Fish-borne trematodosis: Potential risk of infection by Ascocotyle (Phagicola) longa (Heterophyidae)

Abstract

Owing to the veterinary and medical importance of heterophyid trematodes, a survey on Ascocotyle (Phagicola) longa in different organs of mullets Mugil liza from Rio de Janeiro was undertaken. The prevalence of metacercariae varied greatly between different organs of the mullets: spleen (100%), heart (98%), intestine wall (97%), liver (97%), muscle (87%), stomach wall (77%), brain (47%), gonads (30%) and gall bladder (30%). The high level of the intensity of the infection in relation to different fish organs was confirmed in two experimental infections performed during the spring/summer and autumn/winter seasons when 258 and 47 adult parasites were recovered from hamsters fed only with small pieces of muscle tissue. The potential risk of infection was considered to be high in view of the high prevalence and intensity of A. (P.) longa in the muscles of mullets throughout the year. Additionally new confocal imaging of metacercariae and adults experimentally obtained, enabled for the first time the description of a short genital atrium formed by the union of uterus and ejaculatory duct.

Larval trematodes infecting the South-American intertidal mud snail Heleobia australis (Rissooidea: Cochliopidae)

“…(P.) longa were found in mullets from Samborombón Bay, located 550 km northeast of the Bahía Blanca estuary (Martorelli et al 2012). The present study, along with the reports of Martorelli et al (2012) and Santos et al (2013), represents a warning about the potentially major impact of this parasite on public health in South America. We assume that the life cycle of A.…”

Current Knowledge of Small Flukes (Digenea: Heterophyidae) from South America

“…Its life-cycle includes adult parasites in the intestine of fish-eating birds and mammals and the metacercaria mainly in mullets ( Mugil spp.) [ 14 , 18 , 24 , 26 – 31 ]. The life cycle of A. longa is associated with estuaries and coastal lagoons, where the mugilid juveniles become infected [ 7 , 17 , 24 , 26 – 28 , 30 ].…”

“…[ 14 , 18 , 24 , 26 – 31 ]. The life cycle of A. longa is associated with estuaries and coastal lagoons, where the mugilid juveniles become infected [ 7 , 17 , 24 , 26 – 28 , 30 ]. The first intermediate host in Argentina, Brazil and Uruguay is the snail Heleobia australis (d’Orbigny, 1835), in which rediae and parapleurolophocercous cercariae develop [ 7 , 31 ].…”

“…The first intermediate host in Argentina, Brazil and Uruguay is the snail Heleobia australis (d’Orbigny, 1835), in which rediae and parapleurolophocercous cercariae develop [ 7 , 31 ]. Metacercariae have been found encysted in the body musculature, heart, stomach, liver, kidney, spleen, gonads and mesentery of the mullets [ 17 , 26 , 27 , 32 ]. Galván-Borja et al [ 18 ] examined mullets from Colombia and reported that these metacercariae cause inflammatory reactions involving macrophage aggregates and necrosis, thus suggesting that trematodes infecting the liver of mugilids can affect the growth and well-being of the fish.…”

“…In Brazil, only few cases of human trematodosis caused by heterophyids have been reported; these were from São Paulo [ 85 – 87 ]. However, records of metacercariae in mullets from off the Brazilian coast are common [ 24 , 26 , 75 , 76 , 88 – 90 ]. Following a report of the occurrence of metacercariae of A. longa with a prevalence of 100% in mullets from the Rodrigo de Freitas Lagoon, Rio de Janeiro, an alert was given concerning the possibility of a related human disease [ 24 , 26 ].…”