of those who thought malaria could be asymptomatic Bambara 27 3.6 considering they were at increased risk as compared to Turkai 5 0.7 69% of those who did not (p = 0.002). 91% of respondents Other 19 2.6 reported having a mosquito net in the home, and this Knows how to read (English) did not vary by whether the respondent thought malaria Yes 108 14.5 could be asymptomatic or not (91%) and 88% of net use No 630 85.0 respectively (p = 0.168). Occupation (adults and caretakers of participating minors [< 16]) Qualitative interviews indicated that asymptomatic Farmer 673 90.8 malaria was perceived to be hidden in different parts of Public officer 6 0.8 the body and frequently in the head and joints where Business 41 5.53 pain is first experienced. Other 21 2.83 Jaiteh et al. Malar J (2019) 18:39 Page 6 of 10 Table 3 Perceptions of asymptomatic infections in relation to socio-demographic characteristics [% of respondents affirming the statement (n/N)] Hidden malaria Increased risk in same Mosquito bites trigger Hot sun triggers Drinking in the body household symptoms symptoms milk triggers symptoms Total 73% (538/736) 71% (416/586) 89% (520/585) 91% (533/587) 85% (498/586) Gender Male 74% (225/306) 71% (172/243) 87% (210/242) 89% (216/243) 85% (206/243) Female 73% (306/421) 71% (240/336) 91% (306/336) 92% (310/337) 85% (286/336) p-value 0.800 0.865 0.100 0.205 0.909 Ethnicity Mandinka 74% (285/383) 74% (218/296) 90% (267/296) 95% (283/297) 87% (257/297) Fula 73% (159/219) 67% (125/186) 88% (163/185) 83% (155/186) 82% (152/185) Wolof 60% (30/50) 58% (19/33) 79% (26/33) 91% (30/33) 82% (27/33) Other 76% (64/85) 76% (54/71) 90% (64/71) 92% (65/71) 87% (62/71) p-value 0.162 0.108 0.245 < 0.001 0.517 Education level None 72% (380/530) 70% (290/416) 88% (366/415) 91% (378/417) 85% (355/417) Primary 78% (113/144) 76% (91/119) 92% (109/119) 90% (107/119) 84% (100/119) Secondary 76% (29/38) 63% (20/32) 88% (28/32) 100% (32/32) 87% (27/31) p-value 0.242 0.207 0.563 0.182 0.905 Socio-economic status quartile Wealthiest 80% (143/178) 73% (108/148) 92% (139/151) 89% (135/152) 84% (128/152) 2nd 73% (132/180) 73% (105/144) 88% (117/132) 91% (121/133) 81% (107/132) 3rd 69% (124/179) 68% (91/133) 88% (128/145) 97% (140/145) 89% (129/145) Poorest 73% (133/181) 69% (105/152) 87% (129/148) 88% (130/148) 86% (127/148) p-value 0.118 0.745 0.562 0.043 0.313 “Generally, diseases can be housed in different parts was hidden in the body, hot sun can make the symp- of the body. Most times, for malaria the head is the toms appear. This perception significantly varied across problem and it starts with that place.” (Adult man, ethnicity (Mandinka (95%), Wolof (91%) and Fula (83%), Farmer) P < 0.001), and socio-economic levels (wealthiest quartile (89%), 2nd quartile (91%), 3rd quartile (97%) and poor- The time it takes for malaria symptoms to appear var- est quartile (88%), p = 0.043) (Table 3). Among those ied depending on a combination of factors such as: (i) who thought that if malaria was hidden in the body, 85% one’s ability to withstand or cope with illness represented reported that drinking milk could make the symptoms by the concept of ‘body strength’ and, (ii) the duration appear, with similar proportions across socio-demo- the body soldiers of the affected individual fights. For graphic characteristics. instance, the period of pregnancy was considered a phase It was widely acknowledged that mosquitoes could of low body strength and thus pregnant women were directly cause malaria (99.8%) and increased malaria risk perceived to have weaker body soldiers. Following these was associated with mosquito density, which was related logics, the strength of the body (i.e. blood or body sol- to stagnant water. Another commonly mentioned way of diers) can be increased or nourished by consuming cer- contracting malaria was ‘body heat’ transfer, understood tain foods such as green leafy vegetables and decreased as the transmission of heat (and disease) through direct through hard work and taking cold baths. This illustra- (e.g. sleeping together with a malaria case) or indirect tion reinforces the notion that one is asymptomatic when (e.g. sleeping in the place where a malaria case person the body is strong and can thus hide the disease. When was sleeping before) contact. In addition, the dormant the body is weakened by the culmination of a set of exter- state of malaria could be triggered to an active state by a nal triggers (i.e. sun, milk, hard work), the symptoms of mosquito bite (89%) (with similar proportions across the the disease can no longer be hidden and start to emerge. socio-demographic characteristics), resulting in apparent Most of the respondents (91%) thought that if malaria Jaiteh et al. Malar J (2019) 18:39 Page 7 of 10 symptoms such as fever, headache, vomiting and body “If you take anti-malarial treatment, it goes into the aches. blood to fight what it is meant to fight. If you take the When malaria is related to and often even equated pills, it goes through the blood, which gets