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

Factors associated with never treatment and acceptability of mass drug administration for the elimination of lymphatic filariasis in Guyana, 2021

Guyana remains one of four countries in the Americas endemic for lymphatic filariasis (LF). Elimination of LF requires repeated annual mass drug administration (MDA) with sufficient levels of coverage for success. This study assesses the acceptability and never treatment of LF MDA using data from a routine assessment survey in 2021. A subset of individuals, over 20 years of age (n = 2498), were selected to receive an expanded questionnaire to examine factors associated with acceptability and never treatment. Assessed factors include respondent demographics, knowledge, risk perceptions of LF, and opinions on the MDA programme. The majority (73%) of those with scores above the acceptability threshold (score ≥22.5) reported participating in MDA two or more times. Factors strongly and positively associated with scoring above the acceptability threshold include beliefs in importance of participation in MDA for their community (aOR = 2.8, 95%CI (1.1-7.2)), perception of importance of LF treatment (6.9 (3.2-14.7)), receiving treatment in 2021 (2.9 (1.5-5.4)), and the number of self-reported times taking treatment for LF (2.2 (1.1-4.4)). Ten percent of respondents participated in the MDA for the first time in 2021, while 15% reported never treatment during any round of LF MDA. Three factors were statistically associated with participation in MDA across the two levels of the models (level 1: took LF treatment once versus never, and level 2: took LF treatment twice versus never) included: 1) scoring above the acceptability threshold (aOR = 6.2, 95%CI(3.8-10.0)), 2) self-reported importance of participation in MDA for their community (7.1 (2.9-17.8)), and 3) personal beliefs that they should take LF treatment even if they are not sick (2.6 (1.7-3.9)). As Guyana moves closer to LF elimination, these results provide further insight and understanding into programmatic results and could inform further action following MDA activities-particularly if an approach is needed to address never treatment during MDA.

Forest-goers as a heterogeneous population at high-risk for malaria: a case-control study in Aceh Province, Indonesia

BACKGROUND

A major challenge to malaria elimination is identifying and targeting populations that are harbouring residual infections and contributing to persistent transmission. In many near-elimination settings in Southeast Asia, it is known that forest-goers are at higher risk for malaria infection, but detailed information on their behaviours and exposures is not available.

METHODS

In Aceh Province, Indonesia, a near-elimination setting where a growing proportion of malaria is due to Plasmodium knowlesi, a case-control study was conducted to identify risk factors for symptomatic malaria, characteristics of forest-goers, and key intervention points. From April 2017 to September 2018, cases and controls were recruited and enrolled in a 1:3 ratio. Cases had confirmed malaria infection by rapid diagnostic test or microscopy detected at a health facility (HF). Gender-matched controls were recruited from passive case detection among individuals with suspected malaria who tested negative at a health facility (HF controls), and community-matched controls were recruited among those testing negative during active case detection. Multivariable logistic regression (unconditional for HF controls and conditional for community controls) was used to identify risk factors for symptomatic malaria infection.

RESULTS

There were 45 cases, of which 27 were P. knowlesi, 17 were Plasmodium vivax, and one was not determined. For controls, 509 and 599 participants were recruited from health facilities and the community, respectively. Forest exposures were associated with high odds of malaria; in particular, working and sleeping in the forest (HF controls: adjusted odds ratio (aOR) 21.66, 95% CI 5.09-92.26; community controls: aOR 16.78, 95% CI 2.19-128.7) and having a second residence in the forest (aOR 6.29, 95% CI 2.29-17.31 and 13.53, 95% CI 2.10-87.12). Male forest-goers were a diverse population employed in a variety of occupations including logging, farming, and mining, sleeping in settings, such as huts, tents, and barracks, and working in a wide range of group sizes. Reported use of protective measures, such as nets, hammock nets, mosquito coils, and repellents was low among forest-goers and interventions at forest residences were absent.

CONCLUSIONS

Second residences in the forest and gaps in use of protective measures point to key malaria interventions to improve coverage in forest-going populations at risk for P. knowlesi and P. vivax in Aceh, Indonesia. Intensified strategies tailored to specific sub-populations will be essential to achieve elimination.

