Abstract Description

Giardiasis is a globally prevalent infection, affecting over 200 million people annually. Despite the significant effects on public health, surprisingly little is known regarding the prevalence and distribution of this pathogen among South African infants. To address this gap, we evaluated Giardia species in 92 infants from informal settlements across the Western Cape Province of South Africa. Initial screening for Giardia was conducted using microscopy, with confirmation using enzyme-linked immunosorbent (ELISA) and a nested PCR. Giardia prevalence was 64.1% by ELISA and 28.3% by PCR. Assemblages A and B of Giardia intestinalis, which are known to infect both humans and animals, were detected in multiple informal settlements. Assemblage B was more prevalent in diarrheal stools (90.9%) compared with non-diarrheal stools (55.7%), suggesting a potential link to symptomatic giardiasis (p = 0.0044). Infections varied across informal settlements, with Malmesbury displaying the highest prevalence (85.7%). Other variables, such as water source, waste management, gender, age and community cleanliness, were also assessed, but no statistically significant associations were observed with Giardia infections (p > 0.05). Given Giardia’s interaction with the gut, future research should examine its impact on the developing infant gut microbiome, which may play a role in disease and long-term health. This study is the first to describe the prevalence and distribution of G. intestinalis assemblages A and B within informal settlements in the Western Cape, South Africa. Our findings highlight the need for further research to resolve transmission pathways and identify risk factors for giardiasis in vulnerable communities.