Leishmania (Viannia) naiffi : rare enough to be neglected?

In the Brazilian Amazon, American tegumentary leishmaniasis (ATL) is endemic and presents a wide spectrum of clinical manifestations due, in part, to the circulation of at least seven Leishmaniaspecies. Few reports of Leishmania (Viannia) naiffiinfection suggest that its occurrence is uncommon and the reported cases present a benign clinical course and a good response to treatment. This study aimed to strengthen the clinical and epidemiological importance of L. (V.) naiffiin the Amazon Region (Manaus, state of Amazonas) and to report therapeutic failure in patients infected with this species. Thirty Leishmania spp samples isolated from cutaneous lesions were characterised by multilocus enzyme electrophoresis. As expected, the most common species was Leishmania (V.) guyanensis (20 cases). However, a relevant number ofL. (V.) naiffi patients (8 cases) was observed, thus demonstrating that this species is not uncommon in the region. No patient infected withL. (V.) naiffievolved to spontaneous cure until the start of treatment, which indicated that this species may not have a self-limiting nature. In addition, two of the patients experienced a poor response to antimonial or pentamidine therapy. Thus, either ATL cases due to L. (V.) naifficannot be as uncommon as previously thought or this species is currently expanding in this region

Randomized Controlled Clinical Trial to Access Efficacy and Safety of Miltefosine in the Treatment of Cutaneous Leishmaniasis Caused by Leishmania (Viannia) guyanensis in Manaus, Brazil

Miltefosine has been used in the treatment of several new world cutaneous leishmaniasis (CL) species with variable efficacy. Our study is the first evidence on its clinical efficacy in Leishmania (Viannia) guyanensis. In this phase II/III randomized clinical trial, 90 CL patients were randomly allocated (2:1) to oral miltefosine (2.5 mg/kg/day/28 days) (N = 60) or parenteral antimony (15–20 mg/Sb/kg/day/20 days) (N = 30) according to age groups: 2–12 y/o and 13–65 y/o. Patients were human immunodeficiency virus (HIV) noninfected parasitological proven CL without previous treatment. Definitive cure was accessed at 6 months follow-up visit. No severe adverse events occurred. Vomiting was the most frequent adverse event (48.3%) followed by nausea (8.6%) and diarrhea (6.7%). Cure rates were 71.4% (95% confidence interval [CI] = 57.8–82.7) and 53.6% (95% CI = 33.9–72.5) (P = 0.05) for miltefosine and antimonial, respectively. There were no differences in cure rates between age groups within the same treatment arms. Miltefosine was safe and relatively well tolerated and cure rate was higher than antimony