Clinical cases of contagious bovine pleuropneumonia (CBPP) among calves in vaccinated herds in Zambia: A Case Report

An observational study was conducted to ascertain the clinical manifestation of Contagious Bovine Pleuropneumonia (CBPP) in the Western Province of Zambia following an outbreak in an endemic region. It was observed that both calves and adult cattle in 9 herds that were not vaccinated with CBPP T1/44 vaccine reported mortality while 24 herds that had consistently been vaccinated against CBPP only reported mortalities in calves between 2 months and 8 months of age. This observation indicates that in CBPP endemic areas, calves may acquire the disease from the carriers in the infected herds. It may also indicate that cattle vaccinated with the CBPP T1/44 vaccine, when challenged with the field strain, shed the infective bacteria but may not necessarily develop clinical disease. This observation also suggests that calves may not be protected by maternal antibodies obtained passively through colostrum from the vaccinated dams and thus may succumb to the disease with typical clinical signs similar to those observed in older cattle. The result in this study further suggests that it might be necessary to vaccinate calves a short while after birth to boost their immunity against CBPP. It is therefore necessary to conduct further investigation of CBPP in calves in endemic situations