Anthropological musings on animal-human interactions and zoonotic disease

Anthropological musings on animal-human interactions and zoonotic disease

Anthropological musings on animal-human interactions and zoonotic disease

Fruit bat in Ghana. Image: Kofi Amponsah Mensah

Fruit bat in Ghana. Image: Kofi Amponsah Mensah

I was really excited when, a few years ago now, an opportunity arose for me to work on an interdisciplinary project looking at bats and zoonotic disease(diseases that go from animal to humans).  The truth was that I was more excited about the bats than the zoonotic disease stuff.

I’ve always loved bats for their soft, velvet touch, tiny faces full of expression and translucent wings. I also love their mystique and their anthropological symbolism.

Anthropologically, bats are anomalous and liminal animals. They are not easy to categorise: they look like mice but fly like birds; they are social but occupy the night. I had one of the best times in my anthropological career when I was invited to spend a night catching and tagging bats in Ghana.

Working with an interdisciplinary team, I came to learn much more of the many diseases harboured by bats (perhaps I will never again have the opportunity to go bat catching and to handle bats with the same naked enthusiasm). In the social science research on bats and zoonotic diseases (as I did actually have to do some anthropology and wasn’t able to convert to a full-time bat catcher), we focused on bat-human interactions and the policy implications thereof.

Disease spillover

The interactions between humans, domestic animals and wildlife are, in my view, the critical nexus where the scope for disease spillover occurs and, potentially, where a solution might lie. In my conceptualisation of animal-human interactions I focused on immediate, physical interactions – moments when humans and bats came together (men hunting bushmeat; kids playing with bats; families living in close proximity with bats), and in times and spaces where humans came into contact with bats’ bodily fluids or faeces (cleaning bat droppings off the car, eating fruit previously bitten by a bat).

Cast forward a few years, and I’m lucky enough to be involved in another interdisciplinary zoonotic disease project. This time it’s in Tanzania and I am focusing on cattle and pastoralists.

Now cows aren’t bats. And I can’t say that I have always loved cows. But, they are beautiful and regal (and, in Tanzania, a little bit scary).

Masaai woman milking. Image: Tiziana Lembo

Maasai woman milking. Image: Tiziana Lembo

And like bats, cows have important anthropological significance: in Southern Africa, where I grew up, cows are used for bridewealth, for establishing and solidifying social relationships, for determining lineages and for livelihoods. Similarly in Tanzania, where Maasai cattle are critical for establishing marriage relations, they bring children into lineages and have religious significance.

Working in Tanzania, and thinking about zoonotic disease, has made me realise just how complex animal-human interactions can be. I have come to realise that my focus – my own inbuilt bias – emphasised live human beings interacting with either live or dead animals, or with the bodily products of those animals, in a kind of one-to-one relationship. In my head, all these people were villagers or ordinary people going about their normal lives (my anthropological bias coming to the fore). For me, for a zoonotic disease to occur, a human had to interact with an animal that was sick or with the bodily fluids of that animal.

Rethinking animal-human interactions

But attending a workshop in Tanzania, in which vets, geographers, epidemiologists, modellers and more came together to discuss zoonotic diseases forced me to reconceptualise human-animal interaction in relation to zoonoses. It led me to start thinking about the many different ways in which animals can get sick and how human behaviours – often unseen and apparently unconnected – can affect animals’ states of health and the potential for human infection.

I came to realise that I hadn’t really considered how chains of interactions could occur between humans and animals, and nor had I considered the ways in which human-animal interactions could involve a microbial dimension or, if you will, microbial-animal–human interactions.

My work with others on fruit bats had already alerted me to the ways in which in Bangladesh, Australia and elsewhere bats roosting or eating fruit above domestic animals (horses in Australia, pigs in Bangladesh) can cause illness in these animals which can, in turn, infect humans. In some instances, perhaps exemplified in peri-urban environments (i.e. those at the interface between town and country) where wild and domestic animals are often in close proximity, people may not always be aware of the animal-to-animal-to-human interactions that are occurring.

Exactly which animals are interacting with other animals also affects the disease dynamics and which pathogens are involved. For example, fruit bats carry Henipaviruses which can be transmitted to pigs, horses (and humans) but other bats do not; similarly, foot and mouth disease affects ruminant wildlife and livestock, but not carnivores. Brucellosis affects many different animals – buffalo, cattle, pigs, sheep – and there are many different species of Brucella, with goats being associated with the most pathogenic of these species.

