Background: Given the progressive increase in infectious endocarditis (IE) in intravenous drug addicts (IVDA) in the province of Cadiz the present study was designed with the aim of studying the epidemiologic and clinical characteristics of this disease in our environment.
Methods: One hundred fifty episodes of IE occurring in 133 IVDA admitted to 6 hospitals in the province of Cadiz were studied in an open, multicentric study with a protocol of gathering of common data. Well known diagnostic criteria were used for this process and a univariant technique was employed in the analysis of prognostic factors.
Results: Fifty-three percent of the episodes occurred in the county of Campo de Gibraltar and 32% in the area of the Bay of Cadiz. The increase of the disease has been progressive since 1984 and marked over the last two years. All the patients presented fever, abnormal chest radiography in 90% and the process was produced by Staphylococcus aureus in 88%. Echography was abnormal in 85% of the episodes and vegetation was identified in 75%. The IE was located as right in 90%, mixed in 5% and left in 5%. Surgical treatment was required in 4 patients. Mortality was of 9%. Mixed or left location (p = 0.00003) and the development of the respiratory distress syndrome of the adult (p = 0.00001) were significantly associated with greater mortality.
Conclusions: Infectious endocarditis in intravenous drug addicts maintains a well defined pattern of clinical expressivity and presents identifiable factors of prognostic influence. The increase in its prevalence in the province of Cadiz is probably due to a parallel increase in the addiction to intravenous heroin in this area.