title: Horizontal transmission dynamics of White spot syndrome virus by cohabitation trials in juvenile Penaeus monodon and P. vannamei.
abstract: White spot syndrome virus (WSSV), a rod-shaped double-stranded DNA virus, is an infectious agent causing fatal disease in shrimp farming around the globe. Within shrimp populations WSSV is transmitted very fast, however, the modes and dynamics of transmission of this virus are not well understood. In the current study the dynamics of disease transmission of WSSV were investigated in small, closed populations of Penaeus monodon and Penaeus vannamei. Pair cohabitation experiments using PCR as a readout for virus infection were used to estimate transmission parameters for WSSV in these two species. The mortality rate of contact-infected shrimp in P. monodon was higher than the rate in P. vannamei. The transmission rate parameters for WSSV were not different between the two species. The relative contribution of direct and indirect transmission rates of WSSV differed between the two species. For P. vannamei the direct contact transmission rate of WSSV was significantly lower than the indirect environmental transmission rate, but for P. monodon, the opposite was found. The reproduction ratio R0 for WSSV for these two species of shrimp was estimated to be above one: 2.07 (95%CI 1.53, 2.79) for P. monodon and 1.51 (95%CI 1.12, 2.03) for P. vannamei. The difference in R0 between the two species is due to a lower host mortality and hence a longer infectious period of WSSV in P. monodon.
authors.affiliation: Quantitative Veterinary Epidemiology Group, WU Animal sciences, Wageningen University, Radix Building, Droevendaalsesteeg 1, 6708PB Wageningen, The Netherlands; Research Institute for Aquaculture No. 2, 116 Nguyen Dinh Chieu St., HoChiMinh City, Viet Nam. Electronic address: ngoxuan.tuyen@wur.nl.
authors.forename: N X
authors.initials: NX
authors.lastname: Tuyen
authors.affiliation: Aquaculture and Fisheries Group, WU Animal Sciences, Wageningen University, 6700AH Wageningen, The Netherlands.
authors.forename: J
authors.initials: J
authors.lastname: Verreth
authors.affiliation: Laboratory of Virology, Wageningen University, Wageningen, The Netherlands.
authors.forename: J M
authors.initials: JM
authors.lastname: Vlak
authors.affiliation: Quantitative Veterinary Epidemiology Group, WU Animal sciences, Wageningen University, Radix Building, Droevendaalsesteeg 1, 6708PB Wageningen, The Netherlands.
authors.forename: M C M
authors.initials: MC
authors.lastname: de Jong
mesh_terms: D000818:Animals; D017756:Aquaculture; D054884:Host-Pathogen Interactions; D033561:Penaeidae / Q000821:virology*; D046848:White spot syndrome virus 1 / Q000502:physiology*
keywords: Basic reproduction ratio; Pair cohabitation; Penaeus monodon; Penaeus vannamei; Transmission rate parameter; White spot syndrome virus