Phone: +61 7 3362 0410
Dr Cielo Pasay has extensive experience in research on parasitic diseases- such as scabies and malaria.
She was the first to clone the kdr gene conferring drug resistance in scabies mites, developed a real time PCR assay to detect permethrin resistance in scabies , developed enzyme assays to detect metabolic resistance in scabies mites and demonstrated use of insecticide synergist to reverse drug resistance in scabies mites. She has also achieved remarkable milestones in scabies drug discovery such as the use of clove oil (Eugenol) to treat drug resistant scabies and demonstrated acaricidal activity of chemically modified benzyl benzoate against scabies mites.
She led a team of immunomalariologists and molecular parasitologists in demonstrating a multidisciplinary approach to malaria control in an endemic area in the Philippines (research team received an award from PCHRD for successfully eliminating malaria in one endemic town). She initiated genetic diversity studies on malaria vaccine candidates and established a malaria genotyping network among endemic countries using standardised protocols developed from her PhD to enable direct comparison of genetic structures of different parasite populations. She has optimised molecular methods of detecting drug resistance in malaria parasites and used these tools to complement in-vivo therapeutic efficacy surveillance (TES) by the Philippine Dept of Health (DOH) to formulate a National Anti-Malarial Drug Policy. On her initial return to malaria research in 2013, she lead a team to lay the ground work for mosquito transmission studies at the QC3 facility of QIMR Berghofer. During this period, she also initiated molecular evaluation of malaria RDTs and investigated the development of artemisinin resistance in the Asia-Pacific region at the Army Malaria Institute (AMI) with Dr. Qin Cheng. She was also responsible for molecular validation of malaria parasite banks currently used in CHMI trials.
Current QIMR Berghofer appointment
- 2002 – present: Research Officer , Clinical Tropical Medicine, QIMR Berghofer
- 1986 – 2001: Supervising Science Research Specialist, Research Institute for Tropical Medicine, Manila, Philippines
- 1981 – 1985: Senior Research Assistant, College of Public Health, University of the Philippines , Manila, Philippines
Current Area of Research
- The use of Next Generation Sequencing (NGS) Technology to develop a highly sensitive real time PCR to diagnose scabies in the Aboriginal communities of the Northern Territory and Kimberley communities in Western Australia.
- Development of potentially useful vector control tool [i.e., NIRS (Near Infrared Spectroscopy) ] to detect malaria infected mosquitoes
- Use of endectocides (i.e., ivermectin) in domestic animals as complimentary vector control strategy:
- Investigation of ways to keep the drug in residence in vertebrate hosts at therapeutic levels for a sufficient duration (i.e., use of ivermectin implants in pigs) to achieve sufficient impact on transmission.
- Investigation on the utility of mathematical modelling of scenarios where this approach may accelerate malaria elimination.
In the light of emerging resistance to common topical acaricides, Dr. Pasay plays a lead role in scabies drug discovery research at QIMR Berghofer (in collaboration with scientists from UQ, School of Chemistry) .The results of initial work in replacing the benzene ring of benzyl benzoate (a topical acaricide) with cubane analogues (demonstrating mite-killing effect) were very promising (published in Angewandte Chemie International Edition (IF=12). Recently, new benzene bioisostere compounds have been discovered and synthesised by her UQ collaborators and the results of bioassays showed a much better mite killing effects. These are very promising results and will definitely advance scabies drug discovery .
In collaboration with the Mosquito Control Laboratory, Dr. Pasay is working on a proof of concept study to extend the application of the NIRS (Near-Infrared Spectroscopy) technology to detect malaria infection in vector mosquitoes. (NIRS is used for age grading of mosquitoes and detection of Wolbachia infection in Drosophila flies and Aedes aegypti mosquitoes). If optimised and validated, the use of this fibre optic probe can have significant implications in vector control measures aimed at eliminating malaria in endemic areas.
Dr. Pasay is also working on an innovative malaria vector control strategy such as the use of endectocides in domestic animals to help reduce the mosquito population . She recently conducted a proof of concept study (in collaboration with the Mosquito Control Laboratory at QIMR-B and UQ- QASP) to determine insecticidal activity of ivermectin and moxidectin (anti helmintic drugs) against a malaria vector , Anopheles farauti in treated pigs. Lethal effects of ivermectin to mosquitoes that fed on the pigs was observed for two weeks- with a remarkable kill effect (100% mosquito mortality within 48 hrs of feeding). Results of this study will assist in evaluating the potential of utilising domestic animals as a complimentary vector control tool applicable in areas where residual transmission persists impeding progress towards malaria elimination.
