NEW YORKAll children aged 4 to 6 weeks who have been exposed to HIV should receive prophylaxis against Pneumocystis carinii pneumonia (PCP), regardless of CD4 cell count, according to recent report.
Trimethoprim-sulfamethoxazole (TMP-SMX) remains the recommended first-line prophylactic drug, with dapsone and aerosolized pentamidine as alternative agents for children who cannot tolerate TMP-SMX, according to the report, which detailed new guidelines for PCP prophylaxis in children infected with HIV.
Previous guidelines, which were released in 1991, recommended prophylaxis for children who fell below certain CD4 cell levels for their age. Since the release of those guidelines, the Centers for Disease Control and Prevention (CDC) surveillance of AIDS cases indicated no significant decline in PCP among children infected with HIV.
"The continued high incidence of PCP has been attributed in large part to the failure to identify HIV-exposed children in time to begin prophylaxis before the period of highest incidence of PCP early in infancy," stated the report's authors, Samuel Grubman, MD, and R. J. Simonds, MD.
A CDC survey found that 59% of children with PCP who had not received prophylaxis had not been identified as being exposed to HIV early enough to initiate prophylaxis, the report stated. In addition, investigators have found that many young infants with PCP have CD4 cell counts higher than 1,500 cells/ÁL, which is the threshold below which infants younger than 1 year should receive prophylaxis. Investigators also have found that CD4 cell counts may decline rapidly shortly before PCP develops.
The new guidelines were developed by a panel of clinicians, public health officials, researchers, and parents of children infected with HIV. The panel was convened by the National Pediatric and Family HIV Resource Center and the CDC. The guidelines appeared in a report in The Pediatric Infectious Disease Journal.
According to the new guidelines, children who receive zidovudine (ZDV) to prevent perinatal HIV transmission should begin PCP prophylaxis when ZDV is discontinued at age 6 weeks in accordance with the 076 protocol. The objective is to prevent overlapping toxicities with ZDV and TMP-SMX, especially in a group of children expected to have a much lower risk of HIV infection, Grubman explained. Thereafter, prophylaxis should continue through the first year of life or until HIV infection has been reasonably ruled out.
In most cases, HIV infection can be ruled out by two or more negative viral diagnostic testseither polymerase chain reaction (PCR) or HIV cultureone at 1 month of age or older and one at 4 months of age or older. "Once children are determined to be uninfected, prophylaxis should be discontinued," the report stated.
For children aged 1 year or older, the new guidelines recommend PCP prophylaxis for children with CD4 cell counts or percentages indicating severe immunosuppression. The CD4 cell counts or percentages that indicate severe immunosuppression vary according to age. Children aged 1 year to 5 years are severely immunosuppressed if they have a CD4 cell count of fewer than 500 cells/ÁL or a CD4 cell percentage less than 15%. Children aged 6 to 12 years are severely immunosuppressed if they have a CD4 cell count of fewer than 200 cells/ÁL or a CD4 cell percentage less than 15%.
Children who had a CD4 cell count of fewer than 750 cells/ÁL or a CD4 percentage less than 15% in the first year of life should continue prophylaxis until 2 years of age, the report stated. Children aged 1 year or older not receiving prophylaxis should begin prophylaxis if their CD4 cell count or percentage indicates severe immunosuppression. Lifelong prophylaxis is recommended for any child who has had a previous episode of PCP.
"These new guidelines provide the framework necessary to achieve the goal of decreasing the incidence of PCP," the report stated.
Certain challenges face successful implementation of the guidelines, however. These challenges include prompt identification of children who have been exposed to HIV, providing children with access to recommended diagnostic and immunologic monitoring tests, and educating parents and other caregivers about the importance of PCP prophylaxis, according to the report.
"The best time to start preventing PCP is before birth," Grubman and Simonds stated. "Learning about their HIV infection before or early in pregnancy allows HIV-infected women the best chance to protect their children, not only from PCP but [also] from HIV infection altogether."
Grubman emphasized the importance of counseling all pregnant women about HIV and encouraging them to be tested for the virus. Pregnant women infected with HIV can be offered antiretroviral therapy to decrease the risk of HIV transmission. The 076 study showed that pregnant women infected with HIV were almost 70% less likely to transmit HIV to their infants if they received ZDV therapy. Moreover, prenatal testing of pregnant women can give physicians the earliest possible indication of whether children have been exposed to HIV so that PCP prophylaxis can be started at the recommended 4 to 6 weeks, he said. Grubman also stressed that women infected with HIV not breastfeed their infants.
For more information, see:
- Grubman S, Simonds RJ. Preventing Pneumocystis carinii pneumonia in human immunodeficiency virus-infected children: New guidelines for prophylaxis. Pediatr Infect Dis J. 996;15:165-68.
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