Pilosa

Roque, André Luiz R. & Jansen, Ana Maria, 2014, Wild and synanthropic reservoirs of Leishmania species in the Americas, International Journal for Parasitology: Parasites and Wildlife 3 (3), pp. 251-262 : 255-256

4.2. Order Pilosa

This order is composed of anteaters and sloths, which, along with armadillos (order Cingulata ), compose the superorder Xenarthra (odd joints), previously known as Edentata ( Moller-Krull et al., 2007). Together with the marsupials, these ancient Leishmania hosts are also native American fauna and present a peculiar blood–vessel structure that allows an extremely low metabolic rate, sparing energy ( Bugge, 1979). Since the Tertiary Period, many representatives of this taxon have become extinct, and the extant genera constitute only a small proportion of the order. Mammals from this order have a long co-evolutionary history with trypanosomatids, including several Leishmania and Trypanosoma species, as well as the poorly studied genus Endotrypanum ( Rotureau, 2006) .

Sloths are arboreal inhabitants of tropical regions of Central and South America and are represented by two genera, Bradypus ( Bradypodidae family) and Choloepus (Magalonichidae family). Sloths have reduced muscle mass and move slowly between trees by traveling directly through the arboreal strata, descending only weekly to defecate ( Miranda and Costa, 2006). The two-toed sloth ( Choloepus didactylus ) is a potential reservoir of L. guyanensis , as demonstrated by the high rates of parasite isolation from intact skin (as well as viscera), which vary from 35% to 47% in French Guiana ( Dedet et al., 1989; Gentile et al., 1981) and reach up to 46% in Brazil ( Lainson et al., 1981a).

L. shawi was described infecting the two-toed sloth and the palethroated sloth ( Bradypus tridactylus ), both in Brazil (Lainson et al., 1989). In Panama, L. colombiensis was isolated from the viscera of Hoffmann’s two-toed sloth ( Choloepus hoffmanni ) ( Kreutzer et al., 1991), while L. equatorensis was found infecting the same species in Ecuador ( Grimaldi et al., 1992). Finally, L. panamensis , a species closely related to L. guyanensis , has been described in Choloepus hoffmanni from Panama ( Ashford, 2000) ( Table 1).

The anteaters constitute a single family ( Myrmecophagidae ) that are mainly arboreal, but that may also explore the terrestrial strata. The isolation of Leishmania was described in only one species, the lesser anteater Tamandua tetradactyla . L. guyanensis ( Lainson et al., 1981a) , L. amazonensis ( Mimori et al., 1989) , and L. infantum , this last in mixed infection with T. cruzi and T. rangeli ( de Araujo et al., 2013) , were found infecting the lesser anteater ( Table 1).

The diversity of Leishmania species already known to infect sloths and anteaters suggests that these mammals may be important hosts for parasite species that are transmitted in the arboreal strata. In fact, most of the Leishmania species found infecting these hosts are transmitted by vectors associated with the arboreal strata, such as Lu. umbratilis and Lu. whitmani .