Diseases of livestock in the Pacific Islands region: setting priorities for food animal biosecurity

A practical stakeholder-focused approach for assessing the biosecurity system in Pacific Island countries

AIMS

To develop a structured process for a transparent, efficient, high-level review of a low-resource biosecurity system (limited by physical infrastructure, financial, and human resources), in order to identify and prioritise key areas for future focus which could then lead to interventions, tailored by country, to improve the system. A key requirement was that the approach developed was culturally sensitive and respectful to Pasifika people within the country.

METHODS

Animal health and biosecurity systems need to be urgently strengthened by Pacific Island countries and territories (PICTs) if they are to respond to current and future threats. Understanding where additional resources should be allocated to maximise benefit and ensuring buy-in from PICT stakeholders are critical for uptake of any recommendations made. However, there is little available literature on reviewing biosecurity systems, particularly where there is a need for efficiency, simplicity, and cultural sensitivity. A framework was developed through initial in-person consultation between four New Zealand experts who had experience working in international animal health development and support programmes. This was followed by input from informal discussions with selected heads of agriculture in PICTs and included their experiences with previous system reviews, as well as general advice from experts in Pasifika culture. Foundational objectives included simplicity, local inclusivity, and a structured approach, which could be undertaken over a relatively short period of time.A rapid evidence assessment methodology was used to search the available literature (published and grey, search terms biosecurity, system, Pacific, animal, framework, and review used in AND/OR combinations), to establish an evidence base for other methods of biosecurity system review. The developed framework for review of biosecurity systems in low-resource PICTs was based on elements from expert elicitation frameworks, the SurF surveillance evaluation framework and the Performance of Veterinary Services tool from The World Organisation for Animal Health.

RESULTS

The developed framework involved bringing stakeholders together in a workshop environment and comprised up to 10 steps including mapping the PICT biosecurity system and exploring attributes of component activities. Understanding the system at a high level enables stakeholders to make informed recommendations on improvements to address future needs. Using the Delphi method, recommendations were then prioritised by stakeholders.

CONCLUSIONS AND CLINICAL RELEVANCE

A distinctive difference flowing from the use of the needs analysis described in this process was the empowerment of PICT stakeholders to determine their own needs and priorities, rather than have these developed by external parties.

Approaches for disease prioritization and decision-making in animal health, 2000-2021: a structured scoping review

This scoping review identifies and describes the methods used to prioritize diseases for resource allocation across disease control, surveillance, and research and the methods used generally in decision-making on animal health policy. Three electronic databases (Medline/PubMed, Embase, and CAB Abstracts) were searched for articles from 2000 to 2021. Searches identified 6, 395 articles after de-duplication, with an additional 64 articles added manually. A total of 6, 460 articles were imported to online document review management software (sysrev.com) for screening. Based on inclusion and exclusion criteria, 532 articles passed the first screening, and after a second round of screening, 336 articles were recommended for full review. A total of 40 articles were removed after data extraction. Another 11 articles were added, having been obtained from cross-citations of already identified articles, providing a total of 307 articles to be considered in the scoping review. The results show that the main methods used for disease prioritization were based on economic analysis, multi-criteria evaluation, risk assessment, simple ranking, spatial risk mapping, and simulation modeling. Disease prioritization was performed to aid in decision-making related to various categories: (1) disease control, prevention, or eradication strategies, (2) general organizational strategy, (3) identification of high-risk areas or populations, (4) assessment of risk of disease introduction or occurrence, (5) disease surveillance, and (6) research priority setting. Of the articles included in data extraction, 50.5% had a national focus, 12.3% were local, 11.9% were regional, 6.5% were sub-national, and 3.9% were global. In 15.2% of the articles, the geographic focus was not specified. The scoping review revealed the lack of comprehensive, integrated, and mutually compatible approaches to disease prioritization and decision support tools for animal health. We recommend that future studies should focus on creating comprehensive and harmonized frameworks describing methods for disease prioritization and decision-making tools in animal health.

