This study aims to develop and evaluate a nanobody-based urine diagnostic test for Schistosoma haematobium infection through IPSE antigen detection. Approximately 2500 participants will be recruited and divided into five groups: confirmed S. haematobium infection, S. mansoni infection, urinary tract infection, nephritis or other renal diseases, and healthy controls (about 500 individuals per group). Each participant will provide a single morning midstream urine sample (30-50 mL), which will be used both for the development and optimization of the nanobody-based colloidal gold lateral flow assay (LFIA) and for evaluation of its diagnostic performance compared with urine-filtration microscopy.

Inclusion Criteria:

1. Signed written informed consent must be obtained from the participant. If the participant is a minor or legally incompetent, written informed consent must be obtained from the parent(s) or legal guardian, together with assent from the participant where applicable.
2. Able to provide a 30-50 mL first-morning midstream urine sample as required and willing to comply with all study-specified procedures, including

1) Index assay: nanobody-based lateral flow chromatography; 2) Reference assay: urine filtration microscopy; 3) Stool Kato-Katz examination if clinically indicated. 3. Complete basic demographic and clinical data (including age, sex, presenting symptoms, medical history, etc.) are available, and the participant has consented to the use of these data for study analysis.

4. Participants must fulfill one of the following group definitions:

1. S. haematobium infection group: Schistosoma haematobium eggs detected by urine filtration microscopy, with ≥1 egg per 10 mL urine.
2. S. mansoni infection group: Schistosoma mansoni eggs detected in stool by Kato-Katz thick smear.
3. Nephritis group: Clinical diagnosis of nephritis supported by abnormal urinalysis (e.g., proteinuria).
4. Urinary tract infection (UTI) group: Clinical diagnosis of urinary tract infection supported by abnormal urinalysis (e.g., leukocyturia, bacteriuria).
5. Healthy control group: Negative parasitological test results and no clinical evidence of the aforementioned diseases.

Exclusion Criteria:

1. Participant did not provide written informed consent or was unable to complete the informed consent process.
2. Participant is unable to provide a qualified specimen as required:

1) Unable to provide first morning midstream urine; 2) Urine volume < 30 mL; 3) Specimen is obviously contaminated, improperly preserved, or lacks complete labeling; 4) Index assay or reference assay cannot be completed, or results are uninterpretable.

3. Clinical or laboratory data are insufficient to allow for group assignment or subsequent study analysis.

4. Presence of any condition that may significantly interfere with the interpretation of study results (as assessed by the investigator or clinician), including:

1. Other concurrent, clearly defined severe urinary tract diseases or acute/critical illnesses that preclude differentiation of the cause of abnormal urinalysis parameters;
2. Recent treatment that may affect parasitological or urinalysis results (e.g., recent antiparasitic therapy, antibiotic therapy, etc.), potentially leading to unreliable group assignment (specific time windows may be defined in the protocol).

5. In the investigator's judgment, the participant is otherwise unsuitable for enrollment or unable to comply with study procedures.

A total of 2500 urine samples will be collected. These samples will be divided into five groups, each consisting of 500 individuals: Healthy control group; Schistosoma haematobium infection group; Schistosoma mansoni infection group; Nephritis patient group; Urinary tract infection patient group.