Surveillance of zoonoses in livestock and humans: experiences from AHITI interns cohort 5

Our participation in the ZooLinK suite of projects will remain memorable. We have acquired sufficient knowledge and experience through the exposure given to us by ZooLinK staff and our participation in the target areas of the project. Since we joined the project on May 2018, we have rotated among the three functional units of the project, namely: (1) veterinary team who visit the livestock markets and slaughterhouses; (2) laboratory team and (3) clinicians team who visit the health centres. The following report will focus on the veterinary team. It describes the activities carried out therein and their relevance to the project.

Two of the interns working in the laboratory (foreground)

A normal ZooLinK day begins with packing the field car with the required consumables a day before the field. Such consumables include; red and purple topped vacutainers, nasal swabs, digital thermometer, heart girth measuring tape, ziplock bags, barcodes, consent forms, faecal pots, gloves, disinfectant, water, coveralls and gumboots etc.

“…our internship has equipped us with adequate disease surveillance skills in the animal field that will help us to extend the knowledge of disease control to farmers…”

In the field, the veterinary team splits into two groups; one group works at the livestock markets and the other at the slaughterhouse. Upon arrival, at the livestock market, the animal is randomly selected and the owner identified to seek consent for sampling the animal and to answer a few questions. If he/she agrees, he/she signs two consent forms one of which goes with the animal owner while the other one remains for ZooLinK records. Before sampling, the animal is humanely restrained to ensure the safety of the animal, handler and person collecting the samples. Physical examination begins before the actual sample collection. Which entails checking for any abnormal discharges from the mouth, eyes, genitals and nose. On the skin swellings and injuries are recorded when present. Nature of the ocular mucous membranes is assessed and recorded, the mouth is checked for any lesions and sores as well the ageing is done from the dentition. The pre-scapula lymph nodes are palpated on both sides to ascertain any enlargement. Lifting of the loose skin of the neck is done to test for skin elasticity. The body condition of the animal is cored in a scale of 1-5. The fleece condition is recorded as either rough or normal and a tape measure used to measure the heart-girth to estimate the weight of the animal. The temperature is taken per-rectal. After the physical examination, the actual collection of the samples begins. Blood is collected from the jugular vein into a red top vacutainer (plain blood) for serology and an EDTA-purple top vacutainer (uncoagulated blood) for parasitology and hematology.

One of the AHITI interns sampling blood from a sheep

Nasal swabs are used to collect swabs from the nose. Nasal swabs are later cultured in the lab and used to test for the presence of Staphylococcus aureus. Fresh faeces are collected per-rectal and placed into a faecal pot. The faecal sample is cultured in the lab to determine the presence of E. coli, Salmonella and Campylobacter. External parasites like ticks, lice etc. are also collected if encountered. The same procedure takes place in the slaughterhouses but in addition, post-motem lesions like cysts, flukes, are recorded and collected inclusive of mesenteric lymph nodes from the pigs.

We are glad to declare that our internship has equipped us with adequate disease surveillance skills in the animal field that will help us to extend the knowledge of disease control to farmers and other stakeholders back at home.

This article was authored by the cohort 5 interns from the Animal Health and Industry Training Institute (AHITI): Sarah Nyambura, John Parkasio and Silas Muriithi.

Establishing a serum bank of samples from confirmed cysticercosis positive and negative pigs

This serum bank will serve as a platform for future development and validation of diagnostic tools that will allow for a quicker and more accurate diagnosis of porcine cysticercosis. The disease is zoonotic, meaning that it can be transmitted between humans and animals (pigs). The tapeworm, Taenia solium, causes taeniasis in people and can cause abdominal pain, diarrhoea, nausea and indigestion. The larval stage of the worm can infect both pigs and people. In people, the larval stage can become encysted in the brain and/or spinal cord, causing neuro-cysticercosis. This is an important cause of acquired epilepsy – a debilitating disease. The signs of the disease in humans include seizures, chronic headaches, dementia, and may result in death.

“The project aims to establish a bank of serum samples from confirmed cysticercosis positive and negative pigs.”

