Serological and molecular evidence ofMycobacterium bovisin dairy cattle and dairy farm workers under the intensive dairy production system in Egypt

Aims We employed a combination of diagnostic tests including single cervical tuberculin test (SCT), rapid lateral-flow test (RT), TB-Feron, conventional PCR and culture to investigate the prevalence ofMycobacterium bovisinfections in dairy cattle under the intensive dairy production system in Egypt. Methods and Results In total, 2710 dairy cows from 11 herds in six Governorates were tested by SCT and 444 (16 center dot 4%) were TB reactors. Only 65 cows responded toM. bovisantigen by RT and TB-Feron. A postmortem examination showed that 49 (75 center dot 4%) of slaughtered cows have visible lesions. Testing of 215 out 444 SCT reactor cows by culture and PCR using blood and milk samples revealed thatM. boviswere more frequently identified in the blood (6 center dot 1-20 center dot 5%) than milk (2 center dot 3-5 center dot 6%) samples. Additionally, in this study, we investigated the prevalence and potential risk factors associated withM. bovisinfection in dairy farm workers. Overall, 100 dairy farm workers were tested using QuantiFERON-TB Gold In-Tube test to detectMycobacterium tuberculosiscomplex (MTC) and 35 (35%) were positive. In all, 23 (23%) of MTC positive wereM. bovispositive using PCR.Mycobacterium bovispositive cases were associated with workers who had respiratory signs and did not wash or disinfect their hands after handling cows. Conclusions The prevalence ofM. bovisin dairy cows and dairy farm workers under the intensive dairy production system in Egypt is high. It is therefore essential to disseminate effective prevention and control measures to prevent the spread ofM. bovisbetween dairy cows and dairy workers. Significance and Impact of the Study This study revealed that the use of RT or TB-Feron as an ancillary test of SCT reactor cows resulted in a significant reduction in the SCT false-positive slaughtered cows. A high prevalence ofM. bovisinfection among farm workers provides evidence of occupational risk in the intensive dairy production system in Egypt.