Factors Associated with Non-Participation and Non-Adherence in Directly Observed Mass Drug Administration for Malaria in The Gambia

Prospective acceptability of mass drug administration for malaria in Kedougou region in Senegal: a mixed method study

BACKGROUND

In Senegalese high-burden regions, the existing package of interventions is insufficient to reach the malaria elimination goal. Asymptomatic carriers of Plasmodium contribute significantly to malaria persistence and are not targeted by current interventions. The systematic treatment of all individuals in a community (mass drug administration, MDA) is a relevant intervention to tackle asymptomatic infections. The intervention can only be effective with a high participation of the population and, therefore, depends largely on its acceptability. This study aims to investigate the prospective acceptability of MDA in the Kedougou region to inform its potential use in a future strategy.

METHODS

Following a 7-construct theoretical framework, prospective acceptability of MDA implemented in the rainy season was studied. In four villages, a sequential mixed design, from qualitative to quantitative, was used. In November 2021, interviews with healthcare professionals and focus groups with villagers were conducted. Findings from thematic analysis informed the development of a questionnaire administered to individuals aged ≥ 15 years in March 2022. Based on the questionnaire, an acceptability score was constructed and associations with socio-demographic factors were investigated using a linear mixed model.

RESULTS

The 7 interviews, the 12 focus groups, and the questionnaire administered to 289 individuals demonstrated a good acceptability of MDA. Two potential barriers were identified: the contradiction of taking a medication without feeling sick and the occurrence of side effects; and four facilitators: the perception of malaria as a burden, a good understanding of MDA, a good perceived effectiveness, and the resulting economic benefits. The average acceptability score was 3.5 (range from -7 to + 7). Young adults aged 15 to 21 had a lower acceptability score compared to the other age groups, indicating an additional barrier to acceptability (β = -0.78 [-1.67;0.1]).

CONCLUSION

MDA is a priori acceptable to communities of Kedougou region in Senegal. Sensitization campaigns co-constructed with the communities, especially targeting young adults, are essential to ensure good acceptability.

Impact of annual community-directed treatment with ivermectin on the incidence of epilepsy in Mvolo, a two-year prospective study

OBJECTIVES

The potential impact of cumulative community-directed treatment with ivermectin (CDTI) on epilepsy epidemiology in Mvolo County, South Sudan, an onchocerciasis-endemic area with high epilepsy prevalence, was investigated. Annual CDTI was introduced in 2002 in Mvolo, with interruptions in 2016 and 2020.

METHODS

Comprehensive house-to-house surveys in Mvolo (June 2020 and 2022) identified cases of epilepsy, including probable nodding syndrome (pNS). Community workers screened households in selected sites for suspected epilepsy, and medical doctors confirmed the diagnosis and determined the year of seizure onset. The incidence of epilepsy, including pNS, was analysed using 95% confidence intervals (CIs). Data on ivermectin intake and onchocerciasis-associated manifestations (itching and blindness) were collected.

RESULTS

The surveys covered 15,755 (2020) and 15,092 (2022) individuals, identifying 809 (5.2%, 95% CI: 4.8-5.5%) and 672 (4.5%, 95% CI: 4.1-4.8%) epilepsy cases, respectively. Each survey reported that a third of the surveyed population experienced skin itching, and 3% were blind. Epilepsy incidence per 100,000 person-years gradually declined, from 326.5 (95% CI: 266.8-399.1) in 2013-2015 to 96.6 (95% CI: 65.5-141.7) in 2019-2021. Similarly, pNS incidence per 100,000 person-years decreased from 151.7 (95% CI: 112.7-203.4) to 27.0 (95% CI: 12.5-55.5). Coverage of CDTI was suboptimal, reaching only 64.0% of participants in 2019 and falling to 24.1% in 2021 following an interruption in 2020 due to COVID-19 restrictions. Additionally, while 99.4% of cases had active epilepsy in 2022, less than a quarter of these had access to antiseizure medication.

CONCLUSIONS

The observed decrease in epilepsy incidence despite suboptimal CDTI coverage highlights the potential impact of onchocerciasis control efforts and underscores the need to strengthen these efforts in Mvolo County and across South Sudan. As a proactive measure, Mvolo and neighbouring counties are transitioning to biannual CDTI. Furthermore, the substantial epilepsy treatment gap in Mvolo should be addressed.

Acceptability and perceived barriers to reactive focal mass drug administration in the context of a malaria elimination program in Magude district, Southern Mozambique: A qualitative study

This study analysed acceptability and perceived barriers to reactive focal mass drug administration (rfMDA) among community members exposed to community engagement campaigns and malaria elimination interventions in Magude district, following mass drug administration (MDA) in the same district. The study used a formative qualitative study design, consisting of 56 semi-structured interviews with community members, including community leaders, household heads, women of reproductive age, members of the community and adolescents, 4 semi-structured interviews with community health workers, 9 semi-structured interviews with healthcare professionals; and 16 focus group discussions with the general adult population. Data were collected between June and September 2017. A content thematic analysis approach was used to analyse the data. The results of this study showed that rfMDA was accepted due to awareness about the intervention, experience of a previous similar programme, the MDA campaign, and due to favourable perceptions built on the believe that rfMDA would help to prevent, treat and eliminate malaria in the community. Perceived barriers to rfMDA include lack of access to accurate information, reluctance to take a pregnancy test, concern on drug adverse reactions, and reluctance to take antimalarial drugs without any symptom. In conclusion, the community found rfMDA acceptable for malaria intervention. But more community engagement is needed to foster community involvement and self-appropriation of the malaria programme elimination.

Mass drug administration of ivermectin and dihydroartemisinin-piperaquine against malaria in settings with high coverage of standard control interventions: a cluster-randomised controlled trial in The Gambia

BACKGROUND

Although the malaria burden has substantially decreased in sub-Saharan Africa, progress has stalled. We assessed whether mass administration of ivermectin (a mosquitocidal drug) and dihydroartemisinin-piperaquine (an antimalarial treatment) reduces malaria in The Gambia, an area with high coverage of standard control interventions.

