In a cross-sectional survey of a rural Indian village, tuberculosis showed a prevalence of 8 per 1000, while newly diagnosed cases in the same year numbered 2 per 1000. In contrast, acute malaria showed an incidence of 50 per 1000 in the same year but a prevalence of only 3 per 1000. Which feature best explains why tuberculosis has a higher prevalence-to-incidence ratio than malaria?