Fatores da vulnerabilidade associados à sífilis e HIV em uma comunidade ribeirinha amazônica

Abstract

Background: There is an intensification of cases by the human immunodeficiency virus (HIV) and syphilis in some population segments, mainly in the northern region of Brazil. The state of Pará has the second highest AIDS mortality rate in the country, and a growing increase in the incidence of notifiable sexually transmitted infections (STIs). In this epidemiological sphere, the riverside population of the Amazon is included, which are miscegenations of indigenous peoples, Africans, and others, who suffer from low socioeconomic indicators, geographic barriers and access to health. Objective: To analyze vulnerability factors associated with the occurrence and knowledge of STIs (syphilis and HIV) in a riverside population in the Brazilian Amazon. Method: This is a cross-sectional study carried out in Ilha do Combu – Belém/PA. The sample calculation was performed using the Statcalc module – Sample size and power of the EPI INFO Version 7.2.2.16 program. For the sample, people aged 18 years or older and residents of the island were considered. Data collection took place through the application of two instruments: Sexually Transmitted Disease Knowledge Questionnaire (STD­-KQ) used to measure the level of knowledge of riverside people; and to survey the population and the dimensions of vulnerability, the adapted instrument applied in the nationwide household survey of the “Research of Knowledge, Attitudes and Practices in the Brazilian Population” (PCAP) was used. The investigation for infections was carried out by means of a rapid test for HIV and syphilis, and peripheral blood collection for rapid plasma reaginine in cases of rapid test reagents for syphilis. For data analysis, descriptive statistics and a logistic regression model were used. In univariate binary regression were selected for multiple regression. The variables with the highest p-value were removed one at a time until the final fit of the multiple ordinal logistic regression model. All statistical analyzes were performed using Minitab 20® software. A significance level of 5%, confidence interval (CI) of 95% and Odds Ratio (OR) were adopted. Results: The total consisted of 325 riverside dwellers with a prevalence of syphilis of 6.15% (20) and of HIV of 0.61% (2), being a co­infection. 190 were female and 135 were male. 68.9% (220) had a mean age of 40 years and 56.6% (184) had never attended school or had elementary school. The variables related to individual vulnerability that were associated with the outcome/chance of infection for STIs in the final regression were almost four times higher in participants aged 48 years or older (p=0.022), having had a blood transfusion (p=0.023 ), people who had more than one sexual partner in the last 6 months (p=0.028) and did not know the female condom (p=0.031); and having a current sexual partner (p=0.041) had a low risk of 0.33 for the outcome. For social vulnerability, no variable was associated. And in the programmatic dimension, not having taken a rapid test for HIV presented a low risk of 0.26 (p=0.021). Regarding the level of knowledge in the riverside population, 65.5% (213) participants had low knowledge (0 to 14 correct answers/28 questions). On the other hand, in the association between the factors of level of knowledge about STIs, the three dimensions of vulnerability were present. Among them, participants aged 48 years or older had a risk 1.93 times higher (p=0.012) for low level of knowledge about STIs, not knowing their partner's serology had a risk of 1.92 times (p=0.011 ); almost 4 times greater chance (p=0.000) was obtained among riverside dwellers with low schooling; never having been tested for STIs in life had a chance of 2.51 (p=0.000), and not having access to condoms in the last year the risk was 1.95 times (p=0.006) of low knowledge. Conclusion: The riverside population was vulnerable to syphilis and HIV in the individual and programmatic dimensions. Regarding the level of knowledge about STIs, this population suffers from a deficit, and is vulnerable in all dimensions.