METHODS

This open-label, cluster-randomised controlled trial was done in the Upper River region of eastern Gambia. Villages with a baseline Plasmodium falciparum prevalence of 7-46% (all ages) and separated from each other by at least 3 km to reduce vector spillover were selected. Inclusion criteria were age and anthropometry (for ivermectin, weight of ≥15 kg; for dihydroartemisinin-piperaquine, participants older than 6 months); willingness to comply with trial procedures; and written informed consent. Villages were randomised (1:1) to either the intervention (ivermectin [orally at 300-400 μg/kg per day for 3 consecutive days] and dihydroartemisinin-piperaquine [orally depending on bodyweight] plus standard control interventions) or the control group (standard control interventions) using computer-based randomisation. Laboratory staff were masked to the origin of samples. In the intervention group, three rounds of mass drug administration once per month with ivermectin and dihydroartemisinin-piperaquine were given during two malaria transmission seasons from Aug 27 to Oct 31, 2018, and from July 15 to Sept 30, 2019. Primary outcomes were malaria prevalence by qPCR at the end of the second intervention year in November 2019, and Anopheles gambiae (s l) parous rate, analysed in the intention-to-treat population. This trial is registered with ClinicalTrials.gov, NCT03576313.

FINDINGS

Between Nov 20 and Dec 7, 2017, 47 villages were screened for eligibility in the study. 15 were excluded because the baseline malaria prevalence was less than 7% (figure 1). 32 villages were enrolled and randomised to either the intervention or control group (n=16 in each group). The study population was 10 638, of which 4939 (46%) participants were in intervention villages. Coverage for dihydroartemisinin-piperaquine was between 49·0% and 58·4% in 2018, and between 76·1% and 86·0% in 2019; for ivermectin, coverage was between 46·9% and 52·2% in 2018, and between 71·7% and 82·9% in 2019. In November 2019, malaria prevalence was 12·8% (324 of 2529) in the control group and 5·1% (140 of 2722) in the intervention group (odds ratio [OR] 0·30, 95% CI 0·16-0·59; p<0·001). A gambiae (s l) parous rate was 83·1% (552 of 664) in the control group and 81·7% (441 of 540) in the intervention group (0·90, 0·66-1·25; p=0·537). In 2019, adverse events were recorded in 386 (9·7%) of 3991 participants in round one, 201 (5·4%) of 3750 in round two, and 168 (4·5%) of 3752 in round three. None of the 11 serious adverse events were related to the intervention.

INTERPRETATION

The intervention was safe and well tolerated. In an area with high coverage of standard control interventions, mass drug administration of ivermectin and dihydroartemisinin-piperaquine significantly reduced malaria prevalence; however, no effect of ivermectin on vector parous rate was observed.

FUNDING

Joint Global Health Trials Scheme.

TRANSLATION

For the French translation of the abstract see Supplementary Materials section.

Acceptability and feasibility of malaria prophylaxis for forest goers: findings from a qualitative study in Cambodia

BACKGROUND

In the Greater Mekong Subregion, adults are at highest risk for malaria, particularly those who visit forests. The absence of effective vector control strategies and limited periods of exposure during forest visits suggest that chemoprophylaxis could be an appropriate strategy to protect forest goers against malaria.

METHODS

Alongside a clinical trial of anti-malarial chemoprophylaxis in northern Cambodia, qualitative research was conducted, including in-depth interviews and observation, to explore the acceptability of malaria prophylaxis for forest goers, the implementation opportunities, and challenges of this strategy.

RESULTS

Prophylaxis with artemether-lumefantrine for forest goers was found to be acceptable under trial conditions. Three factors played a major role: the community's awareness and perception of the effectiveness of prophylaxis, their trust in the provider, and malaria as a local health concern. The findings highlight how uptake and adherence to prophylaxis are influenced by the perceived balance between benefits and burden of anti-malarials which are modulated by the seasonality of forest visits and its influence on malaria risk.

CONCLUSIONS

The implementation of anti-malarial prophylaxis needs to consider how the preventive medication can be incorporated into existing vector-control measures, malaria testing and treatment services. The next step in the roll out of anti-malarial prophylaxis for forest visitors will require support from local health workers.

The role of social cohesion in the implementation and coverage of a mass drug administration trial for malaria control in the Gambia: An in-depth comparison of two intervention villages

Mass drug administration (MDA), used increasingly in malaria eradication efforts, involves administering medication to an entire target population regardless of individual-level disease status. This strategy requires high levels of coverage and compliance. Previous studies have assessed individual and structural factors affecting MDA coverage, but there is a need to better understand the influence and expressions of community dynamics and social structures, such as social cohesion. We conducted a social science study concurrent to an MDA clinical trial for malaria control in The Gambia; ethnographic research was conducted prior to, throughout, and between MDA implementation July-November 2018, January-March 2019, and July-November 2019. We assessed how social cohesion, as expressed by the trial population, affects trial coverage through an in-depth ethnographic analysis of two trial villages, using observations, interviews, and focus group discussions with community members who took the trial medication and those who did not. We found that the villages had unique expressions of social cohesion. This was reflected through community participation in the trial implementation and may have affected coverage and compliance. The village with low coverage expressed a form of social cohesion where members followed advice to participate through a hierarchal system but did not actively participate in the MDA or its implementation. The village with high coverage expressed social cohesion as more participatory: individuals took the directive to participate but contextualized the trial implementation to their needs and wants. We analyze these different expressions of social cohesion and the important differences they make for the coverage and compliance levels reached in the two different villages.

Reactive, self-administered malaria treatment against asymptomatic malaria infection: results of a cluster randomized controlled trial in The Gambia

BACKGROUND

Selectively targeting and treating malaria-infected individuals may further decrease parasite carriage in low-burden settings. Using a trans-disciplinary approach, a reactive treatment strategy to reduce Plasmodium falciparum prevalence in participating communities was co-developed and tested.

METHODS

This is a 2-arm, open-label, cluster-randomized trial involving villages in Central Gambia during the 2017 and 2018 malaria transmission season. Villages were randomized in a 1:1 ratio using a minimizing algorithm. In the intervention arm, trained village health workers delivered a full course of pre-packed dihydroartemisinin-piperaquine to all residents of compounds where clinical cases were reported while in the control arm, compound residents were screened for infection at the time of the index case reporting. All index cases were treated following national guidelines. The primary endpoint was malaria prevalence, determined by molecular methods, at the end of the intervention period.