Movement and social networks

Cattle market in Tanzania. Image: Mary Ryan

Cattle market in Tanzania. Image: Mary Ryan

Movement and transportation offer further scope for understanding interactions and affect the possibility of infection. Transporting animals (sick and healthy) is significant as it can allow diseases to ‘jump’ across time and space, and markets play a key role. Here the length of time the animals are together is significant: for bovine tuberculosis short contacts at markets are not important, but foot and mouth is highly contagious even over brief contact periods.

The effect of movement is also influenced by the social networks of the livestock owners, both in terms of who these owners come into contact with and in terms of who they exchange animals with. And some livestock owners may act as ‘super spreaders’ by having a large number of networks and frequent interactions with many different people.

Thus, indirect human-to-human interactions completely removed from the animals themselves can shape how human-animal interactions take place.

The microbial dimension

Another dimension, although surely not the last, occurs at the level of microbial-animal-human ‘interactions’ and food-borne zoonotic diseases such as non-typhodial Salmonella and Campylobacter. Here, abattoirs, slaughter practices and cooking habits are particularly relevant as these diarrhoea-causing bacteria live on the skin and in the guts of animals.

Factors such as how an animal is slaughtered come into play: does, for example, raw meat come into direct contact with skin or faeces when a knife penetrates the intestines? But these bacteria could equally well live independently of animals – on knives, cutting surfaces, in the vehicles used to transport meat, on human hands – and can in this way infect both humans and animals. So microbial-human ‘interactions’ have a role to play too in considering zoonotic disease infection.

Now microscopic bugs are not cute, aren’t regal and don’t have an important symbolic role in anthropological literature. But isn’t it fascinating how many different kinds of interactions shape whether or not zoonotic disease infection occurs?

Having to think well beyond immediate face-to-face, physical interactions between humans and animals opens new horizons on how we conceptualise Livestock, Livelihoods and Health and in terms of how we respond to zoonotic diseases. Which reminds me: my role in this interdisciplinary project is to focus on policy understandings of zoonotic disease. I wonder what conceptualisations of animal-human interaction underlie current zoonoses-relevant policies in Tanzania?

Dr Linda Waldman is a Research Fellow at the STEPS Centre (Institute of Development Studies/University of Sussex).

Article originally appeared on the Livestock, livelihood and Health website on 30th March, 2016 authored by Dr Linda Waldman. Available at: http://livestocklivelihoodsandhealth.org/blog/musings/

Updates direct to your Email

Enter your email address to receive notifications of new posts and opportunities by email.

Join 7,243 other subscribers

Post categories

The Philippines Rabies vaccination campaign: a One Health success story

The Philippines Rabies vaccination campaign: a One Health success story

The Philippines Rabies vaccination campaign: a One Health success story

Philipines Rabies vaccinationRabies still causes the death of tens of thousands of people every year. Knowing that dog bites are responsible for more than 95% of all human rabies cases, the eradication of canine rabies is the only way to end the disease’s animal-human transmission cycle. It is estimated that vaccinating 70% of dogs in zones where rabies is present can dramatically reduce human cases.

The World Organisation for Animal Health Director-General, Dr Monique Eloit, explains the work of the OIE carried out regarding the One Health concept, with a particular focus on the success story of the Philippines Rabies vaccination campaign, where 1,701,150 doses of rabies vaccines have been delivered between January and February 2016. These recent deliveries raise the number of doses purchased by a beneficiary country in collaboration with WHO through the OIE rabies vaccine bank to almost 8 million.

The OIE thanks the WHO Pandemics and Epidemics Diseases Department for authorizing the use of the interview’s footage recorded in December 2015.

?

View the recording below

Updates direct to your Email

Enter your email address to receive notifications of new posts and opportunities by email.

Join 7,243 other subscribers

Post categories

Researchers offer new insights into animal-to-human disease transmission

Researchers offer new insights into animal-to-human disease transmission

Researchers offer new insights into animal-to-human disease transmission

Key findings on who gets sick and why from the Dynamic Drivers of Disease in Africa Consortium are being shared at One Health for the Real World: zoonoses, ecosystems and wellbeing, a high-level international symposium taking place at the Zoological Society of London this week.