Knowledge, compliance, and challenges in anti-malarial products usage: a systematic review of at-risk communities for zoonotic malaria

BACKGROUND

Zoonotic malaria is a growing public health threat in the WHO Southeast Asia (SEA) and Western Pacific (WP) regions. Despite vector-control measures, the distribution of Macaque fascicularis and M. nemestrina, and Anopheles mosquitoes carrying non-human simian malaria parasites poses challenges to malaria elimination. The systematic review assesses the literature on knowledge and malaria-preventive practices in zoonotic malaria-affected areas across the WHO SEA and WP, aiming to identify challenges for malaria control.

METHODS

Peer-reviewed articles published in English, Malay and Indonesian between January 2010 and December 2022 were searched in OVID Medline, Scopus, Web of Science, and Google Scholar. Studies of any design-excluding reviews, conference proceedings, and reports from all WHO SEA and WP countries vulnerable to zoonotic malaria-were included. Backwards-reference screening and thematic analysis were conducted.

RESULTS

Among 4,174 initially searched articles, 22 peer-reviewed articles met the inclusion criteria. An additional seven articles were identified through backwards-reference screening, resulting in a total of 29 articles for this review. Half of these studies were conducted in Cambodia, Myanmar, Malaysia, and Thailand, mainly in forests and remote communities. The review highlighted inconsistencies in the operationalization of knowledge, and five major themes were identified related to knowledge: causation and transmission, symptoms, treatment, severity and complications, and malaria prevention. While participants generally had some understanding of malaria causation/transmission, minority and indigenous ethnic groups demonstrated limited knowledge and held misconceptions, such as attributing malaria to drinking dirty water. Preventive practices included traditional and non-traditional or modern methods-with a preference for traditional approaches to avoid mosquito bites. Challenges to malaria control included feasibility, cost, and access to healthcare services.

CONCLUSION

This review provides insights into knowledge, local understandings, and preventive practices related to malaria in the WHO SEA and WP regions. The findings highlight the need for future research to explore the knowledge of at-risk communities regarding zoonotic malaria, their perceive threat of the disease and factors exposing them to zoonotic malaria. New strategies must be developed for zoonotic malaria programs tailored to local contexts, emphasizing the significance of community participation, health education, and socio-behavioural change initiatives. It is important to consider the interconnectedness of human health, environmental and non-human primates conservation. Socio-cultural nuances should also be carefully considered in the design and implementation of these programs to ensure their effect tailored to local contexts.

Assessing the acceptability and feasibility of reactive drug administration for malaria elimination in a Plasmodium vivax predominant setting: a qualitative study in two provinces in Thailand

BACKGROUND

Reactive case detection (RACD) or testing and treatment of close contacts of recent malaria cases, is commonly practiced in settings approaching malaria elimination, but standard diagnostics have limited sensitivity to detect low level infections. Reactive drug administration (RDA), or presumptive treatment without testing, is an alternative approach, but better understanding regarding community acceptability and operational feasibility are needed.

METHODS

A qualitative study was conducted as part of a two-arm cluster randomized-controlled trial evaluating the effectiveness of RDA targeting high-risk villages and forest workers for reducing Plasmodium vivax and P. falciparum malaria in Thailand. Key informant interviews (KIIs) and focus group discussions (FGDs) were conducted virtually among key public health staff, village health volunteers (VHVs), and household members that implemented or received RDA activities. Transcriptions were reviewed, coded, and managed manually using Dedoose qualitative data analysis software, then underwent qualitative content analysis to identify key themes.

RESULTS

RDA was well accepted by household members and public health staff that implemented it. RDA participation was driven by fear of contracting malaria, eagerness to receive protection provided by malaria medicines, and the increased access to health care. Concerns were raised about the safety of taking malaria medicines without having an illness, particularly if underlying health conditions existed. Health promotion hospital (HPH) staff implementing RDA noted its operational feasibility, but highlighted difficulty in traveling to remote areas, and requested additional travel resources and hiring more VHVs. Other challenges were highlighted including the need for additional training for VHVs on malaria activities and the inability of HPH staff to conduct RDA due to other health priorities (e.g., Covid-19). More training and practice for VHVs were noted as ways to improve implementation of RDA.

CONCLUSIONS

To maximize uptake of RDA, regular education and sensitization campaigns in collaboration with village leaders on the purpose and rationale of RDA will be critical. To alleviate safety concerns and increase participant safety, a rigorous pharmacovigilance program will be important. To accelerate uptake of RDA, trust between HPH staff and VHVs and the communities they serve must continue to be strengthened to ensure acceptance of the intervention.

