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Revista de Saúde Pública

Print version ISSN 0034-8910

Rev. Saúde Pública vol.47 no.1 São Paulo Feb. 2013

http://dx.doi.org/10.1590/S0034-89102013000100019 

ORIGINAL ARTICLES
PUBLIC HEALTH PRACTICE

 

Congenital syphilis: a sentinel event in antenatal care quality

 

Sífilis congénita: evento centinela de la calidad de la asistencia pre-natal

 

 

Rosa Maria Soares Madeira DominguesI; Valeria SaraceniII; Zulmira Maria de Araújo HartzIII; Maria do Carmo LealIV

IInstituto de Pesquisa Clínica Evandro Chagas. Fundação Oswaldo Cruz. Rio de Janeiro, RJ, Brasil
IICoordenação de Análise de Situação da Saúde. Superintendência de Vigilância em Saúde. Secretaria Municipal de Saúde e Defesa Civil do Rio de Janeiro. Rio de Janeiro, RJ, Brasil
IIIInstituto de Higiene e Medicina tropical. Universidade Nova de Lisboa. Lisboa, Portugal
IVDepartamento de Epidemiologia e Métodos Quantitativos em Saúde. Escola Nacional de Saúde Pública Sérgio Arouca. Fundação Oswaldo Cruz. Rio de Janeiro, RJ, Brasil

Correspondence

 

 


ABSTRACT

OBJECTIVE: To evaluate antenatal care in reducing the vertical transmission of syphilis.
METHODS: A cross-sectional study was designed to be representative of low-risk pregnancies in women cared for at the Brazilian Unified Health System (SUS) network in the city of Rio de Janeiro, from November 2007 to July 2008. Pregnant women diagnosed with syphilis were identified through interviews, checking their antenatal care card and searching for reported cases in the public health information systems. Cases of congenital syphilis were sought at the disease reporting system (Sinam), the Mortality Information System (SIM) and the SUS's Hospital Information System (SIH).
RESULTS: Syphilis was identified in 46 of the pregnancies, and 16 cases of congenital syphilis were identified, resulting in a prevalence of 1.9% (95%CI 1.3;2.6) of syphilis in pregnancy and an incidence of 6/1,000 (95%CI 3;12/1,000) of congenital syphilis. The vertical transmission rate was 34.8% with three cases resulting in death (1 abortion, 1 stillborn and 1 neonatal death) and high proportions of prematurity and low birth weight. The healthcare pathway of those women revealed flaws in the care they received, such as late entry to antenatal care, syphilis remaining undiagnosed during pregnancy and lack of treatment for the partner.
CONCLUSIONS: Innovative strategies are needed to improve the outcomes of syphilis in pregnancy, including improving the laboratory network, the quality of care delivered to the pregnant women and their sexual partners and, most important of all, investigating every case of congenital syphilis as a sentinel event in the quality of antenatal care.

Descriptors: Syphilis, Congenital, epidemiology. Syphilis Serodiagnosis, utilization.Infectious Disease Transmission, Vertical, prevention & control. Prenatal Care. Quality of Health Care.


RESUMEN

OBJETIVO: Analizar la asistencia pre-natal en la prevención de la transmisión vertical de la sífilis.
MÉTODOS: Estudio transversal representativo para las gestantes de bajo riesgo atendidas en unidades de salud del municipio de Rio de Janeiro, Sureste de Brasil, período de 2007 a 2008. La identificación de gestantes con diagnóstica de sífilis en la gestación fue realizada por medio de entrevistas, verificación de la tarjeta de pre-natal y búsqueda de casos notificados en sistemas públicos de información en salud. Los casos de sífilis congénita se identificaron por medio de búsqueda en los sistemas de información en salud: Sistema de Información de Agravios de Notificación (SINAN), Sistema de Información sobre Mortalidad (SIM) y Sistema de Informaciones Hospitalarios (SIH) del SUS.
RESULTADOS: Se identificaron 46 casos de sífilis en la gestación y 16 casos de sífilis congénita con una prevalencia estimada de 1,9% (IC95% 1,3;2,6) de sífilis en la gestación y de 6/1.000 (IC95% 3;12/1.000) de sífilis congénita. La tasa de transmisión vertical fue de 34,8% y tres casos fueron fatales, un aborto, un óbito fetal y un óbito neonatal, con proporciones elevadas de bajo peso y prematuridad. La trayectoria asistencial de las gestantes mostró fallas en la asistencia, como inicio tardío del pre-natal, ausencia de diagnóstico en el embarazo y ausencia de tratamiento de las parejas.
CONCLUSIONES: Estrategias innovadoras son necesarias para enfrentar la sífilis en la gestación, que incorporen mejorías en la red de apoyo diagnóstico, en el manejo clínico de la enfermedad en la gestante y sus parejas y en la investigación de los casos como evento centinela de la calidad de la asistencia pre-natal.

