Bovine tb ethiopia ejhd special 2008

More documents

Recommendations

Info

118 Ethiop.J.Health Dev. ______________________________________________________________________________________ options and (g) determine future research and evaluation needs to identify the most cost-effective locally adapted interventions. Participating countries engage in identifying funding for research and policy development. The documented public health component of bovine tuberculoses in Nigeria, Tanzania and Uganda justifies efforts to make it part of current global programs and initiatives on tuberculosis control [5,6](). Recognition of these facts ought to result in applications by affected countries to the Global Fund to Fight AIDS, TB and malaria (GFATM) [7]. Furthermore International bodies like OIE, FAO and WHO should foster support to Africa, establishing standards for zoonoses surveillance and control. This is also part of the WHO International Health Regulations that came into force in mid-2007 and that require all countries to do a better job of disease surveillance for diseases that can spread between countries (www.int/gb/edwha/pdf_files/WHA58- REC1/english/Resolutions.pdf). In conclusion, bovine tuberculosis in Africa cannot be controlled without extensive public engagement in animal health research. This calls for a rethinking of research and control efforts and its economic consequences as bovine tuberculoses still goes unrecorded in most cases. Reference 1. Schwabe C W. Veterinary medicine and human health. Williams & Wilkins: Baltimore (USA), 1984. 2. Gathura G. Kenya: So much research, so little benefit. The Nation. Nairobi. 2007;19-2-2006. 3. Zinsstag J. Animal health research. Science 2007;315:1193. 4. Ayele, W. Y., Neill SD, Zinsstag, Weiss, M. G., and Pavlik, I. Bovine tuberculosis: an old disease but a new threat to Africa. Int.J Tuberc.Lung Dis 2004;8(8):924-937. 5. Cadmus S, Palmer S, Okker M, Dale J, Gover K, Smith N, Jahans K, Hewinson R G, Gordon S V. Molecular analysis of human and bovine tubercle bacilli from a local setting in Nigeria. J.Clin.Microbiol. 2006;44: 29-34. 6. Mfinanga S G, Morkve O, Kazwala R R, Cleaveland S, Sharp J M, Shirima G, Nilsen R. The role of livestock keeping in tuberculosis trends in Arusha, Tanzania. Int.J.Tuberc.Lung Dis. 2003;7:695-704. 7. Zinsstag J, Schelling E, Roth F, Bonfoh B., de Savigny D., Tanner M. Human Benefits of Animal Interventions for Zoonosis Control. Emerging Infectious Diseases 2007;13:527-531. Ethiop.J.Health Dev. 2008;22(0)
Mycobacterial genomics and its application to disease control Stephen V. Gordon Abstract The publication of the Mycobacterium tuberculosis genome sequence in 1998 heralded a new phase in mycobacterial research. The subsequent decade has seen an enormous increase in our understanding of the basic biology, virulence mechanisms, drug targets and evolution of the M. tuberculosis complex, an acceleration in knowledge that would not have been possible without the genome. This review summarises some key findings from mycobacterial genomics and highlights how this knowledge can be applied to disease control in the developing world. [Ethiop.J.Health Dev. 2008;22(Special Issue):119-122] Introduction From anywhere in the world with an internet connection, researchers can now access the genome sequences of all the major mycobacterial pathogens, such as Mycobacterium tuberculosis 1 , Mycobacterium leprae 2 , Mycobacterium bovis 3 and Mycobacterium ulcerans 4 , as well as the vaccine strains M. bovis BCG 5 and Mycobacterium microti OV254 6 . Indeed, through the Wellcome Trust Sanger Institute 7 , The Institute for Genome Research 8 , and the Broad Institute 9 we currently have genome sequences for six different strains of M. tuberculosis (H37Rv, CDC1551, 210, C, F11, Haarlem), with many more to follow through projects underway at the Broad. The “TubercuList” M. tuberculosis H37Rv genome database regularly receives more than 70,000 “hits” per month from all over the world (S. Cole, personal communication), showing how the genome has become a cornerstone of mycobacterial research; we now all work in a post-genomic landscape. How has the availability of this mass of genome data changed our understanding of the tubercle bacilli? How are we to apply this information to improve disease control? This review will briefly summarise key findings from the genome sequences of M. tuberculosis, M. bovis