Epidemiology of leishmaniasis in the time of drug resistance (the miltefosine era)

Abstract

In the first edition of this chapter (Dujardin J-C, Decuypere S, Epidemiology of leishmaniasis in the time of drug resistance. In: Ponte-Sucre A, Padron-Nieves M, Diaz E (eds) Drug resistance in Leishmania parasites: consequences, molecular mechanism and possible treatments. Spinger, pp 65-83), we updated various aspects of leishmaniasis epidemiology, with a particular emphasis on their relation with parasite drug resistance (DR), with a focus on antimonials (SSG). We made a clear distinction between DR, a parasite phenotype measured in the laboratory and treatment failure (TF), a clinical phenotype assessed in the patient. In this second edition, the objective is to update knowledge (whatever the drug) in this domain and to focus on miltefosine (MIL), contrasting wherever relevant with SSG. In the first part, we present data on the current efficacy of MIL, highlighting the increase in TF, and only a few cases of DR. Then, we update information on the risk factors for (re)emergence and spreading of leishmaniasis, focusing on the link between DR and TF: among others, we discuss the role of asymptomatics and animals, the importance of co-infection (considering the usual suspect HIV but also newcomers as Leishmania RNA viruses (LRV)), and the risk related with massive human migrations and environmental changes. Finally, we review the advances made about tools for epidemiological surveillance of TF/DR, ranging from clinical ones to laboratory ones. Recommendations and perspectives for further research will be discussed at the end.