Malaysian Borneo Research Articles

Serological analysis in humans in Malaysian Borneo suggests prior exposure to H5 avian influenza near migratory shorebird habitats

Cases of H5 highly pathogenic avian influenzas (HPAI) are on the rise. Although mammalian spillover events are rare, H5N1 viruses have an estimated mortality rate in humans of 60%. No human cases of H5 infection have been reported in Malaysian Borneo, but HPAI has circulated in poultry and migratory avian species transiting through the region. Recent deforestation in coastal habitats in Malaysian Borneo may increase the proximity between humans and migratory birds. We hypothesise that higher rates of human-animal contact, caused by this habitat destruction, will increase the likelihood of potential zoonotic spillover events. In 2015, an environmentally stratified cross-sectional survey was conducted collecting geolocated questionnaire data in 10,100 individuals. A serological survey of these individuals reveals evidence of H5 neutralisation that persisted following depletion of seasonal H1/H3 HA binding antibodies from the plasma. The presence of these antibodies suggests that some individuals living near migratory sites may have been exposed to H5 HA. There is a spatial and environmental overlap between individuals displaying high H5 HA binding and the distribution of migratory birds. We have developed a novel surveillance approach including both spatial and serological data to detect potential spillover events, highlighting the urgent need to study cross-species pathogen transmission in migratory zones.

Potential use of anti-thrombospondin-related apical merozoite protein (TRAMP) polyclonal antibodies in sandwich enzyme-linked immunosorbent assay (ELISA) for detection of Plasmodium knowlesi.

Plasmodium knowlesi, primarily a zoonotic malaria species is the most common malaria pathogen in the Southeast Asia especially in Malaysian Borneo, Malaysia. Due to morphological resemblance of P. knowlesi to other human Plasmodium, the sensitivity for microscopic detection of P. knowlesi, which is the gold standard, is compromised. Thus, efforts have been made in finding alternatives for the disease diagnosis. This study described the potential use of anti-PkTRAMP polyclonal antibodies in sandwich ELISA for P. knowlesi detection. Anti-PkTRAMP polyclonal antibodies raised from mice and rabbit were first evaluated for their binding capability towards native proteins in P. knowlesi lysates using Western blot. These mice and rabbit polyclonal antibodies were then used in the sandwich ELISA as capture and detection antibodies, respectively. P. knowlesi A1H1 culture was utilised to determine the limit of detection (LOD) of this assay. Its clinical performance was determined by testing with archived human malaria and uninfected samples. Western blot analysis affirmed the polyclonal antibodies reactivity to P. knowlesi. The LOD obtained from three replicated assays was at 0.015% parasitaemia. The assay has 76% sensitivity and 75% specificity for P. knowlesi. Its positive and negative predictive values were 76% and 75%, respectively. No cross reactivity with P. falciparum and healthy samples was observed, except for P. vivax where 10 out of 12 samples were detected. In conclusion, anti-PkTRAMP polyclonal antibodies can be useful in detecting P. knowlesi. Regardless, the full potential of anti-PkTRAMP antibodies for diagnostic purposes need to be explored further.

Incidence and severity of pertussis among hospitalized infants, Sarawak, Malaysia, 2015-2021.

A resurgence of pertussis has been reported in numerous countries. This study aimed to determine the incidence, clinical characteristics, and outcome of pertussis among infants in Sarawak, Malaysia. We conducted a descriptive retrospective study of infants aged < 12 months with laboratory-confirmed pertussis admitted to Bintulu Hospital in Sarawak, Malaysian Borneo, from 2015 until 2021. Pertussis was confirmed in all patients using a polymerase chain reaction of nasopharyngeal aspirates. Of 588 infants who had a nasopharyngeal aspirate, 108 (18%) had laboratory-confirmed pertussis. The average annual incidence was 482 per 100,000 infants aged < 12 months between 2015 and 2019, with a marked decline in 2020 and 2021. Eighty-two (76%) were < 3 months of age. Seventy-eight (72%) were unvaccinated for pertussis, including 75 (96%) who were too young to receive the first dose. A third of the cases had atypical presentations. Severe disease characterized by hypoxemia, pulmonary hypertension, recurrent apnea, encephalopathy, or cardiovascular dysfunction occurred in 32%. Forty-eight percent required humidified high-flow nasal cannula oxygen therapy and 22% required invasive ventilation. Twenty-four percent overall needed intensive care. One (1%) infant had a fatal outcome. Nearly all cases of severe disease or those that required invasive ventilation or intensive care had received ≤ 1 dose of pertussis vaccination. A high incidence of pertussis with a high rate of severe disease was observed in Sarawak, Malaysia, predominantly among infants too young to be vaccinated. Additional vaccination strategies such as maternal vaccination or cocooning should be considered.

