Japanese encephalitis (JE) is a major public health problem in the South Asian countries including India. Pigs serve as a relevant sentinel model, the surveillance of which could predict a potential JE outbreak in human population nearby. However, existing serological detection methods like Enzyme-Linked Immuno Sorbent Assay (ELISA), virus neutralization test (VNT) and Haemagglutination Inhibition (HI) require elaborative laboratory facilities which are invariably not available in field conditions. Recognizing the lacunae, attempts were made to develop recombinant antigen (rNS1) based latex agglutination test (LAT) as a rapid on-site test using covalent coupling method. Four different formats were evaluated using different coupling buffers, blocking buffers and reaction conditions. The format in which borate buffer at alkaline pH (8.5) was used for coupling of antigen with carboxylated beads followed by blocking with skimmed milk powder was found to be the best amongst all. Developed latex based test was used for screening of 207 pig serum samples for JE which revealed relative diagnostic sensitivity and specificity of 80.2% and 95.2%, respectively in comparison with indirect IgG ELISA. Hence, the present study demonstrated that covalently coupled recombinant antigen based LAT could be used as a reliable screening test for surveillance of JE in pigs under field conditions.

日本脑炎（JE）是包括印度在内的南亚国家的主要公共卫生问题。猪用作相关的前哨模型，对其进行监视可以预测附近人群中可能爆发的JE。但是，现有的血清学检测方法，如酶联免疫吸附测定（ELISA），病毒中和试验（VNT）和血细胞凝集抑制（HI），都需要精巧的实验室设施，而这些设施在现场条件下始终不可用。认识到该缺陷，尝试开发基于重组抗原（rNS1）的乳胶凝集试验（LAT），以作为使用共价偶联方法的快速现场试验。使用不同的偶联缓冲液，封闭缓冲液和反应条件评估了四种不同的格式。硼酸盐在碱性pH（8。5）用于使抗原与羧化的珠子偶联，然后用脱脂奶粉封闭是所有中最好的。已开发的基于乳胶的测试用于筛查207例猪血清样本中的JE，与间接IgG ELISA相比，其相对诊断敏感性和特异性分别为80.2％和95.2％。因此，本研究证明基于共价偶联重组抗原的LAT可以作为田间条件下猪JE监测的可靠筛选测试。与间接IgG ELISA比较。因此，本研究证明基于共价偶联重组抗原的LAT可以作为田间条件下猪JE监测的可靠筛选测试。与间接IgG ELISA比较。因此，本研究证明基于共价偶联重组抗原的LAT可以作为田间条件下猪JE监测的可靠筛选测试。