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PurposeThe Maroni basin –delineating the border between Suriname and French Guiana— presents sociocultural, geographical and economic circumstances that have been conducive to the circulation of sexually transmitted infections and to delays in diagnosis and care. Given the scarcity of published data, we aimed to describe different sexually transmitted infections along the Maroni and to gain a broader understanding of the epidemiologic situation.MethodsWe conducted a scoping review of the efforts to approach the problem of sexually transmitted infections in this complex border area. Temporal trends were plotted and crude numbers were divided by local population numbers.ResultsFor HIV, despite increasing testing efforts, most patients still present at the advanced HIV stage (median CD4 count at diagnosis is < 20 per mm3), and 25% of patients in Saint Laurent du Maroni were lost to follow-up within 6 years. However, progress on both sides has led to a decline in AIDS cases and mortality. Despite a rapid increase in the 1990’s along the Maroni, the current HIV prevalence seemed lower (0.52%) in the rural villages than in coastal urban centers (> 1%). High risk HPV infection prevalence among women reaches 23.3%. The incidence of gonorrhea was 4.2 per 1,000 population aged 15-59. For chlamydiasis it was 3.4 per 1,000 population aged 15-59. For syphilis, the incidence was 2.5 per 1,000 population aged 15-59. Gonorrhea, chlamydiasis, hepatitis B detection increased over time with greater testing efforts and new diagnostic tests. Since the COVID-19 epidemic, congenital syphilis has dramatically increased in Saint Laurent du Maroni reaching 808 per 100,000 live births.ConclusionSexually transmitted infections seemed more prevalent in Saint Laurent du Maroni –the sole urban center—than in the remote villages along the Maroni. The syndromic approach and the heterogeneity of diagnostic platforms presumably overlook most infections in the region. Therefore, a concerted approach and a shared diagnostic upgrade with molecular diagnosis and rapid diagnostic tests seem necessary to reduce the burden of sexually transmitted infections on both sides of the Maroni. Congenital syphilis resulting from COVID-19 disruption of health services requires urgent attention.

S10.2 Fungal Infections in Transplant Patients, September 24, 2022, 10:30 AM - 12:00 PM Objectives Diagnosis of histoplasmosis in people living with HIV (PLWHIV) remains challenging despite developments in Histoplasma antigen and molecular detection tools. Fungal markers such as Beta-(1,3)-D-glucan (BDG) and galactomannan Aspergillus antigen (GM) are widely available, but the experience is limited during PLWHIV workup for suspicion of histoplasmosis. Our objective was to evaluate and compare BDG and GM performances for the diagnosis of HIV-associated histoplasmosis. Methods We performed a diagnostic accuracy study using primary serum samples stored frozen in a certified biorepository (CRB Amazonie-DC-2021-4649). Samples consisted of consecutive hospitalized PLWHIV unexposed to oral antifungals during the previous month (EDIRAPHIS study-NCT01884779). All patients gave consent for biobanking and ancillary studies on fungal markers. Histoplasmosis cases, proven (EORTC/MSG criteria) and probable (polyclonal or monoclonal Histoplasma antigen detections in urines or serum), as well as negative controls, were randomly selected. Patients with a proven or suspected Pneumocystis jirovecii infection were excluded. Following manufacturers’ instructions, samples were blindly tested for BDG and GM using Fungitell® and PlateliaTM Aspergillus Ag assays, respectively. Gold standard definition used three scenarios: EORTC scenario (cases and controls defined according to the EORTC/MSG 2020 criteria for endemic mycoses); strict scenario with proven cases restricted to those positives to all three previous Histoplasma antigen detections, and controls conversely negatives for all methods; and a large scenario with proven or probable cases and controls negatives for all methods. Results We included 121 samples, 92 HIV-associated histoplasmosis cases (34 proven and 58 probable), and 29 negative controls. Compared with controls, histoplasmosis cases were significantly younger and advanced in the course of HIV disease [median CD4 count level 33/mm3 (15-87) vs 116 (62-245)]. BDG and GM median detection levels were significantly higher among histoplasmosis cases compared with controls across all scenarios [368 (176-441) pg/ml vs 142 (89-211) for BDG and 2.5 (1.3-4.8) vs 0.19 (0.14-0.36) for GM, in cases vs controls of the strict scenario, respectively]. In the strict scenario, at 150 pg/ml and 0.5 for BDG and GM respectively, sensitivity, specificity, positive and negative likelihood ratios were respectively: 95% [95%confidence interval (CI), 85-100] vs 90% [77-100], 52% [34-70] vs 83% [69-97], 2 [1.4-3.0] vs 5.3 [2.4-12.0], and 0.1 [0.01-0.7] vs 0.12 [0.03-0.45]. ROC curves found AUCs of 0.82 [0.68-0.91] vs 0.92 [0.80-0.98], and optimal thresholds at 288 pg/ml and 1.29, for BDG and GM, respectively (Fig. 1). Post-test probabilities showed best performances at the lowest thresholds for negative testing of both BDG and GM, and at the 0.7 thresholds for a positive GM test (Fig. 2). Conclusion BDG and GM may not be used for the same objective when searching for HIV-associated histoplasmosis. Although a negative BDG test at the lowest thresholds should rule out histoplasmosis in a screening context, limitations of a positive BDG test, even at the highest thresholds, call for a consecutive positive GM test before starting patients on antifungal therapy targeting histoplasmosis. Still, when considering the highest costs of BDG testing, higher balanced diagnostic performances, and lower costs of GM testing alone, one may favor the use of GM, notably in resources-limited settings.

S2.2 Histoplasmosis and talaromycosis, September 21, 2022, 3:00 PM - 4:30 PM In sub-Saharan Africa (SSA) and West African countries, histoplasmosis is rarely diagnosed probably due to lack of epidemiological information, insufficient training and awareness of frontline healthcare workers, and clinical features very similar to those of tuberculosis that can be misleading. This fungal infection mainly affects immunocompromised patients and particularly advanced HIV patients, with a high case-fatality rate in the absence of treatment (from 40%). The classical diagnostic methods are microscopic observation of yeasts with suggestive morphology and a positive culture from a biological sample. However, direct examination requires regular practice, and the yeasts can be confused with other pathogens and culture takes prolonged incubation (often 2-6 weeks) and involves, when positive, handling in a level 3 security laboratory. Implementing non-invasive diagnostic tools will allow us to improve histoplasmosis diagnosis for the most exposed patients and also to evaluate the prevalence of this fungal infection in countries where data are still lacking. Rapid diagnostic tests (RDTs) such as the TB Lam for the diagnosis of tuberculosis or the Cryptococcal antigen (CrAg) lateral flow assay (LFA) for cryptococcosis have demonstrated their usefulness for the management of advanced HIV patients in similar contexts. Recently, two RDTs have been made commercially available for the diagnosis of histoplasmosis, based on urinary monoclonal antigen detection: (1) Histoplasma Capsulatum Urinary Antigen Rapid Test from Optimium Imaging Diagnostics (OIDx) and (2) Histoplasma Urine Antigen Lateral Flow Assay from MiraVista Diagnostics (MV). Objectives and Methods Our objective was to evaluate these new tools, by experimenting with their feasibility in low-and middle-income countries (LMICs) and by studying their diagnostic performances using different sample collections recovered from patients with disseminated histoplasmosis (culture proven), other HIV-related infections, and proven negative urines (culture and other Histoplasma antigen detections). Results Preliminary results were obtained using the EDIRAPHIS study frozen samples from hospitalized patients diagnosed with proven positive and negative histoplasmosis from French Guiana and Suriname (n = 43) tested with OIDx and MV tests. We calculated a Se = 74.2% and a Sp = 83.3% for OIDx and a Se = 77.4% and a Sp = 91,7% for MV. A low number of false positives for both tests, Conclusion These first results are very promising and will be completed with two other specimen collections to increase the total numbers of our sampling and get a whole picture of the performances of these two RDTs. The next step will be to implement these new tools at the bedside or in laboratories together with other tests in different settings across SSA. Diffusion of RDTs together with appropriate training of clinical and laboratory teams and accessibility to treatment may help reduce the burden of histoplasmosis in endemic areas of SSA where the prevalence of the advanced-HIV disease is high.