and M. bovis BCG, and highlight how genome findings are being applied in the fight against disease. Evolution The emergence of M. tuberculosis has often been viewed as a classic zoonotic infection, with the generalist animal pathogen M. bovis crossing the species barrier into man at the time of cattle domestication. Initial work on 1 (http://genolist.pasteur.fr/TubercuList) 2 (http://genolist.pasteur.fr/Leproma) 3 (http://genolist.pasteur.fr/BoviList) 4 (http://genolist.pasteur.fr/BuruList) 5 (http://genolist.pasteur.fr/BCGList) 6 (http://www.sanger.ac.uk/Projects/M_ microti) 7 (www.sanger.ac.uk) 8 (ww.tigr.org) 9 (www.broad.mit.edu) defining genetic diversity across the M. tuberculosis complex using single nucleotide polymorphisms (SNPs) suggested that M. tuberculosis arose ~15,000 years ago (1), a similar date to that proposed for cattle domestication (2), seemingly providing further support for the zoonosis model. However, subsequent attempts to date the clonal expansion of M. tuberculosis using SNP data gave a date of ~35,000 years ago (3). Indeed, using SNP data to define a molecular clock may not be appropriate for M. tuberculosis, given its small effective population size and distinctive DNA repair systems. An alternative method to explore the evolution of the M. tuberculosis complex employed comparative genomics. With the M. tuberculosis genome as a starting point, the genomes of all members of the M. tuberculosis complex were scanned for deletion events (4). This defined a set of 12 deletions that could then be mapped across a reference collection that encompassed the diversity of the M. tuberculosis complex (5). This comparative analysis allowed a novel evolutionary scenario to be proposed, with M. tuberculosis closer to the common ancestor of the complex than M. bovis (Figure 1). This scenario appears to overturn conventional evolutionary thinking, suggesting that tuberculosis is in fact a reverse zoonosis given by man to domesticated animals. However, the host association of the common ancestor of the complex is unknown, and valid cases can be made for a human or animal associated ancestor. Recent work from strains causing tuberculosis in East Africa has added a further twist to the evolution of the M. tuberculosis complex (6). These strains, classed as “smooth” tubercle bacilli due to their characteristic colony appearance, were characterised using multilocus sequencing and revealed to have an unexpected degree of sequence variation. However, most surprising was evidence for horizontal gene transfer among this population of strains, which goes against current data suggesting a purely clonal population structure for the M. tuberculosis complex. Based on these data the authors proposed that these in fact were isolates of the progenitor of the M. tuberculosis complex, Mycobacterium _______________________________________________________________________________________________ TB Research Group, VLA Weybridge, Woodham Lane, New Haw, Addlestone, Surrey KT15 3NB, UK. Tel: (44) 01932 357 850, E-mail: s.v.gordon@vla.defra.gsi.gov.uk
Page 1 and 2: Editor-in-Chief Yemane Berhane Asso
Page 3 and 4: Tuberculosis: A Global Overview Dou
Page 5 and 6: Tuberculosis: A Global Overview 99
Page 7 and 8: Development of cattle TB vaccines b
Page 9 and 10: Development of cattle TB vaccines b
Page 11 and 12: “One health”: The potential of
Page 13 and 14: "One health": The potential of clos
Page 15 and 16: Cross-disciplinary and participator
Page 17 and 18: Cross-disciplinary livestock and hu
Page 23: Towards effective control of bovine
Page 27 and 28: Mycobacterial genomics and disease
Page 29 and 30: Wellcome Trust initiative: Animal H
Page 31 and 32: Animal Health in the Developing Wor
Page 33 and 34: The role of bovine tuberculosis as
Page 35 and 36: The Wellcome Trust Bovine TB Projec
Page 37 and 38: Welcome Trust Bovine TB Project in
Page 39 and 40: A comparative study on the epidemio
Page 41 and 42: Epidemiology and immuno-pathology o
Page 43 and 44: Approach to assess the economic imp
Page 45 and 46: Economic impact of bovine tuberculo
Page 47 and 48: Summary of Working Group Discussion
Page 49 and 50: Ethiop.J.Health Dev. 143 __________
Page 51 and 52: Ethiop.J.Health Dev. 145 __________
Page 53: Ethiop.J.Health Dev. 147 __________

Bovine tb ethiopia ejhd special 2008

Create successful ePaper yourself

Delete template?

Save as template?