Diagnostic assays developed for the control of foot-and-mouth disease in India

Table 1 Diagnostic assays for foot-and-mouth disease virus diagnosis with their associated advantages and disadvantage

FMD diagnostic assay	Specimen materials	Target region	Sensitivity	Specificity	Advantages	Disadvantages
Sandwich ELISA	RNA from TE, FL, TE,	VP1 protein	80%	100%	Easy to perform Suitable for handling large number of samples	Less sensitive, not suitable for certain type of clinical samples
Multiplex PCR	RNA from TE, FL, TE, Semen, Milk	1D region	Minimum detection limit of 1 × 10-1 TCID50/mL	100% specific for cross serotype detection	Rapid and sensitive Suitable for samples like semen and milk	High risk of generating false positives
Taqman real-time PCR	RNA from TE, FL, TE, Semen, Milk	1D region	Minimum detection limit of 101.0 TCID50/mL	100% specific for cross serotype detection	More sensitive and specific than gel based assay	high risk of generating false positives
Virus isolation and neutralization	Triturated material of TE, FL, TE,	--			Gold standard assay for FMD diagnosis	Slow takes 1-4 d for confirmatory results
RNA transfection	RNA from TE, FL, TE, Semen, Milk	--	--	--	FMDV can be isolated from deteriorated clinical materials	--
LAMP	RNA from TE, FL, TE, Semen, Milk	3D region	Minimum detection limit up to 1.1 × 10-4 TCID50/mL	--	Require no specialized instruments, can be used as point-of-care diagnosis	High risk of generating false positives
3AB3 I-ELISA	Serum	3AB3 region	96%	99.1% -96.4%	Sensitive and Specific	Only for bovine species
3ABC C-ELISA	Serum	3ABC region			Specific assayUniversal for all species	Less sensitive than I-ELISA
2Ct I-ELISA	Serum	2C region			Sensitive and Specific	Only for bovine species

FMD: Foot-and-mouth disease; ELISA: Enzyme-linked immunosorbent assay; PCR: Polymerase chain reaction; LAMP: Loop-mediated isothermal amplification.

Table 2 Details of the clinical materials suspected for Foot-and-mouth disease tested by sandwich enzyme-linked immunosorbent assay and multiplex polymerase chain reaction during the last five years

Year	Sample tested	Serotype O	Serotype A	Serotype Asia1	Total FMD diagnosed
2009-2010	1155	423	15	7	445
2010-2011	345	83	10	10	171
2011-2012	567	265	4	40	309
2012-2013	701	218	15	52	285
2013-2014	3130	1295	24	10	1329
Total	5898	2284	68	119	2539

FMD: Foot-and-mouth disease.

Table 3 Details of the total number of serum samples screened for reactivity to foot-and-mouth disease virus NSP 3AB3 during the last five years in India

Year	Total samples tested	Total positive	% animals 3AB3 reactors in India
2009-2010	29763	8303	27.90
2010-2011	31042	8341	26.87
2011-2012	37467	10410	26.09
2012-2013	40934	10811	26.41
2013-2014	52224	15268	29.20
Total	191430	53133	27.70