RESULTS

The trial was carried out in 50 villages: 34 in 2017 and 16 additional villages in 2018. At the end of the 2018 transmission season, malaria prevalence was 0.8% (16/1924, range 0-4%) and 1.1% (20/1814, range 0-17%) in the intervention and control arms, respectively. The odds of malaria infection were 29% lower in the intervention than in the control arm after adjustment for age (OR 0.71, 95% CI 0.27-1.84, p = 0.48). Adherence to treatment was high, with 98% (964/979) of those treated completing the 3-day treatment. Over the course of the study, only 37 villages, 20 in the intervention and 17 in the control arm, reported at least one clinical case. The distribution of clinical cases by month in both transmission seasons was similar and the odds of new clinical malaria cases during the trial period did not vary between arms (OR 1.04, 95% CI 0.57-1.91, p = 0.893). All adverse events were classified as mild to moderate and resolved completely.

CONCLUSION

The systematic and timely administration of an anti-malarial treatment to residents of compounds with confirmed malaria cases did not significantly decrease malaria prevalence and incidence in communities where malaria prevalence was already low. Treatment coverage and adherence was very high. Results were strongly influenced by the lower-than-expected malaria prevalence, and by no clinical cases in villages with asymptomatic malaria-infected individuals.

TRIAL REGISTRATION

This study is registered with ClinicalTrials.gov, NCT02878200. Registered 25 August 2016. https://clinicaltrials.gov/ct2/show/NCT02878200 .

From informed consent to adherence: factors influencing involvement in mass drug administration with ivermectin for malaria elimination in The Gambia

Background

The World Health Organization (WHO) recommends consideration of mass drug administration (MDA) for malaria control in low-endemic settings approaching elimination. However, MDA remains a controversial strategy, as multiple individual, social, and operational factors have shown to affect its acceptability at local levels. This is further complicated by inconsistent definitions of key indicators derived from individual and community involvement—coverage, adherence, and compliance—that cast doubts about the actual and potential epidemiological impact of MDA on disease control and elimination. This study aimed to identify limitations and enabling factors impacting involvement at different stages of a large cluster-randomized trial assessing the effect of combining dihydroartemisinin-piperaquine (DP) and ivermectin (IVM) in malaria transmission in The Gambia.

Methods

This social science study used a mixed-methods approach. Qualitative data were collected in intervention and control villages through ethnographic methods, including in-depth interviews (IDIs), focus group discussions (FGDs), and participant observation conducted with trial participants and decliners, community leaders, and field staff. A cross-sectional survey was conducted in the intervention villages after the first year of MDA. Both strands of the study explored malaria knowledge and opinions, social dynamics influencing decision-making, as well as perceived risks, burdens, and benefits associated with this MDA.

Results

157 IDIs and 11 FGDs were conducted, and 864 respondents were included in the survey. Barriers and enabling factors to involvement were differentially influential at the various stages of the MDA. Issues of social influence, concerns regarding secondary effects of the medication, costs associated with malaria, and acceptability of the implementing organization, among other factors, differently affected the decision-making processes throughout the trial. Rather than a linear trajectory, involvement in this MDA trial was subjected to multiple revaluations from enrolment and consent to medicine intake and adherence to treatment.

Conclusions

This study went beyond the individual factors often associated with coverage and adherence, and found that nuanced social dynamics greatly influence the decision-making process at all phases of the trial. These issues need to be consider for MDA implementation strategies and inform discussions about more accurate ways of reporting on critical effectiveness indicators.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12936-021-03732-z.

The IHAT-GUT Iron Supplementation Trial in Rural Gambia: Barriers, Facilitators, and Benefits

Introduction: In most sub-Saharan African countries iron deficiency anaemia remains highly prevalent in children and this has not changed in the last 25 years. Supplementation with iron hydroxide adipate tartrate (IHAT) was being investigated in anaemic children in a phase two clinical trial (termed IHAT-GUT), conducted at the Medical Research Council Unit the Gambia at the London School of Hygiene and Tropical Medicine (LSHTM) (abbreviated as MRCG hereof). This qualitative study aimed to explore the personal perceptions of the trial staff in relation to conducting a clinical trial in such settings in order to highlight the health system specific needs and strengths in the rural, resource-poor setting of the Upper River Region in the Gambia. Methods: Individual interviews (n = 17) were conducted with local trial staff of the IHAT-GUT trial. Data were analysed using inductive thematic analysis. Results: Potential barriers and facilitators to conducting this clinical trial were identified at the patient, staff, and trial management levels. Several challenges, such as the rural location and cultural context, were identified but noted as not being long-term inhibitors. Participants believed the facilitators and benefits outnumbered the barriers, and included the impact on education and healthcare, the ambitious and knowledgeable locally recruited staff, and the local partnership. Conclusions: While facilitators and barriers were identified to conducting this clinical trial in a rural, resource-poor setting, the overall impact was perceived as beneficial, and this study is a useful example of community involvement and partnership for further health improvement programs. To effectively implement a nutrition intervention, the local health systems and context must be carefully considered through qualitative research beforehand.

Complexities in Defining the Unit of Intervention for Reactive Community-Based Malaria Treatment in the Gambia

With significant declines in malaria, infections are increasingly clustered in households, or groups of households where malaria transmission is higher than in surrounding household/villages. To decrease transmission in such cases, reactive interventions target household members of clinical malaria cases, with the intervention unit (e.g., the "household/s") derived from an epidemiological and operational perspective. A lack of unanimity regarding the spatial range of the intervention unit calls for greater importance to be placed on social context in conceptualizing the appropriate unit. A novel malaria elimination strategy based on reactive treatment was recently evaluated by a cluster randomized trial in a low transmission setting in The Gambia. Transdisciplinary research was used to assess and improve the effectiveness of the intervention which consisted, among others, of reflecting on whether the household was the most adequate unit of analysis. The intervention was piloted on the smallest treatment unit possible and was further adapted following a better understanding of the social and epidemiological context. Intervention units defined according to (i) shared sleeping spaces and (ii) household membership, showed substantial limitations as it was not possible to define them clearly and they were extremely variable within the study setting. Incorporating local definitions and community preference in the trial design led to the appropriate intervention unit-the compound-defined as an enclosed space containing one or several households belonging to the same extended patrilineal family. Our study demonstrates the appropriateness of using transdisciplinary research for investigating alternative intervention units that are better tailored to reactive treatment approaches.