Impact of climate change on sustainable livestock production and existence of wildlife and marine species in the South Pacific island countries: a review

Climate change poses a significant threat to humanity by intensifying multiple hazards. South Pacific Island countries (SPICs) are affected and face a dire challenge to survival. Sea level rise is reducing the already limited land for human and animal habitation. Tropical cyclones and droughts are having devastating effects on the lives of humans and animals. Tropical cyclone Winston, for example, destroyed infrastructure for humans and animals in some parts of Fiji, and infectious diseases are spreading to regions where they are not commonly seen following cyclones and floods. Likewise, climate change is making droughts worse. Droughts are destroying crops and pasturelands and making freshwater unavailable for human and animal populations in the Solomon Islands and Tuvalu. There is an urgent need to ascertain the best approaches to tackle the events, which are already happening. Short-term changes can be managed at local levels through public awareness campaigns, understanding the weather patterns to prepare for disasters, reclaiming land, improving livestock breeds, introducing zoos and wildlife sanctuaries and inventing economically feasible technologies to harvest water. Long-term solutions depend on the implementation of international agreements, international aid and collective effort.

A Combinative Assembly Strategy Inspired Reversibly Borate-Bridged Polymeric Micelles for Lesion-Specific Rapid Release of Anti-Coccidial Drugs

HIGHLIGHTS

A combined assembly strategy from hydrophobicity-driving and reversible borate bridges is proposed for high drug-loading efficiency and superior stability. Intestinal environment-triggered drug delivery system represents an effective treatment for local infection due to the site-specific targeting and shuttling of drugs. The reduced dosage brought by the drug-loading micelles could solve the problem of drug residue in breeding industry.

ABSTRACT

Stimuli-triggered drug delivery systems hold vast promise in local infection treatment for the site-specific targeting and shuttling of drugs. Herein, chitosan conjugates (SPCS) installed with sialic acid (SA) and phenylboronic acid (PBA) were synthesized, of which SA served as targeting ligand for coccidium and reversible-binding bridge for PBA. The enhanced drug-loading capacity of SPCS micelles was attributed to a combination assembly from hydrophobicity-driving and reversible borate bridges. The drug-loaded SPCS micelles shared superior biostability in upper gastrointestinal tract. After reaching the lesions, the borate bridges were snipped by carbohydrates under a higher pH followed by accelerated drug release, while SA exposure on micellar surface facilitated drug cellular internalization to eliminate parasites inside. The drug-micelles revealed an enhanced anti-coccidial capacity with a higher index of 185.72 compared with commercial preparation. The dual-responsive combination of physicochemical assembly could provide an efficient strategy for the exploitation of stable, safe and flexible anti-infectious drug delivery systems. [Image: see text]

ELECTRONIC SUPPLEMENTARY MATERIAL

The online version of this article (10.1007/s40820-020-00495-1) contains supplementary material, which is available to authorized users.

Potential of ethno-veterinary medicine in animal health care practices in the South Pacific Island countries: a review

The South Pacific island countries (SPIC) are among the most vulnerable countries in the world to economic shocks, climate change and natural disasters. Agriculture including livestock production makes important contribution to socio-economic development in the region. However, the livestock sector is marred by many livestock diseases, which are crippling the economies as well as threatening the food security of the island nations, most of which have high dependence on imports. Limited veterinary medical facilities, high cost of conventional medicine and remoteness of some rural farming communities make it difficult for farmers to treat their diseased animals. Nevertheless, the island nations are endowed with vast reserves of medicinal plants in diverse ecosystems including mangroves, rainforests and tropical dry forests. Despite the ubiquity of traditional medicine systems, most of the plant species have been used to treat human aliments in the SPIC and very few farmers utilise herbal medicine to treat their animals. This review highlights the common diseases affecting livestock production in the SPIC, threats to ethno-veterinary knowledge, and potential plant species and their efficacies to treat animal diseases and parasites. It also discusses the common methods of preparation of veterinary herbal medicine and possible ways of making the medicine available in the formal and informal markets in the region. It is envisaged that the review will stimulate further ethno-veterinary research among livestock disease management practices in the SPIC.

