Infection prevention strategies for children with cancer and AIDS: contrasting dilemmas

Infectious complications represent significant challenges for children with cancer and those infected with HIV. Although both have similarities in the disease- and treatment-related alterations in host defences, there are significant differences that can have an impact on the approach to treatment and prevention of the dominant infectious complications. An important difference is that children with cancer readily recover from neutropenia. Thus, the immune deficits are interspersed with intervals of immunological recovery. On the other hand, children with HIV infection do not appreciably recover from the progressive, immunological changes associated with the underlying HIV infection. The loss of cellular and humoral immunity is generally not reversible, and thus the risk of infection only increases over time. Bacteria constitute the predominant pathogen for paediatric cancer patients but invasive mycoses, viruses and parasitic infections are emerging as important pathogens. In paediatric cancer patients, strategies have been directed at altering or suppressing the endogenous colonization patterns of pathogenic bacteria. The success of this approach has been limited and at the expense of selecting for antibiotic-resistant bacterial infections. Children with HIV infection are at risk of developing a wide spectrum of pathogens. Strategies for infection prevention in the HIV setting have been directed at specific organisms, generally using more specific antimicrobial agents and with greater success.