Table 1.

Virus Attachment in Respiratory Tract of Humans and Five Animal Species

Results summarising virus attachment of a variety of strains, in the respiratory tract of humans and five animal species. (reproduced from van Riel et al. 2007 [42] with permission from Elsevier)

		Trachea		Bronchus		Bronchiole		Alveolus
			Predominant		Predominant		Predominant		Predominant
Virus	Species	Score	cell type	Score	cell type	Score	cell type	Score	cell type
H3N2	Human	++†	cil	++†	cil	+	cil	+	Type I
	Mouse	−		−		−		±
	Ferret	++*	cil	±*		±		+	Type I
	Macaque	−		−		−		−
	Pig	++†	cil	++†	cil	++	cil	+	Type I
	Cat	−		−		−		−
H1N1	Human	++†	cil	++†	cil	+	cil	+	Type I
	Mouse	−		−		−		±
	Ferret	+*	cil	+*	cil	±		+	Type I
	Macaque	−		−		−		−
	Pig	++†	cil	++†	cil	++	cil	+	Type I
	Cat	−		−		−		−
H5N1	Human	−*		+*	cil	+	non-cil	+‡	Type II
	Mouse	++	Both	+	non-cil	+	non-cil	+	Type II
	Ferret	−		−		±		+	Type II
	Macaque	−		±		±		+	Type I
	Pig	−		−		−		+	Type II
	Cat	−		−		+	non-cil	+‡	Type II
H5N9	Human	−*		+*	cil	+	non-cil	+‡	Type II
	Mouse	++	Both	++	non-cil	++	non-cil	+	Type II
	Ferret	−		−		−		±
	Macaque	−		−		±		±
	Pig	−		−		±		±
	Cat	−		−		±		+‡	Type II
H6N1	Human	±*		±*		+	non-cil	+‡	Type II
	Mouse	++	Both	+	non-cil	+	non-cil	+
	Ferret	−		−		−		±	Type II
	Macaque	−		±		±		+	Type I
	Pig	−		−		±		+	Type II
	Cat	−		−		±	non-cil	+‡	Type II

The mean abundance of cells to which virus attached was scored as follows: −, no attachment; ±, attachment to rare or few cells; +, attachment to a moderate number of cells; ++, attachment to many cells. Where possible, the predominant cell type to which virus attached is indicated: ciliated cells (cil), nonciliated cuboidal cell (non-cil), type I pneumocytes (type I), or type II pneumocytes (type II).

^*Subrnucosal glands positive.

^†Goblet cells occasionally positive.

^‡Alveolar macrophages positive.