The prevalence of Leptospira among invasive small mammals on Puerto Rican cattle farms

Leptospirosis, an emerging infectious disease caused by bacteria of the genus Leptospira, is thought to be the most widespread zoonotic disease in the world. A first step in preventing the spread of Leptospira is delineating the animal reservoirs that maintain and disperse the bacteria. Quantitative PCR (qPCR) methods targeting the LipL32 gene were used to analyze kidney samples from 124 House mice (Mus musculus), 94 Black rats (Rattus rattus), 5 Norway rats (R. norvegicus), and 89 small Indian mongooses (Herpestes auropunctatus) from five cattle farms in Puerto Rico. Renal carriage of Leptospira was found in 38% of the sampled individuals, with 59% of the sampled mice, 34% of Black rats, 20% of Norway rats, and 13% of the mongooses. A heterogeneous distribution of prevalence was also found among sites, with the highest prevalence of Leptospira-positive samples at 52% and the lowest at 30%. Comparative sequence analysis of the LipL32 gene from positive samples revealed the presence of two species of Leptospira, L. borgpetersenii and L. interrogans in mice, detected in similar percentages in samples from four farms, while samples from the fifth farm almost exclusively harbored L. interrogans. In rats, both Leptospira species were found, while mongooses only harbored L. interrogans. Numbers tested for both animals, however, were too small (n = 7 each) to relate prevalence of Leptospira species to location. Significant associations of Leptospira prevalence with anthropogenic landscape features were observed at farms in Naguabo and Sabana Grande, where infected individuals were closer to human dwellings, milking barns, and ponds than were uninfected individuals. These results show that rural areas of Puerto Rico are in need of management and longitudinal surveillance of Leptospira in order to prevent continued infection of focal susceptible species (i.e. humans and cattle).

World Health Organization Methodology to Prioritize Emerging Infectious Diseases in Need of Research and Development

The World Health Organization R&D Blueprint aims to accelerate the availability of medical technologies during epidemics by focusing on a list of prioritized emerging diseases for which medical countermeasures are insufficient or nonexistent. The prioritization process has 3 components: a Delphi process to narrow down a list of potential priority diseases, a multicriteria decision analysis to rank the short list of diseases, and a final Delphi round to arrive at a final list of 10 diseases. A group of international experts applied this process in January 2017, resulting in a list of 10 priority diseases. The robustness of the list was tested by performing a sensitivity analysis. The new process corrected major shortcomings in the pre-R&D Blueprint approach to disease prioritization and increased confidence in the results.

Re-evaluating the LD50 requirements in the codified potency testing of veterinary vaccines containing Leptospira (L.) serogroup Icterohaemorrhagiae and L. serogroup Canicola in the United States

Approximately one-third of the reportable USDA Category D and E laboratory animals in the United States are expended on the potency testing of leptospiral vaccines by the codified hamster vaccination-challenge assay. Valid tests require ≥80% of challenge controls to succumb to disease and an LD50 between 10 and 10,000. This work evaluates the risk associated with the removal of LD50 limits; thereby, eliminating back-titration hamsters from in vivo potency assays for Leptospira (L.) serogroups Canicola and Icterohaemorrhagiae. The impact was assessed through 1) retrospective analysis of industry and CVB serial release data from July 2011-April 2015 and 2) evaluation through vaccination-challenge assays. For the initial vaccination-challenge assays (n = 3/serogroup), one group received potent bacterin (PB) and six groups received subpotent bacterins (SB1-SB6). PB and SB1 were challenged with a single dilution of Leptospira between 10 and 10,000 LD50. SB2-SB6 received serial dilutions of more concentrated challenge. Based on the retrospective analysis and in vivo assays, 80% of the challenge controls succumbing to disease reasonably ensured the minimal LD50 was administered. Subpotent vaccines were not at increased risk for being deemed potent when challenged with >10,000 LD50, but potent vaccines were at risk of being deemed subpotent when challenged with >10,000 LD50.

