Victoria Alday-Sanz

• Doctor of Veterinary Medicine
• Director at NAQUA

Circular, viral copy DNA (cvcDNA) can reveal the existence of endogenous viral elements (EVE) in shrimp genomic DNA. Here we describe isolation and sequencing of cvcDNA from a breeding stock of the whiteleg shrimp Penaeus vannamei. The stock was developed by onward breeding and selection for white spot syndrome virus (WSSV)-free individual survivor...

The challenges and problems of managing good biosecurity are wide-ranging and multifactorial with many compounding factors to pre-dispose farmed stocks to an increased risk of infection with consequential stock losses. Many challenges are anthropogenic in origin and may be the result of the physical location (site) and/or the poor design of the pro...

With the rapid growth of the aquaculture production since the 1980s, there has been a concomitant increase in disease outbreaks. The injudicious and/or incorrect use of anti-microbial agents against diseases of farmed aquatic species poses a considerable threat to the development and growth of a successful and sustainable aquaculture industry. An i...

The document is based, in large part, on information presented and discussed by participants at the Second Interregional Workshop of the Food and Agriculture Organization of the United Nations (FAO) Project TCP/INT/3502: Reducing and managing the risks of Acute Hepatopancreatic Necrosis Disease (AHPND) of cultured shrimp, one of a series of interre...

Bondad-Reantaso MG, Mackinnon B, Hao B, Huang J, Tang-Nelson K, Surachetpong W, Alday-Sanz V, Salman M, Brun E, Karunasagar I, Hanson L, Sumption K, Barange M, Lovatelli A, Sunarto A, Fejzic N, Subasinghe R, Mathiesen ÁM, Shariff M. (2020). Viewpoint: SARS-CoV-2 (the cause of COVID-19 in humans) is not known to infect aquatic food animals nor conta...

White spot disease, caused by infection with white spot syndrome virus (WSSV), is a serious panzootic affecting prawn aquaculture. The disease has spread rapidly around the prawn-culturing regions of the world through a number of previously identified mechanisms. The ability to distinguish and trace strains of WSSV is of great benefit to identify,...

These Technical Guidelines on the Prudent and Responsible Use of Veterinary Medicines in Aquaculture (No. 5 Suppl. 8) are developed to support Section 9 – Aquaculture Development of FAO’s Code of Conduct for Responsible Fisheries (CCRF) and The FAO Action Plan on Antimicrobial Resistance 2016–2020. They also support the international aquatic animal...

Aquaculture is the world’s fastest-growing food-production sector and a crucial contributor to the United Nations’ Sustainable Development Goals. As a group of scientists, ocean-policy experts, aquaculture professionals and technical consultants from international organizations, we argue that, despite recent legislation, fish farms may still be at...

The World Organisation for Animal Health (OIE) Aquatic Animal Health Code recommends that programmes forthe monitoring and surveillance of antimicrobial resistance in microorganisms associated with aquatic animals be initiated by the appropriate authorities. This paper discusses the classes of bacteria to be studied in such programmes and the metho...

As some literature on the susceptibility of different life stages of Macrobrachium rosenbergii to white spot syndrome virus (WSSV) is conflicting, the pathogenesis, infectivity and pathogenicity of 2 WSSV strains (Thai-1 and Viet) were investigated here in juveniles using conditions standardized for Penaeus vannamei. As with P. vannamei, juvenile M...

This study was carried out to gather quantitative data on the moult cycle and stages in laboratory-raised shrimp, kept at a constant temperature of 27°C. The stages of the moult cycle were differentiated and characterised by microscopic analysis of cuticle, epidermis and moulting processes in the uropods of P. vannamei and P. monodon. Five major mo...

The EC Council Directive 2006/88/EC adopted during 2008 has listed three crustacean disease: White Spot Disease (WSD) caused by the White Spot Syndrome Virus (WSSV), Yellowhead disease (YHD) caused by Yellowhead Virus (YHV) and Taura syndrome (TS) caused by Taura Syndrome Virus (TSV). Their inclusion within the Directive acknowledges a lack of prot...

Transmission of white spot syndrome virus (WSSV) in shrimp has been reported to occur by feeding and immersion. In the present study, the impact of the molt process and artificial lesions in the cuticle on shrimp susceptibility to WSSV was examined using intramuscular and immersion routes. For the intramuscular route, Penaeus (Litopenaeus) vannamei...

This study was conducted to investigate the effect of dose and challenge routes of Vibrio spp. on co-infection with white spot syndrome virus (WSSV) in specific pathogen-free (SPF) Penaeus vannamei shrimp. Juvenile shrimp were first injected with WSSV at a dose of 30 SID50 shrimp− 1 (SID50 = shrimp infectious dose with 50% endpoint) and 24 h later...

The concept of polymicrobial disease is well accepted in human and veterinary medicine but has received very little attention in the field of aquaculture. This study was conducted to investigate the synergistic effect of white spot syndrome virus (WSSV) and Vibrio campbellii on development of disease in specific pathogen-free (SPF) shrimp Litopenae...

