Factors influencing the accuracy of infectious disease reporting in migrants: A scoping review

We conducted a scoping review of literature to improve our understanding of the accuracy of infectious disease monitoring in migrants in the Europe. We searched PubMed for papers relevant to the topic including: case reports, observational and experimental studies, reviews, guidelines or policy documents; published after 1994. We identified 532 papers, 27 of which were included in the review. Legislation and right to access health care influence both the accuracy of rates and risk measures under estimating the at risk population, i.e., the denominator. Furthermore, the number of reported cases, i.e., the numerator, may also include cases not accounted for in the denominator. Both biases lead to an overestimated disease occurrence. Restriction to healthcare access and low responsiveness may cause under-detection of cases, however a quantification of this phenomenon has not been produced. On the contrary, screening for asymptomatic diseases increases ascertainment leading to increased detection of cases. Incompleteness of denominator data underestimates the at-risk population. In conclusion, most studies show a lower probability of under-reporting infectious diseases in migrants compared with native populations.