Advances towards detecting and preventing the spread of multispecies disease - bovine TB - Dr Wynand J. Goosen
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Advances towards detecting and
preventing the spread of multispecies
disease – bovine TB.
Dr Wynand J. Goosen
Postdoctoral Researcher
Stellenbosch University Animal TB Group
Faculty of Medicine and Health Sciences
Animal TB Research Group
Biomedical Research Institute
Faculty of Medicine and Health Sciences
Stellenbosch University
• TB is a disease of the past
• TB is the leading cause of mortality due to an
infectious disease
Zoonotic TB
o Zoonotic TB is a neglected disease
o In 2016, 147,000 new cases of zoonotic TB diagnosed
o 12 500 human deaths
o Estimated that 30% of all TB cases are zoonotic in Africa
o Especially in African countries where unpasteurized milk is consumed
TB in cattle
• TB in cattle was widespread in
Europe during medieval times
• Disease increased with advent of
diary industry
• In 1900, tuberculosis was the
leading cause of death in the
United States.
• More than 20% of TB cases were
caused by M. bovis prior to
eradication program in the U.S.
Other Mycobacteria tuberculosis Complex Members
• M. mungi
M. pinnipedii M. caprae
• M. suricattae
M. microti M. orygis
Reports of TB in SA wildlife
Emergence of TB in wildlife created concern.
Priorities for Addressing Zoonotic TB (2017)
Improve scientific evidence base
Surveillance Diagnostic tools Research
Reduce transmission at animal-human interface
Disease control Food safety
in animals Key populations
Strengthen intersectoral approaches
Raising awareness Policies and Joint human/animal Political
and engaging guidelines health interventions commitment
stakeholders and fundingTransmission
Improving scientific evidence in wildlife
– Challenges
• Detection/diagnosis
• Lack of validated tests
• Logistics of sample collection
• Pathogenesis & epidemiology
• Susceptibility
• Routes of infection
• Disease progression
• Interactions at interfaces
• Treatment & controlTB Detection/Diagnosis in Animals
Identification of TB Biomarkers in Different Species
10000
**
9700
3500
2000
500
IP-10 (pg/ml)
300
200
100
0
Positive Negative
M. bovis culture resultCytokine production assay
Adaptation of Human
QuantiFERON Tubes for
Stimulation of Wildlife
Whole Blood
Novel Biomarkers
for TB in Wildlife
Cytokine gene expression assayModifying Available Techniques for Unique Species
Modified QuantiFERON assay
Stimulations:
“Nil”; ESAT-6/CFP-10 Equine IFN-ɣ ELISAAnte-Mortem Detection of Tuberculosis
Ante-Mortem Detection of Tuberculosis
Common Name Species KNP GKNP HiP KZN MGR SNR Other
African buffalo
African elephant
Syncerus caffer
Loxodonta africana
√
√
√
-
√
-
√
-
√
-
√
-
Mpumalanga
-
M. bovis infection
African leopard
African lion
Panthera pardus
Panthera leo
√
√
√
-
√
√
-
√
-
√
√
√
-
- in wildlife
African wild dog Lycaon pictus √ - √ - - - -
Black rhinoceros Diceros bicornis √ - - - - - -
Blue wildebeest Connochaetes taurinus - √ - - - - -
Bushbuck Tragelaphus scriptus √ - - - - - -
Bush pig Potamochoerus porcus - - √ - - - -
Chacma baboon Papio ursinus √ - √ √ - - Limpopo
Cheetah Acinonyx jubatus √ √ - - - - Limpopo
Common duiker Syvicapra grimmia - - - - - - Eastern Cape
Common warthog Phacochoerus africanus √ √ - √ - - -
Eland Taurotragus oryx - √ √ - - - -
Giraffe Giraffa camelopardalis - √ - - - - -
Greater kudu Tragelaphus strepsiceros √ √ √ √ - √ -
Hippopotamus Hippopotamus amphibius - √ - - - - -
Honey badger Mellivora capensis √ - √ - - - -
Impala Aepyceros melampus √ - - - - - -
Spotted genet Genetta tigrina √ - √ - - - -
Nyala Tragelaphus angasii - - - - - - Gauteng
Springbok Antidorcas marsupialis - - - - - - -
White rhinoceros Ceratotherium simum √ - - - - - -
KNP: Kruger National Park; GKNP: Greater Kruger National Park; HiP: Hluhluwe iMfolozi Park; KZN: KwaZulu-Natal;
MGR: Madikwe Game Reserve; SNR: Spioenkop Nature ReserveTB Pathogenesis & Epidemiology Clinical Presentations Variable
Pathological Lesions between species
Warthog
Lion
Kudu
Buffalo
Elephant
Lion
BuffaloDirect
contact
between
species
Contact Environmental
within
species
TB factors
Shared
habitatPriorities for Addressing TB Across ALL Hosts o Reduce transmission at the animal-human interface o M. bovis & M. tuberculosis reportable diseases in most countries
Reducing Transmission between Humans and Animals - Control of Animal TB
1. Economic and social impact on animal owners, farmers especially in
rural communities
2. International trade restrictions – economic impact on affected
countries
3. Impact on conservation programs for wildlife aimed at improving
biodiversity.
4. Programs often only cover cattle
-Some countries include a few wildlife species – bison, cervids,
elephants, African buffaloAnimal-Animal interactions If TB testing and eradication is only implemented for some species, how can TB be controlled?
Costs of TB Control • TB control programs have been effective in eradicating/reducing disease in Australia, U.S.A., and many countries in Europe o Costly o Require political & stakeholder buy-in o Ongoing surveillance to maintain control
Evidence based priorities for Addressing TB Across ALL Hosts tailored to the needs of specific countries. • Continues generation of scientific evidence. • Strengthen intersectoral and collaborative approaches • Engage stakeholders • Increase awareness • Develop policy and guidelines together.
Lack of systematic surveillance for M. bovis as a
causal agent of TB in people in low-income, high TB
burden countries where bovine TB is endemic.
Inability of laboratory procedures most commonly
used to diagnose human TB to identify and
differentiate M. bovis from M. tb.You can also read
