Table 1.

Suggestions to circumvent obstacles for therapeutic studies on optimal treatment of therapy-refractory giardiasis

Obstacle	Circumvention strategy
Low numbers of patients with     therapy-refractory giardiasis	Multi-centric trials and focusing on limited numbers of treatment arms with drugs, dosages and drug combinations
Lacking standardized     diagnostics for antimicrobial     resistance in G. duodenalis	Combination of culture-based, sequence-based and comparative proteomics approaches as well as clinical and diagnostic case definitions
Lacking reliability of     microscopy for the outcome     assessment	Use of more sensitive real-time PCR approaches in combination with clinical case definitions
Imperfect accuracy of case     definitions	Assessment of sensitivities and specificities in pilot studies, then application of accuracy adjusted estimators