Population biology of infectious diseases shared by wild and farmed fish

Global fisheries landings ceased increasing decades ago, causing an increasing shortfall in wild seafood supply and an expansion of aquaculture. The abundance of domesticated fishes now dwarfs related wild fishes in some coastal seas, changing the dynamics of their infectious diseases. Transport and trade of seafood, feed, eggs, and broodstock bring pathogens into new regions and into contact with naïve hosts. Density-dependent transmission creates threshold effects where disease can abruptly switch from endemic to epizootic dynamics. Hydrodynamics allow pathogens to disperse broadly, interconnecting farms into metapopulations of domesticated host fish in regions that also support related species of wild fish. Spillover and spillback dynamics of pathogen transmission between wild and farmed fish can create novel transmission pathways or bioamplify pathogen abundance, potentially depressing or endangering wild fish. Mortality from natural predator–prey interactions may be synergistic or compensatory with these increased infections. Domestic environments may favour the evolution of undesirable pathogen traits, such as virulence and drug resistance, leading to the emergence of strains that cause high mortality and (or) evade treatment. Overall, these changes to the dynamics of infectious disease in coastal seas impose new constraints on the sustainability of both wild and farmed fish.

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Effects of Malachite Green on the Microbiomes of Milkfish Culture Ponds

Water ◽

10.3390/w13040411 ◽

2021 ◽

Vol 13 (4) ◽

pp. 411

Author(s):

Chu-Wen Yang ◽

Yi-Tang Chang ◽

Chi-Yen Hsieh ◽

Bea-Ven Chang

Keyword(s):

Infectious Diseases ◽

Microbial Communities ◽

Malachite Green ◽

Fish Farming ◽

Cyanobacterial Blooms ◽

Anoxygenic Phototrophic Bacteria ◽

Fish Mortality ◽

Veterinary Drug ◽

Degrading Bacteria ◽

Microbial Infections

Intensive fish farming through aquaculture is vulnerable to infectious diseases that can increase fish mortality and damage the productivity of aquaculture farms. To prevent infectious diseases, malachite green (MG) has been applied as a veterinary drug for various microbial infections in aquaculture settings worldwide. However, little is known regarding the consequences of MG and MG-degrading bacteria (MGDB) on microbial communities in milkfish culture ponds (MCPs). In this study, small MCPs were used as a model system to determine the effects of MG on the microbial communities in MCPs. The addition of MG led to cyanobacterial blooms in the small MCP. The addition of MGDB could not completely reverse the effects of MG on microbial communities. Cyanobacterial blooms were not prevented. Microbial communities analyzed by next generation sequencing revealed that cyanobacterial blooms may be due to increase of nitrogen cycle (including nitrogen fixation, nitrate reduction and anammox) associated microbial communities, which raised the levels of ammonium in the water of the small MCP. The communities of anoxygenic phototrophic bacteria (beneficial for aquaculture and aquatic ecosystems) decreased after the addition of MG. The results of this investigation provide valuable insights into the effects of MG in aquaculture and the difficulties of bioremediation for aquatic environments polluted by MG.

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Challenges and Opportunities Developing Mathematical Models of Shared Pathogens of Domestic and Wild Animals

Veterinary Sciences ◽

10.3390/vetsci5040092 ◽

2018 ◽

Vol 5 (4) ◽

pp. 92 ◽

Cited By ~ 3

Author(s):

Kathryn Huyvaert ◽

Robin Russell ◽

Kelly Patyk ◽

Meggan Craft ◽

Paul Cross ◽

...