Descriptores: Sífilis Congénita, epidemiología. Serodiagnóstico de la Sífilis, utilización. Transmisión Vertical de la Enfermedad Infecciosa, prevención & control. Cuidado Pre-natal. Calidad de la Asistencia a la Salud.


 

 

INTRODUCTION

Congenital syphilis is an avoidable disease. Routine antenatal care practices are effective in preventing cases.1,2,4 Deaths due to congenital syphilis in infants under five are considered avoidable with care resources available in the SUS (Brazilian Unified Health System).7 It is a sentinel event,9 as it can be avoided through effective health care, and retrospective investigation of cases is obligatory in order to obtain information about the care provided and propose appropriate measures to be taken.5

In the city of Rio de Janeiro, Southeastern Brazil, despite the efforts which have been made to control congenital syphilis since the late 1990s, a high incidence of cases and serious forms of the disease persist.a Data from monitoring syphilis in pregnancy from 1999 to 2004 show deficiencies in antenatal care, such as problems carrying out the screening exam (VDRL), in appropriate treatment for pregnant women and principally in treatment for their sexual partners.13

The aim of this study was to evaluate antenatal care in preventing vertical transmission of syphilis.

 

METHODS

Cross-sectional studyb of 2,422 pregnant women receiving antenatal care in SUS health care units in the city of Rio de Janeiro between 2007 and 2008.

Cluster sampling was carried out in two stages. In the first stage, health centers providing antenatal care to low risk pregnancies were selected, and in the second stage the pregnant women attending the selected health centers were selected.

The health care centers provided were stratified according to their type: primary healthcare centers, hospitals/maternity hospitals, birthing centers and family health centers.

Simple random selection of eligible units for the hospitals/maternity hospitals and primary healthcare centers was carried out in the ten program areas (PAs) of the city. The same proportional distribution was kept in the sample as was found in the city itself at the time of the study. The only birthing centers which exists in the city was included in the study.

The family health centers were selected using a different sampling system, and the units chosen were those in the areas of greatest expansion of family health strategy which best met certain criteria established for the research (not being located in an area with a high risk of violence, having a larger number of teams and having been established for longer).

The size of the sample was established considering the outcome "adequacy of prenatal care", estimated to be 50.0% and the level of significance to be 5.0%. A bilateral error margin of 2.5% for the primary healthcare centers, hospitals/maternity hospitals and the birthing center and 5.2% for the family health centers was set. Finite population correction and correction for design effect, estimated as 1.5, was carried out, with a final sample of 2, 187 women in the primary healthcare centers, hospitals/maternity hospitals and birthing center and 230 interviews in the family health centers. As the few refusals to participate (fewer than 5.0%) were replaced, the estimated size was achieved and 2,422 pregnant women were interviewed.

Any pregnant woman seen in the selected units was eligible to participate, regardless of age, place of residence or stage of pregnancy.

The pregnant women were interviewed and data taken from their antenatal care cards. A standardized questionnaire was used and data collection was carried out by previously trained health care professionals and students, under the supervision of the researchers, in the health care centers themselves. The cards were copied and the relevant data extracted later by a group of higher level professionals with experience in antenatal care.

The instruments were evaluated and pre-tested in the pilot study. The field work took place between November 2007 and July 2008.

The questionnaires were revised and codified by members of the team and the data stored using the Access program, with the questionnaires entered twice and errors corrected until 100% agreement was obtained.

