Diagnosis

The Giardia parasite was first identified by Antony van Leeuwenhoek in 1861, who identified the characteristic flagellated trophozoite and infective cyst forms (Yilmaz and Uslu, Turkiye Parazitol Derg., 2020);.
Since 2004, Giardia lamblia has remained a part of the 'neglected disease initiative', deemed by the World Health Organisation (WHO).
Giardia lamblia infections can be challenging to diagnose, because of the high incidence (50% of cases) of asymptomatic infections, especially in the case of reinfections. Additionally, the parasite's thick prevalence in disadvantaged socio-economic regions leaves diagnostic services under-facilitated and poorly maintained. In such regions, faecal sampling does not take precedence in routine procedures, further exacerbating the under-reporting of disease occurrences, and high rates of spread. Detection is also largely dependent on the skills and expertise of clinicians and technicians, of which there is an ongoing lack of in parasitology particularly (Vicente, et al., 2024).

In order to compensate for the cyclic or intermittent transformation of cysts to trophozoites (and vice versa), and the passing of both in the faeces, repeated sample collection should be employed over multiple days, at least 2-3 days apart. Samples should be collected in sterile, labeled screw-cap containers to indicate the patient identification, the date and time of the sample collection (Vicente, et al., 2024).