Human tuberculosis caused by Mycobacterium bovis: a retrospective comparison with Mycobacterium tuberculosis in a Mexican tertiary care centre, 2000–2015

Abstract

BackgroundHuman tuberculosis caused by Mycobacterium bovis is believed to be frequent in developing countries. Transmission is usually through ingestion of unpasteurized dairy products, although airborne contagion is possible. Disease caused by M. tuberculosis or M. bovis is clinically indistinguishable from each other. The aim of this study was to determine the factors associated with M. bovis disease.MethodsRetrospective analysis of all culture-positive cases of M. bovis and M. tuberculosis from 2000 to 2015, in a Mexican tertiary-care centre. Sociodemographic, clinical, and radiographic data from medical records were compared. Disease site was classified as pulmonary, extrapulmonary, or pulmonary and extrapulmonary, based on cultures.ResultsWe evaluated 533 cases, 372 (69.7 %) of which were caused by M. tuberculosis and 161 (30.2 %) by M. bovis. Characteristics associated with M. bovis disease were: younger age (aOR 0.97, 95 % CI 0.95–0.98), glucocorticoid use (aOR 2.27, 95 % CI 1.42–3.63), and extrapulmonary disease (aOR 1.80, 95 % CI 1.21–2.69). M. tuberculosis was associated with lower socioeconomic status (aOR 0.52, 95 % CI 0.28–0.97). When we analysed only pulmonary cases, younger age (aOR 0.97, 95 % CI 0.96–0.99), glucocorticoid use (aOR 2.41, 95 % CI 1.30–4.46), and smoking (aOR 1.94, CI 95 % 1.15–3.27) were associated with M. bovis. Both groups showed similar proportions of direct microscopy smear results (respiratory samples) and chest X-ray cavitations.ConclusionsYounger age, glucocorticoid use, and extrapulmonary disease were associated with M. bovis as the causative agent of tuberculosis in a group of patients from a tertiary care centre in a country where bovine tuberculosis is endemic. Further studies must be conducted in the general population to determine pathogen-specific associated factors and outcomes.

Human as a potential vector of bovine tuberculosis in cattle

“…M. bovis -induced tuberculosis in 2 Polish patients caused by M. bovis, was described for the first time in 2016 [18]. This is a very small number of M. bovis human cases compared with the number of TB patients in Poland and worldwide [19,20,21].…”

Long-lasting cutaneous tuberculosis owing to Mycobacterium bovis masquerading as sarcoidosis

“… 1 , 2 It is transmitted to humans through unpasteurized milk or by direct contact with animals, notably in cattle workers and veterinarians. 1 , 2 , 3 , 4 , 5 , 6 Isolated cases of cutaneous tuberculosis caused by M bovis have been reported. In most of them, the lesions presented as lupus vulgaris and were long lasting from 10 to 60 years, with possible contamination during childhood.…”

“… 3 , 4 , 6 , 7 Pyrazinamide should not be used to treat M bovis owing to its intrinsic resistance. 2 , 5 , 8 Diseases caused by either M bovis or M tuberculosis are considered clinically and radiologically indistinguishable from each other. Tissue culture and PCR were the keys to the diagnosis, allowing identification of the Mycobacterium species involved and its suitable treatment, as species have different sensibility and resistance to antituberculosis antibiotics.…”

Animal tuberculosis: impact of disease heterogeneity in transmission, diagnosis, and control

“…The growing populations of cattle in India, Ethiopia, South Africa and China could represent a serious animal and human health issue due to the circulation of M. bovis and also M. tuberculosis (the aetiological agent of human TB; Ameni et al, 2011; Chen et al, 2009; Hlokwe, Said, & Gcebe, 2017; Sweetline Anne, Ronald, Kumar, Kannan, & Thangavelu, 2017). When considering the Americas, both Mexico and United States reported details of TB epidemiology of zoonotic origin in specific areas, showing an increasing percentage of infections by M. bovis (Mark, Neha, & Jennifer, 2015; Torres‐Gonzalez et al, 2016). In Europe, several countries, namely Austria, Germany and Spain, have reported cases of zoonotic TB due to M. bovis and also M. caprae (Borna et al, 2013; Kubica, Rusch‐Gerdes, & Niemann, 2003; Prodinger, Eigentler, Allerberger, Schönbauer, & Glawischnig, 2002).…”