- 2002 – present: Australian Society for Parasitology , Member
- 1994 – present: American Society of Tropical Medicine and Hygiene, Member
- 1994 –1997: Ph.D. Scholarship , NHMRC, Australia
- 1991 – 1993: Master of Science Scholarship , SEAMEO-TROPMED , Philippines
- 1993 (Sept – Nov): NIH (USA) Fellow, IC-TDR Scholars Program , QIMR, Australia
- 1993 (July): THP, Fellow, UQ, Australia
- 1988: JICA Fellow: Japan International Cooperation Agency , Japan
- 1997: Ph.D. in Tropical Health, SPH-UQ, Australia
- 1993: Master of Science in Public Health. UP-CPH, Manila , Philippines
- 1981: Bachelor of Science in Public Health, UP-CPH, Manila, Philippines
- Griffin P*, Pasay C*, Elliott S, Sekuloski S, Sikulu M, Hugo L, Khoury D, Cromer D, Davenport M, Sattabongkot J, Ivinson K, Ockenhouse C, McCarthy J. (2016) Safety and reproducibility of a clinical trial system using induced blood stage vivax infection and its potential as a model to evaluate malaria transmission. PLoS Negl Trop Dis 10 (12): e0005139. (*equal first author)
- Wesley D*, Pasay C*, Guintran JO, Iata H, Anderson K, Nausien J, Gresty KJ, Waters NC, Vestergaard LS, Taleo G, Cheng Q. (2016) The utility of malaria rapid diagnostic tests as a tool in enhanced surveillance for malaria elimination in Vanuatu. PLoS ONE 11(11): e0167136 (*equal first author)
- Pasay CJ, Rockett R, Sekuloski S, Griffin P, Marquat L, Peatey C, Wang CY, O’Rouke P, Elliott S, Baker M, Mohrle JJ, McCarthy JS. (2016) Piperaquine monotherapy of drug sensitive falciparum infection results in rapid clearance of parasitemia but is followed by the appearance of gametocytemia. J Infect Dis. Apr 7. pii: jiw 128.
- Chalmers BA, Xing H, Houston S, Clark C, Ghassabian S, Kuo A, Cao B, Reitsma A, Murray CE, Stok JE, Boyle GM, Pierce CJ, Littler SW, Winkler DA, Bernharddt PV, Pasay C, De Voss JJ, McCarthy J, Parson PG, Walter GH, Smith MT, Cooper HM, Nilsson SK, Tsanaktsidis J, Savage GP, Williams CM. (2016) Validating Eaton’s hypothesis: cubane as a benzene bioisostere. Angew Chem Int Ed Engl 7; 55(11):3580-5.
- Grigg MJ, William T, Menon J, Dhanaraj P, Barber BE, Wikes CS, von Seidlein L, Rajahram GS, Pasay C, McCarthy JS, Price RN, Anstey NM, Teo TW. (2016) Artesunate-mefloquine versus chloroquine for treatment of uncomplicated knowlesi malaria in Malaysia (ACT KNOW): an open-label, randomized controlled trial. Lancet Infect Dis 16 (2):180-8.
- Britton S, Cheng Q, Grigg MJ, Poole CB, Pasay C, William T, Fornace K, Anstey NM, Sutherland CJ, Drakeley C, McCarthy JS. (2016) Sensitive detection of vivax using a high-throughput colorimetric loop mediated isothermal amplification (Ht-LAMP) Platform: a potential novel tool for malaria elimination. PLoS Negl Trop Dis 12; 10 (2):e0004443.
- Mounsey KE, Murray HC, Bielefedt-Ohmann H, Pasay C, Holt DC, Currie BJ, Walton SF, McCarthy JS (2015) Prospective study in a porcine model of Sarcoptes scabiei indicates the association of Th2 and Th17 pathways with the clinical severity of scabies. PLoS Negl Trop Dis. 2; 9 (3):e0003498.
- Rampton M, Walton S, Holt D, Pasay C, Kelly A, Currie BJ, McCarthy JS, Mounsey KE.(2013) Antibody responses to Sarcoptes scabiei apolipoprotein in a porcine model: relevance to immunodiagnosis of recent infection. PLoS One 6; 8(6):e65354
- Pasay C, Rothwell J, Mounsey K, Kelly A, Hutchinson B, McCarthy J. (2011) An exploratory study to assess the activity of the acarine growth inhibitor, fluazuron, against Sarcoptes scabei infection in pigs. Parasit Vectors 16; 5:40.
- Pasay C, Mounsey K, Stevenson G, Davis R, Arlian L, Morgan, M, Vyszenski-Moher, D, Andrews K , McCarthy J. (2010) Acaricidal activity of eugenol-based compounds against scabies mites. PLoS ONE 5(8): e12079.
- Mounsey KE*, Pasay CJ*, Arlian LG, Morgan MS, Walton SF, McCarthy JS. (2010) Increased transcription of glutathione S-transferases in acaricide exposed scabies mites. Parasit Vectors 18; 3:43. (*equal first author)
- Mounsey K, Ho MF, Kelly A, Willis C, Pasay C, Kemp DJ, McCarthy JS, Fischer K. (2010) A tractable experimental model for study of human and animal scabies. PLoS Negl Trop Dis. 4(7):e756.
