Inspection of lymph nodes for caseous lymphadenitis and its effect on the density of microbes on sheep carcasses

Jordan, David; Sentance, C.B.; Spooncer, W.F.; Balan, J.A.; Morris, Stephen

doi:10.1016/j.meatsci.2012.07.010

Cited by 9 publications

(5 citation statements)

References 14 publications

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“…1 It has been argued recently that the intense scrutiny of adult sheep carcasses for CLA has questionable benefit from a public health viewpoint, particularly as estimates of the impact of inspection for CLA on the density of indicator organisms on the surface of carcasses suggested that carcass hygiene could be improved if CLA inspection procedures were curtailed. 31 However this may have the disadvantage of reducing the effectiveness of abattoir surveillance for estimates of prevalence for other diseases, including OJD.…”

Section: Change-management Perspectives For Cla and Ojd Controlmentioning

confidence: 99%

Managing control programs for ovine caseous lymphadenitis and paratuberculosis in Australia, and the need for persistent vaccination

Windsor¹

2014

VMRR

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Ovine caseous lymphadenitis (CLA) and ovine Johne's disease (OJD) or paratuberculosis have been serious diseases in the Australian sheep industry, mainly causing losses from abattoir condemnations from CLA or mortalities on the farm from OJD. CLA is now a disease of minimal concern, with clinical cases reported rarely. Although OJD continues to spread through parts of the sheep population, the catastrophic losses in flocks occurring prior to the introduction of vaccination are now uncommon. Change-management factors relevant to the improvements in both prevalence and producer concerns for CLA and OJD were examined, including drivers and motivation for change, resistance to change, knowledge management, farming system dimensions and leadership. Although extension programs addressing disease risk factors are likely to be of relevance to improved knowledge and attitudes towards disease risk management of producers, improvements in disease-control practices were considered largely attributable to the introduction of vaccination programs for CLA in 1983 and OJD in 2002. Inclusion of the CLA antigen within clostridial vaccines ("6 in 1" vaccine) enabled routine annual CLA vaccination to occur in an increasing proportion of the national flock, with estimates of CLA prevalence suggesting a decline from 26% in 1995 to 5.2% in 2009. Encouraging the routine vaccination of lambs for OJD (Gudair vaccine) in infected flocks to reduce or avoid losses significantly reduced the within-flock prevaccination-postvaccination median prevalence from 2.72% to 0.72%, based on estimated shedding rates of Mycobacterium avium subsp. paratuberculosis determined by pooled fecal culture in 37 infected flocks vaccinating for at least 5 years. Although persistent use of CLA vaccine is a convenient intervention for producers, promoting the persistent use of OJD vaccination to continue disease suppression when clinical cases are undetectable, plus improvements in biosecurity, remain a challenge for animal-health authorities. Despite concerns of vaccine efficacy and safety issues with OJD vaccination, persistent vaccination has produced a profound improvement in the health of Australian sheep, and is a positive development of relevance to sheep production in other countries.

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Section: Change-management Perspectives For Cla and Ojd Controlmentioning

confidence: 99%

Managing control programs for ovine caseous lymphadenitis and paratuberculosis in Australia, and the need for persistent vaccination

Windsor¹

2014

VMRR

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“…The work described is one of a series of investigations that apply risk‐based principles 1 in the modernisation postmortem inspection procedures for cattle, sheep goats and pigs in Australia 7 9 23 27–29 . Opportunities for reallocation of food safety resources proportionate with risk, particularly arise for CLA of sheep and goats due to CLA not being caused by an identified foodborne hazard, where the prevalence has been reduced substantially over the last 30 years due to better disease prevention strategies 13 17 18 20 and where counterproductive contamination of edible tissue may arise from extensive palpation 9 30 …”

Section: Discussionmentioning

confidence: 99%

“…Additionally, EFSA observes the main weakness of postmortem inspection is that postmortem inspection procedures are not able to detect the public health hazards identified as the main concerns for food safety. Potential for this ‘hidden’ hazard transfer has been found in Australia for palpation of LNs for CLA, 9 where the expected Escherichia coli density per unit area was six times higher after inspection (13 cfu/cm 2 ) compared with before inspection (2 cfu/cm 2 ). As CLA is not of public health significance and palpation marginally increases contamination of edible tissues, these alternative procedures will deliver at least an equal food safety outcome.…”

