Effects of shrimp density on transmission of penaeid acute viremia in Penaeus japonicus by cannibalism and the waterborne route

Protection against white spot syndrome virus (WSSV) infection in kuruma shrimp orally vaccinated with WSSV rVP26 and rVP28

“…Moreover, RPS values after oral challenge were also higher than those after immersion and IM challenges. These results strongly support the importance of the oral route mediated by cannibalism in the infection of shrimp with WSSV as described by Wu et al (2001) and Momoyama & Muroga (2005). Furthermore, our findings suggest that the horizontal transmission of WSSV through cannibalism in shrimp farms can be prevented by oral vaccination with rVP26 or rVP28.…”

“…While it is generally considered that the quantity of WSSV-infected tissue needed to achieve an LD 50 varies according to exposure method, shrimp species, and viral strain, we did confirm that infection efficiency of WSSV by the oral route was significantly lower than by the immersion and IM routes. Wu et al (2001) suggested that cannibalism is one of the most important modes of WSSV transmission, as shrimp mortality decreased significantly when cannibalism was prevented in a WSSV infection experiment. Thus, it appears that WSSV infection is easily established when shrimp cannibalize WSD shrimp even though the efficiency of virus transmission by the oral route is low.…”

“…The major route of WSSV infection appeared to be through vertical transmission in kuruma shrimp hatcheries, because the occurrence of WSD in postlarvae notably decreased following selection of WSSV-free broodstock . However, horizontal transmission of WSSV, both by cannibalism and through waterborne exposure, is an infection route of concern in kuruma shrimp farms (Wu et al 2001, Momoyama & Muroga 2005. Stable seed production of specificpathogen-free (SPF) kuruma shrimp was accomplished using countermeasures for the prevention of WSSV, such as selection of WSSV-free broodstock by PCR, disinfection of eggs with iodine, and sterilization of rearing water , Satoh et al 2001.…”

Investigations on white spot disease outbreak in Penaeus monodon (Fabricius, 1798) in association with Vibrio mimicus infection in the Sunderbans, West Bengal, India

“…The major clinical signs such as lethargy, loss of balance, preening and no response to stimulus, reduced feeding, presence of white spots initially on the carapace which later progressed to the whole body, reddish discolouration, dark necrotic spots and finally death (Wongteerasupaya et al, 1995, Tan et al, 2001Wu et al, 2001) were observed during the outbreak. PCR analyses showed that the shrimp samples were I and II step positive for WSSV (Fig.…”

Preparation of an Inoculum of White Spot Syndrome Virus for Challenge Tests in Penaeus japonicus.

“…In shrimp farming system, horizontal transmission of the vi rus occurs via oral ingestion and the waterborne route (Corsin et al, 2001), however, cannibalism has been demonstrated to be more important in transmission of the virus in Penaeus vannamei (=Litopenaeus vannamei), P. setiferus (=L. setiferus) and P. japonicus (kuruma shrimp) in experimental conditions (Soto and Lotz, 2001;Wu et al, 2001). In hatcheries, vertical transmission has been identified to be the major route (Mushiake et al, 1999 .…”