Jeremy Farrar, Director, Wellcome Trust

Jeremy Farrar, Director, Wellcome Trust

Resilient global health systems, strong civil society and leadership for those health systems and broad research agendas from disparate fields are the three essentials to face the challenges of 21st century equity and health, according to Professor Jeremy Farrar, Director of the Wellcome Trust.

Speaking at  the One Health for the Real World: zoonoses, ecosystems and wellbeing symposium, co-organised by the STEPS-led Dynamic Drivers of Disease in Africa Consortium and the Zoological Society of London, with support from the Royal Society, Professor Farrar stressed that people were not passive observers in history and could bring about these changes.

However he said a move to individualised medicine would act against public access, equity and a holisitic approach to health.

Key findings from the Drivers of Disease consortium are being shared with high-level policymakers, practitioners and academics at the two-day symposium, which is taking place at the Zoological Society of London. They include representatives of the World Health Organization, the UK Department for International Development, the UN Food and Agricultural Organization and EcoHealth Alliance.

The Consortium has been researching the relationships between diseases transmitted from animals to people (zoonoses), ecosystems and wellbeing for the past four years. In particular it has explored henipavirus infection in Ghana, Rift Valley fever in Kenya, Lassa fever in Sierra Leone, and trypanosomiasis (sleeping sickness) in Zambia and Zimbabwe.

One Health

Importantly, it took a One Health approach to its research. One Health recognises the interconnectedness of human and animal health with environmental health. It seeks to promote the collaborative effort of multiple disciplines, working locally, nationally and globally to attain optimal health for people, animals and the environment.

The Drivers of Disease Consortium involved 20 partners in Africa, Europe and America. It saw social scientists from STEPS (IDS/University of Sussex) working together with ecologists, epidemiologists, virologists and other natural scientists – with the integration of multiple disciplines and research approaches proving essential to learn how diseases transmit from animals to people.

Local and participatory

The research has underlined the value of taking a ‘local’ approach. First, understanding the local circumstances in which diseases pass from animals to people was shown to be essential for disease preparedness and prevention.

Second, participatory research undertaken by the Consortium showed the importance of considering local people’s various perspectives to open up new lines of inquiry and reveal links otherwise missed.

Policy and practice

Professor Melissa Leach, Director of the Institute of Development Studies (IDS) and lead researcher for the Consortium, said: “This work has many implications for policy and practice. It suggests opportunities for new integrated interventions involving collaboration between vets, medics, environmental planners, agricultural technicians, social development practitioners and more.

“Such interventions need to be adapted to diverse local settings and contexts yet also have the potential to scale up and out. Identifying and taking these opportunities forward is what doing ‘One Health for the real world’ means.”

Silos and hierarchies

She added that the work was just beginning: “Unfortunately, there are forces that make the One Health approach difficult. These include the tendency for sectoral and disciplinary silos and the dominance of old hierarchies, interests and perspectives. Findings ways to overcome these forces is the key challenge now.”

The research has been funded by the Ecosystem Services for Poverty Alleviation (ESPA) programme. ESPA spokesperson Rob Bruce said: “We are a proud partner in this project. The work of the team has been phenomenal, delivering real game-changing science that could genuinely save and improve lives. This is what ESPA is all about: helping nature to help people in an effort to make the world a better place for both.”

This originally appeared on the Institute for Development Studies website on 17th March, 2016 authored by Naomi Marks. Available at: http://www.ids.ac.uk/news/researchers-offer-new-insights-into-animal-to-human-disease-transmission

Updates direct to your Email

Enter your email address to receive notifications of new posts and opportunities by email.

Join 7,243 other subscribers

Post categories

New SARS-like virus is poised to infect humans

New SARS-like virus is poised to infect humans

New SARS-like virus is poised to infect humans

Otonycteris_hemprichiiA SARS-like virus found in Chinese horseshoe bats may be poised to infect humans without the need for adaptation, overcoming an initial barrier that could potentially set the stage for an outbreak according to a study at the University of North Carolina at Chapel Hill.

