Strongyloides stercoralis Infection in Khuzestan Province, Iran: Epidemiology, Clinical Profiles, and Diagnostic Challenges

Strongyloidiasis remains a neglected tropical disease associated with significant diagnostic and therapeutic challenges in Khuzestan Province, Iran, due to its autoinfection cycle and serious threat to immunocompromised patients. Despite efforts to control soil-transmitted helminths, Strongyloides stercoralis remains prevalent, with many chronic cases remaining undiagnosed. In the current study, risk factors, clinical manifestations, and laboratory markers in confirmed cases were compared with those in uninfected individuals, as well as those suspected of being infected. A retrospective analysis (2019-2023) of 246 individuals, stratified into infected (29 direct smear-positive, 65 culture-positive), suspected (48 antibody-positive/larva-negative), and uninfected (104 antibody-negative/larva-negative) groups, was conducted. Data included demographics, comorbidities, occupational exposures, complete blood count results, and clinical symptoms. Diagnosis involved a combination of direct microscopy, agar plate culture (APC), and ELISA. The infected and suspected groups were significantly older (mean ages 67.0 ± 10.9 and 66.0 ± 11.2 years, respectively) than the controls (46.5 ± 23.0 years; P <0.001). No significant differences in sex distribution (P = 0.759) or place of residence (P = 0.610) were observed between groups. Farmers and housewives constituted the majority of infected individuals (P <0.001), with soil contact (77.4% versus 34.8% in controls; P <0.001) and close contact with dogs (P = 0.010) identified as key risk factors. Metabolic and cardiopulmonary comorbidities were prevalent in the infected group (P <0.001). Eosinophilia (absolute/relative; P <0.001) and leukocytosis (P = 0.006) served as significant hematologic markers, whereas neutrophils exhibited no intergroup variation (P = 0.093). Gastrointestinal symptoms, particularly abdominal pain (P = 0.001), were prominent, but no symptom clusters were correlated with infection status or diagnostic method. Treating strongyloidiasis in Khuzestan requires targeted interventions, including screening programs for aging populations, agricultural workers, and immunocompromised individuals. Enhanced diagnostics (APC/ELISA), along with community health education on soil exposure mitigation, are critical for reducing the burden of this underdiagnosed yet life-threatening infection.