End-user perspectives on preventive antimalarials: A review of qualitative research

Antimalarials have been administered widely to prevent clinical malaria and researchers have explored how end-users' perspectives influence uptake and adherence. Drawing on a systematic search, this review aims to synthesise qualitative research on end-user perceptions of antimalarials for disease prevention. Searches were undertaken in PubMed and ISI Web of Knowledge. After applying exclusion criteria, identified sources underwent thematic analysis. Identified sources were published between 2000 and 2020 and drew on studies undertaken across Africa, Asia, Europe, Oceania and America. The sources revealed end-user concerns about the potential benefits and harms of preventive treatment that are entwined with broader understandings of the disease, the intervention, its implementation, accompanying information, and how it is embedded in wider healthcare and social relationships. The implications for antimalarials as preventive therapy encompass the need to build trust, including interpersonal trust, engage diverse stakeholders and to address broader health and wellbeing concerns during implementation.

Rapid ethnographic assessment for potential anti-malarial mass drug administration in an outbreak area of Santo Domingo, Dominican Republic

BACKGROUND

In the Dominican Republic, a recent outbreak of malaria in the capital, Santo Domingo, threatens efforts to eliminate the disease. Mass drug administration (MDA) has been proposed as one strategy to reduce transmission. The success of MDA is contingent upon high levels of acceptance among the target population. To inform the design of future MDA campaigns, this rapid ethnographic assessment examined malaria-related knowledge and attitudes toward malaria MDA among residents of a transmission focus in Santo Domingo.

METHODS

In October 2019, a rapid ethnographic assessment was conducted in the Los Tres Brazos transmission focus, which had not previously received MDA. National malaria programme staff conducted 61 structured interviews with key informants, recorded observations, and held 72 informal conversations. Using a grounded theory approach, data were analysed during three workshop sessions with research team members.

RESULTS

Among those who had heard of malaria in the structured interviews (n = 39/61; 64%), understanding of the disease was largely based on personal experience from past outbreaks or through word-of-mouth. Community health workers (promotores) were trusted for health information and malaria diagnosis more so than professional clinicians. No participant (0%) was familiar with malaria MDA. After learning about MDA, almost all study participants (92%) said that they would participate, seeing it as a way to care for their community. Reasons for not participating in future MDA included not trusting drug administrators, feeling reluctant to take unprescribed medicine, and fear of missing work. Additional identified challenges to MDA included reaching specific demographic groups, disseminating effective MDA campaign messages, and managing misinformation and political influence.

CONCLUSION

Residents appear accepting of MDA despite a lack of prior familiarity. Successful MDA will depend on several factors: fostering relationships among community-based health workers, clinicians, community leaders, and others; developing clear health messages that use local terms and spreading them through a variety of media and social networks; and contextualizing MDA as part of a broader effort to promote community health.

Understanding adherence to reactive treatment of asymptomatic malaria infections in The Gambia

The impact of different types of reactive case detection and/or treatment strategies for malaria elimination depends on high coverage and participants’ adherence. However, strategies to optimise adherence are limited, particularly for people with asymptomatic or no infections. As part of a cluster-randomized trial to evaluate the effect of reactive treatment in The Gambia, all residents in the compound of a diagnosed clinical malaria patient received dihydro-artemisinin–piperaquine (DP). Using a mixed method approach, we assessed which factors contribute to adherence among the contacts of malaria cases that showed no symptoms. Adherence was defined as the proportion of compound members that (1) returned all medicine bags empty and (2) self-reported (3-day) treatment completion. Among the 273 individuals from 14 compounds who received DP, 227 (83.1%) were available for and willing to participate in the survey; 85.3% (233/273) returned empty medicine bags and 91.6% (208/227) self-reported treatment completion. Although clinical malaria was not considered a major health problem, reported adherence was high. The drivers of adherence were the strong sense of responsibility towards protecting the individual, compound and the village. Adherence can be optimised through a transdisciplinary implementation research process of engaging communities to bridge the gap between research goals and social realities.

Comparison of Reported and Survey-Based Coverage in Onchocerciasis Programs over a Period of 8 Years in Cameroon and Uganda

Mass drug administration (MDA) with ivermectin must reach a high treatment coverage (90% of the eligible population) if onchocerciasis is to be eliminated. Questions have been raised as to whether reported treatment figures reaching such high coverage are reliable. Sample surveys are proposed as the method of choice for "validating" reported coverage figures. The purpose of this study was to compare the district-level MDA coverage reported by programs with contemporaneous surveys of randomly selected respondents living in those same districts. Over an 8-year period, 19,219 households were selected using multistage random sampling; 38,433 adult male and female heads of those households were asked about their recent ivermectin MDA treatment experience. District coverage reports were considered "accurate" if they fell within the 95% CIs determined by the corresponding district's survey. Ninety-eight treatment rounds were evaluated over an 8-year period. Overall, the reported coverage of 96.5% (range: 68-100%) was significantly higher than the 92.5% surveyed coverage (range: 62.1-99.6%, 95% CI: 91.9-93.2%). However, only 20% of districts reported significantly higher coverage than surveys, 68% of district program reports were judged as accurate, and 12% of districts reported significantly lower coverage figures than their corresponding surveys. Eighty-eight percent of districts reported coverage ≥ 90% threshold for success, compared with 97% of surveys that included 90% in their 95% CIs. We conclude that when analyzed statistically at the district level, most surveys verified the reported coverage.

