Etiological Deciphering of Imported Cases of Community-Acquired Pneumonia in the Irkutsk Region in 2024

Abstract

In 2024, two cases of community-acquired pneumonia (CAP) imported from Thailand were registered and etiologically deciphered in the Irkutsk Region, including the first case of acute melioidosis resulting in death, which was diagnosed for the first time in the Russian Federation. In the second case, Acinetobacter radioresistens was isolated from a patient with CAP. The aim of the work was to conduct indication and species identification of pathogens causing community-acquired pneumonia, obtained from biological material from patients who had arrived from Thailand to the Irkutsk Region. Materials and methods . The culture of a microorganism isolated from a liver sample of a patient with the fatal outcome, preliminarily identified by mass spectrometry as a causative agent of the genus Burkholderia and clinical material (blood, throat swab, sputum, urine) from a patient with suspected melioidosis were studied. The research was performed using bacteriological, bacterioscopic, molecular-genetic, proteomic, and serological methods of laboratory diagnostics. Results and discussion . In the first imported case, a culture of Burkholderia pseudomallei was isolated from a patient with a postmortem clinical diagnosis of community-acquired bipartite pneumonia; rapid identification of the causative agent of melioidosis was carried out using MALDI-TOF MS and PCR methods. For the purpose of in-depth identification, the isolated culture was studied by a range of laboratory diagnostic methods for melioidosis. The sensitivity of the isolated B. pseudomallei strain to some first- and second-line antibacterial drugs was established, and its species resistance to penicillins, aminoglycosides, and macrolides was confirmed. In the second imported case of community-acquired pneumonia, the causative agent of melioidosis and its DNA were not found in the patient’s clinical material. A culture was isolated from the patient’s urine sample, which was identified by mass spectrometry as Acinetobacter radioresistens . In view of the growing number of imported cases of exotic infections in the Russian Federation, including melioidosis, it is necessary to increase the alertness of medical personnel, incorporate melioidosis in the differential diagnostics of community-acquired pneumonia in people with a “traveler’s history”, maintain the readiness of specialized laboratories, strengthen awareness-raising among the population traveling to regions endemic for dangerous infectious diseases, and ensure effective interdepartmental cooperation within the framework of sanitary protection of the territory of Russia in order to establish an etiological diagnosis of community-acquired pneumonia and correct treatment scheme.