Fig.1. Making 3mm thick slices

We have organized to visit and buy pigs from 13 slaughter slabs spread across Busia and Kakamega Counties. The process involves contacting a trader/farmer at the slaughterhouse to deliver a pig on site. On the day of slaughter, intricate bargaining with the trader/farmer to ensure value for money ensues. This is a complex process given that the pricing is usually fluid, with no clear parameters to determine the price. The prices are usually based on the physical appearance of the pig which requires a lot of experience. Once the prices have been settled, photos of the pig are taken, and demographic information, such as age, heart-girth measurement and back length, are recorded. The blood is collected at ante-mortem and lingual palpation is performed. The pig is slaughtered and weighted perimortem, and then skinned. This is a source of amusement among the butchers who have christened this ‘naked pig carcass’ as Mbuzi ulaya loosely translating to a ‘European goat.’ The carcass, together with the head, lungs, liver and diaphragm, are chilled overnight and sliced (Fig.1.) in the morning.

The slices ought to be at least 3mm thick to ensure any cyst present can be exposed. This is a laborious process that usually takes 3-4 hours to complete. The most recent studies carried out in the same region recorded a prevalence of 37.6% using a serological method, and 34.4% by lingual palpation. It is such findings, combined with an increase in pig keeping and consumption, that call for such a study. Currently, there exist several serological tests which detect circulating T. solium cyst antigens in humans and animals. Yet most of these tests have poor specificity, leading to a large number of false positives and hence, limiting their diagnostic capacity. We look forward to sharing more insights from this project in subsequent newsletters.

This article was authored by Dr Maurice Karani who is ZooLinK Research Assistant and Field Coordinator.

Surveillance of Zoonoses in livestock and humans: a note from the post-doc

After many months of careful planning and preparation, the main ZooLinK surveillance project has set sail! We have been sampling in the twelve selected live-stock markets, four each in the counties of Busia, Bungoma and Kakamega. At each market, we are collecting data on, and biological samples from, up to ten randomly selected cattle and small ruminants. Sampling in livestock markets can be challenging as traders are busy people who want to sell their animals. Moreover, some shared with us the perception that having their animal sampled may send the wrong message to future buyers. We are reminded once again of the importance of engaging local stakeholders at an early stage to help explain the study purpose and facilitate study participation.

Public engagement session in one of our sampling sites

We then expanded our sampling by including cattle, small ruminants and pigs that are taken for slaughter at selected slaughterhouses and slaughter slabs in the surroundings of the included livestock markets. Concurrently, we are also sampling outpatients at the three County referral hospitals and other selected health centres in the study area. All collected biological samples are processed and tested for fifteen selected zoonotic diseases at our field lab in Busia. Some of the animal samples shall also be used for genetic studies to identify changes in breeds as farming systems intensify over time.

We are all looking forward to working and learning together during our ZooLinK journey!

This article was authored by Dr Laura Falzon who is the Post-doctoral scientist (surveillance component) in the ZooLinK suite of projects.

International One Health Day

International One Health Day, 2017

This blog entry was authored by Matthew Baylis, Principal Investigator-HORN Project

November 3rd is International One Health Day. One Health is the idea that the health of people, animals, plants and the environment are interlinked, and that health will be optimised by different disciplines (such as medicine, veterinary science, social science, economics, environmental science) working together rather than independently. It goes to the heart of multidisciplinarity in science, with large gains to be made by bringing together experts who may approach the similar problems with different skill sets and approaches.

Community members at the Mara being trained about holistic land management to optimize livestock productivity with minimal environmental impact by trainers from the Savory Institute; Photo credit: ZED Group

There are innumerable examples of advances in human medicine that have led to improvements in animal health – as just one example, some of the biggest equipment in the University of Liverpool’s animal clinics (such as MRI scanners) come from human hospitals.  But there are also many examples of veterinary medicine leading to improvements in human health or medicine.  In the UK, we are now safe to eat raw or undercooked eggs owing to a major programme to eliminate salmonellosis from the layer industry. The incidence of human rabies in much of East Africa has declined, owing to vaccination not of people, but of dogs.  My favourite example relates to transmissible spongiform encephalopathies. In the early 1960s members of the Foré tribe in Papua New Guinea were dying from a novel disease called Kuru (related to variant CJD). An American medic attempted transmission experiments with chimps that were not successful, leading to the conclusion that the disease was of genetic origin. The medic spoke on this in the UK and, in the audience, was a veterinarian.  The vet recognised that the characteristics of Kuru seemed identical to that of a sheep disease called scrapie, which had been shown to be transmissible. He alerted the medic, who repeated the experiments, this time successfully, and went on to get the Nobel Prize for Physiology (the medic, not the vet, of course).

