Non-typhoidal Salmonella (NTS) in pigs in Busia, Nairobi and Malawi

Non-typhoidal Salmonella (NTS) in pigs in Busia, Nairobi and Malawi

This blog post was authored by Catherine Wilson an MRES Student from the University of Liverpool attached under our #ZooLink project

I am investigating the prevalence of Non-typhoidal Salmonella (NTS) in pigs in both Kenya and Malawi in extensive, low input production systems.  The aim is to determine whether invasive NTS are present in the pig population of three study areas; one rural and one urban area in Kenya and one rural region of Malawi. In sub-Saharan Africa, NTS is a leading cause of human mortality, particularly in the very young, old, malnourished, or those suffering from co-morbidities such as HIV or malaria.

Pig slaughter slab in Bumala

Pig slaughter slab in Bumala

An invasive NTS serovar has been found to be able to cause severe disease in chickens; suspicion is therefore arising that transmission between humans is not the sole route of spread of NTS, and that zoonotic transmission, especially from pigs, may have a role to play in the epidemiology of the disease. Should this invasive strain of bacteria be found in pigs, we will assess whether the same serovar clinically affects humans in the same geographical location, using data already gathered from human hospitals. A correlation between the two would indicate that zoonotic transmission may be occurring.

The final part of this study will assess the presence of drug resistance in the strains of NTS isolated from pigs, and whether this bears any correlation to a similar antimicrobial resistance pattern of NTS to that previously detected in humans in the same area.  Should antimicrobial resistance be detected, other management techniques for the swine, such alterations in husbandry and hygiene, may be trialed.  In the longer-term vaccination development may be a possibility as an important method of preventing zoonotic disease transmission in the study areas, for which research is currently in the very early stages.

For sampling,  both faecal and mesenteric lymph nodes samples were collected post mortem from 256 pigs in Busia and 304 pigs in Nairobi.  The location in which the pigs were reared, as well as details of signalment, any previous antibiotic treatment if known and the method of transport of the pig to the slaughterhouse, were recorded for each individual pig.

Samples were processed at the Busia Field Lab and ILRI laboratories respectively. Culture and serotyping was carried out to confirm the presence of Salmonella followed by antimicrobial susceptibility testing to a range of antibiotics.  Positive isolates have then been stored for transport to the UK, where whole genome sequencing will be undertaken to identify the presence of any antimicrobial resistance genes. Once the results have returned, analysis is planned compare antimicrobial resistance profiles of the pig samples to those of humans in the same geographical location, to assess whether zoonotic transmission may be occurring.

Confronting the rising threat of antibiotic resistance in livestock

Confronting the rising threat of antibiotic resistance in livestock

This blogpost was authored by Tim Robinson a co-principal investigator in two of our projects (#UrbanZoo and #ZooLink) and originally appeared on Cambribge Core Blog available at: http://blog.journals.cambridge.org/2017/01/24/confronting-the-rising-threat-of-antibiotic-resistance-in-livestock/

Resistance to antimicrobials is developing faster than ever before due to decades of abusing these important drugs. A ‘post-antibiotic’ world looms as a result, the consequences of which would be many people and farm animals sickening and dying of what, until now, have been preventable or treatable infections.

The good news is that the world is taking notice. On 21 September 2016, the United Nations General Assembly addressed this global challenge. At the UN headquarters in New York, member states reaffirmed their commitment to develop national action plans to stem and reduce the continuing rise in antimicrobial resistance (AMR). These action plans will be based on a Global Action Plan on Antimicrobial Resistance developed in 2015 by the World Health Organisation (WHO) together with the Food and Agriculture Organization (FAO) and the World Organisation for Animal Health (OIE)—the so called ‘Tripartite’. The aims of the Tripartite are first, to ensure that antimicrobial agents continue to be effective and useful to cure diseases in humans and animals; second, to promote prudent and responsible use of antimicrobial agents; and last, to ensure global access to medicines of good quality. Countries will be required to report on their progress in September 2018.

Addressing the rising threat of antimicrobial resistance requires a holistic and multisectoral ‘One Health’ approach, because of the interconnected roles played by animals, people and the environment in the evolution and spread of AMR. The potential role of the livestock sector in mitigating AMR in pathogens of medical as well as veterinary importance is critical. Livestock consume at least half of all antibiotics produced globally and there is a substantial and growing body of evidence linking antibiotic use in livestock production to the development of antibiotic resistance in disease-causing bacteria that pose major threats to public health.

It is widely held that the use of antibiotics in livestock production—in particular, to promote livestock growth and prevent disease, but also to treat disease—could be reduced considerably through improved production practices and other interventions. Robinson and colleagues propose interventions that can be made directly on farms; those that can help create enabling environments; and others that can raise awareness of the problem and ways to solve it.

The potential to reduce use of antibiotic drugs is particularly large in low- and middle-income countries where the use of antibiotics in livestock production is already high and is predicted to grow massively—if mitigation measures are not taken—in line with projected livestock sector growth. It is critical that this unique window of opportunity, with heightened public awareness and across-the-board political will so recently expressed, is harnessed to guide research and policy in AMR, and so to exploit fully the potential of livestock sector development to mitigate antibiotic resistance. The lives, health and well-being of people and livestock depend on our conserving these precious drugs as part of our arsenal against microbial infections.