Keyword(s):

Mathematical Models ◽

Domestic Animals ◽

Domestic Animal ◽

Pathogen Transmission ◽

Management Actions ◽

Animal Populations ◽

Challenges And Opportunities ◽

Conservation Concern ◽

Transmission Pathways ◽

And Control

Diseases that affect both wild and domestic animals can be particularly difficult to prevent, predict, mitigate, and control. Such multi-host diseases can have devastating economic impacts on domestic animal producers and can present significant challenges to wildlife populations, particularly for populations of conservation concern. Few mathematical models exist that capture the complexities of these multi-host pathogens, yet the development of such models would allow us to estimate and compare the potential effectiveness of management actions for mitigating or suppressing disease in wildlife and/or livestock host populations. We conducted a workshop in March 2014 to identify the challenges associated with developing models of pathogen transmission across the wildlife-livestock interface. The development of mathematical models of pathogen transmission at this interface is hampered by the difficulties associated with describing the host-pathogen systems, including: (1) the identity of wildlife hosts, their distributions, and movement patterns; (2) the pathogen transmission pathways between wildlife and domestic animals; (3) the effects of the disease and concomitant mitigation efforts on wild and domestic animal populations; and (4) barriers to communication between sectors. To promote the development of mathematical models of transmission at this interface, we recommend further integration of modern quantitative techniques and improvement of communication among wildlife biologists, mathematical modelers, veterinary medicine professionals, producers, and other stakeholders concerned with the consequences of pathogen transmission at this important, yet poorly understood, interface.

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Occurrence of Fungi and Mycotoxins in Fish Feeds and Their Impact on Fish Health

International Journal of Microbiology ◽

10.1155/2019/6743065 ◽

2019 ◽

Vol 2019 ◽

pp. 1-17 ◽

Cited By ~ 6

Author(s):

Esther Marijani ◽

Emmanuel Kigadye ◽

Sheila Okoth

Keyword(s):

Developing Countries ◽

Fish Mortality ◽

Fish Nutrition ◽

Human Consumption ◽

Plant Origin ◽

Feed Conversion ◽

Farmed Fish ◽

Mycotoxin Contamination ◽

Fish Feeds ◽

Mycotoxigenic Fungi

The rapid population growth in developing countries has led to strong pressure on capture fisheries. However, capture fisheries have reached their maximal limits of fish production and are supplemented by farmed fish. The growth in aquaculture has led to high demand for fish feeds, which play a very important role in fish nutrition and health. Use of animal protein in fish feeds is expensive; hence, a majority of farmers from developing countries use local feed ingredients from plant origin as a source of dietary protein. However, these ingredients of plant origin provide the best natural substrates for fungi, which can be easily accompanied by mycotoxin development under suitable conditions. The locally made feed comprises ingredients such as soybeans, cottonseed cake, and wheat and maize bran which are mixed together and ground after which the compounded feed is pelleted and stored. Among the ingredients, maize and oilseeds are more susceptible for mycotoxigenic fungi compared to other ingredients. The outcomes of mycotoxin contamination in fish feeds are not different from other animal species intended for human consumption, and they are directly associated with production losses, particularly decreased weight gain and feed conversion, impaired immune system and reproductive performance, and increased fish mortality. Fish may also carry mycotoxin residues along the food chain, thus compromising human health. Hence, it is important to ensure the control of mycotoxin contamination in fish feeds, especially during the production and storage.

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Population biology of infectious diseases: Part I

Nature ◽

10.1038/280361a0 ◽

1979 ◽

Vol 280 (5721) ◽

pp. 361-367 ◽

Cited By ~ 1622

Author(s):

Roy M. Anderson ◽

Robert M. May

Keyword(s):

Infectious Diseases ◽

Population Biology

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Reared fish, farmed escapees and wild fish stocks—a triangle of pathogen transmission of concern to Mediterranean aquaculture management

Aquaculture Environment Interactions ◽

10.3354/aei00060 ◽

2013 ◽

Vol 3 (2) ◽

pp. 153-161 ◽

Cited By ~ 34

Author(s):

P Arechavala-Lopez ◽

P Sanchez-Jerez ◽

JT Bayle-Sempere ◽

I Uglem ◽

I Mladineo

Keyword(s):

Pathogen Transmission ◽

Wild Fish ◽

Fish Stocks ◽

Aquaculture Management ◽

Farmed Escapees

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Dynamics of a Fractional-Order Predator-Prey Model with Infectious Diseases in Prey

Communication in Biomathematical Sciences ◽

10.5614/cbms.2019.2.2.4 ◽

2019 ◽

Vol 2 (2) ◽

pp. 105 ◽

Cited By ~ 1

Author(s):

