Transmission of Pneumocystis carinii DNA from a Patient with P. carinii Pneumonia to Immunocompetent Contact Health Care Workers
This study provides molecular evidence that airborne person-to-person transmission of P. carinii sp. f.hominis is possible, thus suggesting that patients with PCP should not come into close contact with immunocompromised persons. Immunocompromised patients who are not receiving PCP prophylaxis should not enter the room of a patient with PCP. The data show that the immunocompetent contacts of patients with PCP can acquire transient colonization by the organism.
The transmission of Pneumocystis carinii from person to person was studied by detecting P. carinii-specific DNA in prospectively obtained noninvasive deep-nasal-swab samples from a child with a documented P. carinii pneumonia (PCP), his mother, two contact health care workers, and 30 hospital staff members who did not enter the patient's room (controls). Nested-DNA amplification was done by using oligonucleotide primers designed for the gene encoding the mitochondrial large subunit rRNA of rat P. carinii(P. carinii f. sp. carinii) that amplifies all forms of P. carinii and internal primers specific for humanP. carinii (f. sp. hominis). P. carinii f. sp. hominis DNA was detected in samples from the patient and all of his contacts versus none of the 30 hospital staff members. The results, as previously shown in murine models ofP. carinii pneumonia, document that person-to-person transmission of P. carinii is possible. This observation suggests that immunocompromised patients not on PCP prophylaxis should not enter the room of a patient with PCP, and it also raises the question as to whether healthy contacts can transmit the disease to immunocompromised patients at risk.
