Praziquantel: An update on the mechanism of its action against schistosomiasis and new therapeutic perspectives

Praziquantel (PZQ) is the drug of choice for the treatment of all forms of schistosomiasis, although its mechanisms of action are not completely understood. PZQ acts largely on adult worms. This narrative literature review describes what is known about the mechanisms of action of PZQ against schistosomes from in vitro and in vivo studies and highlights the molecular targets in parasites and immune responses induced in definitive hosts by this drug. Moreover, new therapeutic uses of PZQ are discussed. Studies have demonstrated that in addition to impacting voltage-operated Ca2 + channels, PZQ may interact with other schistosome molecules, such as myosin regulatory light chain, glutathione S-transferase, and transient receptor potential channels. Following PZQ administration, increased T regulatory type 1 (Tr1) cell differentiation and decreased inflammation were observed, indicating that PZQ promotes immunoregulatory pathways. Although PZQ is widely used in mass drug administration schemes, the existence of resistant parasites has not been proven; however, it is a concern that should be constantly investigated in human populations. In addition, we discuss studies that evaluate health applications of PZQ (other than helminth infection), such as its effect in cancer therapy and its adjuvant action in vaccines against viruses.

A review on the occurrence of Cochliomyia hominivorax (Diptera: Calliphoridae) in Brazil

Cochliomyia hominivorax (Coquerel, 1858), the New World screwworm, causes primary myiasis in wild and domestic animals in tropical and subtropical regions of Brazil. Although this species is considered to occur throughout the country, organized information about its recorded distribution has not been available until now. This article aimed to provide a comprehensive review of the historical and current data published on both immature (myiasis) and adult stages of C. hominivorax in Brazil. A total of 174 articles were found; of these, 141 articles reported myiasis cases in cattle (146 records), humans (68 records), and other mammalian hosts (40 records), and captures of adult flies were reported in 33 articles. C. hominivorax is widespread in Brazil, having been recorded in 208 municipalities in all major biomes of the country.