TRIAL REGISTRATION

This study was approved by the Committee on Human Research at the University of California San Francisco (19-28,060) and the local Ethics Committee for Research in Human Subjects at Tak Provincial Health office (009/63) and Kanchanaburi Provincial health office (Kor Chor 0032.002/2185). Local authorities and health officers in the provinces, districts, and villages agreed upon and coordinated the implementation of the study. All methods in this study were carried out in accordance with relevant guidelines and regulations.

Community engagement among forest goers in a malaria prophylaxis trial: implementation challenges and implications

BACKGROUND

Malaria transmission in Southeast Asia is increasingly confined to forests, where marginalized groups are exposed primarily through their work. Anti-malarial chemoprophylaxis may help to protect these people. This article examines the effectiveness and practical challenges of engaging forest-goers to participate in a randomized controlled clinical trial of anti-malarial chemoprophylaxis with artemether-lumefantrine (AL) versus a control (multivitamin, MV) for malaria in northeast Cambodia.

METHODS

The impact of engagement in terms of uptake was assessed as the proportion of people who participated during each stage of the trial: enrolment, compliance with trial procedures, and drug intake. During the trial, staff recorded the details of engagement meetings, including the views and opinions of participants and community representatives, the decision-making processes, and the challenges addressed during implementation.

RESULTS

In total, 1613 participants were assessed for eligibility and 1480 (92%) joined the trial, 1242 (84%) completed the trial and received prophylaxis (AL: 82% vs MV: 86%, p = 0.08); 157 (11%) were lost to follow-up (AL: 11% vs MV: 11%, p = 0.79); and 73 (5%) discontinued the drug (AL-7% vs MV-3%, p = 0.005). The AL arm was associated with discontinuation of the study drug (AL: 48/738, 7% vs 25/742, 3%; p = 0.01). Females (31/345, 9%) were more likely (42/1135, 4%) to discontinue taking drugs at some point in the trial (p = 0.005). Those (45/644, 7%) who had no previous history of malaria infection were more likely to discontinue the study drug than those (28/836, 3%) who had a history of malaria (p = 0.02). Engagement with the trial population was demanding because many types of forest work are illegal; and the involvement of an engagement team consisting of representatives from the local administration, health authorities, community leaders and community health workers played a significant role in building trust. Responsiveness to the needs and concerns of the community promoted acceptability and increased confidence in taking prophylaxis among participants. Recruitment of forest-goer volunteers to peer-supervise drug administration resulted in high compliance with drug intake. The development of locally-appropriate tools and messaging for the different linguistic and low-literacy groups was useful to ensure participants understood and adhered to the trial procedures. It was important to consider forest-goers` habits and social characteristics when planning the various trial activities.

CONCLUSIONS

The comprehensive, participatory engagement strategy mobilized a wide range of stakeholders including study participants, helped build trust, and overcame potential ethical and practical challenges. This locally-adapted approach was highly effective as evidenced by high levels of trial enrolment, compliance with trial procedures and drug intake.

Understanding work-related travel and its relation to malaria occurrence in Thailand using geospatial maximum entropy modelling

BACKGROUND

Estimating malaria risk associated with work locations and travel across a region provides local health officials with information useful to mitigate possible transmission paths of malaria as well as understand the risk of exposure for local populations. This study investigates malaria exposure risk by analysing the spatial pattern of malaria cases (primarily Plasmodium vivax) in Ubon Ratchathani and Sisaket provinces of Thailand, using an ecological niche model and machine learning to estimate the species distribution of P. vivax malaria and compare the resulting niche areas with occupation type, work locations, and work-related travel routes.

METHODS

A maximum entropy model was trained to estimate the distribution of P. vivax malaria for a period between January 2019 and April 2020, capturing estimated malaria occurrence for these provinces. A random simulation workflow was developed to make region-based case data usable for the machine learning approach. This workflow was used to generate a probability surface for the ecological niche regions. The resulting niche regions were analysed by occupation type, home and work locations, and work-related travel routes to determine the relationship between these variables and malaria occurrence. A one-way analysis of variance (ANOVA) test was used to understand the relationship between predicted malaria occurrence and occupation type.

RESULTS

The MaxEnt (full name) model indicated a higher occurrence of P. vivax malaria in forested areas especially along the Thailand-Cambodia border. The ANOVA results showed a statistically significant difference between average malaria risk values predicted from the ecological niche model for rubber plantation workers and farmers, the two main occupation groups in the study. The rubber plantation workers were found to be at higher risk of exposure to malaria than farmers in Ubon Ratchathani and Sisaket provinces of Thailand.

