How common are intestinal parasite co‑infections among people with diabetes in different regions?

1. What the pooled evidence shows

A global meta‑analysis pooling dozens of studies estimated that about one quarter of diabetic patients harbor intestinal parasites—the pooled prevalence was reported as 26.5% (95% CI: 21.8–31.7%) in one systematic review and similar pooled findings are reported across complementary reviews ^{[1] [2] [3]}. That same literature also calculated an increased likelihood of intestinal parasite infection among diabetics versus non‑diabetic controls (pooled OR approximately 1.7), indicating a consistent association across case‑control and cross‑sectional studies ^{[1] [4]}.

2. How prevalence varies by region

Regional estimates differ sharply: some meta‑analyses identified the Region of the Americas as having the highest pooled prevalence in their dataset (~13.3% by region in one report, noting differences in how regions and studies were grouped), while Africa‑focused reviews and country studies often report higher local prevalences—individual country studies show a range from roughly 10–40% depending on setting ^{[1] [6] [5]}. Country‑level cross‑sectional reports exemplify that variation: Ghana reported a 12.5% prevalence among diabetics in one municipal study, Nigeria and Ethiopia studies reported rates in the teens to high‑teens, while some Egyptian and Nigeria case‑control series documented prevalences approaching or above 30% ^{[7] [8] [5]}.

3. Parasite mix and urban–rural differences

The specific parasites found in diabetic cohorts follow local endemic patterns: Giardia, Entamoeba species, Cryptosporidium and common soil‑transmitted helminths like Ascaris appear repeatedly in studies (e.g., Giardia dominance in some Ghanaian data; mixed protozoa/helminth profiles elsewhere) ^{[7] [9] [10]}. Several studies report markedly higher rates in rural than urban diabetics, tying prevalence to poorer sanitation and water access; one case‑control study found 77.3% of infections in rural residents versus 22.7% in urban patients ^{[11] [8]}.

4. Who is at higher risk and why

Reports link uncontrolled diabetes, longer disease duration, complications and some social determinants (rural residence, low sanitation) to higher intestinal parasite prevalence in diabetic cohorts, suggesting immunologic impairment plus environmental exposure drives risk ^{[11] [7] [8]}. Meta‑analyses and primary studies acknowledge bidirectionality and confounding—parasites affect nutrition and metabolism and diabetes may impair parasite clearance—so association does not prove a one‑way causal relationship ^{[1] [12]}.

5. Evidence quality, heterogeneity and alternative findings

The literature contains substantial heterogeneity (I2 values very high in pooled analyses) and mixed results: some studies show higher parasite prevalence in non‑diabetic controls or fail to find significant differences, and diagnostic methods vary from stool microscopy to serology, affecting sensitivity and comparability ^{[1] [13] [10]}. Recent reviews explicitly warn that geographic, methodological and socioeconomic differences—and study design (case‑control vs cross‑sectional)—drive variability, and one Africa‑focused meta‑analysis highlighted particularly high local estimates but emphasized poor sanitation as a major confounder ^{[5] [4]}.

6. Practical interpretation and unanswered questions

Taken together, the evidence supports that intestinal parasite co‑infections are a common and regionally variable problem among people with diabetes, particularly in low‑resource and rural settings, and that diabetics appear modestly more likely to be infected than matched controls in pooled analyses ^{[1] [6] [5]}. However, high heterogeneity, differing diagnostic approaches and some contradictory single‑site reports limit precise global prevalence figures and causal inference; the literature calls for better standardized surveillance, routine screening in high‑risk settings and more longitudinal work to clarify directionality ^{[1] [2] [3]}.