Syphilis hospitalisations in Portugal over the last decade

Although several studies have reported an increase of syphilis incidence over the last decade in Western Europe, information concerning syphilis epidemiology in Portugal remains scarce. Therefore, we sought to characterise acquired syphilis-associated hospitalisations in Portugal according to demographic and clinical data. We used a database containing all hospitalisations that occurred in mainland Portugal public hospitals with discharges between 2000 and 2014. We analysed all hospitalisations associated with ICD-9-CM codes 091-097.x (corresponding to acquired syphilis diagnosis) concerning inpatients' gender, age and comorbidities. The median length of stay and in-hospital mortality rates were also studied. Between 2000 and 2014, there were a total of 8974 syphilis-related hospitalisations in mainland Portugal. The rate of acquired syphilis hospitalisations per 100,000 inhabitants increased by 33 % during the studied period. Syphilis hospitalisation rates increased by 70 % in males and 139 % among patients aged over 55 years. On the other hand, they declined by 10 % in females and 20 % among patients younger than 55 years old. The percentage of syphilis episodes presenting cardiovascular and neuropsychiatric comorbidities increased, while the percentage of syphilis episodes presenting HIV co-infection decreased by 69 %. A fatal outcome was reported in 5 % of episodes; 4.6 % of them had acquired syphilis as the main reason for hospitalisation. This study illustrates that, despite being a preventable infection, syphilis remains a public health problem. The analysis of hospitalisation and administrative data helps to understand syphilis epidemiology and provides a supplement to traditional case notifications.