Conferencia Dra. Maia-Elkhoury

Leishmaniasis in the Americas: Advances and Challenges

MAIA-ELKHOURY, Ana Nilce Silveira1

¹ Neglected, Tropical and Vector-Borne Diseases – Communicable Diseases Prevention, Control, and Elimination Department, Pan American Health Organization. Duque de Caxias, Rio de Janeiro, Brazil. 
E-mail address: aelkhoury@paho.org 

Leishmaniasis is an infectious disease transmitted to humans and vertebrate animals by insects of the Psychodidae family. It has a wide geographical distribution and continues to be a public health problem in 4 regions of the world: the Americas, East Africa, North Africa, West and South-East Asia.
In the Americas, the surveillance and control of leishmaniasis represents a great challenge, because in addition to being a vector-borne disease, its transmission cycle includes wild and domestic reservoirs that harbor and maintain the parasite of the genus Leishmania in the environment. A total of 15/22 identified pathogenic species are distributed in the Americas, which can cause cutaneous (CL), mucosal (ML) and visceral (VL) leishmaniasis. 
From 2005 onwards, there has been a downward trend of CL and VL in almost all endemic countries of the Region, except for Mexico, where CL is increasing, and in Paraguay and Argentina for VL. Among the most severe forms, we highlight ML, with about 5% of reported cases, and VL, with a high and growing proportion of VL-HIV co-infection (19%) and a 9% lethality rate, being threefold higher than the global rate. Furthermore, despite the reduction in VL cases in recent years, there has been a geographic expansion within and between countries, as observed in 2023 at the borders between Argentina, Bolivia, Brazil, and Paraguay. 
In 2024, the Plan of Action to Strengthen the Surveillance and Control of Leishmaniasis in the Americas 2023-2030 was published, with the objective of moving forward towards the targets of the World Health Organization’s Roadmap for Neglected Tropical Diseases 2030, as well as, including, monitoring and establishing systematized goals and epidemiological, process and operational indicators, applied to the Region. 
In recent years, advances have been observed, such as standardization of techniques and procedures for surveillance, patient care, and control of leishmaniasis. For diagnosis and treatment, we have seen improved access to drugs with their inclusion in the PAHO Strategic Fund, validation of qPCR methodology for CL diagnosis, and rK39 rapid tests for VL. Recommendations for the treatment of leishmaniasis in the Americas have been updated based on regional evidence, and among them are the strong recommendations for: local treatment for uncomplicated CL cases, use of miltefosine for CL, and use of Liposomal Amphotericin B for VL. Likewise, recommendations for the control of leishmaniasis vectors and reservoirs at the global level have recently been approved, considering for the first time the different epidemiological scenarios of leishmaniasis. Despite these advances, challenges persist due to the complexity of control seeing the absence of tools and technologies with direct impact in the transmission, which has not yet allowed public policy decision-makers to include leishmaniasis in the list of the regional initiative for the elimination of communicable diseases in the Americas. 

Key words: Leishmaniasis, Americas, Advances