hot to fight with the folk illness joontinoji (Fula), it is perceived to the disease and when you sweat, then they say that progress from its symptomatic phase to yellow fever you are feeling better from malaria and the medi- (Chawnabee-Fula). cine is good for you.” (Adult man, Farmer) “When malaria has power, it can change into yellow The efficacy of the anti-malarial medication was also fever” (Adult farmer, Talen Fula). perceived to be contingent on the prior ‘body strength’ of the individual. As a result, there was a general notion that This progression was said to be more common dur- individuals differed substantially and therefore that the ing the rainy season. Yellow fever, locally referred to as treatment might work for some (eliminating the disease) Chawnabee (Fula), Sumuyaa (Tilibonka), Sai (Tilibonka) and fail for others (hiding the disease only). The failure and Paices (Wollof ), was believed to affect mostly chil- of treatment for some individuals was also attributed to dren. The symptoms (yellowing of the eyes and vomit, the perceived strength of the anti-malarial medication fever, the changing colours of the palms of the hands) in relation to its dosage. Especially taking an incomplete appear temporarily and then the disease hides again. anti-malarial regimen could trigger the symptoms to The appearance of the symptoms is triggered by the con- reappear. sumption of specific food items, such as milk, which were more commonly available during the rainy season. Dur- ing the symptomatic phase the disease can be transmit- Attitudes towards health workers ted to others by looking into the sick person’s eyes. 77% of respondents said they received good or very good advice from the VHWs. This varied by whether the Perceptions of anti‑malarial treatment for asymptomatic respondent thought malaria could be asymptomatic, with carriers 73% of those who thought malaria could be asympto- Diagnosis and uncertainty matic receiving good or very good advice, compared to Although most people accepted that malaria could be 86% of those who did not (p = 0.002). 95% of respondents asymptomatic, people do not actively seek treatment said they received good or very good advice from the per- when symptoms are absent. People perceived analgesics sonnel at the health facility. This did not vary by whether (paracetamol or ibuprofen) taken after experiencing mild the respondent thought malaria could be asymptomatic, malaria symptoms to strengthen the body enough so it with 95% of those who thought malaria could be asymp- can hide the remaining malaria. Such hidden malaria is tomatic receiving good or very good advice, compared then considered undetectable by biomedical diagnostic to 93% of those who did not (p = 0.235). Qualitative data tools, such as RDTs. further showed that trust in health workers (VHWs and health facility personnel) was relatively high. However, Anti‑malarial treatment for asymptomatic malaria the main limitation for VHWs which generated dis- Informants generally considered it unnecessary to take trust in the community was the common complaint that medication without having any symptoms. However, the provision of RDTs and treatment was continuously when anti-malarial treatment is given after screening and deteriorating. the individual found to be positive, it was perceived to be a necessary means of disease prevention. This is consist- ent with local practices of self-protection with amulets or Discussion charms commonly referred to as fankanta (Mandinka) to This study explored how local perspectives on asymp- prevent ailments such as jinn afflictions, common child- tomatic carriage were structured in relation to specific hood illnesses or the ‘evil eye’ during women’s pregnancy. health interventions. Perceptions of asymptomatic car- Once anti-malarial medication is consumed after screen- riage reflect a dynamic understanding of health and ill- ing, the medication is perceived to increase the body’s ness, where every individual is vulnerable to hidden strength, enabling it to engage in a fight with the disease. conditions where disease agents are constantly per- In contrast to analgesics, malaria medication strength- ceived to be engaged in a battle with the body’s defences ens the body to the point where it can eliminate the dis- (i.e. body soldiers). If the body soldiers are defeated, ease rather than hide it. During this process, the blood the body’s ability to resist or cope with illness (body becomes hot, making people sweat. Observed sweating strength) diminishes, leading to manifestation of the after taking anti-malarial treatment was therefore seen as symptoms of the disease. Similarly, in a study carried out evidence of treatment efficacy. on perceptions of vaccinations in The Gambia, medical Jaiteh et al. Malar J (2019) 18:39 Page 8 of 10 interventions such as immunizations were perceived as of diagnostic uncertainty, which has been described to protecting the health of the child by giving ‘strength’ or occur in situations where the decision-maker