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.

An account of the 11th TAWIRI conference featuring presentations from our team

The eleventh Tanzania Wildlife Institute (TAWIRI) conference themed, “People, livestock, and climate change: Challenges for sustainable biodiversity conservation”, was held from 6th to 8th December 2017 at the Arusha International Conference Centre (Fig.1). The conference had over 300 local and global participants with diverse knowledge on wildlife conservation with 4 keynote papers, 3 symposia, and 7 parallel sessions amounting to 167 oral and 19 poster presentations whose findings are intended to contribute to wildlife conservation in Tanzania and the region.

Figure 1: 11th TAWIRI conference information banner

The opening speech by the guest of honour, Deputy Minister-Tanzania Ministry of Natural Resources and Tourism (Fig.2), noted that the ever-increasing demand for land is a concern to all of us and puts preservation of natural resources in limbo and that there’s a danger of forgetting the fundamental principle that natural resources are not invulnerable and will be vulnerable indefinitely. In this regard, he urged wildlife scientists to continue providing scientific information to the government, wildlife management authorities, conservation and management partners to help reduce anthropogenic impacts on nature as well as information that will help guide effective development and conservation strategies.

Figure 2: Opening speech session – Guest speaker (5th from the right among seated)

The conference was timely to address the current conservation challenges facing Tanzania characterised by an increasing trend of livestock that interact with wildlife within protected areas. It was reiterated that scientific information has been and should be the backbone of the country’s success story in wildlife conservation. Thus, more scientific information is needed and required on how to improve the livelihood of communities around protected areas by enhancing economic growth by preserving natural resources and mitigating climate change impacts for sustainable conservation of biodiversity.

A key message from the conference presentations, as noted by Prof Sinclair (Fig.3), was that both protected areas and human-based areas are necessary but neither is sufficient for conservation. All ecosystems change continuously and therefore static boundaries will not solve conservation problems since they cannot accommodate change. It was reiterated that what is applicable today would be obsolete in 100 years and therefore important to improve human-dominated landscapes to make them more suitable for biodiversity for the future of protected areas and the stability of human ecosystems.

Figure 3: Keynote address by Prof Anthony Sinclair on, “The future of conservation”

Two of our ZED Group members were involved in organizing and participating in one of the 11th TAWIRI conference symposium themed, “Wildlife Diseases and Ecosystem Health” in collaboration with the Wildlife Disease Association, Africa and the Middle East (WDA-AME) section.

Dr Annie Cook (Fig.4) presented a collaborative work entitled, “a successful vaccine trial to control wildebeest-associated Malignant Catarrhal Fever in cattle.” The vaccine was noted to have an efficacy 92.2%.

Figure 4: Presentation on a successful vaccine trial to control wildebeest-associated Malignant Catarrhal Fever in cattle by Dr Annie Cook

Dr Kelvin Momanyi (Fig.5) presented a collaborative work as part of the NEOH case study entitled, “Evaluation of the implementation of One Health in Kenya: A case study of the Zoonotic Disease Unit”. The presentation noted that the One Health office in Kenya (the Zoonotic Disease Unit) had performed moderately from the evaluation applying the NEOH One Health framework with a One Health Index of 0.73269.

Figure 5: Presentation on Evaluation of the implementation of One Health in Kenya by Dr Kelvin Momanyi

Everybody needs to work together to address antibiotic resistance

This article was authored by Judy Bettridge. (Twitter @JudyBettridge)

Not that many years ago, I went to the doctor with a chesty cough that had been hanging around for several weeks.  Normally, I wouldn’t have bothered, but it made cycling to work difficult, so I went to get it checked out. The doctor gave me a course of antibiotics. After a week, I went back to report that they had made no difference to the cough at all. So he offered me a choice – did I want an inhaler or just some more antibiotics? I was rather surprised – surely the choice to take the antibiotics should not rest with me? He was the qualified professional, after all. Responsible antibiotic use was already widely promoted, so why was the medical professional suggesting simply dishing out more of these precious drugs to prolong a treatment that wasn’t working? Maybe he was simply having a bad day, but it seemed to me to show an irresponsible attitude towards the doctor’s role of antibiotic stewardship.

