Laboratory-based longitudinal surveillance of malignant catarrhal fever in Lephalale municipality in Limpopo province, South Africa: 2001–2021

2021. Laboratory registry data for 385 samples were analysed. The data included the date of sampling, sample type, animal species, location and the MCF test result (PCR and/or histopathology). Altogether, 57.4% ( n = 221) of the samples were positive with a frequency of detection of 86.4% ( n = 191) and 13.6% ( n = 30) for samples tested using PCR and histopathology respectively. Of the PCR-positive samples, 99.5% were positive for AIHV-1 and 0.5% for OvHV-2. AIHV-1 infection was recorded during various seasons throughout the two decades while OvHV-2 was only reported in spring of the year 2010. Moreover, AIHV-1 was detected with a high frequency in blood (66.5%), brain (22.5%) and organ (10.5%) samples from different areas within the municipality, while OvHV-2 was only detected in blood (0.5%) samples. A retrospective study such as this provides useful information on the occurrence of MCF in the Lephalale municipality. Data from this study suggests that MCF caused by AIHV-1 is regularly diagnosed in the Lephalale municipality with concomitant adverse effects on the cattle population. Therefore, there is a need to formulate policies and strategies for disease control and enhance farmer education on the epidemiology of the disease within the study area to improve animal health and production.