High incidence of leptospirosis in an observational study of hospital outpatients in Vanuatu highlights the need for improved awareness and diagnostic capacities

BACKGROUND

Estimates of leptospirosis morbidity identified Oceania as the region with highest burden. Besides Australia and New Zealand, Oceania is home of Pacific Island Countries and Territories, most of which are developing countries facing a number of challenges. Their archipelago geography notably affects health infrastructure and access to healthcare. Although human leptospirosis was formerly identified in Vanuatu, there is a lack of knowledge of this disease in the country. We aimed to identify leptospirosis in outpatients visiting the hospital.

METHODOLOGY/PRINCIPAL FINDINGS

We conducted a clinical study to investigate leptospirosis as a cause of non-malarial acute febrile illness in Vanuatu. A total 161 outpatients visiting the outpatient clinics at Port Vila Central Hospital for internal medicine were recruited over 20 month. We showed that leptospirosis significantly affects humans in Vanuatu: 12 cases were confirmed by real-time PCR on acute blood samples (n = 5) or by high serology titers evidencing a recent infection (MAT titer ≥800 or ELISA≥18 Units, n = 7). A high rate of positive serology was also evidenced, by MAT (100

CONCLUSIONS/SIGNIFICANCE

The high numbers of both seropositive patients and acute leptospirosis cases observed in outpatients visiting Port Vila Central Hospital suggest a high exposure to pathogenic Leptospira in the population studied. The MAT serology pointing to serogroup Australis as well as exposure history suggest that livestock animals largely contribute to the burden of human leptospirosis in Vanuatu. The analysis of residential and travel data suggests that the risk might even be higher in other islands of the Vanuatu archipelago. Altogether, our study emphasizes the need to increase awareness and build laboratory capacity to improve the medical care of leptospirosis in Vanuatu.

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MESH Headings

• Adolescent
• Adult
• Aged
• Agglutination Tests
• Antibodies, Bacterial/blood
• Enzyme-Linked Immunosorbent Assay
• Female
• Geography
• Health Knowledge, Attitudes, Practice
• Humans
• Incidence
• Leptospira/genetics
• Leptospira/immunology
• Leptospira/isolation & purification
• Leptospira/pathogenicity
• Leptospirosis/diagnosis
• Leptospirosis/epidemiology
• Leptospirosis/immunology
• Male
• Middle Aged
• Outpatients
• Real-Time Polymerase Chain Reaction
• Serogroup
• Vanuatu/epidemiology
• Young Adult

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Affiliation(s)

Junior George Pakoa Department of Pathology and Medical Diagnostic Laboratory Medicine PMB 9013, Vila Central Hospital, Ministry of Health, Port Vila, Vanuatu
Marie-Estelle Soupé-Gilbert Institut Pasteur International Network, Institut Pasteur in New Caledonia, Leptospirosis Research and Expertise Unit, Nouméa Cedex, New Caledonia
Dominique Girault Institut Pasteur International Network, Institut Pasteur in New Caledonia, Leptospirosis Research and Expertise Unit, Nouméa Cedex, New Caledonia
Dexter Takau Department of Pathology and Medical Diagnostic Laboratory Medicine PMB 9013, Vila Central Hospital, Ministry of Health, Port Vila, Vanuatu
Justina Gaviga Department of Pathology and Medical Diagnostic Laboratory Medicine PMB 9013, Vila Central Hospital, Ministry of Health, Port Vila, Vanuatu
Ann-Claire Gourinat Institut Pasteur International Network, Institut Pasteur in New Caledonia, Serology and Molecular Diagnostics Unit, Nouméa Cedex, New Caledonia Centre Hospitalier Territorial de Nouvelle-Calédonie, Medical Biology Laboratory, Nouméa Cedex, New Caledonia
Arnaud Tarantola Institut Pasteur International Network, Institut Pasteur in New Caledonia, Medical Epidemiology Research Unit, Nouméa Cedex, New Caledonia
Cyrille Goarant Institut Pasteur International Network, Institut Pasteur in New Caledonia, Leptospirosis Research and Expertise Unit, Nouméa Cedex, New Caledonia

