Syphilus: investigação de sífilis adquirida em pessoas idosas

Abstract

Introduction: Acquired syphilis is a sexually transmitted infection caused by Treponema pallidum, which is still considered an important public health problem. The objective of this research was to investigate data on the detection rate of acquired syphilis in Brazil among individuals aged 60 to 120, characterize the epidemiological profile and associated determinants, and conduct a temporal trend analysis of the infection's distribution in the country from 2010 to 2020. Additionally, In addition, detect the seroprevalence of the disease in elderly people assisted in the Family Health Strategy Units of the city of Natal/RN and analyze the variations, and analyze the variables associated with the disease. Methodology: After approval by the Research Ethics Committee, the detection rate of acquired syphilis in elderly people (aged 60 to 120) across Brazil was analyzed over a 10-year period. Data was obtained from the Notifiable Diseases Information System. Subsequently, elderly people enrolled with Family Health Units were mobilized to participate in an initiative to investigate sexually transmitted infections, particularly acquired syphilis. Participants underwent a rapid test, and if the result was positive, a blood sample was collected for the Venereal Disease Research Laboratory test. A Data Collection Instrument was applied. The acquired syphilis detection rate was calculated using the 2010 census and projections for the elderly population from the Brazilian Institute of Geography and Statistics. Joinpoint analysis identified significant changes in the disease detection rate at inflection points. For local data, descriptive analysis was performed using absolute and relative frequencies. Statistical analysis (Pearson's chi-square test or Fisher's exact test) assessed the significance of associations between variables. Prevalence Ratios were calculated, and statistical tests were performed using the Statistical Package for the Social Sciences, version 19.0. Results: In the analysis of the acquired syphilis detection rate among elderly people (2010–2020), a progressive increase in disease diagnoses was observed from 2011, intensifying in 2018, followed by a progressive decrease from 2019 to 2020. The highest detection rates were found among men, white and black individuals, those with primary and secondary education, and in the South and Southeast regions. The age groups with the highest rates were 60–64 years and 65–69 years. The average age of individuals with acquired syphilis was 68.04 years (±7.15). Annual and average annual percentage variations in acquired syphilis rates indicated significantly homogeneous trends in disease growth by sex, regions of Brazil, and age groups involved. In the local-level analysis of acquired syphilis cases, a total of 434 patients were investigated. The majority were female, brown-skinned, with incomplete primary education, and aged between 60–69 years. The participants’ ages ranged from 60 to 93 years, with an average of 68.80 years. The prevalence of positive acquired syphilis tests was 3.00% (1.4 < µ < 4.6), and the prevalence of a reactive result for confirmatory testing was 1.15% (-9.0 < µ < 11.4). One patient had a titer of 1:8, and four patients had a titer of 1:2. The only factor associated with the seroprevalence of acquired syphilis was male gender (p=0.036, PR=3.11, 95%CI=1.02-9.48). Conclusions: The research confirmed the increase in cases of acquired syphilis among elderly people in Brazil, showing its rise across all age groups. It also contributed to the epidemiological data on the disease in the municipality of Natal/RN, demonstrating that the seroprevalence rate of the infection in elderly individuals is considered high, especially for males. The study contributed to the consolidation of indicators and, consequently, encourages better planning and management of actions to combat STIs, specifically directed toward this population.