Section: Discussionmentioning

confidence: 99%

“…This is in response to redundancy of some traditional inspection procedures due to improvements in animal health status (including eradication of zoonoses) and risks arising from meatborne hazards that are not detected by postmortem inspection 7 8 . It is also increasingly noted that current postmortem inspection practices (ie, incision and palpation) may have an adverse effect on product hygiene with contamination of edible tissues by foodborne hazards 3 4 9 . Additionally, alternative procedures should not only be validated for product safety, and suitability 1 (ie, includes gross abnormalities of no public health risk) but also be assessed for any adverse effects on animal health (including zoonoses) and welfare surveillance 1 10 …”

Section: Introductionmentioning

confidence: 99%

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Comparison of postmortem inspection procedures for detecting caseous lymphadenitis of Australian sheep and goats

Pointon¹,

Hamilton

Kiermeier³

2019

Veterinary Record

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Alternative postmortem inspection procedures for the detection of gross abnormalities due to Caseous Lymphadenitis (CLA) of sheep and goats were compared quantitatively against the current Australian Standard (AS4696). Studies on sheep and goats in Australia during 2016 addressed data gaps regarding current prevalence, combinations of multiple lesions within affected carcases and sensitivity of inspection procedures enabling a comparison of alternative with current procedures. Using these contemporary inspection data from 54 915 sheep and 48 577 goats a desktop study estimated the effect of implementing alternative procedures of reduced palpation from eleven carcase sites to the four sites most commonly affected. Under current procedures it was estimated that 86 sheep and 34 goat carcases with CLA lesions are missed per 10,000 carcases. Under alternative procedures it is estimated that an additional 48.4 sheep and 10.5 goat carcases with CLA lesions would be missed per 10 000 carcases. Of these, 38.2 sheep and 5.6 goat per 10 000 carcases would contain CLA only in routinely discarded, non-edible tissue sites. Hence, only an additional 10.2 sheep and 4.9 goat carcases per 10 000 inspected, with CLA in edible tissue sites are estimated to be missed. These alternative procedures have now been officially implemented in the Australian domestic standard.

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“…Elsewhere, Minas Gerais in the southeast region also has a high prevalence of CLA [5,6]. The establishment of CLA in herds of sheep is directly associated with economic loss, due to the loss of animal products such as milk, wool, and even the carcass of the animal [7]. Although there is no way to fight C. pseudotuberculosis infections, herd immunization is among the most commonly employed strategies against the dissemination of the pathogen [8].…”

Section: Introductionmentioning

confidence: 99%

The Association of Bacterin and Recombinant Proteins Induces a Humoral Response in Sheep against Caseous Lymphadenitis

et al. 2022

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In this study, we investigated the capacity of the recombinant proteins SpaC, NanH, SodC, and PLD of C. pseudotuberculosis to trigger protective humoral and cellular immune responses against experimentally induced C. pseudotuberculosis infection in sheep. The antigens were produced in a heterologous system and were purified by affinity chromatography. Nine sheep were randomly divided into three groups, which were immunized as follows: Group 1 (control)—a mix of adjuvants composed of the inactivated T1 strain of C. pseudotuberculosis and commercial Montanide™ISA 61 VG (T1M); Group 2—rSpaC, rSodC, rPLD, and T1M; Group 3—rNanH, rSodC, rPLD, and T1M. All groups were immunized twice (on days 0 and 30) and challenged on day 90 of the experiment. Humoral and cellular immune responses were evaluated by Enzyme-Linked Immunosorbent Assay (ELISA) to quantify the IgG antibodies and interferon-gamma (IFN-y). Both vaccine formulations with recombinant proteins (groups 2 and 3) could induce a significant humoral IgG immune response in sheep. The proteins rSodC, rPLD, and rNanH were more immunogenic, inducing significant levels of IgG antibodies after the first dose of the vaccine or after the challenge, maintaining constant levels until the end of the experiment. However, it was not possible to differentiate between the cellular responses induced by the vaccines. This lack of effectiveness points toward the need for further studies to improve the efficacy of this subunit-based vaccine approach.

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Inspection of lymph nodes for caseous lymphadenitis and its effect on the density of microbes on sheep carcasses

Cited by 9 publications

References 14 publications

Managing control programs for ovine caseous lymphadenitis and paratuberculosis in Australia, and the need for persistent vaccination

Managing control programs for ovine caseous lymphadenitis and paratuberculosis in Australia, and the need for persistent vaccination

Comparison of postmortem inspection procedures for detecting caseous lymphadenitis of Australian sheep and goats

The Association of Bacterin and Recombinant Proteins Induces a Humoral Response in Sheep against Caseous Lymphadenitis

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