How using light touch immersion research revealed important insights into the lack of progress in malaria elimination in Eastern Indonesia.

BACKGROUND: By 2022, the Government of Indonesia had successfully eliminated malaria in 389 out of 514 districts but continues to face a challenge in Eastern Indonesia where 95% of the total 2021 malaria cases were reported from Papua, West Papua and Nusa Tenggara Timur provinces. There is an increased recognition that malaria elimination will require a better understanding of the human behavioural factors hindering malaria prevention and treatment, informed by local context and local practice. METHODS: This research used a light-touch immersion research approach. Field researchers lived in communities over several days to gather data through informal conversations, group-based discussions using visual tools, participant observation and direct experience. The study was conducted in four high malaria endemic areas in Papua, West Papua, and Sumba Islands in Nusa Tenggara Timur. RESULTS: The research highlights how people's perception of malaria has changed since the introduction of effective treatment which, in turn, has contributed to a casual attitude towards early testing and adherence to malaria treatment. It also confirms that people rarely accept there is a link between mosquitoes and malaria based on their experience but nevertheless take precautions against the annoyance of mosquitoes. There is widespread recognition that babies and small children, elderly and incomers are more likely to be seriously affected by malaria and separately, more troubled by mosquitoes than indigenous adult populations. This is primarily explained by acclimatization and strong immune systems among the latter. CONCLUSIONS: Using immersion research enabled behaviour research within a naturalistic setting, which in turn enabled experiential-led analysis of findings and revealed previously unrecognized insights into attitudes towards malaria in Eastern Indonesia. The research provides explanations of people's lack of motivation to consistently use bed nets, seek early diagnosis or complete courses of treatment. The felt concern for the wellbeing of vulnerable populations highlighted during light touch immersion provides an entry point for future social behaviour change communication interventions. Rather than trying to explain transmission to people who deny this connection, the research concludes that it may be better to focus separately on the two problems of malaria and mosquitoes (especially for vulnerable groups) thereby resonating with local people's own experience and felt concerns.

Defining malaria risks among forest workers in Aceh, Indonesia: a formative assessment.

BACKGROUND: Following a dramatic decline of malaria cases in Aceh province, geographically-based reactive case detection (RACD) was recently evaluated as a tool to improve surveillance with the goal of malaria elimination. While RACD detected few cases in households surrounding index cases, engaging in forest work was identified as a risk factor for malaria and infections from Plasmodium knowlesi-a non-human primate malaria parasite-were more common than expected. This qualitative formative assessment was conducted to improve understanding of malaria risk from forest work and identify strategies for targeted surveillance among forest workers, including adapting reactive case detection. METHODS: Between June and August, 2016, five focus groups and 18 in-depth interviews with forest workers and key informants were conducted in each of four subdistricts in Aceh Besar and Aceh Jaya districts. Themes included: types of forest activities, mobility of workers, interactions with non-human primates, malaria prevention and treatment-seeking behaviours, and willingness to participate in malaria surveys at forest work sites and using peer-referral. RESULTS: Reported forest activities included mining, logging, and agriculture in the deep forest and along the forest fringe. Forest workers, particularly miners and loggers, described often spending weeks to months at work sites in makeshift housing, rarely utilizing mosquito prevention and, upon fever, self-medicating and seeking care from traditional healers or pharmacies rather than health facilities. Non-human primates are frequently observed near work sites, and most forest work locations are within a day's journey of health clinics. Employers and workers expressed interest in undertaking malaria testing and in participating in survey recruitment by peer-referral and at work sites. CONCLUSIONS: Diverse groups of forest workers in Aceh are potentially exposed to malaria through forest work. Passive surveillance and household-based screening may under-estimate malaria burden due to extended stays in the forest and health-seeking behaviours. Adapting active surveillance to specifically target forest workers through work-site screening and/or peer-referral appears promising for addressing currently undetected infections.

Analysis of serological data to investigate heterogeneity of malaria transmission: a community-based cross-sectional study in an area conducting elimination in Indonesia.

