Clinical and parasitological factors in parasite persistence after treatment and clinical cure of cutaneous leishmaniasis

Abstract

BackgroundThe determinants of parasite persistence or elimination after treatment and clinical resolution of cutaneous leishmaniasis (CL) are unknown. We investigated clinical and parasitological parameters associated with the presence and viability of Leishmania after treatment and resolution of CL caused by L. Viannia.MethodsSeventy patients who were treated with meglumine antimoniate (n = 38) or miltefosine (n = 32) and cured, were included in this study. Leishmania persistence and viability were determined by detection of kDNA and 7SLRNA transcripts, respectively, before, at the end of treatment (EoT), and 13 weeks after initiation of treatment in lesions and swabs of nasal and tonsillar mucosa.ResultsSixty percent of patients (42/70) had evidence of Leishmania persistence at EoT and 30% (9/30) 13 weeks after treatment initiation. A previous episode of CL was found to be a protective factor for detectable Leishmania persistence (OR: 0.16, 95%CI: 0.03–0.92). kDNA genotyping could not discern differences between parasite populations that persisted and those isolated at diagnosis.ConclusionsLeishmania persist in skin and mucosal tissues in a high proportion of patients who achieved therapeutic cure of CL. This finding prompts assessment of the contribution of persistent infection in transmission and endemicity of CL, and in disease reactivation and protective immunity.

Leishmania spp. seropositivity in Austrian soldiers returning from the Kosovo

“…Of course, a positive ELISA index does not necessarily reflect a recent Leishmania infection. Anti-Leishmania antibodies and possibly also the parasites themselves, are known to persist for very long (occasionally life-long), even in asymptomatic infections [9][10][11]; however, in the current study, relatively high ELISA indices were observed. Moreover, the seroprevalence in soldiers returning from their first mission tripled the prevalence found in a large group of Austrian soldiers tested prior to missions [12].…”

Presence of parasite DNA in clinically unaffected nasal mucosa during cutaneous leishmaniasis caused by Leishmania (Viannia) braziliensis

“…Interestingly, recent reports from Colombia demonstrated a higher occurrence of Leishmania DNA in mucosal swab samples (45%e61.5%) from individuals with acute CL with apparently unaffected mucosa [8,9]. We speculate that this difference may be due to the mucosal tropism of the Leishmania (V.) subspecies circulating in Colombia since Leishmania panamensis causes concomitant cutaneous and mucosal lesions more frequently than other subspecies [10].…”

Case Report: Squamous Cell Carcinoma Referred for Mohs Surgery Found to be Cutaneous Leishmaniasis

“…Because of the persistence of Leishmania infection following treatment and difficulties to isolate the parasite after treatment, the definition of therapeutic outcome is based solely on clinical findings, as explained by Olliaro et al 14,15 In case of a nonhealing lesion at the end of follow-up (persistent inflammatory signs or incomplete epithelialization), efforts should be made to isolate the parasite strain; however, the clinical outcome is independent of the persistence of infection. 14,16 If, at the end of follow-up, the lesion remains unhealed and no alternative diagnosis is considered, the recommendation is to give a new course of therapy. 17 Therefore, clinical expertise is crucial to define the outcome of treatment and to consider possible alternative diagnosis.…”