Novel Praziquantel Treatment Regime for Controlling Asian Tapeworm Infections in Pond‐Reared Fish

Abstract

The Asian tapeworm Bothriocephalus achelognathii is an intestinal fish parasite that is nonnative to but widespread throughout the southwestern United States. Praziquantel is an anthelminthic drug commonly used to treat fish for Asian tapeworm; however, it does not kill tapeworm eggs, so the water in ponds used for fish rearing must be exchanged after treatment. Our objective was to determine whether a system containing both an intermediate copepod host and a definitive fish host for Asian tapeworm could be treated without exchanging the water by using a follow-up treatment for any tapeworms that developed from eggs released before or during the first treatment. Here, we have described a new praziquantel treatment regimen to control Asian tapeworm infections in freshwater-reared fish. To evaluate the efficacy of this regimen, we stocked 50 red shiners Cyprinella lutrensis and an intermediate copepod host, Cyclops vernalis, into each of six pond mesocosms containing artificial macrophytes, sand, and gravel to simulate natural pools and provide suitable substrate for the copepod's life history. The test fish population had been naturally infected with B. achelognathii and had an initial infection prevalence of 14% and an infection intensity of 2.14 ± 2.19 (mean ± SD) worms per fish. Three mesocosms were treated twice, each with 2.5 mg/L praziquantel; 19 d passed between treatments to allow for possible reinfection to occur. After a 2.5-month posttreatment period to allow any remaining tapeworms to reestablish themselves, we killed and dissected all of the remaining fish. No worms were found in treated fish; however, the control group had an infection prevalence of 18 ± 6% and an infection intensity of 3.45 ± 2.1 worms per fish. Based on these results, we concluded that the praziquantel treatment regime administered was efficacious and suggest testing it on a larger scale. We caution that praziquantel has not been approved by the U.S. Food and Drug Administration for use on fish but can be used legally in some situations.

Efficacy and toxicity of praziquantel in helminth‐infected barbel (Barbus barbus L.)

“…However, the bathing of fish is labour‐intensive, usable in limited conditions, and not suitable for pond ecosystems. Oral administration of PZQ has been shown to be effective in controlling tapeworms (Iles, Archdeacon, & Bonar, ; Sudova, Piackova, Velisek, Pijacek, & Svobodova, ) and skin and blood flukes (Shirakashi et al., ; Yamamoto, Shirakashi, Morimoto, Ishimaru, & Murata, ) and is considerably more economical than bath administration.…”

Praziquantel degradation in marine aquarium water

“…Though the exact mechanism of its functionality is largely unknown ( Cioli et al, 2014 ; Olliaro, Delgado-Romero & Keiser, 2014 ), praziquantel (PZQ) has been utilized in the treatment of human schistosomiasis since 1984 ( Olliaro, Delgado-Romero & Keiser, 2014 ) and due to its efficacy, cost, safety and convenience of dispersal it has remained the primary treatment for this condition worldwide ( Cioli et al, 2014 ). It is well documented that PZQ is also useful in the treatment of other parasitic infections ( Chai, 2013 ) including those that parasitize animals ( Chisholm & Whittington, 2002 ; Forwood, Harris & Deveney, 2013 ; Iles, Archdeacon & Bonar, 2012 ; Ishimaru et al, 2013 ; Janse & Borgsteede, 2003 ; Masimirembwa, Naik & Hasler, 1993 ; Mitchell & Darwish, 2009 ; Mitchell, 2004 ; Schmahl & Mehlhorn, 1985 ; Schmahl & Taraschewski, 1987 ; Shirakashi et al, 2012 ; Steiner et al, 1976 ; Tubbs, Mathieson & Tingle, 2008 ; Tubbs & Tingle, 2006a ; Ward, 2007 ; Yamamoto et al, 2011 ).…”

“…In the aquarium industry, PZQ has been used to treat trematode, cestode and monogene infestations in both freshwater ( Forwood, Harris & Deveney, 2013 ; Iles, Archdeacon & Bonar, 2012 ; Mitchell & Darwish, 2009 ; Mitchell, 2004 ; Santamarina et al, 1991 ) and marine fish and elasmobranchs ( Chisholm & Whittington, 2002 ; Ishimaru et al, 2013 ; Janse & Borgsteede, 2003 ; Shirakashi et al, 2012 ; Thoney, 1990 ; Tubbs & Tingle, 2006a ; Tubbs & Tingle, 2006b ; Yamamoto et al, 2011 ). Though this drug can be administered to fish orally ( Forwood, Harris & Deveney, 2013 ; Janse & Borgsteede, 2003 ; Tubbs, Mathieson & Tingle, 2008 ; Tubbs & Tingle, 2006a ; Tubbs & Tingle, 2006b ), it is also common for it to be dissolved in the water in which the infested animal lives ( Chisholm & Whittington, 2002 ; Forwood, Harris & Deveney, 2013 ; Iles, Archdeacon & Bonar, 2012 ; Mitchell & Darwish, 2009 ; Mitchell, 2004 ). “Bath” treatments can range in duration from several minutes to several days to effectively remove parasites.…”

Pharmacokinetics and residue depletion of praziquantel in rice field eels Monopterus albus

“…Praziquantel (PZQ: 2-cyclohexylcarbonyl-1, 2, 3, 6, 7, 11b-hexahydro-4H-pyrazino [2,1-a] iso-quinoline-4-one) is a broad-spectrum anthelmintic drug used in human and veterinary medicine. In aquaculture, PZQ is mainly used for controlling and killing acanthocephalans (Paterson et al 2013), trematodes (Kim & Cho 2000, Montero et al 2004, Mansell et al 2005, Reimschuessel et al 2011, cestodes (Pool 1985, Kline et al 2009, Iles et al 2012, and other parasites of fish. Although PZQ is applied widely in the treatment of aquatic animals, only a few studies have examined the pharmacokinetics and tissue residues of PZQ in fish (K. Kim et al 2001, C. Kim et al 2003, Tubbs & Tingle 2006a,b, Osman et al 2008, Xie et al 2015.…”