Prevalence of BTB in Cattle Slaughtered in Nigerian Abattoirs
In the absence of meaningful control and eradication measures against BTB, abattoir meat inspection currently remains the only hope for protecting the public from zoonotic TB in Nigeria.
The abattoir regulations thus provide a key control point in the meat and meat product processing chain. Hence, data collected by veterinary meat inspection officers are a useful source of information to determine the extent of BTB in Nigeria. Over the years, study reports in Nigeria were mostly based on abattoir meat inspection (Table 17.2). Other procedures, including Ziehl-Neelsen (ZN) staining and microscopy to detect acid-fast bacilli (AFB), culture, biochemical tests, and molecular techniques, in a few instances (Table 17.3; Fig. 17.1), were used to confirm the diagnoses in abattoirs.Early reports of BTB from Nigerian abattoirs were chronicled for Northern Nigeria (between the 1930s through 1958) followed by those from the southern parts (between 1937 and 1947) (Alhaji 1976). An overall prevalence of 0.02-15.9% was recorded in the respective abattoirs during this period. From 1970 to date, few data have been reported to the various State Veterinary Departments, the former Federal Livestock Department, and individual research initiatives (Tables 17.2 and 17.3). In general, studies carried out within the last two decades in most abattoirs showed a prevalence of BTB ranging from 0.34 to 26.6% (although the diagnosis was rarely confirmed by culture).
Table 17.2 Tuberculous lesions detected during post-mortem meat inspection in Nigerian abattoirs
| Location/ region | Prevalence (n) | Date | References |
| South-west | 28.9% (568,694) | 1976-1979 | Antia and Alonge (1982) |
| Southern | 8.2% (5407) | - | |
| North-east | 9.0% (376,500) | 1981-1990 | Alaku and Moruppa (1993) |
| North-west | 0.49% (104,416) | 1989-1993 | Dusai and Abdullahi (1994) |
| Southern | 2.25% (66,680) | 1991-2000 | Bikom and Oboegbulem (2000) |
| North-east | Overall—28% (47,544) Maiduguri—2.5% Damboa—20% Gashua—2.6% Damaturu—1.9% | 1994-1998 | Igbokwe et al. (2001) |
| North-east | Overall—4.05% (302,700) Adamawa—0.3% Bauchi—0.9% Borno—1.7% Gombe—12.3% Taraba—5.0% Yobe—8.7% | 2000-2004 | Aliyu et al. (2009) |
| North-east | 1.1% (2902) | May-June, 2008 | Raufu and Ameh (2010) |
| South-east | 1.4% (748) | 2004-2008 | Nwanta et al. (2011) |
| South-east | 3.4% (247) | March-November, 2010 | Opara et al. (2012) |
| South-west | 1.78% (52,273) | 2011-2012 | Oluwasile et al. (2013) |
| North-east | 1.9% (1172) | 2008-2012 | Ejeh et al. (2014b) |
| North-east | 26.6% (85) | March-July, 2015 | Adang et al. (2015) |
17.5