Prevalence of asymptomatic malaria parasitaemia following mass testing and treatment in Pakro sub-district of Ghana

Background

Global efforts to scale-up malaria control interventions are gaining steam. These include the use of Long-Lasting Insecticide Nets, Indoor Residual Spraying, Intermittent Preventive Treatment and Test, Treat and Track. Despite these, the drive for malaria elimination is far from being realistic in endemic communities in Africa. This is partly due to the fact that asymptomatic parasite carriage, not specifically targeted by most interventions, remains the bedrock that fuels transmission. This has led to mass testing, treatment and tracking (MTTT) as an alternative strategy to target asymptomatic individuals. We report the impact of MTTT on the prevalence of asymptomatic malaria parasitaemia over a one-year period in Ghana, hypothesizing that implementing MTTT could reduce the rate of asymptomatic parasitaemia.

Methods

A population of about 5000 individuals in seven communities in the Pakro sub-district of Ghana participated in this study. A register was developed for each community following a census. MTTT engaged trained community-based health volunteers who conducted house-to-house testing using RDTs every 4 months and treated positive cases with Artemisinin–based Combination Therapy. Between interventions, community-based management of malaria was implemented for symptomatic cases.

Results

MTTT Coverage was 98.8% in July 2017 and 79.3% in July 2018. Of those tested, asymptomatic infection with malaria parasites reduced from 36.3% (1795/4941) in July 2017 to 32.9% (1303/3966) in July 2018 (p = 0.001). Prevalence of asymptomatic parasitaemia among children under 15 years declined from 52.6% (1043/1984) in July 2017 to 47.5% (820/1728) in July 2018 (p = 0.002). Implementing MTTT significantly reduced asymptomatic parasitaemia by 24% from July 2017 to July 2018 after adjusting for age, ITN use and axillary temperature (OR = 0.76, CI = 0.67, 0.85 p ≤ 0.001).

Conclusion

This study has demonstrated that implementing MTTT is feasible and could reduce the prevalence of asymptomatic malaria parasitaemia in children under 15 years of age. Furthermore, the use of community-based health volunteers could ensure high coverage at lower cost of implementation.

Trial registration

NCT04167566, Date 14/11/2019. Retrospective registration.

Field performance of the malaria highly sensitive rapid diagnostic test in a setting of varying malaria transmission

BACKGROUND

The Gambia has successfully reduced malaria transmission. The human reservoir of infection could further decrease if malaria-infected individuals could be identified by highly sensitive, field-based, diagnostic tools and then treated.

METHODS

A cross-sectional survey was done at the peak of the 2017 malaria season in 47 Gambian villages. From each village, 100 residents were randomly selected for finger-prick blood samples to detect Plasmodium falciparum infections using highly sensitive rapid diagnostic tests (HS-RDT) and PCR. The sensitivity and specificity of the HS-RDT were estimated (assuming PCR as the gold standard) across varying transmission intensities and in different age groups. A deterministic, age-structured, dynamic model of malaria transmission was used to estimate the impact of mass testing and treatment (MTAT) with HS-RDT in four different scenarios of malaria prevalence by PCR: 5, 15, 30, and 60%, and with seasonal transmission. The impact was compared both to MTAT with conventional RDT and mass drug administration (MDA).

RESULTS

Malaria prevalence by HS-RDT was 15% (570/3798; 95% CI 13.9-16.1). The HS-RDT sensitivity and specificity were 38.4% (191/497, 95% CI 34.2-42.71) and 88.5% (2922/3301; 95% CI 87.4-89.6), respectively. Sensitivity was the highest (50.9%, 95% CI 43.3-58.5%) in high prevalence villages (20-50% by PCR). The model predicted that in very low transmission areas (≤ 5%), three monthly rounds of MTAT with HS-RDT, starting towards the end of the dry season and testing 65 or 85% of the population for 2 consecutive years, would avert 62 or 78% of malaria cases (over 2 years), respectively. The effect of the intervention would be lower in a moderate transmission setting. In all settings, MDA would be superior to MTAT with HS-RDT which would be superior to MTAT with conventional RDT.

CONCLUSION

The HS-RDT's field sensitivity was modest and varied by transmission intensity. In low to very low transmission areas, three monthly rounds per year of MTAT with HS-RDT at 85% coverage for 2 consecutive years would reduce malaria prevalence to such low levels that additional strategies may achieve elimination. The model prediction would need to be confirmed by cluster-randomized trials.

Mass Drug Administration With Dihydroartemisinin-piperaquine and Malaria Transmission Dynamics in The Gambia: A Prospective Cohort Study

BACKGROUND

Mass drug administration (MDA) may further reduce malaria transmission in low-transmission areas. The impact of MDA on the dynamics of malaria transmission was determined in a prospective cohort study.

METHODS

Annual rounds of MDA with dihydroartemisinin-piperaquine (DP) were implemented were implemented in 2014 and 2015 in six village pairs before the malaria transmission season. Blood samples were collected from residents between July and December for microscopy and nested PCR. Incidence and prevalence of infection, clinical disease, and risk of malaria reinfection post-MDA were determined.

RESULTS

Coverage of three DP doses was 68.2% (2014) and 65.6% (2015), compliance was greater than 80%. Incidence of infection was significantly lower in 2014 (incidence rate [IR] = 0.2 per person year [PPY]) than in 2013 (IR = 1.1 PPY; P < .01); monthly infection prevalence declined in the first three months post-MDA. Clinical malaria incidence was lower in 2014 (IR = 0.1 PPY) and 2015 (IR = 0.2 PPY) than in 2013 (IR = 0.4 PPY; P < .01), but remained higher in eastern Gambia. Individuals infected before MDA had a 2-fold higher odds of reinfection post-MDA (adjusted odds ratio = 2.5, 95% confidence interval 1.5-4.3; P < .01).

CONCLUSIONS

MDA reduced malaria infection and clinical disease during the first months. The reduction was maintained in low-transmission areas, but not in eastern Gambia. Annual MDA could be followed by focal MDA targeting individuals infected during the dry season. Repeated MDA rounds, some during the dry season over larger geographical areas, may result in a more marked and sustained decrease of malaria transmission.

