ABSTRACT
Introduction
There are 12 protozoan genera that provoke zoonotic disease in humans and animals. We discuss the most common ones with a highlight on Babesia spp and Entamoeba histolytica, also mentioning Toxoplasma gondii, Trypanosoma cruzi, and Leishmania spp.
Areas covered
The complex life cycle of pathogenic protozoans is deeply understood but this did not contribute to the discovery of new drugs. The clinical armamentarium is poor and includes antiinfectives originally proposed as antibacterial (azithromycin, clindamycin, paromomycin, sulfadrugs), antifungals (amphotericin B), or they are outdated compounds with poor efficacy and many side effects (nitroazoles, antimonials, etc.). Few patents and innovative ideas are available.
Expert opinion
Protozoan diseases are not restricted to tropical countries and are difficult or impossible to treat with currently available drugs, which are limited and restricted to a low number of clinical classes. The antiprotozoal drug targets are also limited, and this had deleterious effects on translational studies for designing efficient antiprotozoal drugs. There is a stringent need for innovative approaches to tackle these problems.
Article highlights
A number of 12 protozoan genera provoke zoonotic disease in humans and animals, varying from mild to life threatening.
Protozoal infections such as babesiosis, amebiasis toxoplasmosis, Chagas’ disease, and leishmaniasis affect a large number of patients worldwide.
Protozoal infections such as babesiosis, amebiasis toxoplasmosis, Chagas’ disease, and leishmaniasis affect a large number of patients worldwide.
Most clinically used drugs for the management of these infections belong to antiinfectives originally developed as antibacterial (azithromycin, clindamycin, paromomycin, sulfadrugs), antifungals (amphotericin B), or are outdated agents with poor efficacy and many side effects (nitroazoles, antimonials, etc.).
Several antimalarials were also repurposed for the management of babesiosis (antimalarials are not dealt with in the article).
Few new drug targets emerged for the development of new antiprotozoal drugs and the patent landscape is rather scarce.
With significant drug resistance to the currently used drugs and with low innovation in the field, new approaches for designing effective antiprotozoal agents are stringently needed.
Declaration of interests
CT Supuran is Editor-in-Chief of the Expert Opinion on Therapeutic Patents. He was not involved in the assessment, peer review, or decision-making process of this paper. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.
Reviewer disclosures
Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.
Author contribution statement
C Capasso: Writing – original draft; Writing – review and editing CT Supuran: Writing – review and editing.