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Creating a framework for the prioritization of biosecurity risks to the New Zealand dairy industry

The New Zealand dairy sector relies on robust biosecurity measures to control and mitigate a wide range of threats to the industry. To optimize the prioritization of organisms and manage the risk they pose to the sector in a transparent and credible way, the Dairy Biosecurity Risk Evaluation Framework (D-BRiEF) was developed. This comprehensive framework was specifically designed for decision support, using a standardized approach to address the full spectrum of biosecurity threats to the sector, including exotic and endemic animal disease organisms, pest plants and insects. D-BRiEF is underpinned by three main processes, namely (i) hazard identification; (ii) multicriteria risk assessment; and (iii) communication for risk management. Expert knowledge and empirical data, including associated uncertainty, are harnessed in a standardized format. Results feed into a probability-impact model that was developed in close collaboration with dairy sector economists to provide overall comparative 10-year quantitative economic impact estimates for each assessed risk organism. A description of the overarching framework, which applies to diverse organism groups, is presented with detailed methodology on both endemic and exotic animal disease risk organisms. Examples of visual outputs are included, although actual ranking results are not reported due to industry confidentiality. D-BRiEF can provide a decision advantage to DairyNZ biosecurity risk managers and sector stakeholders by creating a transparent process that can be interrogated and updated at multiple levels to fully understand the layers of risk posed by different organisms.

Field application of a combined pig and poultry market chain and risk pathway analysis within the Pacific Islands region as a tool for targeted disease surveillance and biosecurity

Limited resources are one of the major constraints in effective disease monitoring and control in developing countries. This paper examines the pig and poultry market chains of four targeted Pacific Island countries and territories (PICTs): Fiji, Papua New Guinea, Solomon Islands and Vanuatu and combines them with a risk pathway analysis to identify the highest risk areas (risk hotspots) and risky practices and behaviours (risk factors) of animal disease introduction and/or spread, using highly pathogenic avian influenza (HPAI) and foot-and-mouth disease (FMD) as model diseases because of their importance in the region. The results show that combining a market chain analysis with risk pathways is a practical way of communicating risk to animal health officials and improving biosecurity. It provides a participatory approach that helps officials to better understand the trading regulations in place in their country and to better evaluate their role as part of the control system. Common risk patterns were found to play a role in all four PICTs. Legal trade pathways rely essentially on preventive measures put in place in the exporting countries while no or only limited control measures are undertaken by the importing countries. Legal importations of animals and animal products are done mainly by commercial farms which then supply local smallholders. Targeting surveillance on these potential hotspots would limit the risk of introduction and spread of animal diseases within the pig and poultry industry and better rationalize use of skilled manpower. Swill feeding is identified as a common practice in the region that represents a recognized risk factor for dissemination of pathogens to susceptible species. Illegal introduction of animals and animal products is suspected, but appears restricted to small holder farms in remote areas, limiting the risk of spread of transboundary animal diseases along the market chain. Introduction of undeclared goods hidden within a legal trade activity was identified as a major risk pathway. Activities such as awareness campaigns for pig and poultry farmers regarding disease reporting, biosecurity measures or danger of swill feeding and training of biosecurity officers in basic animal health and import-associated risks are recommended to prevent and limit the spread of pathogens within the PICTs.