A standardized inoculation model was used in 2 separate experiments to gauge the virulence of 3 white spot syndrome virus (WSSV) isolates from Thailand and Vietnam (WSSV Thai-1, WSSV Thai-2, and WSSV Viet) in Penaeus vannamei juveniles. Mortality patterns (Expt 1) were compared and WSSV-positive cells quantified (Expt 2) in tissues following intram...

Since it first appeared in 1992, white spot syndrome virus (WSSV) has become the most threatening infectious agent in shrimp aquaculture. Within a decade, this pathogen has spread to all the main shrimp farming areas and has caused enormous economic losses amounting to more than seven billion US dollars. At present, biosecurity methods used to excl...

A Joint FAO/WHO/OIE Expert Meeting on Critically Important Antimicrobials was held from 26 to 30 November 2007 in Rome, Italy. The meeting was convened as a continuation of the consultative process on antimicrobial resistance, arising from non-human use of antimicrobials in food-producing animal species, that was implemented jointly by the three Or...

This study investigated the effect of high water temperature (33 °C) at different stages of infection with a highly virulent and low virulent white spot syndrome virus strain (WSSV Thai-1 and WSSV Viet) in Penaeus vannamei juveniles. Shrimp were inoculated intramuscularly with either a high dose (HD) or low dose (LD). Water temperature was kept eit...

This study evaluated the effect of daily fluctuations between optimum (27 °C) and high water temperature (33 °C) on the clinical and virological outcome of a WSSV infection in Penaeus vannamei juveniles. Shrimp were inoculated intramuscularly with a dose of 10,000 SID50 of either virulent WSSV Thai-1 or less virulent WSSV Viet or mock inoculated. T...

White-spot disease is a relatively recent but widespread epizootic of cultured shrimp in Asia. This epizootic probably began in China in 1993 and subsequently spread from there to Japan, Taiwan, and the rest of Asia as far as India. Pond-side losses in 1996 in Thailand alone reached approximately 70000 metric tonnes, valued at over half a billion U...

White spot syndrome virus (WSSV) causes disease and mortality in cultured and wild shrimp. A standardized WSSV oral inoculation procedure was used in specific pathogen-free (SPF) Litopenaeus vannamei (also called Penaeus vannamei) to determine the primary sites of replication (portal of entry), to analyze the viral spread and to propose the cause o...

White spot syndrome virus (WSSV) is the most lethal pathogen of cultured shrimp. Previous studies done with undefined WSSV titers showed that high water temperature (32–33 °C) reduced/delayed mortality of WSSV-infected shrimp. This study evaluated the effect of high water temperature on the clinical and virological outcome of a WSSV infection under...

Larvae and post-larvae of Penaeus vannamei (Boone) were submitted to primary challenge with infectious hypodermal and haematopoietic necrosis virus (IHHNV) or formalin-inactivated white spot syndrome virus (WSSV). Survival rate and viral load were evaluated after secondary per os challenge with WSSV at post-larval stage 45 (PL45). Only shrimp treat...

The antiviral product cidofovir and a diet supplemented with Spirulina platensis were tested for their efficacy to prevent or delay/reduce mortality due to white spot syndrome virus (WSSV) infection in specific pathogen free (SPF) shrimp Litopenaeus vannamei juveniles. Cidofovir was injected intramuscularly at 200 mg/kg shrimp mean body weight (MBW...

In the past, strategies to control white spot syndrome virus (WSSV) were mostly tested by infectivity trials in vivo using immersion or per os inoculation of undefined WSSV infectious doses, which complicated comparisons between experiments. In this study, the reproducibility of 3 defined doses (10, 30 and 90 shrimp infectious doses 50% endpoint [S...

White spot syndrome virus (WSSV) is a devastating pathogen in shrimp aquaculture. Standardized challenge procedures using a known amount of infectious virus would assist in evaluating strategies to reduce its impact. In this study, the shrimp infectious dose 50% endpoint (SID50 ml(-1)) of a Thai isolate of WSSV was determined by intramuscular inocu...

Mortalities of cultured shrimp, Penaeus vannamei (Boone), induced by white spot syndrome virus (WSSV) have occurred in Ecuador since May 1999. Three epidemiological surveys in Ecuadorian farms were carried out and showed an apparent association between lower temperature and increased mortality rates in commercial ponds. Infected animals showed a re...

Vibrio species' infections are a common sequelae to environmental stress or other disease processes in shrimp, but the mechanism by which the shrimp eliminate the bacteria is poorly understood. In this study, the penetration, fate and the clearing of V. vulnificus were investigated in Penaeus monodon. A bacterial disease isolate from a shrimp farm...

In response to complaints from shrimp farmers, samples were taken to determine whether stunting in cultured Penaeus monodon was related to the presence of known infectious agents. Shrimp were arbitrarily defined as normal at >8 cm length and stunted at

Despite the major financial losses caused by vibriosis in shrimp culture, no reliable laboratory model has yet been developed for this disease. A reproducible experimental model is therefore urgently required for further study. In this study, a bath challenge technique was developed for juveniles of the marine shrimp Penaeus Õannamei. Four differen...