Melioidosis, caused by the Gram-negative bacterium Burkholderia pseudomallei, is a potentially life-threatening infection that can affect humans and a wide variety of animals in the tropics. In December 2017, a swine melioidosis case was discovered during a meat inspection at a privately-owned slaughterhouse in Nakhon Si Thammarat Province in southern Thailand. The infection, which continued for several months, caused a dispute about where the disease began. An environmental investigation into two farms—both involved in raising the first infected pig—ensued. Through genetic analysis, the investigation revealed that a contaminated water supply at one farm was the probable source of infection. The three local sequence types identified in the investigation were types 51, 298 and 392.

Background and Aim: Melioidosis is a potentially fatal disease affecting humans and a wide range of animal species; it is often underdiagnosed and underreported in veterinary medicine in Indonesia. This study aimed to characterize morphological and molecular features of Burkholderia pseudomallei, the causative agent of melioidosis which caused the death of a Bornean orangutan. Materials and Methods: Pulmonary abscess samples were cultured on several types of media, including Ashdown agar, Ashdown broth, and MacConkey agar. Type three secretion system orf 2 real-time polymerase chain reaction (PCR) and latex agglutination tests were performed to identify the bacteria. Morphological characteristics were compared to all previously published morphotypes. Subsequently, the bacteria were characterized by multilocus sequence typing (MLST) and Yersinia-like flagellum/Burkholderia thailandensis-like flagellum and chemotaxis PCR. The results of the genotyping were afterward compared to all genotypes from Southeast Asia. Results: Multiple morphotypes of B. pseudomallei were perceived during the growth on Ashdown agar. Furthermore, it was identified by MLST that the Type I and Type II morphotypes observed in this study were clones of a single ST, ST54, which is predominantly found in humans and the environment in Malaysia and Thailand, although a very limited number of reports was published in association with animals. Moreover, the E-BURST analysis showed that the ST is grouped together with isolates from Southeast Asian countries, including Malaysia, Thailand, Singapore, and Cambodia. ST54 was predicted to be the founding genotype of several STs from those regions. Conclusion: B. pseudomallei ST54 that caused the death of a Bornean orangutan has a distant genetic relationship with other STs which were previously reported in Indonesia, implying a vast genetic diversity in Indonesia that has not been discovered yet.

Burkholderia pseudomallei, the Gram-negative bacterium which causes melioidosis, is a threat to human and a wide range of animal species. There is an increased concern of melioidosis in Indonesian primate facilities, especially following case reports of fatal melioidosis in captive macaques and orangutans. Our preliminary serosurveillance of immunoglobulin G (IgG) to B. pseudomallei lipopolysaccharide showed that a significant number of captive and wild macaques in the western part of Java, Indonesia, have been exposed to B. pseudomallei. To better characterize the humoral immune response in those animals, a panel of assays were conducted on the same blood plasma specimens that were taken from 182 cynomolgus macaques (M. fascicularis) and 88 pig-tailed macaques (M. nemestrina) reared in captive enclosures and wild habitats in the western part of Java, Indonesia. The enzyme-linked immunosorbent assays (ELISAs) in this study were conducted to detect IgG against B. pseudomallei proteins; alkyl hydroperoxide reductase subunit C (AhpC), hemolysin-coregulated protein (Hcp1), and putative outer membrane porin protein (OmpH). The performances of those immunoassays were compared to ELISA against B. pseudomallei LPS, which has been conducted previously. Seropositivity to at least one assay was 76.4% (139/182) and 13.6% (12/88) in cynomolgus macaques and pig-tailed macaques, respectively. Analysis of demographic factors showed that species and primate facility were significant factors. Cynomolgus macaques had higher probability of exposure to B. pseudomallei. Moreover, macaques in Jonggol facility also had higher probability, compared to macaques in other facilities. There were no statistical associations between seropositivity with other demographic factors such as sex, age group, and habitat type. There were strong positive correlations between the absorbance results of AhpC, HcpI, and OmpH assays, but not with LPS assay. Our analysis suggested that Hcp1 assay would complement LPS assay in melioidosis serosurveillance in macaques.