cannot ‘power’ to withstand or cope with illness [37]. assign definite values to objects and events and/or an For some conditions such as yellow fever and malaria, individual is unable to predict outcomes because suf- the manifested symptoms are seen as interchange- ficient cues are lacking [39]. Because they had a clear able, thereby representing the transformative nature of understanding of malaria symptoms, the lack of these asymptomatic conditions. The perceived elements mak- symptoms in asymptomatic phases led to a state of ing up the disease process inside the body, mirrors both uncertainty exemplified by respondents’ insistent ques- components from local knowledge systems related to tions of how they could be aware of having the disease ‘hidden diseases’ described elsewhere [25, 29, 37, 38], when they did not experience any symptoms. Previous and biomedical health information related to the body’s studies on asymptomatic conditions have shown that defence mechanism with antibodies. Indeed, in the study uncertain outcomes related to one not knowing whether area, there has been a long presence of health campaign they had a disease that was asymptomatic were reasons groups, including malaria programmes, that use meta- for treatment refusal or abandonment [25, 40]. phoric terms such as body soldiers in their health promo- However, unlike the findings of the malaria elimina- tion activities in order to explain the process of natural tion programme in the Solomon Islands where asymp- immunity against parasites and other invading pathogens tomatic individuals were not considered as sick and in the body [37]. Furthermore, the knowledge on body refused treatment, most of our informants ascertained soldiers are conceptually linked to more general notions anti-malarials to cure malaria even if the disease was of body and blood strength. Following these logics, the in a dormant phase. Furthermore, the study population act of consuming certain foods such as green leafy vege- showed willingness to accept RDT positive results in the tables to strengthen the body soldiers to withstand illness absence of symptoms. Since 2008, there has been a signif- could be compared to the perceived protective nature of icant roll-out in The Gambia of RDTs with artemisinin- pharmaceuticals and vaccinations to strengthen the body. based combined therapy (ACT) including the availability In relation to asymptomatic malaria and its treatment, and accessibility to long-lasting insecticide-treated bed this merging of different knowledge systems is neither nets (LLINs) and indoor residual spraying (IRS) for arbitrary nor incoherent, as it follows an internal logic of malaria control [41]. These developments are reported disease transformations (from asymptomatic to sympto- to have contributed to the reduction of malaria burden matic, malaria to yellow fever), which was key for under- [35]. Although current conventional tests cannot detect standing people’s acceptance of the condition as relevant. asymptomatic infections, the positive perceptions held These findings also support recommendations to move by this population on the accuracy of positive diagnostic away from the term ‘asymptomatic’ malaria in favour results highlight the need for the continuous strengthen- of ‘chronic malaria’ [10], or even ‘inapparent sympto- ing of health worker capacity, especially VHWs to effec- matic’ as used for other infections [9]. Such a reconcep- tively manage malaria cases. tualization would allow for a clinical spectrum of mild In the situation of diagnostic uncertainties highlighted symptoms, disease progressions and associated co-mor- by this study, the authority of and trust in an expert may bidities, which the assumption of a ‘benign’ asympto- become more important than people’s perceptions of matic infection without any clinical symptoms does not health and illness. This warrants an active engagement of currently support. communities in research projects in order to strengthen their trust in biomedical specialists’ diagnosis and health Implications for MDA strategies including reactive mass information on particular malaria risks in this context. treatment This further relates to the expectation that when pursu- The perception of malaria to be potentially asymptomatic ing malaria elimination, programmes will find themselves was relatively high with most respondents believing that working in and with communities that progressively living in the same household as someone having malaria adapt their perceptions of malaria risk to decreasing increased their personal risk of getting malaria. Qualita- incidence [42]. Interventions designed to actively engage tive data supported illness progression pathways where communities could provide an opportunity to re-estab- malaria is perceived to hide, grow and eventually mani- lish or heighten awareness of malaria risk and thereby fest when triggered by external factors. This concept of foster trust in health authorities. illness progression was often used to