Diseases of Gastropoda

Gastropods (class Gastropoda) form the largest of the classes in the phylum Mollusca and inhabit terrestrial, fresh water and marine environments. A large number of these species are of major conservation importance and are an essential component of ecosystems. Gastropods may be deemed as pests, having a negative impact in horticulture and agriculture, whereas others may be used as a food source for human consumption and therefore are beneficial. Gastropods are susceptible to primary diseases and also act as intermediate hosts for diseases which affect other animals, including humans. The diseases described include two that are notifiable to the World Organisation for Animal Health (OIE): Xenohaliotis californiensis and Abalone viral ganglioneuritis caused by Haliotid herpesvirus-1 (HaHV-1). Research into the diseases of gastropods has often focused on those species that act as intermediate disease hosts, those that are used in research or those cultured for food. In this paper we review the viral, bacterial, fungal, parasitic and miscellaneous conditions that have been reported in gastropods and mention some of the factors that appear to predispose them to disease. The pathogenicity of a number of these conditions has not been fully ascertained and more research is needed into specifying both the etiological agent and significance in some of the diseases reported.

Vaccines for Mycoplasma Diseases of Small Ruminants: A Neglected Area of Research

Mycoplasmas cause some of the most economically important diseases of sheep and goats, including diseases listed by the World Organisation for Animal Health (OIE) such as contagious caprine pleuropneumonia (CCPP) and contagious agalactia (CA). Other important mycoplasma diseases include chronic respiratory and arthritic syndrome (CRAS) and atypical pneumonia, both present on all continents where small ruminants are farmed. Unfortunately, owing to a lack of investment, most commercial vaccines for these diseases are of poor quality, being mostly composed of killed bacteriocins of dubious or unknown efficacy. Several Mediterranean laboratories produce autogenous vaccines, but these can only be used on farms where outbreaks have been officially declared, and consequently have limited impact on disease nationally. Effective live vaccines are available, but their use is often restricted because of safety concerns. With the necessary safeguards in place, we argue for their greater use. This review examines reported vaccines for mycoplasma diseases of small ruminants and attempts to identify new candidate antigens that may enable the development of improved products. Vaccines for CCPP are covered elsewhere.

Review of African swine fever outbreaks history in South Africa: From 1926 to 2018

The article reviews the outbreaks and distribution of African swine fever (ASF) in South Africa since the first probable outbreak that occurred in the Koedoesrand Ward in 1926. Retrospective data on the ASF outbreaks in South Africa were obtained from the World Organisation for Animal Health (OIE) disease database and the South African veterinary services annual reports in addition to published articles and online sources. South Africa has experienced many outbreaks that can be divided into 2 time periods: the period before the development of the OIE diseases database (1993) and the period after. More than 141 outbreaks of ASF were reported during the first period. Since the development of OIE disease database, 72 outbreaks directly involving 2968 cases, 2187 dead and 2358 killed pigs mainly in smallholder pig farms were reported. The median number of cases for a given ASF outbreak is 17, but in 50% of outbreaks no pigs were killed for prevention. The most important ASF outbreak was reported in April 2014 in the Greater Zeerust district (North West province) involving 326 cases and 1462 killed pigs. However, the outbreak with highest mortality involving 250 pigs was reported in 2016 (Free State province). According to phylogenetic analysis, nine p72 genotypes (I, III, IV, VII, VIII, XIX, XX, XXI and XXII) have been identified in South Africa. Season-wise, more outbreaks were recorded during summer. It was also observed that the OIE disease database could contain errors that would have been introduced through compiled forms at country level. Spatiotemporal studies on ASF outbreaks in South Africa are therefore required in order to assess statistically and quantitatively the clustering of outbreaks over space and time.

The Westernmost Mediterranean islands present an endemic varroosis disease pattern

Aim of study: This is the first intensive study of the incidence of Varroa destructor (Acari: Varroidae) in the Westernmost Mediterranean islands (Balearics). Area of study: Mallorca, Menorca, Eivissa and Formentera (Balearic Islands), Spain. Material and methods: The study was carried out in autumn 2010 and in spring 2011 because the presence of the mite is higher in these seasons. A total of 462 honeybee colonies were analyzed from different apiaries on. One sample of adult bees (worker bees, n > 200) and another of bee brood (at all stages of development, n> 400) were collected from each colony. All were frozen until analysis. To detect Varroa each sample was examined individually basing the study on the guide edited by the World Organisation for Animal Health, with some modifications. The beekeepers involved were interviewed to characterize Balearic beekeeping. Main results: Regarding the prevalence, results showed that in the Balearic Islands the percentage was higher in spring (34.78%) than in autumn (44.09%) but the infestation rate was lower in both seasons (Autumn: 0.94%, Spring: 0.77%). The focality percentage was also higher in spring (87.10%) than in autumn (82.61%). The data suggests that Varroa mites in the archipelago have an endemic rather than epidemic disease distribution pattern. Research highlights: These results open an interesting scenario to develop a future resistance breeding strategy against V. destructor in these small islands.