Food for Thought in Malaysian Borneo: Data Mining and Sentiment Analysis of Tripadvisor Reviews for Online Destination Branding

Unique destination branding in tourism is crucial to gaining a competitive advantage. Local food is a significant component of a destination brand which Destination Management Organisations (DMOs) must integrate into their official marketing efforts. DMOs must monitor the popularity and perception of their food promotions against the competition. Online promotion and management are challenging due to the rise of user-generated content. Automatic data mining techniques were used to determine the extent to which tourist food choices on TripAdvisor matched foods promoted by DMOs and how distinct these choices were from a rival DMOs’ promotion. We compared online food promotion between the Sabah Tourism Board and the Sarawak Tourism Board. We developed a software system to automatically extract food branding business intelligence from TripAdvisor restaurant reviews. The application of web crawling and scraping technology was applied to extract data and use Sentiment Analysis for interpretation. Online foods promoted by DMOs for each region were found to contain only a few common dishes, but these were more popular than region-specific foods. Significantly different distributions of food choices were found for each region. Some potentially useful differences between foreign and domestic tourists and locals were also identified. Sentiment analysis revealed hidden information in reviews useful for potential food destination branding. Findings from TripAdvisor confirm practical suggestions for improving brand distinctiveness found in the literature. This study is the first to develop an actual system that DMOs could use to estimate the online popularity of their promoted foods and those of their competition.

Quantifying non-target seahorse fisheries and domestic traditional medicine-based trade in Malaysia

Seahorses (Hippocampus spp.) are sold primarily for traditional medicine (TM) uses in Southeast Asia. Although Malaysia is reportedly an important global seahorse exporter, documentation on the current extent of seahorse catch and trade of seahorse-based TM within the country is limited. This study aimed to quantify patterns of seahorse bycatch, gear-specific biological parameters of caught seahorses, and trade characteristics in Malaysia. Questionnaire-based fisher and TM surveys were administered nationwide from March 2021 to March 2023. Seventy-one percent of fisher respondents (612 out of 860) reported catching seahorses, with gill or drift net fishers (73 %) more likely to have caught seahorses than trawlers (12 %). Significant spatial differences in species composition was observed between Peninsular Malaysia and Malaysian Borneo (Sabah state). The total estimated annual seahorse catch within Malaysia was approximately 3376 kg per year, with 77 % of the catch attributed to gill or drift nets and 23 % to trawling operations. Almost half (40 %) of traditional Chinese medicine (TCM) practitioners/ traders (n = 138), 3 % of Malay TM practitioners (n = 3), and 88 % of other TM traders (n = 7) reported selling seahorse species. This study is one of the first to quantify the often overlooked but critical contribution of small-scale fisheries, especially gill and drift nets, towards seahorse bycatch. The current supply volume and selling price of seahorses were observed to be relatively high, while the present-day demand was reportedly low. Almost half of TCM practitioners/ traders interviewed were still actively selling seahorses, indicating that there is still considerable demand. To ensure the sustainability of seahorse populations in Malaysia, efforts in both small-scale and trawl fisheries must be reduced while strictly enforcing seahorse trade regulations.

Changes of bacterial versus fungal community composition along a forest degradation gradient of logged-over tropical rain forests, and their consequences on soil enzyme activities in Malaysian Borneo

Changes of bacterial versus fungal community composition along a forest degradation gradient of logged-over tropical rain forests, and their consequences on soil enzyme activities in Malaysian Borneo

Use of Comparative Genomics To Resolve an Unusual Case of Aminoglycoside Susceptibility in the Melioidosis Pathogen Burkholderia pseudomallei in Bangladesh.

