Table 6.

Distribution of HI titers against A/Turkey/Egypt/7/06 (H5N1) virus in the yolk sacs of 20 1-d-old hatched chicken eggs from an Egyptian poultry farm

HI antibody titer	Number (%) yolk sacs
	CRBCs	HRBCs
<10	20 (100%)	0 (0%)
10	0 (0%)	3 (15%)
20	0 (0%)	2 (10%)
40	0 (0%)	4 (20%)
80	0 (0%)	9 (45%)
160	0 (0%)	2 (10%)
GMT	—	48

CRBCs, chicken red blood cells: HRBCs, horse red blood cells; GMT, geometric mean titer. Titers are the reciprocals of the highest serum dilutions that inhibited hemagglutination by 4 HA units of virus.