The Susceptibility to Other Infectious Diseases Following Measles During a Three Year Observation Period in Switzerland.

Background: Measles virus infection leads to significant immunosuppression. In developing countries, this translates to an increased nonspecific mortality, whereas its effects in developed countries are less clear. Methods: We performed a cohort study to investigate whether children hospitalized with measles (cases) between 2000 and 2015 in Switzerland would have a higher frequency of hospital admissions due to other infectious diseases thereafter than children who did not have measles (controls). Cases were identified by ICD-10 discharge diagnoses for measles and/or keyword search and matched to 2 controls by time of hospitalization, age and sex. All hospitalizations <= 3 years after original admission, infectious or noninfectious in origin, were identified in cases and controls. Results: One hundred thirteen cases (56% males), mean age 9.0 years (range 2 weeks-17.8 years), and 196 controls were identified. Twelve rehospitalizations due to an infectious disease occurred in 11 cases and 6 in 6 controls (episode rates 0.106 versus 0.031 per person; ratio 3.47; 95% CI: 1.20-11.3; P = 0.012) in 3 years of follow-up. Of these, 9 and 3 occurred in cases and controls, respectively, during year 1 [ratio 5.20 (95% CI: 1.30-29.88; P = 0.012)]. Infectious diseases following measles affected various organ systems, were neither particularly severe nor fatal and revealed no specific pattern. Conclusions: The increased risk for nonspecific infectious disease hospitalizations supports the concept of immunologic amnesia after measles. Universal immunization against measles provides additional benefit beyond protection against measles itself.