Gambian cultural beliefs, attitudes and discourse on reproductive health and mortality: Implications for data collection in surveys from the interviewer's perspective

Background

A community’s cultural beliefs, attitudes and discourse can affect their responses in surveys. Knowledge of these cultural factors and how to comply with them or adjust for them during data collection can improve data quality.

Objective

This study describes implications of features of Gambian culture related to women’s reproductive health, and mortality, when collecting data in surveys.

Methods

13 in-depth interviews of female interviewers and a focus group discussion among male interviewers were conducted in two rural health and demographic surveillance systems as well as three key informant interviews in three regions in The Gambia.

Results

From the fieldworker’s viewpoint, questions relating to reproduction were best asked by women as culturally pregnancies should be concealed, and menstruation is considered a sensitive topic. Gambians were reluctant to speak about decedents and the Fula did not like to be counted, potentially affecting estimation of mortality. Asking about siblings proved problematic among the Fula and Serahule communities. Proposals made to overcome these challenges were that culturally-appropriate metaphors and symbols should be used to discuss sensitive matters and to enumerating births/deaths singly instead of collecting summary totals, which had threatening connotations. This was as opposed to training interviewers to ask standardised and precise verbatim questions.

Contribution

This paper presents indigenous Gambian solutions by fieldworkers to culturally sensitive topics when collecting pregnancy outcomes and mortality data in demographic and health surveys. For researchers collecting maternal mortality data, it highlights the potential shortcomings of the sibling history methodology.

Population coverage and factors associated with participation following a mass drug administration of azithromycin for trachoma elimination in Amhara, Ethiopia

Objectives

Mass drug administration (MDA) with azithromycin is a core component of the WHO‐recommended strategy to eliminate trachoma as a public health problem, but low participation rates in MDA campaigns may undermine the effectiveness of this intervention. We explored factors associated with individual MDA participation at the individual, head of household and household levels in Amhara, Ethiopia.

Methods

We conducted four district‐level, multilevel cluster random coverage surveys to collect data on self‐reported MDA participation and predictors. Random‐effects logistic regression modelling was used to identify correlates of MDA participation while adjusting for nesting of individuals at the household and village level.

Results

The district‐level self‐reported participation in the trachoma MDA ranged from 78.5% to 86.9%. Excellent and fair health status (Odds ratio [OR] = 5.77; 95% Confidence interval [CI]: 3.04, 10.95; OR = 7.08; 95% CI: 3.47, 14.46), advanced knowledge of the MDA campaign (OR = 2.93; 95% CI: 2.04, 4.21) and knowledge of trachoma (OR = 1.60; 95% CI: 1.17, 2.19) were all positively associated with MDA participation. When excluding heads of household from the model, correlates retained similar positive associations to participation, in addition to the head of household participation (OR = 3.34; 95% CI: 2.46, 4.54).

Conclusions

To increase the impact of MDA campaigns, MDA mobilisation strategies—including comprehensive trachoma and azithromycin messaging and MDA campaign awareness—should target heads of household, those in poorer health and older age groups.

Impact of mass drug administration campaigns depends on interaction with seasonal human movement

Background

Mass drug administration (MDA) is a control and elimination tool for treating infectious diseases. For malaria, it is widely accepted that conducting MDA during the dry season results in the best outcomes. However, seasonal movement of populations into and out of MDA target areas is common in many places and could potentially fundamentally limit the ability of MDA campaigns to achieve elimination.

Methods

A mathematical model was used to simulate malaria transmission in two villages connected to a high-risk area into and out of which 10% of villagers traveled seasonally. MDA was given only in the villages. Prevalence reduction under various possible timings of MDA and seasonal travel was predicted.

Results

MDA is most successful when distributed outside the traveling season and during the village low-transmission season. MDA is least successful when distributed during the traveling season and when traveling overlaps with the peak transmission season in the high-risk area. Mistiming MDA relative to seasonal travel resulted in much poorer outcomes than mistiming MDA relative to the peak transmission season within the villages.

Conclusions

Seasonal movement patterns of high-risk groups should be taken into consideration when selecting the optimum timing of MDA campaigns.

Fear and rumours regarding placental biopsies in a malaria-in-pregnancy trial in Benin

Background

A multi-country, community-based trial on scheduled screening and treatment for malaria in pregnancy was conducted in Benin, The Gambia and Burkina Faso. Despite standardized procedures and outcomes, the study became subject to rumours and accusations of placenta being sold for mystical and financial gain by trial staff, leading to drop-out rates of 30% and the consequent halting of placental biopsy sampling in Benin. This paper explores the role of socio-cultural beliefs related to placenta and identified additional factors contributing these rumours.

Methods

A qualitative comparative emergent-theory design was used to assess social factors related to trial implementation and uptake in the three countries. Data from participant observation, informal conversations, group discussions and interviews were triangulated and analysed with NVivo Qualitative Analysis software.

Results

Despite similar sociocultural beliefs about the sacred nature of the placenta in all three study countries, these beliefs did not affect participation rates in Burkina Faso and The Gambia and placenta-related rumours only emerged in Benin. Therefore, the presence of beliefs is not a sufficient condition to have generated placenta-selling fears. The rumours in Benin reflected the confluence of placenta-related beliefs and factors related to the implementation of the trial (including a catalysing adverse event and miscommunication during the informed consent procedure). Furthermore, distinct socio-political factors contributed to the emergence of rumours, including the historical distrust in governmental organizations and the tense relationship between some of the actors involved in the trial.

Conclusion

Transdisciplinary social science research designs should accompany the implementation of the trial. The integration of multiple stakeholders’ knowledge and involvement is required to define and solve upcoming barriers.

Reactive community-based self-administered treatment against residual malaria transmission: study protocol for a randomized controlled trial

Background

Systematic treatment of all individuals living in the same compound of a clinical malaria case may clear asymptomatic infections and possibly reduce malaria transmission, where this is focal. High and sustained coverage is extremely important and requires active community engagement. This study explores a community-based approach to treating malaria case contacts.

Methods/design

This is a cluster-randomized trial to determine whether, in low-transmission areas, treating individuals living in the same compound of a clinical malaria case with dihydroartemisinin-piperaquine can reduce parasite carriage and thus residual malaria transmission. Treatment will be administered through the local health system with the approach of encouraging community participation designed and monitored through formative research. The trial goal is to show that this approach can reduce in intervention villages the prevalence of Plasmodium falciparum infection toward the end of the malaria transmission season.

