TABLE 1.

Development of Pneumocystis infection in CB.17 immunocompetent mice cohoused with infected mice

Length of exposure (wks)	No. of P. carinii f. sp. muris nuclei (log10)		PCR result for P. carinii f. sp. murisa
	Cohoused mice	Control mice	Cohoused mice	Control mice
3	<4.3 ± 0.0b	<4.3 ± 0.0	++	−
5	5.1 ± 0.8c	<4.3 ± 0.0	+++	−
6	<4.3 ± 0.0	<4.3 ± 0.0	+	−

^a+, light band; ++, medium band; +++, heavy band, −, no band.

^bLimit of detection 4.3 log₁₀ P. carinii f. sp. muris nuclei per mouse.

^cSignificantly different than control (P > 0.05).