Tropical Livestock Units: Re-evaluating a Methodology.

The dynamic between humans, livestock, and wildlife is evolving owing to growth in populations, a finite global landmass, and shifting climatic conditions. This change comes with certain benefits in terms of food security, nutrition, and livelihoods as livestock populations increase, but is not without risk. The role of livestock in infectious disease emergence, environmental degradation, and the development of antimicrobial resistance is becoming more apparent. An understanding of these risks and development of mitigation tactics, especially in low- and middle-income countries where the pace of change is most rapid, is increasingly based on comprehensive models and tools built to map livestock populations at the global, regional or national level. Translation of model estimates into evidence is often underpinned by a quantification of livestock biomass to support policy development and implementation. This paper discusses the application of the Tropical Livestock Unit in the context of measuring biomass. It examines the established method of calculation, designating all cattle a standard weight of 175 kg, and compares it to two proposed alternatives. In doing so, the potential to refine estimates of biomass in low and middle-income countries is explored, though this concept could be extrapolated to higher income economies as well. Publicly available data from six countries in sub-Saharan Africa was utilized to demonstrate how breed liveweight, herd structures, and growth rates have the potential to dramatically alter the estimates of cattle biomass in each country. Establishing standardized data collection procedures to capture this information on a regular basis would grant a better understanding of the true nature of livestock populations, aid in the development of superior disease prevention and response measures, bolster food security initiatives through improving livestock production, and inform the intelligent management of shared ecosystems to improve conservation and biodiversity.

COVID-19-Zoonosis or Emerging Infectious Disease?

The World Health Organization defines a zoonosis as any infection naturally transmissible from vertebrate animals to humans. The pandemic of Coronavirus disease (COVID-19) caused by SARS-CoV-2 has been classified as a zoonotic disease, however, no animal reservoir has yet been found, so this classification is premature. We propose that COVID-19 should instead be classified an "emerging infectious disease (EID) of probable animal origin." To explore if COVID-19 infection fits our proposed re-categorization vs. the contemporary definitions of zoonoses, we reviewed current evidence of infection origin and transmission routes of SARS-CoV-2 virus and described this in the context of known zoonoses, EIDs and "spill-over" events. Although the initial one hundred COVID-19 patients were presumably exposed to the virus at a seafood Market in China, and despite the fact that 33 of 585 swab samples collected from surfaces and cages in the market tested positive for SARS-CoV-2, no virus was isolated directly from animals and no animal reservoir was detected. Elsewhere, SARS-CoV-2 has been detected in animals including domesticated cats, dogs, and ferrets, as well as captive-managed mink, lions, tigers, deer, and mice confirming zooanthroponosis. Other than circumstantial evidence of zoonotic cases in mink farms in the Netherlands, no cases of natural transmission from wild or domesticated animals have been confirmed. More than 40 million human COVID-19 infections reported appear to be exclusively through human-human transmission. SARS-CoV-2 virus and COVID-19 do not meet the WHO definition of zoonoses. We suggest SARS-CoV-2 should be re-classified as an EID of probable animal origin.

The growth and strategic functioning of One Health networks: a systematic analysis.

BACKGROUND: The recent increase in attention to linkages between human health, animal health, and the state of the environment has resulted in the rapid growth of networks that facilitate collaboration between these sectors. This study ascertained whether duplication of efforts is occurring across networks, which stakeholders are being engaged, and how frequently monitoring and evaluation of investments is being reported. METHODS: This study is a systematic analysis of One Health networks (OHNs) in Africa, Asia, and Europe. We defined an OHN as an engagement between two or more discrete organisations with at least two of the following sectors represented: animal health, human health, and the environment or ecosystem. Between June 5 and Sept 29, 2017, we systematically searched for OHNs in PubMed, Google, Google Scholar, and relevant conference websites. No language restrictions were applied, but we were only able to translate from English and French. Data about OHNs, including their year of initiation, sectors of engagement, regions of operation, activities conducted, and stakeholders involved, were extracted with a standardised template and analysed descriptively. FINDINGS: After screening 2430 search results, we identified and analysed 100 unique OHNs, of which 86 were formed after 2005. 32 OHNs covered only human and animal health, without engaging with the role of the environment on health. 78 OHNs involved academic bodies and 78 involved government bodies, with for-profit organisations involved in only 23 and community groups involved in only ten. There were few collaborations exclusively between networks in the developing world (four OHNs) and only 15 OHNs reported monitoring and evaluation information. The majority of OHNs worked on supporting communication, collaboration, information sharing, and capacity building. INTERPRETATION: Amid concerns about there being insufficient strategic direction and coordination in the growth of OHNs, our study provides empirical evidence about limitations in stakeholder representation, apparently absent or ambiguous monitoring and evaluation structures, and potential areas of duplication. The collective strategic functioning of OHNs might be improved by more transparent reporting of goals and outcomes of OHN activities, as well as more collaborations led by networks within the developing world and increased attention to environmental health. FUNDING: None.