Discussion

Adherence and cooperation of the local communities are critical for the success of mass treatment campaigns aimed at reducing malaria transmission. By exploring community perceptions of the changing trends in malaria burden, existing health systems, and reaction to self-administered treatment, this study will develop and adapt a model for community engagement toward malaria elimination that is cost-effective and fits within the existing health system.

Trial registration

Clinical trials.gov, NCT02878200. Registered on 25 August 2016. 

Electronic supplementary material

The online version of this article (10.1186/s13063-018-2506-x) contains supplementary material, which is available to authorized users.

Population-based coverage survey results following the mass drug administration of azithromycin for the treatment of trachoma in Amhara, Ethiopia

Background

Trachoma is the leading infectious cause of blindness worldwide. In communities where the district level prevalence of trachomatous inflammation-follicular among children ages 1–9 years is ≥5%, WHO recommends annual mass drug administration (MDA) of antibiotics with the aim of at least 80% coverage. Population-based post-MDA coverage surveys are essential to understand the effectiveness of MDA programs, yet published reports from trachoma programs are rare.

Methods

In the Amhara region of Ethiopia, a population-based MDA coverage survey was conducted 3 weeks following the 2016 MDA to estimate the zonal prevalence of self-reported drug coverage in all 10 administrative zones. Survey households were selected using a multi-stage cluster random sampling design and all individuals in selected households were presented with a drug sample and asked about taking the drug during the campaign. Zonal estimates were weighted and confidence intervals were calculated using survey procedures. Self-reported drug coverage was then compared with regional reported administrative coverage.

Results

Region-wide, 24,248 individuals were enumerated, of which, 20,942 (86.4%) individuals were present. The regional self-reported antibiotic coverage was 76.8% (95%Confidence Interval (CI):69.3–82.9%) in the population overall and 77.4% (95%CI = 65.7–85.9%) among children ages 1–9 years old. Zonal coverage ranged from 67.8% to 90.2%. Five out of 10 zones achieved a coverage >80%. In all zones, the reported administrative coverage was greater than 90% and was considerably higher than self-reported MDA coverage. Main reasons reported for MDA campaign non-attendance included being physically unable to get to MDA site (22.5%), traveling (20.6%), and not knowing about the campaign (21.0%). MDA refusal was low (2.8%) in this population.

Conclusions

Although self-reported MDA coverage in Amhara was greater than 80% in some zones, programmatic improvements are warranted throughout Amhara to achieve higher coverage. These results will be used to enhance community mobilization and improve training for MDA distributors and supervisors to improve coverage in future MDAs.

Mass drug administration (MDA) with antibiotics is a key component of the trachoma control strategy. The World Health Organization (WHO) recommends that at least 80% of the target population should be reached with MDA. Drug coverage estimates from population-based surveys may increase our understanding of factors affecting the effectiveness of MDA. We conducted a region-wide population-based survey to estimate the prevalence of self-reported drug coverage in all ten administrative zones of Amhara region, an area with a population of approximately 21 million people. The self-reported drug coverage was greater than 80% in five of the ten zones and was 76.8% region-wide. Zonal administrative coverage reports were greater than 90% and were considerably higher than self-reported coverage in all zones. The discrepancy between administrative and self-report coverages also suggest that efforts should be made to better understand the reasons for the disparity in the two measures. The main reasons reported for not attending the MDA included being physically unable to get to the distribution site, traveling during the campaign, and lack of knowledge about the campaign. These findings suggest that making the distribution site accessible to all individuals, informing constituents about timing of the campaign to allow for travel, and providing adequate information about the campaign would improve MDA participation.

Factors associated with population coverage of targeted malaria elimination (TME) in southern Savannakhet Province, Lao PDR

Background

Targeted malaria elimination (TME) in Lao PDR (Laos) included three rounds of mass drug administrations (MDA) against malaria followed by quarterly blood surveys in two villages in Nong District at Savannakhet Province. The success of MDA largely depends upon the efficacy of the anti-malarial drug regimen, local malaria epidemiology and the population coverage. In order to explore the reasons for participation in TME, a quantitative survey was conducted after the completion of the three rounds of MDA.

Methods

The survey was conducted in two villages with a total of 158 households in July and August 2016. Among the 973 villagers eligible for participation in the MDA, 158 (16.2%) adults (> 18 years) were selected, one each from every household for the interviews using a quantitative questionnaire.

Results

150/158 (94.9%) respondents participated at least in one activity (taking medicine or testing their blood) of TME. 141/150 (94.0%) respondents took part in the MDA and tested their blood in all three rounds. 17/158 (10.7%) were partial or non-participants in three rounds of MDA. Characteristics of respondents which were independently associated with completion of three rounds of MDA included: attending TME meetings [AOR = 12.0 (95% CI 1.1–20.5) (p = 0.03)], knowing that malaria can be diagnosed through blood tests [AOR = 5.6 (95% CI 1.0–32.3) (p = 0.05)], all members from household participated [AOR = 4.2 (95% CI 1.3–14.0) (p = 0.02)], liking all aspects of TME [AOR = 17.2 (95% CI 1.6–177.9) (p = 0.02)] and the perception that TME was important [AOR = 14.9 (95% CI 1.3–171.2) (p = 0.03)].

Conclusion

Complete participation in TME was significantly associated with participation in community engagement activities, knowledge that the blood tests were for malaria diagnosis, family members’ participation at TME and perceptions that TME was worthwhile. A responsive approach to community engagement that includes formative research and the involvement of community members may increase the uptake of the intervention.

Electronic supplementary material

The online version of this article (doi:10.1186/s12936-017-2070-y) contains supplementary material, which is available to authorized users.

New adenovirus-based vaccine vectors targeting Pfs25 elicit antibodies that inhibit Plasmodium falciparum transmission

Background

An effective malaria transmission-blocking vaccine (TBV) would be a major advance in the current efforts to eliminate and, ultimately, eradicate malaria. Antibodies against Plasmodium falciparum surface protein, Pfs25, are known to block parasite development in the mosquito vector. However, in initial clinical trials the limited immunogenicity of recombinant Pfs25 protein-in-adjuvant vaccines has been a challenge.