- Pasay C, Arlian L, Morgan M, Gunning R, Rossiter L, Holt D, Walton S, Beckham S, McCarthy J. (2009) The effect of insecticide synergists on the response of scabies mites to pyrethroid acaricides. PLoS Negl Trop Dis. 3(1):e354.
- Pasay C, Arlian L, Morgan M, Vyszenski-Moher D, Rose A, Holt D, Walton S, McCarthy J.( 2008). High-resolution melt analysis for the detection of a mutation associated with permethrin resistance in a population of scabies mites. Med and Vet Entomol. 22: 82-88.
- Pasay, C, Walton, S, Fischer K, Holt D, Mc Carthy J. (2006). A PCR-based assay to survey for knockdown resistance to pyrethroid acaricides in human scabies mites (Sarcoptes scabiei var hominis). Am J Trop Med Hyg. 74(4), 649-657.
- Belizario VY, Pasay CJ, Bersabe MJ, de Leon WU, Guerrero DM, Bugaoisan VM. (2005). Field Evaluation of malaria rapid diagnostic tests for the diagnosis of falciparum and non-P. falciparum infections. Southeast Asian J Trop Med Public Health. 36(3):552-561.
- Chen N, Wilson D, Pasay C, Bell D, Martin L, Kyle D, Cheng Q. (2005). Origin and dissemination of chloroquine-resistant falciparum with mutant pfcrt alleles in the Philippines. Antimicrobial Agents Chemother. 49(5):2102-2105.
- Chen N, Kyle DE, Pasay C, Fowler EV, Baker J, Peters JM, Cheng Q. (2003). Pfcrt allelic types with two novel amino acid mutations in chloroquine-resistant falciparum isolates from the Philippines. Antimicrobial Agents Chemother. 47(11):3500-5.
- Torres EP, Ramirez BL, Salazar F, Pasay MCJ, Alamares JG, Santiago ML, Hafalla JCR. (Aug 2001). Detection of bancroftian filariasis in human blood samples from Sorsogon province, the Philippines by polymerase chain reaction. Parasitology Research. 87(8): 677-679.
- Figtree M, Pasay C, Slade R, Cheng Q, Cloonan N, Walker J, Saul AJ. (2000).
- vivax synonymous substitution frequencies, evolution and population structure deduced from diversity in AMA1 and MSP1 genes. Mol Biochem Parasitol, 108:53-66.
- Pasay C. (1999) Parasitological, immunological and molecular aspects of malaria and its control in State-of-the-Art: Malaria Research in the Philippines. A monograph by PCHRD/DOST, 61-72.
- Hafalla JC, Santiago ML, Pasay CJ, Gozar MG, Saul AJ, Kaslow DC. (1997). Minimum variation in the Pfs28 ookinete antigen detected in Philippine field isolates of P. falciparum. Mol Biochem Parasitol. 87:97-99.
- Belizario VY, Saul AJ, Bustos DG, Lansang MA, Pasay CJ, Gatton M, Salazar NP. (1996). Field epidemiological studies on malaria in a low endemic area in the Philippines. Acta Tropica. 63:241-256.
- Pasay CJ, Cheng Q, Rzepczyk, Q, Saul A. (1995). Dimorphism of the C-terminus of P. vivax merozoite surface protein-1. Mol Biochem Parasitol 70, 217-219.
- Pasay CJ, Bustos DG, Belizario VY, Lansang MA, Saul AJ. (1993). A longitudinal study of antibody levels in an area of low malaria endemicity using IFA Technique. Supplement to Am J Trop Med and Hyg. 49(3).249.
- Salazar NP, Pasay CJ, Hugo, CT. (1991). Colonization and experimental infection of Anopheles litoralis king. Mosquito-Borne Disease Bulletin, 8 (3):81-86.
- Salazar NP, Pasay CJ, Renejane MS. (1991). Application of serological procedures in the diagnosis of invasive amoebiasis. Phil J Microbiol and Inf Dis. 20(2):50-53.
- Salazar NP, Pasay CJ, Hugo CT, Renejane MS. (1990). Clindamycin activity against P. falciparum gametocytes. Mosquito-Borne Disease Bulletin, 7(1):73-78.
- Salazar NP, Pasay CJ, Sabordo NT, (1990). Detection of E. histolytica in routine stool examination. Phil J Microbiol Infect. Dis, 19 (2):57-60.
- Salazar NP, Bustos DG, Sabordo NT, Pasay, CJ, Montalban CS, Laurente MC, Tarrayo MG. (1987). A model for the control of soil-transmitted helminthiasis, Phil J Microbiol Infect Dis. 16 (2):65-72.