One Health Outlook最新文献

Background: Many ecologically important plants are pollinated or have their seeds dispersed by fruit bats, including the widely distributed African straw-colored fruit bats (Eidolon helvum). Their ability to fly long distances makes them essential for connecting plant populations across fragmented landscapes. While bats have been implicated as a reservoir of infectious diseases, their role in disease transmission to humans is not well understood. In this pilot study, we tracked E. helvum to shed light on their movement patterns in Tanzania and possible contact with other species.

Methods: Tracking devices were deployed on 25 bats captured in the Morogoro Municipal and Kilombero District area near the Udzungwa Mountains of Tanzania. Nightly flight patterns, areas corresponding to foraging bouts and feeding roosts, and new day roosts were determined from bat movement data and characterized according to their proximity to urban built-up and protected areas. Sites for additional environmental surveillance using camera traps were identified via tracking data to determine species coming in contact with fruits discarded by bats.

Results: Tracking data revealed variability between individual bat movements and a fidelity to foraging areas. Bats were tracked from one to six nights, with a mean cumulative nightly flight distance of 26.14 km (min: 0.33, max: 97.57) based on data from high-resolution GPS tags. While the majority of their foraging locations were in or near urban areas, bats also foraged in protected areas, of which the Udzungwa Mountains National Park was the most frequented. Camera traps in fruit orchards frequented by tracked bats showed the presence of multiple species of wildlife, with vervet monkeys (Chlorocebus pygerythrus) observed as directly handling and eating fruit discarded by bats.

Conclusions: Because we observed multiple interactions of animals with fruits discarded by bats, specifically with vervet monkeys, the possibility of disease spillover risk exists via this indirect pathway. With flight distances of up to 97 km, however, the role of E. helvum in the seed dispersal of plants across both protected and urban built-up areas in Tanzania may be even more important, especially by helping connect increasingly fragmented landscapes during this Anthropocene epoch.

Background: For many emerging or re-emerging pathogens, cases in humans arise from a mixture of introductions (via zoonotic spillover from animal reservoirs or geographic spillover from endemic regions) and secondary human-to-human transmission. Interventions aiming to reduce incidence of these infections can be focused on preventing spillover or reducing human-to-human transmission, or sometimes both at once, and typically are governed by resource constraints that require policymakers to make choices. Despite increasing emphasis on using mathematical models to inform disease control policies, little attention has been paid to guiding rational disease control at the animal-human interface.

Methods: We introduce a modeling framework to analyze the impacts of different disease control policies, focusing on pathogens exhibiting subcritical transmission among humans (i.e. pathogens that cannot establish sustained human-to-human transmission). We quantify the relative effectiveness of measures to reduce spillover (e.g. reducing contact with animal hosts), human-to-human transmission (e.g. case isolation), or both at once (e.g. vaccination), across a range of epidemiological contexts.

Results: We provide guidelines for choosing which mode of control to prioritize in different epidemiological scenarios and considering different levels of resource and relative costs. We contextualize our analysis with current zoonotic pathogens and other subcritical pathogens, such as post-elimination measles, and control policies that have been applied.

Conclusions: Our work provides a model-based, theoretical foundation to understand and guide policy for subcritical zoonoses, integrating across disciplinary and species boundaries in a manner consistent with One Health principles.

The World One Health Congresses are biennial gatherings of approximately 1500 professionals from relevant international organisations, OIE, FAO, WHO, World Bank, leading scientific experts and researchers in the field of One Health, animal production and trade, food safety, animal health, human health and environmentology/ecology, government representatives in public health, human health, food safety, environmental health and global health security. The Congress is organized by the One Health Platform. This white paper summarizes highlights of the 5th International One Health Congress in Saskatoon, Canada, June 2018 and serves as a roadmap for the future, detailing several concrete action points to be carried out in the run-up to the 6th World One Health Congress in Edinburgh, Scotland, June 2020.

Background: Australian brushtail possums (Trichosurus vulpecula) are an introduced pest species in New Zealand, but native to Australia where they are protected for biodiversity conservation. Wobbly possum disease (WPD) is a fatal neurological disease of Australian brushtail possums described in New Zealand populations that has been associated with infection by the arterivirus (Arteriviridae) wobbly possum disease virus (WPDV-NZ). Clinically, WPD-infected possums present with chronic meningoencephalitis, choroiditis and multifocal neurological symptoms including ataxia, incoordination, and abnormal gait.

Methods: We conducted a retrospective investigation to characterise WPD in native Australian brushtail possums, and used a bulk meta-transcriptomic approach (i.e. total RNA-sequencing) to investigate its potential viral aetiology. PCR assays were developed for case diagnosis and full genome recovery in the face of extensive genetic variation.

Results: We identified genetically distinct lineages of arteriviruses from archival tissues of WPD-infected possums in Australia, termed wobbly possum disease virus AU1 and AU2. Phylogenetically, WPDV-AU1 and WPDV-AU2 shared only ~ 70% nucleotide similarity to each other and the WPDV-NZ strain, suggestive of a relatively ancient divergence. Notably, we also identified a novel and divergent hepacivirus (Flaviviridae) - the first in a marsupial - in both WPD-infected and uninfected possums, indicative of virus co-infection.

Conclusions: We have identified marsupial-specific lineages of arteriviruses in mainland Australia that are genetically distinct from that in New Zealand, in some cases co-infecting animals with a novel hepacivirus. Our study provides new insight into the hidden genetic diversity of arteriviruses, the capacity for virus co-infection, and highlights the utility of meta-transcriptomics for disease investigation in a One Health context.