Melioidosis is an emerging tropical infectious disease with a rising global burden caused by the environmental bacterium Burkholderia pseudomallei. It is endemic in Southeast and South Asia, including Bangladesh. A rare aminoglycoside-susceptible B. pseudomallei isolate (Y2019) has recently been reported from a melioidosis patient in Dhaka, Bangladesh. To understand the geographical origins of Y2019, we subjected it and 10 other isolates from Bangladesh to whole-genome sequencing. In a phylogenetic tree with a global set of B. pseudomallei genomes, most Bangladeshi genomes clustered tightly within the Asian clade. In contrast, Y2019 was closely related to ST881 isolates from Sarawak, Malaysian Borneo, a gentamicin-sensitive sequence type, suggesting infection in Borneo. Y2019 also contained the same gentamicin sensitivity conferring nonsynonymous mutation in the drug efflux pump encoding the amrB gene. In the absence of a full travel history, whole-genome sequencing and bioinformatics tools have revealed the likely origin of this rare isolate.

A short review of aquaculture status in Malaysian Borneo: Species, culture systems and diseases

A short review of aquaculture status in Malaysian Borneo: Species, culture systems and diseases

Taxonomic revision of Cantharellus cuticulatus Corner (Cantharellaceae, Basidiomycota) from Sabah (North Borneo), Malaysia

Cantharellus cuticulatus, first described by E.J.H. Corner in 1966, is an edible mushroom distinguished by its vibrant yellow-orange cap, lamellae-like hymenium and the absence of clamp connections. This study reveals a significant shift in its distribution from the high-altitude regions of Mount Kinabalu to lowland areas, raising interesting questions about its habitat preferences and associated host plants. The research was conducted between 2021 and 2023, involving comprehensive macro- and micro-morphological analyses, as well as molecular identification techniques. After a hiatus of over half a century without any new records in Sabah, the study has successfully collected three Cantharellus cuticulatus specimens from three different districts in Sabah. To date, this species has only been documented in Peninsular Malaysia and Northern Borneo (Sabah, Sarawak and Brunei).

From tree to plot: investigating stem CO2 efflux and its drivers along a logging gradient in Sabah, Malaysian Borneo.

Stem respiration constitutes a substantial proportion of autotrophic respiration in forested ecosystems, but its drivers across different spatial scales and land-use gradients remain poorly understood. This study quantifies and examines the impact of logging disturbance on stem CO2 efflux (EA) in Malaysian Borneo. EA was quantified at tree- and stand-level in nine 1-ha plots over a logging gradient from heavily logged to old-growth using the static chamber method. Tree-level results showed higher EA per unit stem area in logged vs old-growth plots (37.0 ± 1.1 vs 26.92 ± 1.14 g C m-2 month-1). However, at stand-level, there was no difference in EA between logged and old-growth plots (6.7 ± 1.1 vs 6.0 ± 0.7 Mg C ha-1 yr-1) due to greater stem surface area in old-growth plots. Allocation to growth respiration and carbon use efficiency was significantly higher in logged plots. Variation in EA at both tree- and stand-level was driven by tree size, growth and differences in investment strategies between the forest types. These results reflect different resource allocation strategies and priorities, with a priority for growth in response to increased light availability in logged plots, while old-growth plots prioritise maintenance and cell structure.

Soil wetting triggered by selective logging in Bornean lowland tropical rainforests