The quality of antenatal care in order to reduce vertical transmission of syphilis was assessed through looking for cases of congenital syphilis and syphilis in pregnant women in the official information systems: Sinam (Information System for Notifiable Diseases), the SIM (mortality information system) and the SUS's SIH (hospitalization information system). Searching the information systems allowed the evaluation of their coverage in relation to the health problems: "syphilis in pregnancy" and "congenital syphilis".

In Sinam, cases of syphilis in pregnancy between 2007 and 2009 were sought.

In Sinam, SIM and SIH the search was for cases of congenital syphilis. Reported cases of early congenital syphilis from 2007 to 2009 were selected in Sinam. In SIM, fetal and non-fetal deaths between 2007 and 2009, with syphilis classified as the cause or associated cause, with ICD-10 (International Classification of Diseases) codes varying between A50.0 and A50.9, were selected. In the SIH, cases of hospitalizations or deaths with ICD-10 codes A50.0 to A50.9 as the main or secondary diagnosis/cause and hospitalizations for miscarriages were selected. This search was restricted to 2008 and 2009 as it was not possible to obtain the data for 2007.

The searches in the information systems for cases of syphilis in pregnancy and congenital syphilis were carried using the RECLINK3 program and the key variable was the name of the pregnant woman interviewed.

The following data were used to aid in identifying the cases correctly: date of birth and/or age, address, due date, date of outcome (delivery or miscarriage) and date reported (in cases of syphilis in pregnancy). Cases were excluded if there was some doubt as to the woman's identity, either because of differences in name, age and/or address, or discrepancies between the outcome date and/or the reporting date and the date on which the woman participated in the study.

A case was considered to be syphilis in pregnancy when: a) the pregnant woman's antenatal care card had a "reactive" result recorded at the time of the interview, except in cases when this referred to a previous bout of syphilis which had been properly treated; b) the pregnant woman reported in the interview that she had been diagnosed with syphilis and the care card did not have a record of this test result; c) the pregnant woman was identified in Sinam as being diagnosed with syphilis and d) the woman's pregnancy outcome was a case of "congenital syphilis", identified in any of the information systems consulted.

Cases of congenital syphilis were defined as all pregnancy outcomes (miscarriage, stillbirth or live birth) identified by any of the information systems (SIM, Sinam or SIH) as "early congenital syphilis".

The Sinasc (information system for live births) was also searched for all cases of "early congenital syphilis" in live births, in order to obtain birth weight and gestational age at birth, as these data were not available on Sinam records. In cases of stillbirth, this data was obtained through SIM itself.

The cases identified in interviews and in each information system were compared and Sinam's coverage was calculated for cases of syphilis in pregnancy and the coverage of Sinam, SIM and SIH for cases of "congenital syphilis".

The prevalence of syphilis in pregnancy, the incidence of congenital syphilis and the rate of vertical transmission were calculated based on the cases identified.

The prevalence of syphilis in pregnancy and the ratio of prevalence were calculated according to demographic, socio-economic and reproductive characteristics and according to access to health care services

Women who were unaware of their diagnosis were excluded from this analysis.

Each element of the sample was weighted by the inverse of its probability of selection and was calibrated in order to restore the known distribution of antenatal consultations in the statistical analysis. The birthing center was included in the family health center strata as it has similar characteristics and to allow the inclusion of design effect.14

Based on the information obtained from the interviews and the various systems, the care pathways of those women whose pregnancy outcome was identified as a case of "early congenital syphilis" were described and deficiencies in any of the procedures recommended by the Ministry of Health in preventing vertical transmission of syphilisc identified.

This project was approved by the ENSP/Fiocruz Ethical Research Committee (Report nº142/06). The data were collected after consent forms had been signed. Every care was taken to ensure the confidentiality of the data.

 

RESULTS

There were forty six pregnant women identified as having syphilis and 16 cases of pregnancy outcomes of congenital syphilis.

Of the 46 pregnant women with syphilis, 34 were identified in the interview (29 through the data on their antenatal care cards and in five cases the woman herself reported it) and 12 identified through searches in the information systems.

