Cerebral filariasis infection with Litomosoides in Molossus barnesi (Chiroptera: Molossidae) in the Brazilian eastern Amazon, with comments on Molossinema wimsatti Georgi, Georgi, Jiang and Fronguillo, 1987

During bacterial and viral pathogen investigation of 30 specimens of bats captured in periurban forest areas in the city of Belém, Pará, Brazil, a case of cerebral filariasis was observed. In the course of histopathological examination, adult filariae were found in pseudocystic cavities brain of Molossus barnesi (Molossidae) and classified morphologically as Litomosoides by the shape of the spicules—left spicule with a handle longer than the blade; right spicule curved, with a sclerotized heel supporting a dorsal notch; the area rugosa constituted by a ventral band of small longitudinal crests; tail rounded in males; long esophagus with a slightly glandular distal portion; and a muscular bent vagina. All the specimens lack a stoma (buccal capsule). We compared our filarioids with the description of specimens of Molossinema wimsatti. Morphological characteristics of M. wimsatti resemble the genus Litomosoides. Thus, we believe that M. wimsatti is a synonym of L. molossi Esslinger, 1973, and filarioid specimens from material reported by Lichtenfels et al. (Trans Am Micros Soc 100:216–219, 1981) and from de Souto et al. (J. Helminthol 1195:e65, 2021) most probably correspond to Litomosoides. We suggest that the reduction of the buccal capsule may be attributable to the ectopic location. No evidence of tissue responses by the host was observed. This is the first record of Litomosoides infecting brain tissue of Molossus barnesi from Brazil, representing a record of a new host species. More specimens of bats should be examined in order to find filarioids in the brain and verify its taxonomic position using molecular techniques.