Browsing by Author "Denipitiya, T."

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Determination of the foraging behaviour and blood meal source of malaria vector mosquitoes in Trincomalee District of Sri Lanka using a multiplex real time polymerase chain reaction assay
(BioMed Central, 2016) Gunathilaka, N.; Denipitiya, T.; Hapugoda, M.; Abeyewickreme, W.; Wickremasinghe, R.
BACKGROUND: Studies of host preference patterns in blood-feeding anopheline mosquitoes are crucial to incriminating malaria vectors. However, little information is available on host preferences of Anopheles mosquitoes in Sri Lanka. METHODS: Adult Anopheles mosquitoes were collected from five selected sentinel sites in Trincomalee District during June-September 2011. Each blood-fed mosquito was processed on filter papers. DNA was extracted using the dried blood meal protocol of the QIAmp DNA mini kit. A multiplexed, real-time PCR assay targeting eight animals was developed for two panels to identify the host meal of Anopheles. Human blood index (HBI), forage ratio (FR) and host feeding index (HFI) were calculated. RESULTS: A total of 280 field-caught, freshly engorged female mosquitoes belonging to 12 anopheline species were analysed. The overall HBI and HFI in the present study were low indicating that humans were not the preferred host for the tested anopheline species. Nevertheless, a small proportion engorged Anopheles aconitus, Anopheles culicifacies, Anopheles barbirostris, Anopheles annularis, Anopheles subpictus, Anopheles peditaeniatus, Anopheles pseudojamesi, and Anopheles barbumbrosus contained human blood. CONCLUSION: The presence of human blood in mosquito species indicates the possibility of them transmitting malaria. Further studies on vector competence are needed to determine the role of each of the above anopheline species as efficient vectors of malaria.
Epidemiological patterns and trends of paediatric snakebites in Sri Lanka
(Biomed Central, 2024-12) Dayasiri, K.; Caldera, D.; Suraweera, N.; Thadchanamoorthy, V.; Hettiarachchi , M.; Denipitiya, T.; Bandara, S.
OBJECTIVES This study aimed to analyse the epidemiological patterns of paediatric snake bites in Sri Lanka over a 4-year period (2020-2024).METHODS A multi-centre, retrospective observational study was conducted from June 2020 to June 2024 across nine governmental hospitals in seven provinces of Sri Lanka. Data were collected based on 757 children presenting with snake bites. The snake bites were analysed based on age, gender, and seasonal variations. Data on the type of snake involved, geographic variations and the temporal trends in snake bite occurrences were also analysed.RESULTS The mean age of the 757 children recruited to the study was 10.3 years (SD-5.00, range-0.1-17 years). Males (57.7%) were significantly more affected than females (42.3%) (p < 0.05). Visual identification confirmed the snake species in 58.4% of cases. The hump-nosed viper (16.7%), Russell's viper (14.7%), and common krait (12.9%) were the most common medically important snakes identified in the study. Seasonal peaks in snake bites occurred in May-July and November-December. An increasing trend in snake bite incidence was noted over the first three years, with a slight decline in the final year.CONCLUSION Paediatric snake bites in Sri Lanka show significant age, gender, and seasonal patterns. Targeted public health interventions are needed to mitigate the impact on children.
Mutational analysis of driver and non-driver mutations of Philadelphia chromosome-negative myeloproliferative neoplasms;diagnosis and recent advances in treatment
(Science Publications, 2024) Afolabi, B.O.; Riwaz, A.; Weerasena, J.; Williams, S.; Denipitiya, T.; Somawardana, B.; Faizan, M.; Galhena, B.P.
Myeloproliferative neoplasms (MPNs) are hematological disorders affecting myeloid stem cells. They are classified as Philadelphia (Ph) chromosome positive-chronic myeloid leukemia, and Ph-negative polycythemia vera, essential thrombocythemia, primary myelofibrosis, chronic neutrophilic leukemia, chronic eosinophilic leukemia, juvenile myelomonocytic leukemia, and MPN unclassifiable. This review is mainly focused on the Ph-negative MPNs namely, PV, ET, and PMF. These affect both males and females with a slight male predominance, with patients mainly presenting in the seventh decade. Patients often present with thrombotic events resulting in complications that lower survival rates. The major driver mutations that have been identified in MPNs are JAK2 Exon 14, JAK2 Exon 12, MPL Exon 10, and CALR Exon 9. The importance of these driver mutations gives due recognition to their inclusion into the 2022 diagnostic criteria of the MPN WHO Classification. However, other non-driver mutations have also been reported, especially in triple-negative cases. These mutations lead to downstream constitutive activation of the JAK/STAT signaling pathway, as well as the MAPK, and PI3K/Akt pathways. Insights into the molecular pathogenesis of MPN and its association with JAK2, CALR, and MPL mutations have identified JAK2 as a rational therapeutic target. Thus, as an approach to MPN therapy, JAK2 inhibitors, such as ruxolitinib, have been shown to effectively inhibit JAK2, and are currently in clinical trials in combination with other drug classes. This review comprehensively examines the molecular markers of the main Ph-negative MPNs, as well as diagnosis and treatment options.