Antecedentes de sífilis em mulheres com Aids e fatores de risco associados, São Paulo, Brasil

Objetivo:

descrição de perfil epidemiológico, comportamentos de risco, frequência de antecedentes de sífilis em mulheres com Aids e investigar fatores associados.

Métodos:

estudo de corte transversal conduzido com mulheres com HIV/Aids atendidas em centro de referência para Aids em São Paulo. Dados demográficos, comportamentais e clínicos foram analisados a partir dos prontuários médicos.

Resultados:

foram incluídas 598 mulheres no estudo e a prevalência de antecedentes de sífilis foi 6,2% (IC 95%: 4,3 a 8,1). Um total de 73% das mulheres tinha menos de 40 anos de idade na época do diagnóstico da Aids e 49,6% alcançaram mais de 8 anos de escolaridade, sendo que 67,2% eram brancas e 65,9% não eram casadas nem viviam com parceiro, 53,2% alegaram primeiro coito com mais de 15 anos de idade, 56,5% referiram apenas um parceiro no último ano, 13% referiram uso de drogas e 83,8% apresentavam CD4+ < 500 cél/mm³ no diagnóstico da Aids. Foram fatores associados à infecção por sífilis: uso de crack [ORaj = 6,8 (IC 95% 1,7 – 27,5)], mais de 1 parceiro sexual no último ano [ORaj = 6,6 (IC 95% 1,2 – 37,1)], CD4+ < 500 cél/mm³ [ORaj = 3,8 (IC 95% 1,1 – 13,6)], diagnóstico do HIV > 8 anos [ORaj = 2,4 (IC 95% 1,0 – 5,8)].

Conclusão:

elevada prevalência de sífilis foi encontrada na população estudada e o uso de crack foi o principal fa-tor identificado dentre os fatores associados. É necessário reforçar as intervenções para a redução do risco de transmissão sexual do HIV e da sífilis, com implementação de ações para o seu controle e estratégias de rastreamento, diagnóstico e tratamento precoces, evitando complicações e diminuindo a morbidade com melhoria da saúde sexual e reprodutiva.

Methods

Cross-sectional study conducted by the Sexually Transmitted Diseases and AIDS Reference and Training Center in São Paulo (CRT-DST/AIDS). This center monitors approximately 4,000 people with HIV/AIDS, 1,100 of whom are women.

The data was collected from the medical records of all of the women living with AIDS that had gynecological consultations scheduled in the period from June 1^st 2008 to May 31^st, 2009. Social and demographic, behavioral and clinical characteristics, such as age, level of education, marital status, age at the time of first sexual intercourse, number of sexual partners, drug use, HIV diagnosis time, T CD4+ lymphocytes and viral load (VL), among others, were selected for analysis.

The study included women using high strength antiretroviral drugs, and excluded those that did not have T CD4+ lymphocyte count and HIV viral load results or did not have the gynecological consultation described.

The reports of prior history of syphilis were noted, as well as the results of laboratory exams in the routine of the service, such as HIV infection time, CD4+ count, VL and serology for syphilis. The race/color variable, which was self-reported, considered black women as those who declared themselves as being black or mixed-race. The level of education and human development index (HDI) were used as indicators of the socioeconomic level owed to the association with various lifestyle characteristics. The data collected from medical records was related with the HDI database of the city of São Paulo in the year 2000, using the deterministic linkage method that makes a nominal identification in two databases.

A prior history of syphilis was considered as a dependent variable for conducting the analysis. The risks for prior history of syphilis were studied for all of the independent variables of interest stated above.

The clinical/epidemiological information and the findings of the results of laboratory exams were codified and stored in a database created for this purpose. The statistics program STATA 10.0 was used for saving and analyzing the data.

