Protozoa infection, another type of parasitic infection, is common in urban areas lacking clean water access and may result in severe malnutrition as a consequence of chronic diarrhea or anorexia. Protozoa infection can be asymptomatic and may result in elevated levels of cytokines such as interferon-γ (IFN-γ), a critical mediator in the host immune response to Mycobacterium tuberculosis. We report on the relationship between various parasite infections, including protozoa infection, and TB among children in Lima, Peru.