The open access Opinion paper is published in animal: Antibiotic resistance: mitigation opportunities in livestock sector development
Authors: T. P. Robinson, D. P. Bu, J. Carrique-Mas, E. M. Fèvre, M. Gilbert, D. Grace, S. I. Hay, J. Jiwakanon, M. Kakkar, S. Kariuki, R. Laxminarayan, J. Lubroth, U. Magnusson, P. Thi Ngoc, T. P. Van Boeckel, M. E. J. Woolhouse

Laboratory capacity to diagnose Mycobacterium bovis in East Africa

Laboratory capacity to diagnose Mycobacterium bovis in East Africa

The full report can be accessed at this link: http://www.rr-africa.oie.int/docspdf/en/2016/CHEROTICH1.pdf

A report by Dr. Chepkwony submitted to the OIE- Regional Representation for Africa explores the diagnostic capacities at different scales for both human and animal national tuberculosis reference laboratories in Kenya, Uganda and Tanzania to diagnose Mycobacterium bovis. One recommendation put forward is that national governments should invest in new and more accurate diagnostic technologies for detecting zoonotic tuberculosis. Moreover, it is important to utilize regional and international partnerships and carefully determine how to link these new tests and incorporate them within a country’s national diagnostic algorithm.

One World-One Health at the RSTMH Biennial Meeting, autumn 2016

There are fears that Africa’s next major modern disease crisis will emerge from its cities. Like Ebola, it may well originate from animals”. So writes Eric Fèvre from Nairobi in his conversation “Urban Zoo”

womanandlivestockatdandoragarbagedump_cropped
This intimate association between human and animal health underpins what is known as the One Health agenda, recognised by both the WHO (World Health Organisation) and the OIE (World Animal Health Organisation). And it’s not only in Africa that urgency applies but throughout the world, particularly in developing regions where surveillance systems are at their weakest and pandemic spread is highly likely.

Against this backdrop, the RSTMH is showing great insight in focussing attention on the need to bring together medical and veterinary health delivery systems and expertise under the headline of “One World-One Health” (OW-OH). Lord Soulsby, the veterinary parasitologist and long-time proponent of OW-OH, celebrated his 90th birthday last year. Hence it was entirely fitting for the RSTMH, as part of its Biennial Meeting in autumn last year, to kick off an afternoon programme dedicated to OW-OH by hosting the inaugural Soulsby Lecture followed by a series of presentations by world authorities in their field.

Of great importance was the decision to focus the programme on the challenges and opportunities for human and animal health delivery systems to collaborate and take a more holistic systems-based approach. The message that “the collaborative whole is greater than the sum of the parts” was obvious throughout, from David Heymann’s opening message early in the conference (new challenges in the ‘last mile’ of disease elimination caused by animal reservoirs) to Sandy Trees’ illumination of how veterinary research into onchocerciasis in cattle has given new insight into river blindness in humans; from Sarah Cleaveland’s demonstration of how mass rabies vaccination of dogs is both feasible and cost-effective in eliminating the disease in people, to Eric Fèvre’s plea for disease surveillance systems to consider the human-animal interface in relation to the “Urban Zoo”.

I was particularly drawn to the case made by Bernadette Abela-Ridder that many rural communities in the least developed countries live in close proximity to their animals. This means that eliminating zoonotic diseases is critically important to their own health as well as the health of their animals. Furthermore the financial well-being of these communities is also dependent on the health and well-being of their animals. And Esther Schelling illustrated the importance of generating community engagement and trust to deliver such integrated programmes.

Many health delivery programmes reside in silos directed only towards human populations – either intentionally (“this funding is only for human health benefit”) or through lack of information (“we didn’t realise the relationship with animal health”). By pooling resources, significant cost savings can be made. And the benefits to each sector will be clearly demonstrable by attributing costs carefully.

So for me, there are two massively important take-home messages to be drawn from all this wisdom.

Firstly that eradication of human disease will often be frustrated by failing to appreciate the parallel situation in animal health.  This may be due to lack of awareness of animal reservoirs of infection or to failure to incorporate essential veterinary experience and resources. The  sooner veterinary and medical scientists and practitioners work more effectively together to  contribute to the challenges they all face, the better the world will be.

And secondly, and equally importantly, resources available to achieve disease elimination are necessarily limited and, to be effective, require local involvement. The sustainability of such local involvement may weaken just at the time when it is most needed – the ‘last mile’ when the big gains have already been achieved and the final small but essential gains require relentless and absolute commitment. At such a time, that same local involvement could be sustained by broadening their remit to include animal health matters; same skills – different patient. However the silos of project funding seem often to not support this happening.

By acting on these take-home messages, both human and animal welfare will benefit and opportunities for disease elimination in both populations will become more realistic.

This article originally appeared on the Royal Society of Tropical Medicine and Hygiene website available at (here). Authored by Judy MacArthur Clark

Rapid tool for the surveillance of cysticercosis

Rapid tool for the surveillance of cysticercosis

A blog entry by Kimetrica discusses promising progress in the development of a rapid tool for the surveillance of cysticercosis which will contribute to the global efforts by the World Health Organization in controlling cysticercosis by 2020. The proposed control method is rapid, cheap and requires little resources but which could yield important epidemiological information on community risk.
Read more about these developments on the Kimetrica blog by clicking here.

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