Giardiasis, also known as lambliasis, is a gastrointestinal disease caused by protozoan Giardia lamblia/intestinalis/duodenalis. The protozoan is said to cause water-/food-borne diarrhoea, traveller's diarrhoea and diarrhoeal outbreaks at day-care centres (Leung et al, 2019, pp.134).