Seroepidemiological investigation of foot-and-mouth disease virus serotypes in cattle around Lake Mburo National Park in South-Western Uganda

Foot-and-mouth disease (FMD) outbreaks in cattle occur annually in Uganda. In this study the authors investigated antibodies against FMD virus (FMDV) in cattle in surrounding areas of Lake Mburo National Park in South-Western Uganda. Two hundred and eleven serum samples from 23 cattle herds were examined for the presence of antibodies against FMDV non-structural proteins and structural proteins using Ceditest ® FMDV-NS and Ceditest ® FMDV type O (Cedi Diagnostics BV, Lelystad, The Netherlands). Furthermore, serotype-specific antibodies against the seven serotypes of FMDV were determined using in-house serotype-specific Solid Phase Blocking ELISAs (SPBE). Of the sera tested, 42.7% (90/211) were positive in the ELISA for antibodies against non-structural proteins, while 75.4% (159/211) had antibodies against the structural proteins of FMDV serotype O. Titres of ≥ 1:160 of serotype-specific antibodies in SPBEs were identified in 61% (19/31), 33% (5/15), 6%7 (20/30), 37% (10/27) and 12% (4/33) of the investigated samples for serotypes O, A, SAT 1, SAT 2 and SAT 3, respectively. This study indicates that most of the FMD outbreaks in the cattle herds in the investigated area were probably caused by FMDV serotype O, A and/ or SAT-serotype(s). It also shows that the usage of non-purified, multivalent vaccines in Uganda obscures the serological diagnosis of FMDV outbreaks, and that the sampling strategy needs to be improved. Finally, it emphasizes the importance of isolation and characterization of FMD viruses responsible for outbreaks in the area.