Academia.eduAcademia.edu

Introduction and persistence of tularemia in Bulgaria

2016, Infection Ecology & Epidemiology

Infection Ecology & Epidemiology ISSN: (Print) 2000-8686 (Online) Journal homepage: http://www.tandfonline.com/loi/ziee20 Introduction and persistence of tularemia in Bulgaria Mohammad Khan To cite this article: Mohammad Khan (2017) Introduction and persistence of tularemia in Bulgaria, Infection Ecology & Epidemiology, 7:1, 1323532, DOI: 10.1080/20008686.2017.1323532 To link to this article: http://dx.doi.org/10.1080/20008686.2017.1323532 © 2017 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group. Published online: 13 Jun 2017. Submit your article to this journal Article views: 67 View related articles View Crossmark data Full Terms & Conditions of access and use can be found at http://www.tandfonline.com/action/journalInformation?journalCode=ziee20 Download by: [5.1.64.137] Date: 14 September 2017, At: 09:38 INFECTION ECOLOGY & EPIDEMIOLOGY, 2017 VOL. 7, 1323532 https://doi.org/10.1080/20008686.2017.1323532 LETTER TO THE EDITOR Downloaded by [5.1.64.137] at 09:38 14 September 2017 Introduction and persistence of tularemia in Bulgaria Myrtannas et al. [1] studied new outbreaks of tularemia in Bulgaria. According to the evidence presented and the data corroborated with by the authors, the new outbreaks occurred after a lull of over three decades in a wide area (1000–1500 km2) abutting the Balkan Mountain Range (BMR) near the Bulgarian capital, Sofia. The new epicenter of the tularemia outbreak was 300 km west of the epicenter of the previous outbreak in Eastern Bulgaria. The authors undertook to track the source of the outbreak using molecular methods (e.g. analyses of singlenucleotide polymorphisms of the outbreak isolate). Their study is remarkable for, among other things, the relative lack of the application of traditional epidemiological methods in tandem with the molecular methods. They made no definite conclusion. The authors of the study referred to above did not mention the total number of cases detected during in new outbreaks, making one wonder how the authors defined an outbreak.[2] Also, it was not clear what clinical form of tularemia was detected during the outbreak. This is important, considering that the authors [1] postulated that the high BMR was an inviolable physical barrier to the transmission of Francisella tularensis (FT) from the old to the new foci of outbreaks. However, the high BMR may not necessarily be a physical barrier to the aerosolized transmission of FT.[3] The authors [1] suspected muskrats as the most likely sources of the outbreak strains of FT, yet provided no epidemiologic evidence suggestive of changing activities [4,5] of the animal before (e.g. distinctive muskrat tracks inland or dome-shaped lodges of the animal on water-logged surfaces) or after the outbreaks (e.g. increased number of dead muskrats). Also, absent is any information on the seasonality of the outbreaks studied by Myretennas et al. [1]. Seasonality of the outbreak would have given important clues about the sources of the outbreak strains of FT.[5] The study presented by Myrtannas et al. [1] shows that the genomic study of the outbreak strains of FT uncoupled with traditional epidemiologic approach may not enough to track the source of the pathogen. Disclosure statement No potential conflict of interest was reported by the author. References [1] Myrtannas K, Marinov K, Johansson A, et al. Introduction and persistence of tularemia in Bulgaria. Infect Ecol Epidemiol. 2016;6:32838. DOI:10.3402/iee. v6.32838 [2] Johansson A, Larkeryd A, Winderstrom M, et al. An outbreak of respiratory tularemia caused by diverse clones of Francisella tularensis. Clin Infect Dis. 2014;59:1546–1553. [3] Bowers RM, McCubbin IB, Hallar AG, et al. Seasonal variability in airborne bacterial communities at a high altitude site. Atmos Environ. 2012;50:41–49. [4] Link R. Living with wildlife muskrats. Washington Department of Fish and Wildlife; 2005. [5] Gürcan S. Epidemiology of tularemia. Balkan Med J. 2014;31:3–10. Mohammad Khan Department of Microbiology, School of Medicine, University of Dammam, Dammam, Saudi Arabia [email protected] © 2017 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.