E-Thesis 18 views
Avian Malaria: Investigating the Haemosporidian Parasite Diversity of Bornean Birds in Sabah, Malaysia / PADRAIC MCDONNELL
Swansea University Author: PADRAIC MCDONNELL
Abstract
Avian Haemosporidia are an apicomplexan order of intraerythrocytic vector-borne parasites, capable of infecting a diverse range of birds, worldwide. Primarily belonging to three genera: Haemoproteus, Leucocytozoon, and Plasmodium, avian Haemosporidia are transmitted via various haemotophagous dipter...
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Swansea University
2025
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| Institution: | Swansea University |
| Degree level: | Master of Research |
| Degree name: | MRes |
| Supervisor: | Uren Webster, T. M., and Wells, K. L. |
| URI: | https://cronfa.swan.ac.uk/Record/cronfa71346 |
| Abstract: |
Avian Haemosporidia are an apicomplexan order of intraerythrocytic vector-borne parasites, capable of infecting a diverse range of birds, worldwide. Primarily belonging to three genera: Haemoproteus, Leucocytozoon, and Plasmodium, avian Haemosporidia are transmitted via various haemotophagous dipteran vectors. The island of Borneo, with its steep elevational gradients and vast area of tropical rainforest, harbours an exceptional diversity of avian taxa, providing an ideal environment for the study of avian host-parasite dynamics. However, despite extensive global research over the last few decades, avian Haemosporidia in Borneo remain poorly characterised.Here, we present a preliminary study, investigating the diversity and prevalence of Haemosporidia within Bornean domesticated chicken and wild bird populations. We sampled the blood of 493 wild birds and 124 domesticated chickens across the Malaysian state of Sabah (2019-2023). Using molecular diagnostics (nested PCR and qPCR), we tested each blood-sample for haemosporidian infection presence and quantitative parasitaemia. Then, targeting genus-specific cytochrome b regions, we sequenced and phylogenetically analysed all applicable haemosporidian lineages.Most sampled birds were infected with Haemosporidia (72.9%; 95%CI: 69.3-76.3%), a high infection prevalence relative to previous surveys within the region. We identified 53 distinct undocumented lineages: Haemoproteus (16), Leucocytozoon (14), and Plasmodium (23). The chickens exhibited significantly greater total haemosporidian infection prevalence and parasitaemia concentration than wild birds. Significant results between the chicken and wild bird populations may arise due to biological and ecological differences regarding host-specific haemosporidian lineage-permissiveness and proximity to vector-suitable habitat. Rarefaction analysis indicates considerable under-representative sampling of potential haemosporidian lineages within the wild avian population – due to the substantial avian diversity across Borneo, requiring further investigation to fully characterise. Our results suggest that Borneo exhibits a rich assemblage and abundance of diverse Haemosporidia, rendering it a potential global hotspot. However, much of this diversity remains undetected, underlining the need for further studies across Borneo. |
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| Keywords: |
Avian Malaria, Haemosporidia, Plasmodium, Haemoproteus, Leucocytozoon, Borneo, Sabah, Malaysia |
| College: |
Faculty of Science and Engineering |