Hasan S. Panigoro ◽

Agus Suryanto ◽

Wuryansari Muharini Kusumahwinahyu ◽

Isnani Darti

Keyword(s):

Infectious Diseases ◽

Fractional Order ◽

Predator Prey ◽

Predator Prey Model ◽

Prey Model

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Comparing transmission potential networks based on social network surveys, close contacts and environmental overlap in rural Madagascar

Journal of The Royal Society Interface ◽

10.1098/rsif.2021.0690 ◽

2022 ◽

Vol 19 (186) ◽

Author(s):

Kayla Kauffman ◽

Courtney S. Werner ◽

Georgia Titcomb ◽

Michelle Pender ◽

Jean Yves Rabezara ◽

...

Keyword(s):

Social Network ◽

Spatial Data ◽

Disease Transmission ◽

Close Contact ◽

Pathogen Transmission ◽

Centrality Measures ◽

Data Types ◽

Transmission Potential ◽

Spatial Network Analysis ◽

Transmission Pathways

Social and spatial network analysis is an important approach for investigating infectious disease transmission, especially for pathogens transmitted directly between individuals or via environmental reservoirs. Given the diversity of ways to construct networks, however, it remains unclear how well networks constructed from different data types effectively capture transmission potential. We used empirical networks from a population in rural Madagascar to compare social network survey and spatial data-based networks of the same individuals. Close contact and environmental pathogen transmission pathways were modelled with the spatial data. We found that naming social partners during the surveys predicted higher close-contact rates and the proportion of environmental overlap on the spatial data-based networks. The spatial networks captured many strong and weak connections that were missed using social network surveys alone. Across networks, we found weak correlations among centrality measures (a proxy for superspreading potential). We conclude that social network surveys provide important scaffolding for understanding disease transmission pathways but miss contact-specific heterogeneities revealed by spatial data. Our analyses also highlight that the superspreading potential of individuals may vary across transmission modes. We provide detailed methods to construct networks for close-contact transmission pathogens when not all individuals simultaneously wear GPS trackers.

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COMBINATION VACCINES AGAINST KOIHERPES VIRUS AND Aeromonas hydrophila CO-INFECTION IN KOI AND COMMON CARP

Indonesian Aquaculture Journal ◽

10.15578/iaj.15.2.2020.93-102 ◽

2021 ◽

Vol 15 (2) ◽

pp. 93

Author(s):

Angela Mariana Lusiastuti ◽

Hessy Novita ◽

Lila Gardenia ◽

Taukhid Taukhid ◽

Habil Sven M. Bergmann

Keyword(s):

Aeromonas Hydrophila ◽

Secondary Infection ◽

Effective Means ◽

Fish Mortality ◽

Fish Farms ◽

Farmed Fish ◽

Virus Challenge ◽

Oral Application ◽

Research Areas ◽

Combined Vaccine

Co-infections occur when hosts are infected by two or more pathogens, either simultaneous or as a secondary infection. This research aimed to determine the best compositions of vaccine combinations and their protective efficacies against pathogens co-infection. This research was conducted in two stages. Firstly, surveys were conducted in three research areas: infected, high risk of infection, and virus free areas. Samples (three to five fish per pool) were collected from three fish farms per area. The basic antibody titer of fish from each farm was checked before and after vaccination as well as after the virus challenge in combination with the PCR result. The second stage of the research was conducted in the laboratory. Carp and koi fish were used to determine optimal vaccine combination and dosage for oral application. The results of this research showed that combination of KHV: Aeromonas hydrophila vaccines in the ratio of 1:2 and vaccine volume of 3 mL via the oral application gave higher titer antibody and efficacy against KHV and A. hydrophila. In conclusion, the combined vaccine offers an effective means of preventing the diseases, decreasing fish mortality, and simplifying the immunization schedule, which will eventually increase the overall health of farmed fish and benefit fish farmers and service extension officers. This research recommends that further development of the combined vaccines should be carried out, for example, overcoming the technical difficulties in its manufacturing.

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