Bacterial Coinfections Associated with Schistosoma haematobium Infection: A Scoping Review

Schistosoma haematobium, the causative agent of urogenital schistosomiasis, remains one of the most prevalent parasitic infections globally, with an estimated 112 million people infected predominantly across sub-Saharan Africa (Nazareth et al., 2022). The parasite establishes itself in the blood vessels surrounding the bladder and genitourinary tract, where its eggs become lodged in surrounding tissues and provoke a persistent inflammatory response, leading to bleeding, scarring, and progressive damage to the lining of the urogenital tract (Santos et al., 2021). Beyond these direct consequences of infection, this sustained tissue injury creates conditions that may predispose infected individuals to secondary bacterial infections, establishing a biologically plausible basis for coinfection. The relationship between S. haematobium infection and bacterial pathology is of considerable clinical and public health significance. Urinary tract infections are among the most frequently reported comorbidities in schistosomiasis-endemic settings, yet the extent to which S. haematobium infection actively promotes bacteriuria, modifies the local urogenital microenvironment, or alters immune responses to bacterial pathogens remains incompletely characterised. Proposed mechanisms include urinary stasis secondary to obstructive uropathy, disruption of urothelial integrity by migrating eggs, and parasite-driven immunomodulation that may impair host defences against bacterial colonisation (Afful et al., 2024). Compounding this clinical complexity is the growing burden of antimicrobial resistance in low- and middle-income countries, where S. haematobium is most endemic (O’Ferrall et al., 2024). Bacterial coinfections in schistosomiasis patients are often unrecognised or treated empirically, potentially driving inappropriate antibiotic use and contributing to resistance selection. Conversely, undertreated bacterial infections in this population may worsen renal and reproductive outcomes that are already compromised by chronic schistosomal pathology. Despite the clinical relevance of this intersection, there is no comprehensive synthesis of the available evidence on bacterial coinfections in S. haematobium-infected populations. Studies addressing this topic are scattered across various disciplines and vary substantially in design, diagnostic methodology, and the populations studied. To address this gap, this scoping review maps the existing evidence on the prevalence, bacterial species distribution, antimicrobial resistance patterns, and clinical outcomes associated with bacterial coinfection in individuals infected with S. haematobium, while identifying methodological knowledge gaps to guide future research.