APHA Parasitology Group: Annual Review of Literature and Horizon Scanning Report 2018
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APHA Parasitology Group Annual Review of Literature and Horizon Scanning Report 2018 Published: November 2019 November 2019 © Crown copyright 2019 You may re-use this information (excluding logos) free of charge in any format or medium, under the terms of the Open Government Licence v.3. To view this licence visit www.nationalarchives.gov.uk/doc/open-government-licence/version/3/ or email [email protected] This publication is available at www.gov.uk/government/publications Any enquiries regarding this publication should be sent to us at [email protected] Year of publication: 2019 The Animal and Plant Health Agency (APHA) is an executive agency of the Department for Environment, Food & Rural Affairs, and also works on behalf of the Scottish Government and Welsh Government. October 2018 Contents Summary ............................................................................................................................. 1 Fasciola hepatica ............................................................................................................. 1 Rumen fluke (Calicophoron daubneyi) ............................................................................. 2 Parasitic gastro-enteritis (PGE) ........................................................................................ 2 Anthelmintic resistance .................................................................................................... 4 Cestodes .......................................................................................................................... 4 Ectoparasites ................................................................................................................... 5 Vectors and vector-borne diseases .................................................................................. 5 Abstracts .............................................................................................................................. 5 Fasciola hepatica ................................................................................................................. 5 Epidemiology .................................................................................................................. 10 Non chemical control of Fasciola hepatica ..................................................................... 13 Vaccination ..................................................................................................................... 13 Chemical control of Fasciola .......................................................................................... 16 Diagnosis ....................................................................................................................... 19 Rumen fluke (Calicophoron daubneyi) ............................................................................... 24 Parasitic gastro-enteritis (PGE) ......................................................................................... 26 Diagnosis of PGE ........................................................................................................... 27 Vaccination ..................................................................................................................... 28 PGE Control ................................................................................................................... 29 Parasite immunity ........................................................................................................... 34 Haemonchus contortus ...................................................................................................... 35 Vaccination ..................................................................................................................... 37 Immunity ......................................................................................................................... 39 Molecular studies ........................................................................................................... 40 October 2018 Diagnosis ....................................................................................................................... 42 Anthelmintics ..................................................................................................................... 43 Anthelmintic resistance ...................................................................................................... 46 Parasites of cattle .............................................................................................................. 60 Parasitism and dairy sheep ................................................................................................ 63 Parasitism of dairy goats .................................................................................................... 64 Alternative control of parasites ........................................................................................... 65 Plant based products...................................................................................................... 65 Fungi .............................................................................................................................. 71 Miscellaneous products .................................................................................................. 73 Dictyocaulus spp. ............................................................................................................... 74 Cestodes and other zoonotic parasites .............................................................................. 76 Ectoparasites ..................................................................................................................... 83 Bovine besnoitiosis ............................................................................................................ 87 Neospora caninum ............................................................................................................. 90 Vector borne diseases: ...................................................................................................... 92 Tick borne infections and wild and domestic hosts: ....................................................... 98 Poultry mites .................................................................................................................... 110 Wildlife ............................................................................................................................. 111 Companion animals ......................................................................................................... 112 October 2018 Summary Fasciola hepatica Research into various vaccination candidates and also why research to date has not produced an effective commercialised vaccine continues. Various studies were also published into many new chemicals (some plant derived), adjuvants and routes of vaccination that appear to have potential A study to assist vaccine development showed that a genetic clonal expansion of F hepatica occurs within G. truncatula, highlighting the potential for amplification of drug resistant genotypes. Interestingly in one experiment, a single miracidium infecting a snail, produced over 3000 metacercariae during the snail’s lifetime, showing the potent multiplication step in this intermediate host. The effect of F hepatica on infected hosts’ global immune response has continued to be studied. It is modulated toward a nonproliferative type 2 state following natural challenge with F. hepatica. This has implications in terms of the timing of the administration of vaccination programs and for host susceptibility to coinfecting pathogens. A paper was published which cautiously suggested a link between F. hepatica infection and the shedding of E. coli O157 in cattle. Newer areas of research were also published. In Cuba (and elsewhere but not reported in the UK) the snail Pseudosuccinea columella acts as intermediate host of F. hepatica, Interestingly in Cuba there are populations of susceptible and naturally-resistant populations to F. hepatica within this snail species. Resistance in P. columella is characterized by the encapsulation of the parasite by host's immune cells. The effectiveness of P. columella resistance to F. hepatica does not decline with increasing parasite doses, successive infection or different geographical origins of parasite isolates, Understanding the peculiarities of the P. columella-F. hepatica interaction and the extent of the resistant phenotype is crucial for an effective parasite control and for developing alternatives to tackle fasciolosis transmission. A study was published to determine the effectiveness of Chaetogaster limnaei (a freshwater worm) as a natural controller of Fasciola hepatica in laboratory conditions. It is naturally symbiotically associated with lymnaeid snails as Galba truncatula with this association considered a preventative mechanism against trematode miracidia infection. An effective 70% natural control of Fasciola hepatica in Galba truncatula was observed, in vitro. Study in dairy herds in Denmark resulted in information pertinent for that country and noted that for diagnosis of infection the serum antibody ELISA was able to detect infection first, whereas both copro-antigen ELISA and faecal egg counts tended to increase in the same animals at a later point. Other diagnostic techmiques such as real time PCR and loop-mediated isothermal amplification (LAMP) have been shown to be able to detect F hepatica DNA from as early as one week post