Simpson Gregory J G, Marcotty Tanguy, Rouille Elodie, Chilundo Abel, Letteson Jean-Jacques, Godfroid Jacques
Department of Production Animal Studies, University of Pretoria.
J S Afr Vet Assoc. 2018 Mar 29;89(0):e1-e7. doi: 10.4102/jsava.v89i0.1527.
Brucellosis is of worldwide economic and public health importance. Heifer vaccination with live attenuated Brucella abortus strain 19 (S19) is the cornerstone of control in low- and middle-income countries. Antibody persistence induced by S19 is directly correlated with the number of colony-forming units (CFU) per dose. There are two vaccination methods: a 'high' dose (5-8 × 1010 CFU) subcutaneously injected or one or two 'low' doses (5 × 109 CFU) through the conjunctival route. This study aimed to evaluate serological reactions to the 'high' dose and possible implications of the serological findings on disease control. This study included 58 female cases, vaccinated at Day 0, and 29 male controls. Serum was drawn repeatedly and tested for Brucella antibodies using the Rose Bengal Test (RBT) and an indirect enzyme-linked immunosorbent assay (iELISA). The cases showed a rapid antibody response with peak RBT positivity (98%) at 2 weeks and iELISA (95%) at 8 weeks, then decreased in an inverse logistic curve to 14% RBT and 32% iELISA positive at 59 weeks and at 4.5 years 57% (4/7 cases) demonstrated a persistent immune response (RBT, iELISA or Brucellin skin test) to Brucella spp. Our study is the first of its kind documenting the persistence of antibodies in an African communal farming setting for over a year to years after 'high' dose S19 vaccination, which can be difficult to differentiate from a response to infection with wild-type B. abortus. A recommendation could be using a 'low' dose or different route of vaccination.
布鲁氏菌病在全球范围内具有重要的经济和公共卫生意义。用减毒活疫苗布鲁氏菌流产菌株19（S19）给小母牛接种是中低收入国家控制该病的基石。S19诱导的抗体持久性与每剂的菌落形成单位（CFU）数量直接相关。有两种接种方法：皮下注射“高”剂量（5 - 8×10¹⁰CFU），或通过结膜途径接种一或两剂“低”剂量（5×10⁹CFU）。本研究旨在评估对“高”剂量的血清学反应以及血清学结果对疾病控制的可能影响。本研究纳入了58例在第0天接种疫苗的雌性病例和29例雄性对照。反复采集血清，使用玫瑰红试验（RBT）和间接酶联免疫吸附测定（iELISA）检测布鲁氏菌抗体。病例显示出快速的抗体反应，RBT阳性率在2周时达到峰值（98%），iELISA在8周时达到峰值（95%），然后呈反向逻辑曲线下降，在59周时RBT阳性率降至14%，iELISA阳性率降至32%，在4.5岁时，57%（4/7例）对布鲁氏菌属表现出持续的免疫反应（RBT、iELISA或布鲁氏菌素皮肤试验）。我们的研究首次记录了在非洲社区养殖环境中，“高”剂量S19疫苗接种后一年多至数年抗体的持久性，这可能难以与对野生型流产布鲁氏菌感染的反应区分开来。建议可以使用“低”剂量或不同的接种途径。