Background: Indonesia has made significant progress in malaria control, however hotspots such as Sumba Island continue to experience high rates of malaria transmission, driven by multiple Anopheles mosquito species. The Sumba Livestock Ivermectin for Malaria (SLIM) trial was conducted to assess the efficacy of ivermectin treatment in livestock as a vector control strategy. This study aimed to explore community perceptions of ivermectin-based malaria interventions, including ivermectin livestock treatment (ITL) and potential mass drug administration (MDA) in humans. Methods: A social science study was conducted alongside the SLIM trial between November 2022 and September 2023 across four villages in Southwest Sumba. A mixed-methods approach was used, including focus group discussions, in-depth interviews, and feedback meetings. Community engagement activities such as puppet shows and interactive sessions on malaria transmission were also implemented. Data were transcribed, coded, and thematically analysed using NVivo. Results: A total of 75 individuals participated in qualitative data collection, and approximately 650 individuals engaged in community events. Malaria was ranked as the most pressing health concern by study participants. Initial skepticism about ITL was mitigated through trust-building efforts and respectful communication. Community members actively contributed to the trial, demonstrating acceptance of ITL and expressing interest in future research participation. While there was openness to mass drug administration for humans, concerns about safety, particularly for children, were raised. Local authority approval was deemed essential for intervention acceptance. In one village, low social cohesion posed barriers to research participation, highlighting the importance of pre-trial engagement. Conclusions: Community perceptions of ivermectin-based malaria control strategies were shaped by trust, engagement, and cultural considerations. The study underscores the need for sustained, respectful communication and inclusive stakeholder engagement in malaria research. Future malaria control interventions should account for local social dynamics, ensuring informed community participation to enhance trial feasibility and acceptance.

Global COVID-19 booster vaccination uptake has been low, particularly in low-middle-income countries (LMICs). However, studies on the determinants of COVID-19 booster vaccination remain limited, especially in LMIC settings. This study aims to describe the determinants of COVID-19 booster vaccination uptake in an LMIC context. We analyzed data from a cross-sectional survey that was conducted in September 2022 in four provinces in Indonesia. Participants (n=2,223) were recruited using multiple-stage cluster sampling. Multivariable logistic regression analysis was used to identify factors associated with booster vaccination status. The proportion of COVID-19 booster vaccination among fully vaccinated adults was 29.5%, while fear of transmission (12.4%) and perceived risk of getting a COVID-19 infection (33.5%) were low. Multivariable analysis showed that people living on Java Island (aOR: 2.45, 95% CI: 1.87-3.24), living in the urban area (aOR: 2.04, 95% CI: 1.60-2.61), being an employee in the formal sector (aOR: 3.99, 95% CI: 1.93 - 8.58), experiencing a side effect from previous vaccination (aOR: 1.71, 95% CI: 1.40-2.09), having a history of SARS-COV2 infection (aOR: 2.10, 95%CI: 1.27-3.50), having perception on the upcoming new wave of COVID-19 (aOR: 1.37, 95% CI: 1.07 -1.76), and believing the pandemic has not ended (aOR: 1.29, 95% CI: 1.01, 1.64) were associated with booster shot uptake. Low educational level (aOR: 0.6, 95% CI: 0.39-0.93) inhibited booster vaccination uptake. Current booster dose coverage was considerably lower than the primary vaccination dosage. The low booster vaccination uptake in four provinces was associated with a belief the pandemic has no longer, which might hinder the catch up of wide-population target coverage and COVID-19 control for reduced disease severity and hospitalization. Thus, efforts need to be prioritized in reaching the COVID-19 vulnerable population, which includes elderly and those with comorbidities.

Background: Indonesia has made significant progress in malaria control, however hotspots such as Sumba Island continue to experience high rates of malaria transmission, driven by multiple Anopheles mosquito species. The Sumba Livestock Ivermectin for Malaria (SLIM) trial was conducted to assess the efficacy of ivermectin treatment in livestock as a vector control strategy. This accompanying social science study aimed to explore community perceptions of ivermectin-based malaria interventions, including ivermectin livestock treatment (ITL) and potential mass drug administration (MDA) in humans. Methods: A social science study was conducted alongside the SLIM trial between November 2022 and September 2023 across four villages in Southwest Sumba. Qualitative and participatory approaches were used to explore community perceptions. 75 individuals (>18 years old) from the SLIM study village sites were included in four focus group discussions (59 individuals) and 16 individual in-depth interviews. We also held four feedback meetings for all members of each study village. Community engagement activities, such as puppet shows and interactive sessions on malaria transmission, were also implemented. Data were transcribed, coded, and thematically analysed using Nvivo software. Results: A total of 75 individuals participated in qualitative data collection, and approximately 650 individuals engaged in community events. Malaria was ranked as the most pressing health concern by study participants. Initial skepticism about ivermectin treatment of livestock was mitigated through trust-building efforts such as village meetings and respectful communication. Community members actively contributed to the trial, demonstrating acceptance of ivermectin treatment of livestock and expressing interest in future research participation. While there was openness to mass drug administration for humans, concerns about safety, particularly for children, were raised. Local authority approval was deemed essential for intervention acceptance. In one village, low social cohesion posed barriers to research participation, highlighting the importance of engagement before the trial started. Conclusions: Community perceptions of ivermectin-based malaria control strategies were shaped by trust, engagement, and cultural considerations. In this case there were multiple engagement activities built into the study – before, during and after the research, with stakeholders in local government and village leaders as well as with animal owners, other community members and children. The findings of this social research underscore the need for, and benefits of, sustained, respectful communication, partnership with local leaders and inclusive stakeholder engagement in malaria research. Future malaria control interventions should also account for local social dynamics, ensuring informed community participation to enhance trial feasibility and acceptance.