The work, led by Ralph Baric, Ph.D., professor of epidemiology at UNC’s Gillings School of Global Public Health, comes on the heels of two recent high-profile outbreaks – Ebola and Zika – for which there are no vaccines. The two outbreaks combined claimed thousands of lives and cost billions in foregone economic growth.

“The capacity of this group of viruses to jump into humans is greater than we originally thought,” said Vineet Menachery, Ph.D., the study’s first author. “While other adaptations may be required to produce an epidemic, several viral strains circulating in bat populations have already overcome the barrier of replication in human cells and suggest reemergence as a distinct possibility.”

Baric and Menachery worked with SARS-like coronavirus sequences isolated from Chinese horseshoe bats, where SARS originated. Based on the sequences, they reconstructed the viruses to evaluate their potential to infect human cells and in mice. They found that the newly identified virus, known as WIV1-CoV, could bind to the same receptors as SARS-CoV. They also showed that the virus readily and efficiently replicated in cultured human airway tissues, suggesting an ability to jump directly to humans.

“To be clear, this virus may never jump to humans, but if it does, WIV1-CoV has the potential to seed a new outbreak with significant consequences for both public health and the global economy,” said Vineet, whose work is reported in the Mar. 13, 2016 online version of theProceedings of the National Academy of Sciences.

The research team also found that antibodies developed to treat SARS were effective in both human and animal tissue samples against WIV1-CoV, providing a potent treatment option if there were an outbreak. However, the limitation to treat with antibodies is the same as with ZMapp, the antibody approach used for Ebola: producing it at a large enough scale to treat many people. Also, in terms of prevention, existing vaccines against SARS would not provide protection for this new virus due to slight differences in the viral sequence.

SARS, short for severe acute respiratory syndrome, was first seen in an outbreak in 2002 and resulted in 8,000 cases and nearly 800 deaths. Spread through airborne contact, its onset presents symptoms similar to the flu with a dry cough but can accelerate rapidly to pneumonia, filling the lungs with fluid and putting extreme stress on the body’s immune system. According to the Centers for Disease Control and Prevention, SARS’ mortality rate can range from less than one percent in patients below 24 years old to more than 50 percent in patients aged 60 and older. Baric and his team believe that WIV1-CoV has the potential to induce similar results with proper adaptation to humans.

“This type of work generates information about novel viruses circulating in animal populations and develops resources to help define the threat these pathogens may pose to human populations,” Baric said. “It’s important to note that it’s not an approach that’s limited to SARS or SARS-like viruses. It can be applied to other emerging pathogens to helping us prepare for the next emergent virus, whether it be MERS, the Zika virus or something we haven’t even heard of yet.”

This post originally appeared on the ScienceBlog website on 14th March, 2016. Available at: http://scienceblog.com/483306/new-sars-like-virus-poised-infect-humans/


 

Updates direct to your Email

Enter your email address to receive notifications of new posts and opportunities by email.

Join 7,243 other subscribers

Post categories

Kenya Zoonotic Diseases Priority Map

Kenya Zoonotic Diseases Priority Map

Kenya Zoonotic Diseases Priority Map

Updates direct to your Email

Enter your email address to receive notifications of new posts and opportunities by email.

Join 7,243 other subscribers

Post categories

MRSA in humans and animals in Kenya (an overview)

MRSA in humans and animals in Kenya (an overview)

MRSA in humans and animals in Kenya (an overview)

Introduction

Staphylococcus aureus is an important bacteria because of its ability to cause a wide range of diseases and adapt to diverse environments. The bacteria causes infection to both humans and animals by colonizing their skin, skin glands and mucous membranes, resulting to septicemia, meningitis, and arthritis in man and mastitis in the bovine, as well as poultry limb infections [1]. Methicillin-resistant Staphylococcus aureus (MRSA) is a type of staphyloccocal bacteria that is resistant to beta-lactams. It is a common cause of healthcare-associated infections in both developed and developing countries, though limited information is available from the latter [2] [3].

