Factors Associated with Pulmonary and Extrapulmonary Tuberculosis: A Case-case Study

INTRODUCTION: Despite low TB incidence in Castellon and La Plana-Vila-Real health departments (2013-2016), elimination remains challenging, especially in marginalized populations. However, TB elimination is challenging. It is frequent to find patients with TB, whose disease is very difficult to control because these patients are often marginalized and homeless. The rise in ETB cases adds complexity to TB epidemiology, necessitating targeted control measures. OBJECTIVES: The objective of this study was to identify associated factors in pulmonary tuberculosis (PTB) in comparison to extrapulmonary tuberculosis (ETB) and examine the epidemiological characteristics of these conditions to guide control and prevention strategies. MATERIALS AND METHODS: A 2013-2016 case-case study in Valencia, Spain, compared pulmonary tuberculosis (PTB) and extrapulmonary tuberculosis (ETB) incidences using Hospital General Castellon and La Plana-Vila-Real data. PTB patients were cases, ETB patients controls. Directed acyclic graphs guided factor selection, and logistic regression estimated adjusted odds ratios (AORs). RESULTS: This study examined 50 PTB and 57 ETB patients, with microbiological confirmation rates of 89.8% and 54.7%. Annual median incidence rates were 6.8 and 3.5 per 100,000 for PTB and ETB. PTB patients, generally younger with a higher male proportion, had risk factors like smoking tobacco (AOR = 3.84; 95% CI = 1.49-8.97), social problems (AOR = 3.47; 95% CI = 1.41-10.66), and TB contact (AOR = 2.42; 95% CI = 1.57-5.64). No-smoking and no-drug abuse interaction significantly decreased PTB risk (AOR = 0.34; 95% CI = 0.22-0.51). DISCUSSIONS: This study underscores PTB-ETB distinctions, with PTB linked to social issues, smoking, and TB contact, and reduced by no-smoking/no-drug abuse. ETB associates variably with Maghreb birthplace and HIV. Comparative studies support a 70% PTB, 30% ETB ratio, emphasizing smoking and alcohol. ETB suggests recent infection/reactivation, influenced by immunodeficiencies and genetics. Risk factors involve immunosuppression, long-term diseases, age, gender, race, and ethnicity. ETB rate variations may result from immigration, delayed treatment, underreporting, and genetic diversity. PTB shows higher drug resistance, with minimal multidrug resistance. In conclusion, this research sheds light on the nuanced differences between PTB and ETB, emphasizing the importance of tailored strategies for each form of tuberculosis. The identified risk factors underscore the multifaceted nature of these diseases, requiring targeted interventions for effective control and prevention.