On 18 May 2017, the Netherlands Society for Parasitology and the Belgian Society of Parasitology and Protistology awarded the Merial Award to Prof. Guy Caljon from the University of Antwerp (Laboratory of Microbiology, Parasitology and Hygiene) for his research in parasitology, particularly for his work on insect-transmitted parasitic infections.

Photo: From left to right: Dr. Renske van Rossem (MERIAL), Prof. Guy Caljon and Prof. Lodewijk Tielens.

More than 1 billion people are affected globally by neglected tropical diseases, including several infections that are initiated by the bites of blood feeding insects. Two major lethal diseases, sleeping sickness and visceral leishmaniasis, are initiated by tsetse flies and sand flies respectively. Since 2006, the research of Dr. Guy Caljon with colleagues at Vrije Universiteit Brussel and Instituut Tropische Geneeskunde Antwerpen explores the impact of insects on parasite infection. He discovered that tsetse flies are more than just flying syringes by uncovering particular features of a real infective bite.

This Belgian researcher first used a gene discovery approach to identify and functionally characterize the most abundant saliva proteins encoded in the tsetse fly genome. He subsequently discovered a major defect in the blood feeding behaviour of trypanosome-infected tsetse flies favouring parasite transmission. He could attribute this to a dysregulated saliva composition and a compromised anti-haemostatic activity. Caljon also illustrated that saliva has an immunological impact that exacerbates trypanosome infection. Further exploiting the immunogenicity of the major salivary antigens, he developed an innovative serological test that can be used in epidemiological surveys to evaluate exposure to a range of medically important tsetse fly species.

Dr. Caljon also documented that tsetse flies inoculate a particularly infective form of the trypanosome that can occupy a niche in the skin while engaging into interactions with dermal adipocytes. He also contributed to the identification of parasite virulence factors and to studies on liver pathology, destruction of immunological memory and damage to the blood-brain barrier during trypanosome infection. Caljon has also shown that high affinity biologicals (Nanobodies) can efficiently lyse trypanosomes, which is currently further explored in transmission-blocking approaches. Since his appointment at the University of Antwerp in 2016 as research professor, he extended his research to leishmaniasis for which he initiated a sand fly colony to enable natural infections.

The Merial Award is a professional prize for young, promising researchers in the field of veterinary or medical parasitology. The award consists of a certificate and pecuniary donation of € 3000. It is meant to encourage further professional ambitions in parasitology in the Benelux and to reward the scientific quality