Methods

Novel human adenovirus type 5 (Ad5) vectors were used in heterologous prime boost vaccination strategies to augment the immune response against Pfs25. Specifically, an Ad5 vector that directs expression of full-length, membrane-bound Pfs25 was used as a priming immunization followed by a boost with Ad5 viral particles displaying only the Pfs25 epitope targeted by transmission-blocking antibodies 4B7 and 1D2 (Pfs25 aa 122–134) in hypervariable region 5 of the hexon capsid protein.

Results

This heterologous prime-boost vaccine strategy induced antibodies that significantly inhibit P. falciparum transmission to mosquitoes in a standard membrane-feeding assay. Further, immunized mice generated a robust anti-Pfs25 antibody response characterized by higher titer, higher relative avidity and a broader IgG subclass profile than observed with a homologous prime-boost with recombinant Pfs25/alum.

Conclusion

The data suggest that focusing the immune response against defined epitopes displayed on the viral capsid is an effective strategy for transmission-blocking vaccine development.

Community perceptions of targeted anti-malarial mass drug administrations in two provinces in Vietnam: a quantitative survey

Background

As part of a targeted malaria elimination project, mass drug administrations (MDAs) were conducted in Vietnam. The impact of MDAs on malaria transmission depends largely on the efficacy of the anti-malarial drug regimen, the malaria epidemiology in the site and the population coverage. To explore why some people participate in MDAs and others do not, a quantitative survey of the villagers’ perceptions was undertaken in Vietnam.

Methods

In 2013/2014 MDAs were conducted in a village in Binh Phuoc province and a village in Ninh Thuan province. Within three months of the drug administration, 59 respondents in a village in Binh Phuoc and 79 respondents in a village in Ninh Thuan were randomly selected and interviewed.

Results

Comprehension of the purpose of the intervention was of paramount importance for participation in the intervention. Respondents aware that the intervention aims to protect against malaria were significantly more likely to participate than respondents who were unaware of the MDA’s purpose. Secondly, how and by whom villagers were informed was critical for participation. There was a strong association between sensitization by an informant such as a member of the local health team with participation in the intervention.

Conclusions

The study suggests several approaches to increase participation in mass drug administration campaigns. Training trustworthy informants to sensitize the study population is critical to maximize village participation in this setting. To achieve high coverage the entire community must understand and agree with the intervention.

Electronic supplementary material

The online version of this article (doi:10.1186/s12936-016-1662-2) contains supplementary material, which is available to authorized users.

The acceptability of mass administrations of anti-malarial drugs as part of targeted malaria elimination in villages along the Thai-Myanmar border

Background

A targeted malaria elimination project, including mass drug administrations (MDA) of dihydroartemisinin/piperaquine plus a single low dose primaquine is underway in villages along the Thailand Myanmar border. The intervention has multiple components but the success of the project will depend on the participation of the entire communities. Quantitative surveys were conducted to study reasons for participation or non-participation in the campaign with the aim to identify factors associated with the acceptance and participation in the mass drug administrations.

Methods

The household heads in four study villages in which MDAs had taken place previously were interviewed between January 2014 and July 2015.

Results

174/378 respondents (46 %) completed three rounds of three drug doses each, 313/378 (83 %) took at least three consecutive doses and 56/378 (15 %) did not participate at all in the MDA. The respondents from the two villages (KNH and TPN) were much more likely to participate in the MDA than respondents from the other two villages (HKT and TOT). The more compliant villages KNH and TPN had both an appearance of cohesive communities with similar demographic and ethnic backgrounds. By contrast the villages with low participation were unique. One village was fragmented following years of armed conflict and many respondents gave little inclination to cooperate with outsiders. The other village with low MDA coverage was characterised by a high percentage of short-term residents with little interest in community interventions. A universal reason for non-participation in the MDA applicable to all villages was an inadequate understanding of the intervention.

Conclusions

It is unlikely that community engagement can unite fragmented communities in participating in an intervention, which benefits the community. Understanding the purpose and the reasons underlying the intervention is an important pre-condition for participation. In the absence of direct benefits and a complete understanding of the indirect benefits trust in the investigators is critical for participation.

The Importance of Blood Is Infinite: Conceptions of Blood as Life Force, Rumours and Fear of Trial Participation in a Fulani Village in Rural Gambia

BACKGROUND

Clinical trials require high levels of participation and low drop-out rates to be successful. However, collecting blood samples from individuals recruited into clinical trials can be challenging when there is reticence about blood-taking. In addition to concerns regarding the feasibility of medical research, fears of 'blood-stealing' and 'blood-selling' have ethical implications related to cultural sensitivity and informed consent. This study explores anxieties around blood-taking during a malaria treatment trial in the Gambia.

METHODS

This case study is based on ethnographic research in one theoretically selected village due to the high reticence to screening for the clinical trial 'Primaquine's gametocytocidal efficacy in malaria asymptomatic carriers treated with dihydroartemisinin-piperaquine' carried out in the Gambia between 2013 and 2014. Data collection tools included in-depth interviews, participant observation, informal conversations and group discussions.

RESULTS

In total only 176 of 411 habitants (42%) in the village accepted having a bloodspot taken to screen for malaria. Although trial recruitment was initially high in the village, some families refused screening when rumours started spreading that the trial team was taking too much blood. Concerns about 'loss of blood' were equated to loss of strength and lack of good food to replenish bodily forces. Families in the study village were concerned about the weakness of their body while they had to harvest their crops at the time of recruitment for the trial.

CONCLUSION

A common recommendation to prevent and avoid rumours against public health interventions and trials is the provision of full and consistent information during the consent procedure, which is assumed to lead to more accurate knowledge of the purpose of the intervention and increased trial participation. However, even when information provision is continuous, the emergence of rumours can be related to times of uncertainty and perceptions of vulnerability, which are often a reflection of structural inequalities and diverging value orientations between communities and public health institutions.