explain events post facto or for narrative purposes and was therefore not a Strength and limitations strong determinant for adhering to malaria preventive This study is the first in-depth analysis of community’s measures. The asymptomatic infection was a key cause understanding on the concept of asymptomatic malaria Jaiteh et al. Malar J (2019) 18:39 Page 9 of 10 infections and its implication for malaria elimination in Competing interests The authors declare that they have no competing interests. West-Africa. There is evidence from South East Asia and East Africa depicting populations misunderstandings Availability of data and materials on asymptomatic malaria infections and willingness to For the qualitative strand, the datasets generated and/or analysed during the current study are not publicly available due to the fact that participants did take treatment in MDAs [25, 26, 43]. A recent publica- not consent to have their full transcripts made publicly available. However, tion from Laos in the context of antimalarial resistance the NVivo database with excerpts of the transcripts relevant to the study is in the Greater Mekong sub-Region highlights the need available from the corresponding author on reasonable request. For the quan- titative strand, the datasets used and/or analysed during the current study are for MDA interventions with accompanying community available from the corresponding author on reasonable request. engagements to build trust with different stakeholders [26]. By using a mixed-methods approach our work dem- Consent for publication Not applicable. onstrated the logic behind the study population’s under- standing of asymptomatic infections in order to highlight Ethics approval and consent to participate before implementation, the facilitators and barriers of Ethical approval was obtained from the joint Gambia Government/Medical Research Council Unit, The Gambia, ethics committee and the Institutional adherence for improving acceptability of the strategy. The Review Board of the Institute of Tropical Medicine, Antwerp, Belgium. The study population’s acknowledgement of the increased interviewers followed the Code of Ethics of the American Anthropological risk of asymptomatic malaria for individuals sharing the Association. All interviewees were informed before the interview about the topic and types of questions and their right to decline participation, to inter- same compound with a symptomatic malaria case (71%) rupt or withdraw from the conversation. Oral consent was sought before each could be influenced by pre-intervention information interview and was documented by the interviewer. Oral consent was favoured spread through the community, nonetheless, it signifies since the risk was minimal and the act of signing one’s name on a document was expected to cause mistrust towards the study team since this is not the relevance of understanding perceived malaria trans- customary practice within the local communities. Interviewees confidentiality mission dynamics. was assured by assigning unique identifiers to the collected forms. Funding This study is jointly funded under the Global Health Trials Scheme by the Conclusion Medical Research Council (United Kingdom), the Department for International This study on perspectives of asymptomatic malaria Development (DFID). This UK-funded award is part of the European and Devel- oping Countries Clinical Trials Partnership (EDCTP2) programme supported infections in The Gambia highlights that people’s percep- by the European Union. The funders had no role in the study design or the tion of illness progression could make elimination strate- preparation of the manuscript. gies targeting asymptomatic individuals acceptable in the local context. However, due to the uncertainty of future Publisher’s Note manifestations of malaria symptoms, these perceptions Springer Nature remains neutral with regard to jurisdictional claims in pub- lished maps and institutional affiliations. do not currently act as a motivation for treatment adher- ence. To address the issue of diagnostic uncertainty, Received: 24 October 2018 Accepted: 10 February 2019 elimination strategies will need to actively engage com- munities to foster trust in expert knowledge. Authors’ contributions FJ and JM conceptualized and designed the qualitative strand. FJ, JM, YM, References KPG and JO designed the study for the quantitative strand. FJ and JM mainly 1. Moonen B, Cohen JM, Snow RW, Slutsker L, Drakeley C, Smith DL, et al. collected and analysed the data and YM contributed as well. FJ carried out the Operational strategies to achieve and maintain malaria elimination. literature review and CG contributed as well. FJ wrote the paper and designed Lancet. 2010;376:1592–603. the tables. CG, YM, JO, UDA, JB, JM and KPJ contributed to the final draft of the 2. Laishram DD, Sutton PL, Nanda N, Sharma VL, Sobti RC, Carlton JM, et al. manuscript. All authors read and approved the final manuscript. 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