Biondi, Matt V.

ABSTRACT Background Strongyloides stercoralis is an intestinal parasitic nematode that can infect humans with a 2%–7% prevalence in the United States. Immunosuppression is a crucial risk factor for disseminated infection. Diagnosis is often delayed and targeted treatment is frequently initiated late. We therefore sought to review the prevalence of positive Strongyloides antibody results and undertook a descriptive analysis of such patients. Methods We retrospectively reviewed patients with positive Strongyloides IgG serology from August 2012 to April 2023 across geographically distinct academic medical centers. Study period pre‐dated universal donor and recipient Strongyloides screening recommendation by the Organ Procurement and transplantation network (OPTN). Clinical presentation was classified into three categories: chronic infection (positive Strongyloides IgG serology without additional clinical manifestations), hyperinfection syndrome (positive serology with involvement of the skin, gastrointestinal tract, or lungs), and disseminated infection (positive serology with involvement beyond those typically involved in hyperinfection). Results A total of 412 patients were identified; median age was 59 years and 66% (272) were male. The primary indication for testing was pretransplant evaluation in 230 (56%), eosinophilia workup in 84 (20%), suspicion of symptomatic infection in 74 (18%), testing based on travel history in 27 (7%), and pre‐immunosuppression screening in 27 (7%). Furthermore, 401 patients (97.3%) were categorized as having chronic infection, 10 patients (2.42%) had hyperinfection, and one patient (0.24%) had disseminated infection, presenting with Escherichia coli bacteremia and meningitis. Symptomatic infection was more common at the Mayo Clinic in Rochester and Mayo Clinic Health Sciences than at the Arizona and Florida Mayo Clinic sites (6% vs. 2%, p = 0.079). Treatment was administered to 366/412 (89%) patients. Conclusion Most patients with positive Strongyloides serology were asymptomatic, and treatment regimens were not uniform. Patients who tested positive should be treated prior to immunosuppression initiation, though this was not systematically assessed in this cohort. The observed variability in treatment regimens highlights the need for standardized protocols.

Abstract Background Strongyloides stercoralis is an intestinal parasitic nematode with a 2% - 7% prevalence in the United States. Immunosuppression can predispose to disseminated infection, concurrent bacterial sepsis and significant morbidity and mortality. We sought to review positive Strongyloides serology (PSS) results across 3 academic medical centers. Methods Electronic medical records of patients with PSS were reviewed between 2012 and 2023. Extracted data included demographics, country of origin, travel history, testing indication, clinical presentation, treatment regimen and duration. Patients were classified into chronic infection (PSS without additional clinical manifestations), hyper infection syndrome (cutaneous, gastrointestinal tract, or lung involvement), and disseminated infection (evidence of involvement of distant sites beyond hyper infection such as the brain, liver, kidneys, or bloodstream). Results Overall PSS rate across the 3 sites was 5.5%. A total of 412 patients with PSS were identified with a mean age of 56.7 years (SD ±14.2); 272 (66%) were male. The primary indication for testing was transplant evaluation in 230 (56%), eosinophilia workup in 84 (20%), suspicion of active infection in 74 (18%), travel history in 27 (7%), and pre-immunosuppression screening in 27 (7%). 401 (97.3%) were categorized as chronic infection,10 (2%) as hyper infection, and one patient (0.2%) as disseminated infection. Treatment was administered to 366 (89.3%) patients: 226 (61.7%) received 2 doses of Ivermectin on consecutive days, 94 (25.7%) received a single dose, 26 (7.1%) received 2 doses repeated 2 weeks later, and 20 (5.5%) received alternative regimens. The patient with disseminated infection received 2 weeks of Ivermectin followed by monthly dosing. Conclusion Majority of the patients with PSS were asymptomatic, and treatment regimens were not uniform. Screening should be considered for patients currently receiving or initiating long-term immunosuppression that can potentiate Strongyloides dissemination. Developing a targeted testing algorithm based on epidemiologic factors, clinical suspicion, laboratory parameters and nature of immunosuppression can help identify at-risk patients who can receive pre-emptive therapy if infected. Disclosures All Authors: No reported disclosures

Background. Solid organ transplant recipients are at risk of severe coccidioidomycosis and are given prophylaxis to mitigate the risk. Patients with seropositive testing typically receive lifelong prophylaxis; currently, this prophylaxis strategy includes patients who are positive only for IgM by enzyme immunoassay (EIA-IgM-only), although this result may be falsely positive. Methods. We conducted a retrospective study at a large-volume transplant center in an endemic coccidioidomycosis region to compare outcomes of non–lung transplant recipients who were seropositive for Coccidioides but discontinued prophylaxis (case patients) to outcomes of patients who continued prophylaxis (controls). Results. No case or control patients developed active coccidioidomycosis during the follow-up period. Before transplant, 62 of 77 case patients (80.5%) had a single positive serologic test, of whom 27 of 62 were EIA-IgM-only positive (43.5%). In contrast, 57 of 77 controls (74.0%) had a single seropositive result (16/57 [28.1%] were EIA-IgM-only). The single EIA-IgM-only result was classified as falsely positive by infectious disease consultants in 20 of 43 patients (46.5%) compared with all other Coccidioides serologic results (13/111 [11.7%], P < 0.001). Lifetime antifungal prophylaxis was felt to be unnecessary for 28 of 43 patients (65.1%) who were EIA-IgM-only versus 31 of 111 patients (27.9%) with other serologic results (P < 0.001). Conclusions. For patients repeatedly positive for EIA-IgM-only and no evidence of seroconversion, compatible clinical illness, or radiographic findings, discontinuing antifungal prophylaxis may be reasonable after the first posttransplant year.

Abstract Coccidioidomycosis is a common cause of community-acquired pneumonia in endemic regions. Approximately 20 000 cases of coccidioidomycosis occur annually; however, this statistic is limited by a widespread lack of testing. Here, we analyze emergency medicine provider attitudes toward coccidioidal testing and assess the effect of an intervention to improve testing rates.