Taiwan’s Participation in the World Organisation for Animal Health (oie): Modalities, Utility, and Challenges

This article explores the utility of membership in international organisations for states with specific status within the international community, focusing on Taiwan’s surprisingly neglected involvement in the World Organisation for Animal Health or oie (Office International des Épizooties). The paper shows that in addition to its contribution to the legitimisation of Taiwan’s identities, such participation has also enabled Taiwan to shape international norms in the field of animal health, increase international cooperation opportunities, strengthen domestic and global health security, and facilitate the trade of animal health-related products. Additionally, it has contributed to the domestic implementation of international animal health norms and helped increase the accountability of Taiwanese authorities in the domain of animal health management. Despite tremendous challenges, Taiwan still has plenty of opportunities to enhance its participation in global health governance through its membership in oie.

Near-Complete Genome Sequences of 12 Peruvian Strains of Infectious Hypodermal and Hematopoietic Necrosis Virus Infecting the Shrimp Penaeus vannamei

ABSTRACT Infectious hypodermal and hematopoietic necrosis virus (IHHNV) is a shrimp virus listed by the World Organisation for Animal Health (OIE). In this study, we report the genomic sequences of 12 IHHNV strains obtained from shrimp samples from aquaculture cultures from the Tumbes region of Peru.

PERSPECTIVAS DA NOTIFICAÇÃO OBRIGATÓRIA DE DOENÇAS AO SERVIÇO VETERINÁRIO OFICIAL

Aproximadamente de 75% das doenças infecciosas que afetam os humanos são de origem zoonótica. A saúde e a segurança das gerações animal e humana dependem, em parte, da nossa capacidade contínua de detectar, monitorar e controlar doenças e zoonoses emergentes ou reemergentes. O objetivo nesta revisão foi sintetizar as perspectivas da notificação obrigatória de doenças ao Serviço Veterinário Oficial (SVO), incluindo os instrumentos juridicamente vinculativos, a evolução e o status atual da notificação de doenças animais ao nível nacional, os benefícios e mecanismos da notificação oportuna e os fundamentos para medidas de segurança e controle de doenças. A Instrução Normativa nº 50, de 24 de setembro de 2013, dispõe sobre uma lista de doenças de notificação obrigatória (DNO) no Brasil. A lista contempla, atualmente, um total de 141 doenças, incluindo as DNO para a World Organisation for Animal Health (OIE). Das doenças da lista da OIE no Brasil, 43 estão presentes ou com infecção limitada a uma, ou mais zonas. Na base de dados zoossanitários do Brasil, apenas 13 doenças tiveram casos notificados nos últimos 3 anos disponíveis (2017, 2018 e 2019). Pesquisas indicam elevado índice de subnotificação e falta de conhecimento sobre o processo de notificação. Instruções para notificação foram aqui apresentadas. A conexão entre a saúde humana, animal e ambiental, e a necessidade de estudar as doenças em seu contexto biológico, ecológico, médico e econômico, são apontados como mecanismo para prevenção e controle de doenças, de forma a promover e garantir a saúde nacional e globalmente.

Nearly Complete Genome Sequences of Two Bluetongue Viruses Isolated during the 2020 Outbreak in the Grand Duchy of Luxembourg

ABSTRACT Bluetongue is one of the major diseases of ruminants listed by the World Organisation for Animal Health. Bluetongue virus serotype 8 (BTV-8) has been considered enzootic in France since 2018. Here, we report the nearly complete genome sequences of two BTV-8 isolates from the 2020 outbreak in the Grand Duchy of Luxembourg.

Molecular Characterisation of the GdhA- Derivative of Pasteurella multocida B:2

Pasteurella multocida B:2 is an important veterinary pathogen causing fatal and acute haemorrhagic septicaemia (HS) in bovine. A live vaccine candidate, P. multocida B:2 GDH7 was reported to enable protection in cattle and buffaloes via intranasal (i. n.) administration. This potential vaccine was also reported to be self-transmitted from the vaccinated animal to the free-ranging animals allowing wider vaccination coverage. Prior to commercialisation, this potential vaccine requires further characterisation in accordance with the authoritative guidelines from the World Organisation for Animal Health (OIE). Hence, in this study, the potential vaccine strain, P. multocida B:2 GDH7 and the virulent parent strain were characterised through genomic and proteomic profiling. A crucial first step was to develop a sensitive yet simple and robust identification test to differentiate both strains which has been achieved by the development of a precise yet straightforward PCR method. In genomic profiling, Repetitive Extragenic Palindromic sequence-PCR (REP-PCR) was manipulated and both strains have a different display of genomic DNA band patterns. Some of the major OMPs were observed and prominent immunogens of P. multocida, OmpA and OmpH were observed to be expressed differently between these strains through SDS-PAGE analysis. In conclusion, a reproducible PCR detection method has enabled differentiation of both strains. Further characterisation of these strains shows a significantly different profile through genomic and proteomic profiling.