The analysis was conducted using exploratory techniques on the data to verify the distribution patterns and tendencies for the main variables. Next, a bivariate analysis was undertaken to verify the presence of an association between them. The chi-squared (c²) test was used for differences of proportion and the Student’s t-test and variance analysis for differences between the averages. To estimate associations, the odds ratio was used with a confidence interval of 95%. The variables were selected to compose the model when the likelihood ratio test (LRT) presented a p value equal to or less than 0.25. A multivariate analysis was undertaken to estimate the joint effects of independent variables through the use of logistic regression models. This model was adjusted using the step forward procedure and the inclusion of variables followed the ascending order of OR values. The importance of the variables for the final model was evaluated using the likelihood ratio test, considering p < 0.05.

The project was approved by the Research Ethics Committee at the STD/AIDS Reference and Training Center in São Paulo.

Results

598 women were included from a total of 710 scheduled for gynecological consultations in the period of the study. 112 (15.8%) were excluded, including 33 women whose information about the prior history of syphilis was ignored, 29 that did not present prior or current gynecological consultations, 23 who were not using antiretroviral drugs, 18 with a negative serology for HIV, and 9 women living with HIV acquired by vertical transmission and without sexual activity.

The reports of prior history of syphilis represented 37 cases out of 598 women, with an estimated prevalence of 6.2% (95% CI: 4.3 – 8.1).

The social and demographic characteristics of the women are presented in Table 1. The majority of women were less than 40 years old (73.6%) at the time of being diagnosed with AIDS and in relation to level of education, 49.6% of women had completed more than eight years of education. In relation to race, the majority were white (67.2%) and more than two thirds (65.9%) were not married or living with a partner. It was also noted that more than a third of the women (35.6%) lived in a district with a low human development index (HDI).

Table 2 describes the behavioral characteristics of the population studied. More than half of the population (53.2%) started their sexual life aged over 15 years; 56.5% of the women reported that they had had only one sexual partner in the last year, while 35.1% reported six or more partners during their life (data not shown in the table). Around a third of them (29.9%) had had more than three pregnancies, and 2.7% of the women declared that they were sex workers (data not show in the table). The use of drugs was reported by 13% of the women, with almost a quarter of these reporting the use of crack cocaine (23.1%).

A total of 43.6% of the women had been diagnosed with HIV infection for nine or more years, with extremes of 1 and 22 years of monitoring time. 83.8% presented a T CD4+ lymphocyte count in the AIDS diagnosis below 500 cells/mm³.

The bivariate analysis of the factors associated with a history of syphilis in women living with AIDS and their risks are described in Table 3. Through the multivariate analysis in the logistic regression model, the factors associated with a history of syphilis infection in women living with AIDS were identified, as presented in Table 4. The factors associated with a history of syphilis and the respective risks were the use of crack cocaine [AOR = 6.8 (95% CI 1.7 – 27.5)], more than one sexual partner in the last year [AOR = 6.6 (95% CI 1.2 – 37.1)], T CD4 + lymphocyte count of less than 500 cells/ mm³ [AOR = 3.8 (95% CI 1.1 – 13.6)] and HIV diagnosis for more than 8 years [AOR = 2.4 (95% CI 1.0 – 5.8)].

Discussion

This study intended to describe the epidemiological profile, risk behavior and frequency of the prior history of syphilis in women living with AIDS cared for by the STD/AIDS Reference Center in São Paulo. A high prevalence of prior history of syphilis was found in the population studied.

Despite having adequate diagnostic methods and simple treatment, syphilis remains an important public health problem worldwide. In Brazil, there are few studies available analyzing the prevalence of syphilis in people living with HIV/AIDS (PLWHA).

In a study conducted in Pernambuco¹⁵ with 399 PLWHA, 25% being female, syphilis was the most frequent sexually transmitted disease encountered, with a prevalence of 8.8%, as well as a study in Paraná,¹⁶ with a sample of 44.1% of women, which found a 14.3% prevalence of syphilis. However, both studies failed to describe the exclusive rate among women. Another study of pregnant women infected with HIV in Bahia,¹⁷ also found a high prevalence of syphilis (9.5%).

