Tuberculosis

Ziekteverwekker

Tuberculosis is an ancient disease that can infect many animal species, including humans. It is usually caused by a bacterium of the Mycobacterium tuberculosis complex, which includes M. tuberculosis (which is considered primarily a pathogen in humans), M. bovis (which is normally the causative agent of tuberculosis in ruminants, and is often called bovine tuberculosis or bovine tuberculosis), and several other species.

Gevoelige diersoorten

It is important to realize that these bacteria can infect not only normal, usual hosts, but also other animal species (including humans). For example, M. tuberculosis can also be found in dogs and horses[1,2] and M. bovis in humans[3]. The oldest known case appears to be from the extinct long-horned bison (Bison cf. antiquus), from which genetic material was isolated from bone lesions[4].

Symptomen dieren

In chronic disease, lesions are an indication of the disease. The tissue damage consists of nodules with a creamy white content, and the animal is usually thin or emaciated. However, other diseases can also present a similar picture, but with a different pathogen. Therefore, it is necessary to perform further tests (microscopy and identification of the bacterium by means of cultures or molecular research methods). In addition, it must be taken into account that early and small injuries are so inconspicuous that they are easily overlooked. It is not possible to rule out tuberculosis based on macroscopic examination[5].

Besmetting dieren

The bacterium is usually spread through the air in the form of small droplets released when an infected animal sneezes or coughs and are inhaled. This is why the disease usually starts in the lungs. The bacterium can also be spread through direct contact between animals and the body fluids of sick animals.

Besmetting mensen

Transmission of M. bovis to humans usually occurs through the consumption of unpasteurized milk from infected cows.

Geografische verspreiding

Tuberculosis in farmed animals appears to be under control in most European countries thanks to a strict testing regime for cattle. However, in some countries the bacterium is also present in wild animals. Examples include the presence of M. bovis in Spain and France in wild boars (Sus scrofa) and in red deer (Cervus elaphus), and in England and Ireland in badgers (Meles meles) and other game species [6,7,8].

M. caprae, another mycobacterium from the M. tuberculosis complex, occurs in red deer, cattle, and humans in Austria and southern Germany [9,10].

The Netherlands has tuberculosis-free status. However, individual cases of infected cattle through import occur almost annually [11]. In the period December 2012–April 2014, 104 badgers were examined for the presence of bacteria from the Mycobacterium tuberculosis complex. This was a joint project of DWHC and CVI Lelystad. All badgers examined were negative (see report https://dwhc.nl/2015/07/geen-tbc-dassen-nederland/).

References

  1. Posthaus, H., Bodmer, T., Alves, L., Oevermann, A., Schiller, I., Rhodes, S. G., & Zimmerli, S. (2011). Accidental infection of veterinary personnel with Mycobacterium tuberculosis at necropsy: a case study. Veterinary microbiology, 149(3-4), 374–380. https://doi.org/10.1016/j.vetmic.2010.11.027
  2. Lyashchenko, K. P., Greenwald, R., Esfandiari, J., Lecu, A., Waters, W. R., Posthaus, H., Bodmer, T., Janssens, J. P., Aloisio, F., Graubner, C., Grosclaude, E., Piersigilli, A., & Schiller, I. (2012). Pulmonary Disease due to Mycobacterium tuberculosis in a Horse: Zoonotic Concerns and Limitations of Antemortem Testing. Veterinary medicine international, 2012, 642145. https://doi.org/10.1155/2012/642145
  3. de la Rua-Domenech R. (2006). Human Mycobacterium bovis infection in the United Kingdom: Incidence, risks, control measures and review of the zoonotic aspects of bovine tuberculosis. Tuberculosis (Edinburgh, Scotland), 86(2), 77–109. https://doi.org/10.1016/j.tube.2005.05.002
  4. Rothschild, B. M., Martin, L. D., Lev, G., Bercovier, H., Bar-Gal, G. K., Greenblatt, C., Donoghue, H., Spigelman, M., & Brittain, D. (2001). Mycobacterium tuberculosis complex DNA from an extinct bison dated 17,000 years before the present. Clinical infectious diseases : an official publication of the Infectious Diseases Society of America, 33(3), 305–311. https://doi.org/10.1086/321886
  5. Gavier-Widén, D., Cooke, M. M., Gallagher, J., Chambers, M. A., & Gortázar, C. (2009). A review of infection of wildlife hosts with Mycobacterium bovis and the diagnostic difficulties of the ‘no visible lesion’ presentation. New Zealand veterinary journal, 57(3), 122–131. https://doi.org/10.1080/00480169.2009.36891
  1. Zanella, G., Bar-Hen, A., Boschiroli, M. L., Hars, J., Moutou, F., Garin-Bastuji, B., & Durand, B. (2012). Modelling transmission of bovine tuberculosis in red deer and wild boar in Normandy, France. Zoonoses and public health, 59 Suppl 2, 170–178. https://doi.org/10.1111/j.1863-2378.2011.01453.x
  2. Gortazar, C., Vicente, J., Boadella, M., Ballesteros, C., Galindo, R. C., Garrido, J., Aranaz, A., & de la Fuente, J. (2011). Progress in the control of bovine tuberculosis in Spanish wildlife. Veterinary microbiology, 151(1-2), 170–178. https://doi.org/10.1016/j.vetmic.2011.02.041
  3. Delahay, R. J., Smith, G. C., Barlow, A. M., Walker, N., Harris, A., Clifton-Hadley, R. S., & Cheeseman, C. L. (2007). Bovine tuberculosis infection in wild mammals in the South-West region of England: a survey of prevalence and a semi-quantitative assessment of the relative risks to cattle. Veterinary journal (London, England : 1997), 173(2), 287–301. https://doi.org/10.1016/j.tvjl.2005.11.011
  4. Prodinger, W. M., Eigentler, A., Allerberger, F., Schönbauer, M., & Glawischnig, W. (2002). Infection of red deer, cattle, and humans with Mycobacterium bovis subsp. caprae in western Austria. Journal of clinical microbiology, 40(6), 2270–2272. https://doi.org/10.1128/JCM.40.6.2270-2272.2002
  5. Moser, I., Köhler, H., & Menge, C. (2014). Die Tuberkulose des Rindes – überraschend wieder oder immer noch präsent? [Tuberculosis in cattle – surprisingly re-emerging or continuously present?]. Tierarztliche Praxis. Ausgabe G, Grosstiere/Nutztiere, 42(4), 240–250.
  6. Spierenburg, M. A. H., Valkenburg, S. M., & Van Zijderveld, F. (2014). Import van met TBC besmette runderen uit officieel vrije lidstaten. Tijdschr Diergeneeskd, 12, 28-31.