Aboveground biomass removal and canopy opening by selective logging modifies soil moisture in the main root zone, impacting soil aeration and various biogeochemical processes in tropical production forests. This study investigated the relationship between canopy damage and topsoil (10 cm) moisture in two logged forests in Malaysian Borneo, while simultaneously controlling for logging intensity, time elapsed since historical logging, and spatial autocorrelation. Volumetric soil water content (VSWC), canopy height model (CHM), leaf area index (LAI), and historical logging data were collected from 84 transects placed subjectively in 15 sites exhibiting varying canopies. We generated an index (PC1) quantifying the magnitude of canopy structural degradation from canopy structure metrics (CSM) combining CHM and LAI data within a 20-meter buffer for each transect. PC1 was analyzed for its impact on VSWC across logging periods, and contrasted with topography. Spatial autocorrelation of VSWC was examined regarding to canopy conditions. VSWC was significantly higher in all logged forests (over 0.4 m3 m−3) comparing to non-disturbed forests (0.27 m3 m−3). The immediate wetting could be a result of extracting mature individuals of late-successional species holding large biomass, while the persistent wet condition may be due to retarded canopy and biomass recovery. In the study area, canopy structure was a stronger predictor of soil moisture than topography. The high soil moisture underneath the most degraded canopies presented the largest spatial extent of autocorrelation. This study revealed soil wetting after selective logging in humid tropical forests, driven by reduced transpiration from biomass loss rather than increased evaporative demand resulting from canopy opening. The elevation in soil moisture could have disrupted biogeochemical processes in the below-ground system, which in turn impede forest succession and put stress on the overall vulnerability of disturbed tropical rainforests.

Assessing Borneo’s tropical forests and plantations: a multi-sensor remote sensing and geospatial MCDA approach to environmental sustainability

The assessment of environmental sustainability is of utmost importance for the forests and plantations in Borneo, given the critical need for environmental protection through the identification and mitigation of potential risks. This study was conducted to assess the environmental sustainability of tropical forest and plantations landscape, a case study in northern Sabah, Malaysian Borneo. Applications of the latest high-resolution multi-sensor remote sensing and geospatial MCDA are cost-effective and useful for large-scale environmental sustainability assessment. The land use land cover (LULC) of the study area was mapped with synergistic use of Sentinel-1 Synthetic Aperture Radar (SAR) and Sentinel-2 optical and high-resolution PlanetScope satellite imageries, resulting in overall accuracy of 87.24%. Five sustainability indicator layers: slope erosion protection, river buffer, landscape connectivity and quality, high conservation value (HCV), and water turbidity were developed from the LULC map, ancillary datasets of SRTM, and forest operation basemap with reference to standards from the Environment Protection Department (EPD), Roundtable on Sustainable Palm Oil (RSPO), and Forest Management Plan (FMP) for the analysis using multi-criteria decision analysis (MCDA) model. The results revealed that overall, the study areas are in the high sustainability category at 61%, medium at 31%, and low at only 8%. We analyzed the environmental sustainability of five land use boundaries, and the results showed that Industrial Tree Plantations (ITP) and Village Reserve are mostly in the high category. Meanwhile, oil palm plantations, rubber plantations, and forest reserve (FR) are the majority in the medium category. Both oil palm and rubber plantations are a majority in the medium class due to monocropping land use type having low landscape connectivity and quality individual sustainability indicator layer. The study presented the concept of use of multi-sensor remote sensing for LULC mapping with geospatial MCDA for environmental sustainability assessment useful to stakeholders for improving the management plan also contributing toward the progress of achieving UNSDGs and addressing REDD+.

High freshwater turtle occupancy of streams within a sustainably managed tropical forest in Borneo

AbstractDespite suffering dramatic declines due to habitat loss and overexploitation, tortoises and freshwater turtles in Southeast Asia remain understudied. Sustainable forest management offers a promising approach for advancing the conservation of threatened turtle populations. This study examines the effect of reduced impact logging (RIL), a sustainable forestry method, on 2 freshwater turtle species. We examined detectability patterns and habitat relationships for the threatened Malayan flat‐shelled turtle (Notochelys platynota) and the non‐threatened Malayan soft‐shelled turtle (Dogania subplana) in 8 streams within a commercial forest reserve between March and July 2019, in Sabah, Malaysian Borneo. Using single‐species occupancy models, we identified covariates associated with the detection and occupancy probabilities of these species across a post‐harvest recovery gradient (1–21 years since logging). Covariates used in the models were obtained directly from the field or from open‐source remote sensing data. Results for soft‐shelled turtles were inconclusive. In contrast, we found a negative association between monthly rainfall and flat‐shelled turtle detectability. The occupancy probability of flat‐shelled turtles was positively associated with greater distance from logging roads and higher stream flow accumulation. Occupancy probability for flat‐shelled turtles and soft‐shelled turtles was relatively high throughout the reserve (0.79 ± 0.1 [SD] and 0.57 ± 0.22, respectively). These results, suggest that appropriately managed forests, could serve as invaluable conservation areas for imperiled freshwater turtle species in the region.