CONCLUSION

The results from this study point to occupation-related factors such as work location and the routes travelled to work, being risk factors in malaria occurrence and possible contributors to transmission among local populations.

Antimalarial chemoprophylaxis for forest goers in southeast Asia: an open-label, individually randomised controlled trial

BACKGROUND

Malaria in the eastern Greater Mekong subregion has declined to historic lows. Countries in the Greater Mekong subregion are accelerating malaria elimination in the context of increasing antimalarial drug resistance. Infections are now increasingly concentrated in remote, forested foci. No intervention has yet shown satisfactory efficacy against forest-acquired malaria. The aim of this study was to assess the efficacy of malaria chemoprophylaxis among forest goers in Cambodia.

METHODS

We conducted an open-label, individually randomised controlled trial in Cambodia, which recruited participants aged 16-65 years staying overnight in forests. Participants were randomly allocated 1:1 to antimalarial chemoprophylaxis, a 3-day course of twice-daily artemether-lumefantrine followed by the same daily dosing once a week while travelling in the forest and for a further 4 weeks after leaving the forest (four tablets per dose; 20 mg of artemether and 120 mg of lumefantrine per tablet), or a multivitamin with no antimalarial activity. Allocations were done according to a computer-generated randomisation schedule, and randomisation was in permuted blocks of size ten and stratified by village. Investigators and participants were not masked to drug allocation, but laboratory investigations were done without knowledge of allocation. The primary outcome was a composite endpoint of either clinical malaria with any Plasmodium species within 1-28, 29-56, or 57-84 days, or subclinical infection detected by PCR on days 28, 56, or 84 using complete-case analysis of the intention-to-treat population. Adherence to study drug was assessed primarily by self-reporting during follow-up visits. Adverse events were assessed in the intention-to-treat population as a secondary endpoint from self-reporting at any time, plus a physical examination and symptom questionnaire at follow-up. This trial is registered at ClinicalTrials.gov (NCT04041973) and is complete.

FINDINGS

Between March 11 and Nov 20, 2020, 1480 individuals were enrolled, of whom 738 were randomly assigned to artemether-lumefantrine and 742 to the multivitamin. 713 participants in the artemether-lumefantrine group and 714 in the multivitamin group had a PCR result or confirmed clinical malaria by rapid diagnostic test during follow-up. During follow-up, 19 (3%, 95% CI 2-4) of 713 participants had parasitaemia or clinical malaria in the artemether-lumefantrine group and 123 (17%, 15-20) of 714 in the multivitamin group (absolute risk difference 15%, 95% CI 12-18; p<0·0001). During follow-up, there were 166 malaria episodes caused by Plasmodium vivax, 14 by Plasmodium falciparum, and five with other or mixed species infections. The numbers of participants with P vivax were 18 (3%, 95% CI 2-4) in the artemether-lumefantrine group versus 112 (16%, 13-19) in the multivitamin group (absolute risk difference 13%, 95% CI 10-16; p<0·0001). The numbers of participants with P falciparum were two (0·3%, 95% CI 0·03-1·01) in the artemether-lumefantrine group versus 12 (1·7%, 0·9-2·9) in the multivitamin group (absolute risk difference 1·4%, 95% CI 0·4-2·4; p=0·013). Overall reported adherence to the full course of medication was 97% (95% CI 96-98; 1797 completed courses out of 1854 courses started) in the artemether-lumefantrine group and 98% (97-98; 1842 completed courses in 1885 courses started) in the multivitamin group. Overall prevalence of adverse events was 1·9% (355 events in 18 806 doses) in the artemether-lumefantrine group and 1·1% (207 events in 19 132 doses) in the multivitamin group (p<0·0001).

INTERPRETATION

Antimalarial chemoprophylaxis with artemether-lumefantrine was acceptable and well tolerated and substantially reduced the risk of malaria. Malaria chemoprophylaxis among high-risk groups such as forest workers could be a valuable tool for accelerating elimination in the Greater Mekong subregion.

FUNDING

The Global Fund to Fight AIDS, Tuberculosis and Malaria; Wellcome Trust.

