Table 3.

Kinetics of replication, cytokine release and clinical manifestations of infections with hPIV serotypes 1–3 according to Schaap-Nutt et al. [16•]

Serotype	Locus of replication	Kinetics of replication	Released cytokine upon infection	Clinical manifestations	Remarks
hPIV-1	Upper respiratory tract	Replicates to high titres and does not induce cytokine secretion until late in infection	RANTES IP-10 I-TAC	Upper respiratory tract illnesses, croup	Undetected for several days post infection
hPIV-2	Upper respiratory tract	Replicates less efficiently than hPIV-1 but induces an early cytokine peak	IFN-α IL-6MCP-1 RANTES IP-10 I-TAC	Upper respiratory tract illnesses, croup	Less able to inhibit an early immune response
hPIV-3	Lower respiratory tract	Replicates to high titres but induces a slower increase in cytokine secretion	IFN-α IL-6 MCP-1 RANTES IP-10 I-TAC	Bronchiolitis, pneumonia	Induces a steadily increasing inflammatory response over several days