Gut microbial community in proboscis monkeys (Nasalis larvatus): implications for effects of geographical and social factors.

Recent technological advances have enabled comprehensive analyses of the previously uncharacterized microbial community in the gastrointestinal tracts of numerous animal species; however, the gut microbiota of several species, such as the endangered proboscis monkey (Nasalis larvatus) examined in this study, remains poorly understood. Our study sought to establish the first comprehensive data on the gut microbiota of free-ranging foregut-fermenting proboscis monkeys and to determine how their microbiota are affected locally by environmental factors, i.e. geographical distance, and social factors, i.e. the number of adult females within harem groups and the number of adults and subadults within non-harem groups, in a riverine forest in Sabah, Malaysian Borneo. Using 16S rRNA gene sequencing of 264 faecal samples collected from free-ranging proboscis monkeys, we demonstrated the trend that their microbial community composition is not particularly distinctive compared with other foregut- and hindgut-fermenting primates. The microbial alpha diversity was higher in larger groups and individuals inhabiting diverse vegetation (i.e. presumed to have a diverse diet). For microbial beta diversity, some measures were significant, showing higher values with larger geographical distances between samples. These results suggest that social factors such as increased inter-individual interactions, which can occur with larger groups, as well as physical distances between individuals or differences in dietary patterns, may affect the gut microbial communities.

Examining the relationship between support for tourism development, economic and socio-cultural benefits, perceived costs and community well-being: The case of Kinabalu Geopark, Sabah, Malaysia Borneo

Examining the relationship between support for tourism development, economic and socio-cultural benefits, perceived costs and community well-being: The case of Kinabalu Geopark, Sabah, Malaysia Borneo

Assessment of anthropogenic disturbances on mangrove aboveground biomass in Malaysian Borneo using airborne LiDAR data

Mangroves are known for their carbon storage capacity, yet they are under immense pressure from human activities. This study assessed anthropogenic disturbances on mangroves’ aboveground biomass (AGB) in northern Borneo, Malaysia, using airborne light detection and ranging (LiDAR) data. Three global or pantropical allometries were compared in the development of an AGB estimation model by regressing LiDAR metrics against the AGB. The best model predicted AGB from Saenger and Snedaker allometry with an R2 of 0.85 and a root mean square error (RMSE) of 14.59 Mg/ha (relative RMSE: 7.24 %). The high-resolution AGB map revealed a natural AGB gradient in intact mangroves from the coast to the interior. However, only a weak correlation between the distance from shoreline and AGB in disturbed mangroves was found. The LiDAR estimated AGBs were 196.36 Mg/ha and 157.27 Mg/ha for intact mangroves and disturbed mangroves, respectively. Relatively high AGB areas were abundant in the intact mangroves but scarce in the disturbed mangroves. The LiDAR-based AGB assessment is accurate and high-resolution, supporting carbon stock conservation and sustainable management activities under climate change mitigation programs such as REDD + .

Geopark development and community well-being: The case of Kinabalu UNESCO Global Geopark, Sabah, Malaysian Borneo

On May 26, 2023, the Kinabalu UNESCO Global Geopark obtained the UNESCO Global Geopark status, and it was awarded the UNESCO Triple Crown recognition, making it the third geopark globally to receive this honour. Kinabalu UNESCO Global Geopark is located in Sabah, Malaysian Borneo, and it is the nation's second geopark site. Our study aims to investigate the mediating effect of support for geopark development on the relationship between economic, socio-cultural benefits, and perceived costs of geopark development on community well-being. A total of 301 participants, including those from the Kinabalu UNESCO Global Geopark's three areas of Kota Marudu, Ranau and Kota Belud, participated in the study. The findings indicate that community well-being is positively impacted by economic, sociocultural, and support for geopark development. Moreover, the support for geopark development mediates the relationship between economic and socio-cultural benefits towards community well-being. However, the study reveals that perceived costs of geopark development does not have significant effect on both relationships. Our study suggests that the local community recognizes the benefits of Kinabalu UNESCO Global Geopark in the form of income generation and opportunities for employment. However, because the geopark is still in an early stage of development, it is possible that the local community has not yet become aware of its negative aspects. The study proposes thorough and comprehensive guidelines and policies to be put in place to ensure the sustainability of the geopark regions as well as to continuously improve community well-being.