Behavioural determinants of malaria risk, prevention, and care-seeking behaviours among forest-goers in Cambodia

BACKGROUND

Cambodia has made significant progress towards achieving malaria elimination by 2025. Cases continue to decrease and are primarily concentrated in forested areas. Forest-goers are most at risk of malaria due to their proximity to the forest, poor sleeping conditions, frequent mobility, and distance from health services. Consistent use of long-lasting insecticidal nets or hammock nets (LLINs/LLIHNs), early diagnosis and treatment of cases are central to reducing disease burden. The aim of this study was to understand forest-goers' knowledge, attitudes, and practices related to malaria prevention and care-seeking, and to identify key behavioural determinants of LLIN/LLIHN use and prompt care-seeking within 24 h of developing a fever.

METHODS

A mixed-methods study design consisting of a cross-sectional survey and qualitative in-depth interviews was implemented in two Cambodian provinces. Survey participants (N = 654) were recruited using respondent driven sampling. Interview participants (N = 28) were selected using purposive sampling. Findings from the survey were analysed using univariate and bivariate analysis and multivariate weighted logistic regression. Interviews were coded and analysed using thematic content analysis.

RESULTS

All study participants had heard of malaria and 98% knew that malaria was transmitted by mosquitoes. LLIN/LLIHN ownership was high (94%). Although 99% of participants perceived LLIN/LLIHN use as an important malaria prevention measure, only 76% reported using one during their last visit to the forest. Only 39% of survey participants who reported seeking care did so within the recommended 24 h from fever onset during their last febrile illness. Among all study participants, 43% did not seek any healthcare during their last febrile episode. In controlled regression models, perceived community social norms were significantly associated with LLIN/LLIHN use (OR: 2.7, 96% CI 1.99-2.64) and care-seeking within 24 h of fever onset (OR: 1.7, 95% CI 1.00-2.88). Social support from other forest-goers was also significantly associated with LLIN/LLIHN use (OR: 4.9, 95% CI 1.32-18.12).

CONCLUSIONS

Study findings are consistent with other studies on LLIN/LLIHN use and care-seeking behaviours. While rates of LLIN/LLIHN ownership were high among the study population, rates of use were not as high. More concerning were the delayed care-seeking behaviours. Social behaviour change activities should incorporate social norms and social support as mechanisms for behaviour change given the identified positive correlations with LLIN/LLIHN use and prompt care-seeking.

Forest malaria and prospects for anti-malarial chemoprophylaxis among forest goers: findings from a qualitative study in Thailand

BACKGROUND

Across the Greater Mekong Subregion, malaria remains a dangerous infectious disease, particularly for people who visit forested areas where residual transmission continues. Because vector control measures offer incomplete protection to forest goers, chemoprophylaxis has been suggested as a potential supplementary measure for malaria prevention and control. To implement prophylaxis effectively, additional information is needed to understand forest goers' activities and their willingness to use malaria prevention measures, including prophylaxis, and how it could be delivered in communities. Drawing on in-depth interviews with forest goers and stakeholders, this article examines the potential acceptability and implementation challenges of malaria prophylaxis for forest goers in northeast Thailand.

METHODS

In-depth interviews were conducted with forest goers (n = 11) and stakeholders (n = 16) including healthcare workers, community leaders, and policymakers. Interviews were audio-recorded, transcribed and coded using NVivo, employing an inductive and deductive approach, for thematic analysis.

RESULTS

Forest goers were well aware of their (elevated) malaria risk and reported seeking care for malaria from local health care providers. Forest goers and community members have a close relationship with the forest but are not a homogenous group: their place and time-at-risk varied according to their activities and length of stay in the forest. Among stakeholders, the choice and cost of anti-malarial prophylactic regimen-its efficacy, length and complexity, number of tablets, potential side effects, and long-term impact on users-were key considerations for its feasibility. They also expressed concern about adherence to the preventive therapy and potential difficulty treating malaria patients with the same regimen. Prophylaxis was considered a low priority in areas with perceived accessible health system and approaching malaria elimination.

CONCLUSIONS

In the context of multi-drug resistance, there are several considerations for implementing malaria prophylaxis: the need to target forest goers who are at-risk with a clear period of exposure, to ensure continued use of vector control measures and adherence to prophylactic anti-malarials, and to adopt an evidence-based approach to determine an appropriate regimen. Beyond addressing current intervention challenges and managing malaria incidence in low-transmission setting, it is crucial to keep malaria services available and accessible at the village level especially in areas home to highly mobile populations.