A boy keenly reading a vaccination certification after his dog had been vaccinated against rabies; Photo credit: Rabies Free Kenya

Find out more about International One Health Day here: https://www.onehealthcommission.org/en/eventscalendar/one_health_day/

The University of Liverpool is a big player in the area of One Health. We have had a string of large projects in the area of zoonotic diseases and food systems which contribute significantly to non-communicable diseases. Most recently, we have been given a large RCUK-funded Global Challenges Research Fund (GCRF) Growing Research Capability (GROW) award called One Health Regional Network for the Horn of Africa (HORN), which aims to strengthen institutions and train researchers and support staff in areas relevant to One Health in 4 countries of the Horn of Africa: Kenya, Ethiopia, Eritrea and Somalia. It is early days, but you can follow progress here: https://www.facebook.com/groups/1473530819359799/

The One Health Regional Network Logo

Follow us on Twitter: @OneHealthHORN to get our One Health Day updates at the top of every hour today.

Our website, www.onehealthHORN.net (coming soon!)

 

Uppsala Health Summit: Behaviour change and biosciences necessary to tackle infectious diseases threats

This blog entry has been reblogged from the CGIAR research programme on livestock website featuring the Uppsala Health Summit, themed “Tackling Infectious Disease Threats” that was held as from 10th to 11th October, 2017 of which the team lead of our ZED Group, Prof Eric Fèvre, presented work from our Urban Zoo project on how pathogens from livestock are introduced and spread in urban environments .

Photo credit: Fernanda Dórea

Research shows that six out of 10 emerging human infectious diseases are zoonoses. Thirteen zoonotic diseases sicken over 2 billion people and they kill 2.2 million each year, mostly in developing countries. Poor people are more exposed to zoonoses because of their greater contact with animals, less hygienic environments, lack of knowledge on hazards, and lack of access to healthcare. 80% of the burden of these zoonotic diseases thus falls on people in low and middle income countries.

A workshop at last week’s Uppsala Health Summit zoomed in on zoonotic diseases in livestock and ways to mitigate risk behaviour associated with their emergence and spread. Critical roles and behaviours of people and institutions in preventing, detecting and responding to zoonotic livestock diseases were identified – as well as necessary changes and incentives so we are well-prepared for infections long before they reach people.

These zoonotic infections often originate from livestock which can serve as a bridge for disease transmission between animals and humans. Thus, controlling zoonotic diseases in livestock is an important means to reduce infectious disease threats to humans. Zoonotic diseases are a threat not only to public health, but also to food production, food safety, animal welfare, and rural livelihood.

Within their own sectors, researchers and practitioners from different fields have a considerable understanding of outbreaks of disease and how to handle them. They also know they must bear in mind how local factors, traditions and politics can determine the outcome. But a disease outbreak causing deaths and disruption is always a complex picture. It requires all actors to gather knowledge from beyond their own field of expertise to be fully able to address disease outbreaks efficiently.

The 50 or so workshop participants, comprising vets and medics in a one health context, tackled two objectives. First, they identified who is involved in preventing, detecting and responding to zoonotic livestock diseases and the associated behaviours that need to change. Second, they set out some initial recommendations and incentives to mitigate risky behaviours.

Biosciences and behaviour

Co-organizer Ulf Magnusson from the Swedish University of Agricultural Sciences explained in his opening remarks that the challenge for the group lies at the intersection between biosciences and behaviour. We know a lot about the biosciences; but for the biosciences to be effective, we need to change and strengthen the behaviours of different actors involved in infectious diseases.  He particularly emphasized the ‘one health’ element, that we need to look beyond animals to develop productive collaboration across the veterinary and medical professions.

Three people were charged to set the scene: Barbara Wieland from the International Livestock Research Institute (ILRI) introduced mainly Ethiopian experiences from rural settings; Eric Fèvre from the University of Liverpool and ILRI gave some urban perspectives from Kenya; and Elisabeth Lindahl-Rajala from the Swedish University of Agricultural Sciences shared a case on controlling Brucella in Tajikistan.

Wieland argued that effective prevention, detection and response requires good understanding of the specific ‘local’ situations in which livestock are kept and especially the roles of different people in this. Her research pointed to major gender differences with women closer to the animals, their care and feeding, and the farmstead and men more involved in marketing, slaughter and dealing with externals like vets. She also pointed to local cultural practices and their effect on handling and consumption of some animal-source products like milk or cheese. Taking account of these role differences and cultural aspects is very critical when designing interventions to tackle zoonotic infectious diseases. Focusing on the farmer actor, she identified especially the need for smaller more manageable changes, the transformative opportunities offered by information and communication technologies and the potential of one health to help overcome capacity and infrastructure problems in remote rural areas.