BACKGROUND: Analysis of anti-malarial antibody responses has the potential to improve characterization of the variation in exposure to infection in low transmission settings, where conventional measures, such as entomological estimates and parasitaemia point prevalence become less sensitive and expensive to measure. This study evaluates the use of sero-epidemiological analysis to investigate heterogeneity of transmission in area conducting elimination in Indonesia. METHODS: Filter paper bloodspots and epidemiological data were collected through a community-based cross-sectional study conducted in two sub-districts in Sabang municipality, Aceh province, Indonesia in 2013. Antibody responses to merozoite surface protein 1 (MSP-119) and apical membrane antigen 1 (AMA-1) for Plasmodium falciparum and Plasmodium vivax were measured using indirect enzyme-linked immunosorbent assay (ELISA). Seroconversion rates (SCR) were estimated by fitting a simple reversible catalytic model to seroprevalence data for each antibody. Spatial analysis was performed using a Normal model (SaTScan v.9.4.2) to identify the clustering of higher values of household antibody responses. Multiple logistic regression was used to investigate factors associated with exposure. RESULTS: 1624 samples were collected from 605 households. Seroprevalence to any P. falciparum antigen was higher than to any P. vivax antigen, 6.9% (95% CI 5.8-8.2) vs 2.0% (95% CI 1.4-2.8). SCR estimates suggest that there was a significant change in P. falciparum transmission with no exposure seen in children under 5 years old. Plasmodium falciparum SCR in over 5 years old was 0.008 (95% CI 0.003-0.017) and 0.012 (95% CI 0.005-0.030) in Sukakarya and Sukajaya sub-districts, respectively. Clusters of exposure were detected for both P. falciparum and P. vivax, most of them in Sukajaya sub-district. Higher age, P. vivax seropositivity and use of long-lasting insecticide-treated bed net (LLIN) were associated with higher P. falciparum exposure. CONCLUSION: Analysis of community-based serological data helps describe the level of transmission, heterogeneity and factors associated with malaria transmission in Sabang. This approach could be an important additional tool for malaria monitoring and surveillance in low transmission settings in Indonesia.

A comprehensive assessment of the malaria microscopy system of Aceh, Indonesia, in preparation for malaria elimination.

BACKGROUND: The Health Office of Aceh aims to eliminate malaria from Aceh Province, Indonesia by 2015. Malaria was formerly common in Aceh (population 4.5 million), but has declined dramatically in recent years consequent to post-tsunami control efforts. Successful elimination will depend upon rapid and accurate diagnosis and case follow-up at community level. A prerequisite to this is widespread coverage of high quality malaria diagnosis. This study describes the results of a comprehensive assessment of the malaria diagnostic capacity in Aceh as the province moves towards malaria elimination. METHODS: The study was conducted in 23 districts in Aceh from October 2010 to July 2011. Six types of questionnaires were used to collect data on competency of microscopists and laboratory capacity. Standardized slides were used to evaluate the proficiency of all microscopists. In addition, site visits to 17 primary health centres (PHC) assessed diagnostic practice and logistics capacity. RESULTS: Five hundred and seventy four malaria microscopists have been officially registered and assigned to duty in the 23 districts in Aceh Province. They work in 345 laboratories, predominantly in PHCs (69 %) and hospitals (25 %). Three laboratories were evaluated as adequate for all 30 elements, while 29 laboratories were adequate for less than five of 30 elements. Standardized proficiency tests showed that 413 microscopists were at basic (in training) level, with 10 advanced and 9 reference level. No microscopist achieved expert level. Neither the province nor any of Aceh's districts has a standardized inventory and logistics database for malaria diagnostics, nor did any of the surveyed laboratories operate a quality assurance programme for either microscopy or rapid diagnostic tests. CONCLUSIONS: The study highlights the importance of careful assessment of diagnostic capacity when embarking upon a large-scale malaria elimination programme. Aceh's laboratories have minimal infrastructure with nearly all microscopists still in training. On the positive side, a large workforce of microscopists has been assigned to laboratories with the needed equipment. Aceh will need to embark on a large-scale comprehensive quality assurance scheme if it is to achieve malaria elimination.

Rapid entomological assessment in eight high malaria endemic regencies in Papua Province revealed the presence of indoor and outdoor malaria transmissions.

Malaria in eastern Indonesia remains high despite significant reduction and elimination in other parts of the country. A rapid entomological assessment was conducted in eight high malaria endemic regencies of Papua Province, Indonesia, to expedite malaria elimination efforts in this region. This study aims to characterize specific, actionable endpoints toward understanding where and when malaria transmission is happening, where interventions may function best, and identify gaps in protection that result in continued transmission. The entomological assessment included identifying potential vectors through human landing catch (HLC), indoor morning and night resting collections, identification of larval sites through surveillance of water bodies, and vector incrimination toward understanding exposure to malaria transmission. Human landing catches (HLCs) and larval collections identified 10 Anopheles species, namely Anopheles koliensis, Anopheles punctulatus, Anopheles farauti, Anopheles hinesorum, Anopheles longirostris, Anopheles peditaeniatus, Anopheles tesselatus, Anopheles vagus, Anopheles subpictus and Anopheles kochi. The most common and abundant species found overall were An. koliensis and An. punctulatus, while An. farauti was found in large numbers in the coastal areas of Mimika and Sarmi Regencies. Vector incrimination on Anopheles collected from HLCs and night indoor resting demonstrated that An. koliensis and An. punctulatus carried Plasmodium in Keerom, Jayapura, and Sarmi Regencies. Analysis of HLCs for the most common species revealed that the An. koliensis and An. punctulatus, bite indoors and outdoors at equal rates, while An. farauti predominantly bite outdoors. Larval surveillance demonstrated that most water bodies in and surrounding residential areas contained Anopheles larvae. This study demonstrated indoor and outdoor exposure to mosquito bites and gaps in protection, enabling exposure to infectious bites in all regencies. This explains why current malaria control efforts focusing on indoor protection have failed to substantially reduce malaria incidence in the region. Optimization of insecticide-treated bed nets (ITNs), as well as installment of mosquito screens in houses, may further reduce indoor transmission. For outdoor transmission, the use of community-centric approaches to reduce or eliminate larval sources within and surrounding the village through the guidance of locally stationed entomologists, along with Social and Behavior Change mediated health education towards the local adoption of mosquito protection tools during outdoor activities, may reduce malaria transmission.

