HIV-associated histoplasmosis on the Guiana Shield: a prevalence study

Abstract

Introduction

HIV-associated histoplasmosis is a global public health threat, particularly in Latin America. Although French Guiana is considered a high-endemic region, prevalence data on the Guiana Shield are lacking, notably in neighboring Suriname where it remains elusive, probably due to the difficulty in diagnosing histoplasmosis. The aim of this study was to estimate the prevalence of histoplasmosis in people living with HIV hospitalized in Suriname and French Guiana using Histoplasma-specific antigen assay, a method not routinely available in these two countries.

Method

We conducted a prospective cohort study from 2013 to 2015 in the 5 main hospitals of Suriname and French Guiana. Adult patients living with HIV (known or newly discovered) who presented with fever or altered general condition or symptoms suggestive of an infectious syndrome were included. In addition to conventional etiologic investigations performed following clinicians initiative, two Histoplasma-specific antigen assays were systematically performed on urine and serum samples drawn on inclusion: a double-polyclonal-antibody EIA on serum and urine, and a single-monoclonal-antibody EIA on urine. Proven and probable histoplasmosis were defined according to the criteria of the European Organization for Research and Treatment of Cancer and the Mycoses Study Group Education and Research Consortium.

Results

A total of 478 patients were included – 307 (64.2%) in Suriname and 171 (35.8%) in French Guiana – with a median age of 42 years [34-51], a male/female ratio of 1.1, a first HIV diagnosis rate of 31.5%, and a median LTCD4+ count of 114/µL [32-305]. The prevalence of histoplasmosis was 111/478 (23.2%; CI95%: 19.5-27.3), of which 75 (67.6%) were only probable. Histoplasma-specific antigen assays resulted in a 208% increase in the diagnosis rate (Suriname 420%, French Guiana 57%). The most discriminating Histoplasma-specific antigen assay was the one performed in the serum (AUC: 0.87; CI95%:0.81-0.94). Histoplasmosis was the leading opportunistic infection in both Suriname and French Guiana. Although the majority of infected patients had a LTCD4+ count <100/µL, the prevalence of was of 11.1% in patients with a LTCD4+ count between ≥100 and <350/µL. The 30-day mortality rate was of 15.3% in patients experiencing histoplasmosis compared with 7.1% in other patients. Serum and urine Histoplasma-specific antigen levels were associated with 30-day mortality.

Discussion

The prevalence of histoplasmosis in HIV-infected patients was high in Suriname and French Guiana, regardless of the LTCD4+ count level. As the leading opportunistic infection, histoplasmosis may be a major cause of AIDS-related death in the Guiana Shield. Using high-performance Histoplasmasma-specific antigen tests in high endemic areas may help tackle the burden of disease in people living with HIV.