Danish AIDS Patients 1988–1993: A Recent Decline in Pneumocystis carinii Pneumonia as AIDS-defining Disease Related to the Period of Known HIV Positivity

The frequency of PCP among adult Danish AIDS patients notified in 1988-93 was higher among patients tested HIV-positive less than 4 months prior to AIDS than among those known to be positive for > 1 year. Among the latter, the proportion with PCP decreased significantly over the period, from 45.3% in 1988 to 22.0% in 1993, while no such trend was found among patients tested positive for HIV less than 4 months before AIDS was diagnosed. The incidence of PCP as an AIDS-defining disease has decreased, most likely due to the use of PCP prophylaxis.