94 Epidemics which never came: yellow fever (1883) and bubonic plague (1902- 1903) in Baja California Arturo Fierros-Hernández 1 and Alejandro Ayala-Zúñiga 2 1 Instituto Holy Cross, Tijuana; 2 Family Medicine Unit No. 39, Instituto Mexicano del Seguro Social, Tecate. B.C., Mexico Gac Med Mex. 2018;154:94-99 Contents available at PubMed www.gacetamedicademexico.com Abstract This paper seeks to clarify the epidemic panorama that was generated in Baja California in the late nineteenth and early twentieth 20 th century’s, specifically that occurred in 1883 and 1902, years in which it is claimed occurred epidemics of yellow fever and bubonic plague respectively. However, as demonstrated in our study they never occurred due to social-demograph- ic conditions in the area. KEY WORDS: History. Epidemics. Vectors. Correspondence: Arturo Fierros-Hernández Virrey Luis de Velazco, 8 Col. Anexa Buena Vista C.P. 22414 Tijuana, B.C., México E-mail: arturofierrosh@gmail.com Date of reception: 09-09-2016 Date of acceptance: 01-12-2016 DOI://dx.doi.org/10.24875/GMM.M18000120 GACETA MÉDICA DE MÉXICO SHORT COMMUNICATION Introduction With the perspective conferred by scientific, medical and epidemiological advances, reflections that have been generated, in addition to the conceptual tools his- torians have worked in, we are allowed to observe epi- demiological phenomena of the past and thus being able to make a reconstruction with adherence to reality. Some authors have pointed out that, in Baja California*, epidemics appeared that were related to diseases caused by vectors, such as yellow fever in 1883 1,2 and bubonic plague in 1902 3,4 . Such claims were made based on documentation of the epoch, written by people with different trades and professions (with physicians standing out) not specialized in epi- demiology, which caused for the concept of epidemic to be generalized and indistinctly used, which is a situation that produces an information bias, influenced * During the period studied in the present article, Baja California had the status of District, it was the Baja California Northern District until after 1931 and stopped being it and became a Federal Territory. In 1952, it was granted the geopolitical de- nomination of State. by temporality and under-specialization. There are parameters to define an epidemic, which can be de- scribed in terms of three basic quantifiable variables: people, time and space 5 . This article has the following objectives: 1) historicize the concept of epidemic and its meaning over time, and 2) to conceptually redefine the epidemics that occurred in Baja California during the referred years, based on a hybrid descriptive approach that rescues and relates elements of epidemiology and social sciences, as a sort of an interdisciplinary bridge 6,7 . The concepts of epidemic and epidemiology Currently, an epidemic is considered to be “a dis- ease that is present in a community or population at a high percentage; when the disease spreads to in- habitants of several countries, we can speak of a pandemic” 8 . The use of the concept of epidemic in the western literature is quite ancient 9 . It was Hippocrates of Kos (460-385 B.C) who used the term epidemeion, refer- ring to the act carried out by the physician when he No part of this publication may be reproduced or photocopying without the prior written permission of the publisher. © Permanyer 2018