The baseline distribution of malaria in the initial phase of elimination in Sabang Municipality, Aceh Province, Indonesia.

BACKGROUND: Sabang Municipality, in Aceh Province, Indonesia, plans to initiate a malaria elimination programme in 2013. A baseline survey of the distribution of malaria in the municipality was conducted to lay the foundations for an evidence-based programme and to assess the island's readiness to begin the elimination process. METHODS: The entire population of the municipality was screened for malaria infection and G6PD deficiency. Specimens collected included blood slides, blots and tubes for selected households. RESULTS AND DISCUSSION: Samples were collected from 16,229 residents. Microscopic examination of the blood smears revealed 12 malaria infections; 10 with Plasmodium falciparum and 2 with Plasmodium vivax. To confirm the parasite prevalence, polymerase chain reaction (PCR) diagnosis was performed on the entire positive cases by microscopy and randomized 10% of the microscopically negative blood samples. PCR revealed an additional 11 subjects with malaria; one P. falciparum infection from the village of Paya Keunekai, and nine P. vivax infections and one mixed P. falciparum/P. vivax infection from the village of Batee Shok. The overall slide positivity rate was 0.074% (CI 95%: 0.070-0.078) and PCR corrected prevalence 0,590% (CI 95%: 0.582-0.597). Analysis of 937 blood samples for G6PD deficiency revealed two subjects (0.2%) of deficient G6PD. Analysis of several genes of the parasite, such as Pfdhfr, Pfdhps, Pfmdr1, Pfcrt, Pfmsp1, Pfmsp2, Pvdhfr, Pvdhps, Pvmdr1 and host gene, such as G6PD gene revealed that both P. falciparum and P. vivax carried the mutation associated with chloroquine resistance. CONCLUSION: Malariometric and host genetic analysis indicated that there is a low prevalence of both malaria and G6PD deficiency in the population of Sabang Municipality. Nevertheless, malaria cases were clustered in three rural villages and efforts for malaria elimination in Sabang should be particularly focused on those three villages.

Quantifying spatial heterogeneity of malaria in the endemic Papua region of Indonesia: Analysis of epidemiological surveillance data.

Background: As control efforts progress towards elimination, malaria is likely to become more spatially concentrated in few local areas. The purpose of this study was to quantify and characterise spatial heterogeneity in malaria transmission-intensity across highly endemic Indonesian Papua. Methods: We analysed individual-level malaria surveillance data for nearly half a million cases (2019-2020) reported in the Papua and West Papua provinces and adapted the Gini index approach to quantify spatial heterogeneity at the district and health-unit levels. In this context, high Gini index implies disproportionately distributed malaria cases across the region. We showed malaria incidence trends and the spatial and temporal distribution of sociodemographic characteristics and aetiological parasites among cases. Findings: While Papua province accounted for the majority of malaria cases reported in the region and had seen a rise in transmission since 2015, West Papua province had maintained a comparatively low incidence. We observed that Gini index estimates were high, particularly when the lower spatial scale of health units was evaluated. The Gini index appears to be inversely associated to annual parasite-incidence, as well as the proportions of vivax malaria, male sex, and adults. Interpretation: This study suggests that areas with varying levels of transmission-intensities exhibited distinct characteristics. Malaria was distributed in a markedly disproportionate manner throughout the region, emphasising the need for spatially targeted interventions. Periodic quantification and characterisation of risk heterogeneity at various spatial levels using routine malaria surveillance data may aid in tracking progress towards elimination and guiding evidence-informed prioritisation of resource allocation. Funding: The study was funded by the Australian Government Department of Foreign Affairs and Trade Indo-Pacific Centre for Health Security through the Strengthening Preparedness in the Asia-Pacific Region through Knowledge (SPARK) project.