Transmission of infectious laryngotracheitis virus vaccine and field strains: the role of degree of contact and transmission by whole blood, plasma and poultry dust

Table 2 Details of the experiments: dose, mode of exposure and type of inoculum used in each experiment

Experiment	Treatment	Isolator (n)	Chickens/isolator (n)	ILTV strain	Inoculum	Mode of exposure	Dose	Age at exposure (d)
Expt. 1 CONTACT	Eye drop (donors)	3	8	A20 Serva C9	Virus	Eye drop	^a10^3.5 PFU/bird (A20) 10^2.8 EID/bird (Serva) 10⁴TCID₅₀/bird (Class 9)	14
	In-contact	3	8	A20 Serva C9	Nil	Contact with donors
	Shared air space	3	16	A20 Serva C9	Nil	Shared air with donors
Expt. 2 DUST INF	3 dpe dust	2	15	C9	Dust or dust extract	Eye/URT^b	60 µL extract, 5–10 mg dust	10
	7 dpe dust	2	15	C9				14
	14 dpe dust	2	15	C9				21
Expt. 3 BLOOD INF	A20	1	15	A20	Plasma + fresh whole blood^d	Eye/intra coelemic^c	60 µL plasma + 1 mL blood	20 & 24
	Serva	1	15	Serva
	Class 9	1	15	C9
Control	Normal saline	2	16–17	-	Normal saline	Eye drop	-	7

C9, class 9; URT, upper respiratory tract.
^aDose for eye drop infection of donor birds only.
^bExtract administered by eye drop (n = 15), dust insufflated into nares (n = 5), laryngopharyngeal space (n = 5) or trachea (n = 5).
^cPlasma and whole fresh blood collected at 6 and 10 dpe of infected birds.
^dPlasma administered by eye drop and whole fresh blood by intra-coelemic (“abdominal”) injection to the same chicken.

ISSN: 1297-9716