Degrees:
PhD: 'The evolution of drug-resistance in malaria parasites', Edinburgh University, 2006-2010.
MSc Biology (Specialization entomology/ parasitology), Wageningen University and Research-centre (WUR), 2003-2006
BSc Biology (Specialization zoology), Wageningen University and Research-centre (WUR), 2000-2004
Research experience:
MSc thesis: 'Inter-specific competition between Anopheles gambiae and An. arabiensis larvae in a semi-field situation in Western Kenya', Kenya Medical Research Institute (Kisumu, Kenya), Nov 2005 - June 2006
MSc thesis: 'The role of drug treatment, in response to clinical signs, on within-host competition and relative transmission of malaria parasites', Edinburgh University, Oct 2004 - March 2005
MSc thesis: 'Avian malaria in Rotterdam Zoo' a study on the natural history of avian malaria in the Netherlands', Wageningen University, June 2003 - Jan 2004
I’m interested in the evolution of drug resistance in general but of malaria parasites in particular. Drug resistance in parasites is currently a big problem in malaria control programs and will be a major obstacle in future malaria eradication attempts. Resistance against most antimalarials is widespread and resistance against artemisinins, the ‘magic bullet, appears to be on the rise. Much effort is put into R&D of new antimalarials, but, as of yet, there are no alternatives available for when artemisinins fail. The question I’m asking is ‘Are there ways to slow the evolution of drug resistant parasites?’.
We believe there might be, by harnessing the within-host ecology of the parasites: drug sensitive parasites are natural suppressors of drug resistant parasites in a co-infection. Rather than removing all susceptible parasites with the conventional way of aggressive chemotherapy that results in the greatest possible selection for resistant parasites, lower dosages of drug treatment will result in less selection for drug resistant parasites but possibly still equivalent improvement of host health. My work involves studying the competitive interactions between a drug resistant and drug susceptible Plasmodium chabaudi strain under various ecological scenario’s and following different treatment regimes.
I am currently finishing my post-doctoral work on this project while based at CRESIB, Barcelona. In May 2013 I was awarded a Branco Weiss Fellowship to continue my work on the evolution of drug resistance but in a clinical setting. To better understand the selective forces of resistance in different ecological contexts, I will study the selection for resistant parasites in not only malaria but also leishmaniasis. By studying clinical samples from HIV-positive and HIV-negative pregnant women of five malaria-endemic countries I aim to unravel the link between HIV infection and the frequency of malaria drug resistance. Using placental samples taken from the same women, the study will then show if the placenta serves as a reservoir for resistant malaria parasites. Additionally, I wiIl study the selection for resistant leishmaniasis parasites in the non-human host. Explicitly, I will research the risk of the veterinary treatment practices that tend to facilitate resistant parasites in dogs for human public health. I am expecting to commence this work in October 2013.
Vanaerschot, M., Huijben, S., Van den Broeck, F., Dujardin, J-C. (in press). Drug resistance in vector-borne parasites: multiple actors and scenarios for an evolutionary arms race. FEMS Microbiology Reviews
Bell, A.S, Huijben, S., Paaijmans, K.P., Sim, D., Chan, B.H.K., Nelson, W.A., & Read A.F. (2012). Enhanced transmission of drug-resistance parasites to mosquitoes following drug treatment in rodent malaria. PLoS One 7: e37172.
Huijben, S., Sim, D., Nelson, W.A., & Read, A.F. (2011), The fitness of drug resistant malaria parasites in a rodent model: multiplicity of infection. Journal of Evolutionary Biology 24: 2410-2422 doi: 10.1111/j.1420-9101.2011.02369.x
Metcalf, C.J.E., Graham, A.L., Huijben, S., Barclay, V.C., Long, G.H., Grenfell, B.T., Read, A.F., & Bjornstad, O.N. (2011) Partitioning and quantifying regulatory mechanisms acting on within host malaria using the effective propagation number. Science 333: 984-988.
Read, A.F., Day, T., & Huijben, S. (2011). The evolution of drug resistance and the curious orthodoxy of aggressive chemotherapy. PNAS 108: 10871
Huijben, S., Nelson, W.A., Wargo, A.R., Sim, D.G., Drew, D.R., & Read, A.F. (2010). Chemotherapy, within-host ecology and the fitness of drug resistant malaria parasites. Evolution 64: 2952-2968.. DOI: 10.1111/j.1558-5646.2010.01068.x
KP Paaijmans, S Huijben, AK Githeko & W Takken. (2009). Competitive interactions between larvae of the malaria mosquitoes Anopheles arabiensis and Anopheles gambiae under semi-field conditions in western Kenya. Acta Tropica. 109: 124-130.
Read, A.F. & Huijben, S. (2009). Evolutionary biology and the avoidance of antimicrobial resistance. Evolutionary Applications. 2: 40-51.
Huijben, S., Schaftenaar,W., Wijsman,A., Paaijmans, K. & Takken, W. (2007). Avian malaria in Europe: an emerging infectious disease? In: Emerging pests and vector-borne diseases in Europe. Takken W. & Knols B.G.J, editors. Wageningen Academic Publishers, Wageningen.
Takken, W., van Rooij, E.M.A., Verhulst, N.O., Jacobs, F., Huijben, S., Beeuwkes, J., Groot, N ., Vos, J Spitzen, V.C.A ., Heutink, R.C.G. & van Rijn, P.A. (2007). Bluetongue: an emerging vector-borne disease outbreak in North-western Europe. In: Emerging pests and vector-borne diseases in Europe. Takken, W. & Knols, B.G.J, editors. Wageningen Academic Publishers, Wageningen.
Wargo, A. R., Huijben, S., de Roode, J.C., Shepard, J., & Read, A.F. (2007). Competitive release and facilitation of drug resistant parasites following therapeutic chemotherapy in a rodent malaria model. Proceedings of the National Academy of Science USA. 104: 19914-19919.
Wargo A. R., De Roode J. C., Huijben S., Drew D. R., Read A. F. (2007). Transmission stage investment of malaria parasites in response to in-host competition. Proceedings of the Royal Society of London Series B. 274: 2759-2768.
de Roode, J.C., Pansini, R., Cheesman, S.J., Helinski, M.E.H., Huijben, S., Wargo, A.R., Bell, A.S., Chan, B.H.K ., Walliker, D., & Read, A.F. (2005). Virulence and competitive ability in genetically diverse malaria infections. Proceedings of the National Academy of Sciences USA.102: 7624-7628.
Other interests:
When I’m not at work, I am mostly preoccupied with exploring our new environment of Barcelona with my husband and our one and three year olds. This involves a lot of biking, walking the hills (teaching as much natural history as possible as city dwellers), building sandcastles on the beach, cultural sightseeing and of course sampling the culinary goodness of Catalunya. In my very rare ´free´ time I´m trying to learn Spanish and train for my first half marathon.