Description of a new sandstone-dwelling species of genus Cnemaspis (Sauria: Gekkonidae) from Gunung Santubong National Park, southwestern Sarawak, Malaysia

A newly discovered sandstone-dwelling species of the rock gecko, genus Cnemaspis, is described from Santubong National Park, 25 km north of Kuching, southwestern Sarawak, Malaysian Borneo. Molecular phylogenetic analysis confirmed that Cnemaspis puterisantubongae sp. nov. is closely related to other Cnemaspis species in southwestern Sarawak, except for C. kendallii, although these relationships remain unclear. The new species differs from closely related species in having a moderate snout–vent length of up to 66.7 mm; 10–14 precloacal pores in males; 9–14 obviously-convex precloacal pore-bearing scales in females; enlarged, smooth, flat median subcaudal scales; sharp-edged, broad black markings on the trunk dorsum; and a black–gray banding pattern on the posterior part of the original tail, with white median subcaudal scales in males. This discovery of this new species from Santubong National Park, which is highly accessible due to its proximity to Kuching, highlights the need for extensive inventory surveys throughout the national parks of Sarawak.

Variation in fern species richness, assemblages and morphology along a tropical riparian humidity gradient: an example from Borneo

ABSTRACT Riparian vegetation experiences a little spatial distance humidity gradient, especially in the hyper-humid tropics. In Borneo, with almost no seasons and rather constant local climatic conditions, the riparian plant species show a wide range of morphological and physiological adaptations. This study assesses the adaptation strategies of ferns along a riparian humidity gradient in the submontane forest of Sarawak, Malaysia (Borneo). The species richness and cover, morphological traits, leaf area, leaf perimeter, leaf dissection, leaf elongation ratio, and stomatal density of 63 fern species were surveyed in six study areas along six stream transects. Significant trends in species richness and species cover were identified along the six transects, and changes in morphological traits such as leaf area, leaf perimeter, and leaf dissection were also discovered. With increasing distance from the streams (i.e. decreasing humidity), ferns tended to show longer leaves and a lower stomatal density. We conclude that the morphological traits of fronds change significantly within a short tropical riparian humidity gradient. This reveals variations in the energy investment and adaptation efficiency of ferns within a tropical forest microsite.

Risk Exposure of Coastal Inundation from Storm Surge in the Northern part of Malaysian Borneo

Abstract Coastal communities heavily rely on marine resources for their livelihoods. The rising occurrence of extreme weather events have affected both the coastal ecosystems and socio-economic activities. One of the most prevalent extreme events in Malaysia is the storm surge. This study aims to assess the extent of coastal inundation based on three storm surge scenarios (categories by Meteorological Department of Malaysia) and to determine the risk exposure ranking of nine study sites. Field trips and interviews were conducted from March 2020 to March 2023 in Kudat located at the northern part of Malaysian Borneo. One hundred respondents were surveyed using semi-structured open-ended questionnaires to evaluate the risk exposure of coastal inundation caused by storm surges. The findings revealed that Category 1 flooded certain sites of west (Kimihang) and east (Tajau Laut) sides of Kudat. The Category 2 have significantly flooded one site in the west side (Simpang Mengayau) of Kudat. While, for Category 3 of coastal inundation affected two sites in east sides of Kudat (Tanjong Kapor and Landung Ayang). These two sites in east sides of Kudat also experienced a high level of risk exposure due to the lack of diverse coastal ecosystems and high population density. While three sites in west side of Kudat (Kimihang, Kelambu and Simpang Mengayau) faced significant impacts on social services, particularly within the tourism sector. Despite relying on multiple livelihoods, these sites were susceptible to storm surges. Additionally, the increasing development for tourism purposes posed a threat to the richness of the ecosystem. This study suggests that certain sites in east side of Kudat (Tanjong Kapor and Landung Ayang) are highly exposed to risk and require measures for adaptation and mitigation.