MRSA Resistance mechanisms

The resistance of S. aureus against methicillin is caused by expression of Penicillin binding protein 2A (PBP2A) encoded by the mecA gene [4]. PBP2A has low affinity for beta-lactam antibiotics such as amoxicillin, methicillin and oxacillin, rendering these antibiotics ineffective in treating infections caused by Staphylococcus aureus. Lately, a new methicillin resistance mechanism gene, mecC has been reported in isolates from humans and animals [5]. This therefore means that MRSA is not only associated with prior exposure to a health care facility but also raises concerns for infections originating from the community and veterinary species, and there is a possibility of a cross-infection with animals being potential sources of MRSA infection to humans [6].

MRSA the Kenyan perspective

In 1997, documented rates of MRSA in Kenya were 28 percent of all S. aureus tested in city hospitals. A separate hospital-based study during the same year found the prevalence of MRSA to be 40 percent of all S. aureus infections. In 2006, MRSA was found in 33 percent of S. aureus isolates at another hospital based study [2]. Resistance, therefore, may indicate illegal use of drugs by the public. A survey of farmers in Kenya found that the majority conflated treatment with prevention, effectively replacing hygiene and feeding practices as standard disease prevention with disease treatment [2]. Patterns of resistant Staphylococcus aureus in cattle imply a significant difference in resistance profiles of large and small scale farms, with smaller producers using nearly twice the amount of antibiotics per animal compared with larger producers [7]. The prevalence of multidrug resistance, at 34 percent on small farms, was likewise almost double the rate found at large farms [2].

The dillemma

There is evidence that MRSA infection increases the risk of mortality, morbidity, medical care costs and loss of productivity. The increased medical care costs accrued directly as expenses caused by extension of hospital stay, additional diagnostic or therapeutic procedures, and additional antibiotic use while loss of productivity is due to absence from work during hospitalization. At the same time, published data  concerning  the  antibiotic  susceptibility  patterns  of  MRSA  in  sub-Saharan  Africa  are extremely limited, and few studies on it have been conducted in Kenya [2] [3]. Many studies on MRSA in Kenya are mainly cross-sectional with a focus to determine the prevalence, identifying the antibiotic resistance but they have not focused on the zoonotic significance of MRSA. There is need to understand on how the resistance to MRSA is changing over time so as to be able to clearly visualize the mechanism and transfer of resistance genes in the population [3].

Zoonotic directionality of resistance

It is therefore important not only to determine the antibiotic resistance, but also determine what and who is causing this resistance in humans and animals belonging to the same household and also determine the temporal and spatial change of this resistance over time. This is because, by understanding the dynamics and the epidemiology of MRSA infection over time it will be possible to develop more informed prevention and control strategies, develop more sound policies including education on the rational use of antibiotics to the public.  At the same time it is important to  fill the knowledge gap [3] (especially from a developing country setting) in the zoonotic directionality of MRSA.

References 

Waldvogel, F.A., Staphylococcus aureus, in Principles and practices of infectious disease, G.L. Mandell, D. R.G., and B. J.E., Editors. 2000, Pennsylvania, USA.: Churchill Livingstone, Philadelphia, . p. 1754-1777.

Global Antibiotic Resistance Partnership-Kenya Working Group, Situation Analysis and Recommendations: Antibiotic Use and Resistance in Kenya, S. Kariuki, Editor. 2011, Center for Disease Dynamics, Economics & Policy: Washington, DC and New Delhi.

WHO, Antimicrobial resistance global report on surveillance. 2014. p. 1-256.

Wielders, C.L.C., et al., mecA Gene Is Widely Disseminated in Staphylococcus aureus Population. J. Clin. Microbiol., 2002. 40(11): p. 3970-3975.

Paterson, G.K., et al., The newly described mecA homologue, mecALGA251, is present in methicillin-resistant Staphylococcus aureus isolates from a diverse range of host species. J. Antimicrob. Chemother., 2012. 67(12): p. 2809-2813.

Ferreira, J.P., et al., Transmission of MRSA between Companion Animals and Infected Human Patients Presenting to Outpatient Medical Care Facilities. PLoS ONE, 2011. 6(11): p. e26978.

Shitandi, A. and A. Sternesjö, Prevalence of Multidrug Resistant Staphylococcus aureus in Milk from Large and Small Scale Producers in Kenya. Journal of Dairy Science, 2004. 87: p. 4145-4149.

7

Updates direct to your Email

Enter your email address to receive notifications of new posts and opportunities by email.

Join 7,243 other subscribers

Post categories