Background: The USAID Preparedness and Response (P&R) project's publication on Multisectoral Coordination that Works identified five dimensions most critical to creating effective and sustainable One Health platforms: political commitment, institutional structure, management and coordination capacity, technical and financial resources, and joint planning and implementation. This case study describes Tanzania experience in using these dimensions to establish a functional One Health platform. The main objective of this case study was to document the process of institutionalizing the One Health approach in Tanzania.

Methods: An analysis of the process used to establish and institutionalize the MCM in Tanzania through addressing the five dimensions mentioned above was conducted between August 2018 and January 2019. Progress activity reports, annual reports and minutes of meetings and consultations regarding the establishment of the Tanzania national One Health platform were examined. Relevant One Health publications were studied as reference material.

Results: This case study illustrates the time and level of effort required of multiple partners to build a functional multi-sectoral coordinating mechanism (MCM). Key facilitating factors were identified and the importance of involving policy and decision makers at all stages of the process to facilitate policy decisions and the institutionalization process was underscored. The need for molding the implementation process using lessons learnt along the way -- "sailing the ship as it was being built" -- is demonstrated.

Conclusions: Tanzania now has a functioning and institutionalized MCM with a sound institutional structure and capacity to prevent, detect early and respond to health events. The path to its establishment required the patient commitment of a core group of One Health champions and stakeholders along the way to examine carefully and iteratively how best to structure productive multisectoral coordination in the country. The five dimensions identified by the Preparedness and Response project may provide useful guidance to other countries working to establish functional MCM.

Background: One Health (OH) is an integrated approach, formed inclusive of using multiple disciplines to attain optimal health for humans, animals, and the environment. The increasing proximity between humans, livestock, and wildlife, and its role in the transmission dynamics of mycobacterial infections, necessitates an OH approach in the surveillance of zoonotic diseases. The challenge remains as humans, livestock, and wildlife share resources and interact at various interfaces. Therefore, this review explores the potential of the OH approach to understand the impact of mycobacterial infections in Tanzania in terms of lessons learnt and future perspectives.

Materials and methods: Available literature on OH and mycobacterial infections in Tanzania was searched in PubMed, Google Scholar, and Web of Science. Articles on mycobacterial infections in Tanzania, published between 1997 to 2017, were retrieved to explore the information on OH and mycobacterial infections.

Main body: The studies conducted in Tanzania had have reported a wide diversity of mycobacterial species in humans and animals, which necessitates an OH approach in surveillance of diseases for better control of infectious agents and to safeguard the health of humans and animals. The close proximity between humans and animals increases the chances of inter-specific transmission of infectious pathogens, including drug-resistant mycobacteria. In an era where HIV co-infection is also the case, opportunistic infection by environmental non-tuberculous mycobacteria (NTM), commonly known as mycobacteria other than tuberculosis (MOTT) may further exacerbate the impact of drug resistance. NTM from various sources have greatest potential for diverse strains among which are resistant strains due to continued evolutional changes.

Conclusion: A collaborative interdisciplinary approach among professionals could help in solving the threats posed by mycobacterial infections to public health, particularly by the spread of drug-resistant strains.

Background: The governments of Guinea, Liberia, and Sierra Leone have acknowledged that weak health systems and poor coordination of efforts hampered effectiveness of the 2014-2016 Ebola outbreak response. The bitter experience of the Ebola outbreak response served as an important catalyst for increased efforts to comply with World Health Organization (WHO) International Health Regulations (IHR 2005), Performance of Veterinary Services (PVS) Pathway capacities, and Global Health Security Agenda (GHSA) goals. In November 2016, an interministerial meeting held in Dakar, Senegal, resulted in formalized commitments from the three nations to strengthen resilience to health threats by establishing a Regional Strategic Roadmap to institutionalize the One Health approach. Since then, each country has made significant progress towards establishing National One Health Platforms to coordinate health security interventions, in collaboration with international partners. This paper outlines the methodology and results of these efforts for the period June 2016-January 2019, with a specific focus on activities supported by the US Agency for International Development (USAID)-funded Preparedness & Response (P&R) project.

Objectives: In support of the West African Health Organization's November 2016 Regional Strategic Roadmap for institutionalization of the One Health approach, the Preparedness & Response (P&R) project worked in coordination with national partners in Guinea, Liberia, and Sierra Leone to establish multisectoral, One Health coordinating mechanisms.

Methodology: The global USAID-funded P&R project was launched in 2014 to support the achievement of this objective, and began coordinating with partners in Guinea, Liberia, and Sierra Leone in 2016 to tailor its multi-step conceptual framework to fit the priorities and operating constraints of national stakeholders. Organized in phases of Collaboration (building key relationships), Formalization (defining and establishing a coordination structure), and Implementation (using newfound coordination to produce better health security outcomes), the framework features steps such as One Health sensitizations for multisectoral national stakeholders, development of One Health platform terms of reference and other operating guidelines, and application of these tools to coordination of technical assistance during outbreaks.

Results: In Guinea, Liberia, and Sierra Leone, in less than 3 yrs there has been a marked improvement in cross-sectoral coordination on health security actions. All three countries have passed legislation establishing permanent multisectoral coordination mechanisms referred to in this document as National One Health Platforms, or simply Platforms; instituted an annual mechanism for assessing capacity and performance of these platforms to lead health security actions; and have undertaken key steps towards devel