Molecular typing of Strongyloides stercoralis in Latin America, the clinical connection.

REPETTO, S.; BRAGHINI, JUAN QUARROZ; RISSO, M.; ESTELA I. BATALLA; RUYBAL, P.

Conferencia; 15th International Conference on Molecular Epidemiology and Evolutionary Genetics of Infectious Diseases; 2021

This study analysed Strongyloides stercoralis genetic variability based on a 404 bp region ofthe cox1 gene from Latin-American samples in a clinical context including epidemiological,diagnosis and follow-up variables. A prospective, descriptive, observational study wasconducted to evaluate clinical and parasitological evolution after ivermectin treatment of 41patients infected with S. stercoralis. Reactivation of the disease was defined both by clinicalsymptoms appearance and/or direct larvae detection 30 days after treatment or later. Wedescribed 10 haplotypes organized in two clusters. Most frequent variants were also describedin the Asian continent in human (HP24 and HP93) and canine (HP24) samples. Clinicalpresentation (intestinal, severe, cutaneous and asymptomatic), immunological status andeosinophil count were not associated with specific haplotypes or clusters. Nevertheless, presenceof cluster 1 haplotypes during diagnosis increased the risk of reactivation with an oddsratio (OR) of 7.51 [confidence interval (CI) 95% 1.38–44.29, P = 0.026]. In contrast, reactivationprobability was 83 times lower if cluster 2 (I152V mutation) was detected (OR = 0.17, CI95% 0.02–0.80, P = 0.02). This is the first analysis of S. stercoralis cox1 diversity in the clinicalcontext. Determination of clusters during the diagnosis could facilitate and improve the designof follow-up strategies to prevent severe reactivations of this chronic disease.