BACKGROUND : The prevalence of bovine tuberculosis (BTB) in dairy cattle in the three major milk producing regions
of Eritrea was assessed by subjecting 15,354 dairy cattle, 50 % of Eritrea’s dairy cattle population, to the single
intradermal comparative tuberculin test (SICTT). Skin test results were interpreted according to guidelines of the
World Organization for Animal Health (OIE) with >4 mm as cutoff in skin thickness increase. In addition, we studied
the relation between ‘physiological’ variables related to pregnancy and lactation, and the variable ‘region’ on the
probability to be skin test positive.
RESULTS : The BTB prevalences at animal and herd levels were: 21.5 % and 40.9 % in Maekel, 7.3 % and 10 % in
Debub, and 0.2 % and 1.6 % in the Anseba region, respectively. Overall, in the regions included, prevalence was 11.
3 % (confidence interval (CI) 95 % CI, 11.29 – 11.31 %) and 17.3 % (95 % CI, 17.27–17.33 %), at animal and herd
level, respectively. Considering positive herds only, the animal BTB prevalence was 36.8 %, 30.1 %, and 1.8 %, in
Maekel, Debub and Anseba, respectively, and the overall animal prevalence within these herds was 32 %. In adult
dairy cattle the probability of positive reactivity in the SICTT test was highest in pregnant animals as compared to
the other categories.
CONCLUSION : This study reports persistent prevalence of BTB as defined by positive SICTT in the dairy sector of
Eritrea, especially in the regions of Maekel and Debub that are located in the central highlands of the country. To
our understanding this is the first report that has encompassed all the major dairy farms in Eritrea and it will be
instrumental in advocating future BTB control programs in the dairy sector.
Additional file 1: Frequency of skin thickness (mm) after 72 h post
inoculation in both the avian and bovine sites and the differences within
the two (Bovine 72 h - Avian 72 h). The first two columns show the skin
thicknesses on the avian site of injection after 72 h of the PPD-A inoculation
and their frequencies (frq). The following four columns show the skin
thicknesses on the bovine site of injection after 72 h of PPD-B inoculation
and their frequencies. The following six columns show the skin thickness
differences on the bovine sites versus avian sites of injection after 72 h of
inoculations of both PPD-A and PPD-B (PPD-B minus PPD-A) and their