Active measles surveillance in the Russian Federation: implementation principles and current challenges

Abstract

From 2004 to 2006, a pilot project was carried out in 11 territories of the Russian Federation to test the method of active epidemiological surveillance, which makes it possible to identify the true number of measles patients among persons with maculopapular rash and fever, regardless of the primary diagnosis. Objective. To provide a clinical and epidemiological characterization of measles cases detected through active surveillance and to assess the quality of pre-hospital diagnosis. Materials and Methods. A retrospective analysis of data from 2017–2025 was conducted, including 1.691 epidemiological investigation forms for patients identified through active surveillance and 2.517 hospital records of inpatients. Laboratory verification was performed using immunoenzyme assay (IgM/IgG). Descriptive epidemiological and statistical methods were applied. Results. Active surveillance annually detected missed measles cases (ranging from 1 to 743 in different years). The average age of the patients was 22.5 years. At the pre-hospital stage, measles was not recognized in 37.7 % of hospitalized patients. Over 90 % of cases in recent years exhibited a typical clinical picture, indicating low clinical awareness among physicians. Complications were registered in 38–40 % of patients, with infants under one year of age remaining the most vulnerable group. Conclusions. The high proportion of typical measles cases among those missed indicates systemic deficiencies in clinical diagnosis. Continuous training of medical personnel, enhanced laboratory monitoring, and maintenance of high vaccination coverage are necessary maintain measles elimination status.