Beyond strongyloides: rationale for empirical antiparasitic prophylaxis in immunosuppressed patients with rheumatic diseases in endemic areas

Abstract

Intestinal parasitic infections remain highly prevalent in endemic regions such as Brazil and pose a significant risk to patients with immune-mediated rheumatic diseases (IMRDs) undergoing immunosuppressive therapy. Immunosuppression may alter the natural history of parasitic infections, particularly Strongyloides stercoralis , increasing the risk of hyperinfection and disseminated disease with high mortality. To provide a narrative review of the epidemiological, clinical, and pharmacological evidence supporting empirical antiparasitic prophylaxis in immunosuppressed patients with rheumatic diseases in endemic settings—highlighting ivermectin as the cornerstone for Strongyloides stercoralis prevention and the role of complementary broad-spectrum agents, such as albendazole or nitazoxanide—and to propose a practical, context-adapted preventive approach. A narrative review of the literature was conducted, integrating data from epidemiological studies, clinical reports, reviews, and international and national recommendations addressing intestinal parasitic infections, immunosuppression, screening strategies, and preventive chemotherapy in endemic and non-endemic settings. Available evidence demonstrates persistent endemicity, frequent polyparasitism, and substantial diagnostic limitations in detecting latent or low-burden infections in endemic regions. Strongyloides stercoralis represents the main risk for severe and disseminated disease under immunosuppression, supporting the use of ivermectin (200 µg/kg/day for two consecutive days) as the cornerstone of prophylaxis. However, given its limited activity against other soil-transmitted helminths (e.g., Ascaris lumbricoides , Ancylostoma/Necator species) and intestinal protozoa (e.g., Giardia intestinalis and Entamoeba histolytica ), complementary agents such as albendazole (400 mg daily for 3–5 days) or nitazoxanide (500 mg twice daily for 3 days) are proposed to broaden coverage. Empirical combination prophylaxis prior to immunosuppression may be considered in selected patients with substantial epidemiological risk, while periodic repetition in those with ongoing exposure should be individualized given the limited direct evidence supporting this strategy. In endemic settings, empirical combined antiparasitic prophylaxis may represent a pragmatic, context-adapted option for selected patients undergoing immunosuppressive therapy. Although not a formal guideline, this strategy offers a technically grounded framework to support individualized clinical decision-making and to mitigate the burden of intestinal parasitic infections in vulnerable populations.