Reports of a prior history of syphilis were observed in 6.2% of our sample, a higher rate than that found by Saxton et al.¹⁸ in women living with HIV/AIDS in the Ukraine (1.9%). However, the lower age of the population being studied should be taken into account. Our rate was lower than the 11.5% found by Robertson et al., in the USA, where a history of syphilis among women living with HIV/AIDS presented an increased risk of infection by HIV of 2.8.¹⁹ The rate is also lower than the findings of Signorini et al., ²⁰ in Rio de Janeiro, which found a rate of 15.3% of syphilis, considering any concentration of VDRL and active diseases was defined only for concentrations >01:16 AM, with a prevalence of 2.7%, with 1.1% among women, as well as Callegari et al., ²¹ in Espírito Santo with prior history of syphilis in 18.9% of a population of PLWHA, where 45% were women.

In our study, the prior history of syphilis was significantly associated with the use of crack cocaine, more than one sexual partner in the last year, a CD4+ count below 500 cells/mm³ and an HIV infection diagnosis time of more than eight years.

In relation to the use of crack cocaine, the results of this study are corroborated by other research conducted in the United States.^19,22,23 A study conducted in Jamaica also identified an association between syphilis and HIV infection, with the prevalence of the use of crack/cocaine in PLWHA was 8%, which is higher than that identified in our investigation (3%). However, the authors did not present the percentage for the use of crack alone, or exclusively among women.²⁴ In a study by Hwang et al. syphilis was strongly associated with HIV infection, and the majority of injecting drug users (IDUs) is also crack users. However, in the study the use of crack disappeared when adjusted for IDUs.²⁵

A single sexual partner in the last 12 months was shown to be a protection factor for syphilis in women living with AIDS in our study, and it was identified that the more sexual partners, the higher the risk, suggesting a dose-response effect. Fonseca and Bastos²⁶ analyzed the AIDS epidemic in Brazil and identified that among women the dynamic occurs, for the most part, owed to multiple sexual partners, or partners with multiple sexual partners.

Our findings have shown an association between a prior history of syphilis and a reduction in CD4+ levels, in accordance with the study by Buchacz et al.,²⁷ which demonstrated that syphilis is associated with an increase in the HIV viral load and significant reduction in CD4 lymphocytes, as well as Kofoed et al,²⁸ who identified a reduction in CD4 during the course of syphilis infection.

In the same manner, in Brazil, Travassos et al.,¹⁷ found an association between a CD4 count below 500 cells/mm³ with the presence of STDs in women living with HIV. The fact that their analysis did not specify the STDs in isolation, and considering that syphilis presented the second highest prevalence among bacterial STDs, this may have contributed strongly to this association.

The use of retrospective data is one of the limits to this study. However, the good quality of the data in the medical records and the low rate of information loss have reduced this limitation.

In a recent publication systematically reviewing the prevalence of STDs in PLWHA, Kalichman et al., identified syphilis as the most common STD in this population, with an average prevalence of 9.5% in 37 studies.²⁹

In our study, the level of prior history of syphilis in women living with AIDS was high (6.2%), and the associated risk factors were the use of crack cocaine, having more than two sexual partners in the preceding year, a CD4+ count between 350 and 500 cells/mm³ and HIV diagnosis time of over eight years.

Healthcare services are not always ready to deal with the different constraints experienced by women in exercising their sexuality, which impedes the incorporation of protective practices and increases their vulnerability to STDs and HIV.³⁰ Therefore, there is still much work to be undertaken in order to identify innovative interventions relating to the social, cultural and environmental influences on the presence of STDs in this group. There is also a need to find better means of access for the prevention of HIV, so that effective interventions can be more widely used.

Sexually active women need confidential and welcoming services to teach them how to protect themselves from diseases, including sexually transmitted ones which may be asymptomatic in the majority of females, and therefore subject to complications caused by non-treatment.

As syphilis is among the most well established risk factors for the acquisition of HIV, public health programs should be reinforced with the implementation of control actions. Tracking, diagnosis and early treatment actions can help to avoid complications, reduce morbidity with improved sexual and reproductive health of the population.