Fèvre reported on research in Nairobi to understand how pathogens from livestock are introduced and spread in urban environments. He introduced the notion of ‘interfaces’ – physical and social – as useful to help understand disease transmission between livestock and food systems, arguing that the behaviours of people, institutions and policies in and across these interfaces are critical in zoonotic disease spread. Looking at the food systems in a city like Nairobi, value chains connect the many different actors, moving animals and products, moving payments, moving animal health information, and ultimately also accelerating or hindering the spread of diseases. While Wieland focused on rural farmers as a primary actor, the urban systems and chains that Fèvre isolated comprise many different public and private actors, each with specialized roles and sets of desirable behaviours. Mapping and measuring these from a zoonotic perspective will allow current and future disease risks to be understood, leading to improved prevention, detection, and response.

Photo credit: Tanja Strand

Lindahl-Rajala reported on research on the prevalence of Brucella, the cause of brucellosis, in the city of Dushanbe in Tajikistan. Globally, some 500,000 cases of brucellosis occur each year, making it one of the most common bacterial infection spread from animals to humans worldwide. In Tajikistan, increasing urbanization of people is leading to increasing urbanization of animals and increased threats from brucellosis though consumption of raw dairy products or direct contact with infected animals. Research showed Brucella to be widespread in the city’s animals. It also showed low levels of awareness of the diseases among producer and consumers as well as several risky behaviours.  Lindahl-Rajala identified three priority actor groups who need to be targeted to tackle the spread of this disease:  farmers who need to adopt safer behaviours, consumers who need to avoid raw milk from street vendors and policy makers who need to give greater attention and devise a long-lasting control program.

Mapping actors and behaviours

Starting from the three presentations and using their own expertise, the initial task of participants was to take each of the three priorities – prevent, detect and respond – and map the main actors and the desirable behaviours/roles necessary to tackle the spread of zoonotic infectious diseases.

Actors identified across the different priorities included livestock owners and keepers, household members, vets, researchers and academics, diagnostic labs, local government, ministries, traders, transporters, medics and physicians, the media, private companies and consumers. One group, tackling ‘responding’ identified the animals themselves as key actors, in this case to ‘stay put’ and avoid people.

After this broad mapping of the actors, participants were asked to dive deeper, to prioritize the most important actors and behaviour changes for different rural and urban scenarios and likely incentives to achieve these changes. This led to more focus on specific actors and behaviours and to a wide range of useful materials and lessons to build out recommendations in this area (see photos below).

Emerging messages

Sofia Boqvist from the Swedish University of Agricultural Sciences reported some key insights to the summit plenary (see picture top of this post).

Under ‘prevention’, the three key messages identified were: effective biosecurity measures, good communication all round, and long term investment. She emphasized a point from within the group that detecting, and treating, a zoonotic infection in a sick person is an indicator of failure. Investing in up-front prevention of disease in animals will keep people healthy.

Under ‘detection’, the three key messages identified were: good infrastructure in rural areas – to overcome geography, distance and poor connectivity, joint medical/veterinary surveillance so all the key actors look out for all the risks, and proper compensation to protect livelihoods when animals need to be culled to protect lives.

Under ‘response’, the three key messages identified were: the importance of strong and effective institutions that do their assigned tasks and roles well, effective communications and especially media engagement to provide proper information and avoid scares, and sufficient resources and expertise to actually tackle the situations. In an informal unscientific poll of participant perceptions in the workshop, this was the area highlighted as the weakest link among the prevent, detect and respond priorities.

Participants discuss zoonotic disease mitigation priorities. Photo credit: Erik Bongcam-Rudloff

More information

The workshop was organized by Sofia Boqvist and Ulf Magnusson from the Swedish University of Agricultural Sciences. Magnusson leads the Livestock Health Flagship of the CGIAR Research Program on Livestock.

A summary report from the workshop will be produced as part of the overall summit report.

See the presentation by Barbara Wieland; more on this work

See the presentation by Eric Fèvre; more on this work

See more on Elisabeth Lindahl-Rajala’s work in Tajikistan

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