There are many reports of patients putting doctors under pressure to dispense antibiotics, and this is clearly problematic. In many cases, antibiotics are simply not an appropriate treatment and will make no difference to the speed of recovery, especially for viral illness. With widespread media coverage and advertising, many patients are now better informed about the problems of antimicrobial resistance, and that taking unnecessary antibiotics can put them and their families at risk of future infections from antibiotic-resistant bacteria. Doctors are the best-placed to know what is circulating in their local area, and can advise patients when their symptoms are most likely to arise from viral infections – and patients need to be ready to listen and take their advice. However, as my experience shows, doctors may also fall into the trap of anticipating patient expectations for antibiotics where no such pressure exists. Negotiation and understanding between doctor and patient is much more likely to result in satisfaction on both sides – and better compliance with any medication that is prescribed.

Doctors are the best-placed to know what is circulating in their local area, and can advise patients when their symptoms are most likely to arise from viral infections – and patients need to be ready to listen and take their advice.

The very same issues arise in the veterinary profession, with vets and owners or farmers needing to discuss these complex decisions surrounding whether or not antibiotic use is appropriate on a case-by-case basis. Great progress has been made in many areas, especially in eliminating the use of antibiotics as growth promoters in Europe, but there is still much room for improvement. With so much information now available on the internet, it is not uncommon for people to come with very fixed ideas about what is wrong with their animal, and exactly what treatment they want. It is important to remember that many conditions that look the same can have very different causes. The bacteria in our bodies and our environment evolve and change over time, so that even two infections with identical symptoms may be caused by completely different bugs – which need a completely different antibiotic to treat them. For this reason, keeping and reusing antibiotics at a later date is never advisable –especially injectable drugs that can go off within a few weeks of opening. All antibiotics have an expiry date, and using less potent drugs to treat infections is another factor that can encourage antimicrobial resistance to develop.

keeping and reusing antibiotics at a later date is never advisable –especially injectable drugs that can go off within a few weeks of opening

Always check the expiry date of drugs

Where we work in East Africa, as in many other parts of the world, an additional problem is that antibiotic sales and use are frequently unregulated. A lot of commercial animal feed still contains antibiotics – so always check the label and ask the vet or seller if you are in any doubt. Good hygiene in animal production is much better as a preventative, as this can also help reduce viral and parasite infections that will not be helped by in-feed antibiotics in any case. If animals are sick, then involving a vet at an early stage is important to get the right treatment, rather than just buying a drug from an untrained seller and hoping for the best. Especially in remote rural areas, antibiotics may be on sale in the local kiosk, alongside the soap, candles and sweets. These are often human drugs, and so using them in animals is problematic – not only because they are not formulated to give the right dose for that species, but also because there are certain drugs that should simply not be used in animals. This may be because of dangerous residues that pass into the meat, eggs or milk, and so veterinary workers should always advise on how long to leave after treatment before animal products are safe to eat again. If they don’t offer this advice, along with clear instructions on how to use the drugs – ask!  The other reason not to buy antibiotics from unqualified sellers is that there are some drugs that we want to preserve for use in only humans. These critically important antimicrobials are needed to treat difficult and often life-threatening infections in humans that don’t respond to other drugs. Some may be used by vets as a last resort, but their use should always be closely supervised.

Good hygiene in animal production is much better as a preventative, as this can also help reduce viral and parasite infections that will not be helped by in-feed antibiotics in any case.

An antibiotic being administered to a cow

This is why this year’s theme for World Antibiotic Awareness week is “Seek advice from a qualified healthcare professional before taking antibiotics”. Wherever you are in the world, this is sound advice. Advances in science mean that rapid diagnostic tests are coming ever closer, and within a few years, genetic identification not only of the organism causing the infection but also what drugs it is likely to respond to will be possible. This will allow a diagnosis within a few hours, rather than days to weeks it can take with current laboratory methods. Accurate diagnosis, antibiotic selection tailored to every individual case and open discussions between the healthcare professional and the patient or carer as to whether antibiotic use is appropriate in every circumstance are all part of tackling antimicrobial resistance. Whether the healthcare professional is a doctor, nurse, veterinary professional or pharmacist, by making the most of their knowledge to help guide the decision to use antibiotics, everyone can play their part in helping to guard these precious resources for future generations.

Accurate diagnosis, antibiotic selection tailored to every individual case and open discussions between the healthcare professional and the patient or carer as to whether antibiotic use is appropriate in every circumstance are all part of tackling antimicrobial resistance.

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