All of the cases of congenital syphilis were identified through the information systems: 14 in Sinam, two in SIM and seven in SIH. Two cases identified in Sinam were not included in the sample as there were insufficient data to enable a classification of congenital syphilis. One case identified in SIH, a hospitalization for a miscarriage, was classified as a case of congenital syphilis, although there was no record of ICD for syphilis, as the woman's care had begun less than 30 days before the outcomec (Tables 1 and 2).

 

 

 

 

Sinam coverage for cases of syphilis in pregnancy was 23.9%, and 75.0% for congenital syphilis. One serious case of fetal death was not found in Sinam, nor were three cases of hospitalization for congenital syphilis, located in the SIH, one being a miscarriage. The two cases of congenital syphilis which resulted in death were registered in SIM. In SIH, eight cases were identified (53.3%), counting the miscarriage which was not recorded as syphilis and excluding the case of fetal death. The prevalence of syphilis in pregnancy was 1.9% (95%CI 1.3;2.6).

Higher prevalence of syphilis in pregnancy was observed in women with black skin, from less well-off backgrounds and lower levels of education, those who had an obstetric history of risk, those who received antenatal care in primary healthcare centers, those whose antenatal care started later and who had an inadequate number of appointments (Table 3).

The incidence of congenital syphilis was six per 1,000 (95%CI 3;12 per 1,000) and the rate of vertical transmission was 34.8%.

Of the 16 cases of congenital syphilis, three were serious forms of the disease: one miscarriage, one stillbirth and one premature neonatal death. Four newborns were asymptomatic at birth and in seven cases there were no records of clinical diagnosis or of signs or symptoms of the illness in their records or in the AIH (Hospitalization Authorization).

Gestational age was available in the Sinasc and the SIM for 14 cases: 14.3% were premature and 20.0% had low birth weight.

It was not possible to reconstruct the care pathway of one pregnant woman who did not present a diagnosis of syphilis at the time of the interview and whose baby was identified in the SIH, which contained no data on antenatal care.

Of the 15 care pathways analyzed, five of the pregnant women had started receiving antenatal care late and five had moved health care center during antenatal care.

Four of the women had not had an adequate number of appointments up to the time of the interview, all of them having started receiving antenatal care late.

Thirteen women reported the request of the first VDRL test and, of the nine who were in the third trimester, four reported the request of the second test.

Nine of the women presented a diagnosis of syphilis in pregnancy, four received this diagnosis when admitted for the birth and this information was not available for two of the women.

Some discrepancies were observed between what was reported by the women and the data registered on the care card: four women who did not know the VDRL test result or who reported a non-reactive result, presented a "reactive" result on their card: one woman who reported testing positive had no result registered on her card.

Of the nine women diagnosed with syphilis in pregnancy, information on the clinical form of the disease was available for one of them. For four woman recorded as having syphilis in pregnancy in Sinam (which contained a field for this information), the clinical form recorded was 'unknown'.

There was information on prescribed treatment for six of the women. In the only case in which the clinical form was recorded, the treatment prescribed was not appropriate, being of incorrect dosage. In two other cases, treatment started fewer than 30 days before the birth or miscarriage. Discrepancies were identified in relation to the women's treatment in three cases, with the congenital syphilis investigation generally indicating deficiencies in how it was carried out.

Of the three women aware of their diagnosis of syphilis in pregnancy at the time of the interview, two reported having been given information about the risks to the baby and on the use of condoms and one reported the request for a VDRL test for her sexual partner.

There were no records of treatment for the partner in the pregnancy and birth records. Three of the women no longer lived with their partners, in seven cases there was a record that treatment was not carried out and in five cases there was no record of this information.

Table 4 and the Figure show a summary of the care pathway of these 15 women whose pregnancies resulted in cases of congenital syphilis and the missed opportunities due to not following the recommended care protocol.

 

DISCUSSION

The prevalence of syphilis in pregnancy (1.9%) was lower than that reported by Leal et al6 (2.4%) in their 1999-2000 study carried out in public health service maternity hospitals in Rio de Janeiro. It was also lower than that found in the data from epidemiological monitoring between 1999 and 2004, during which the rate presented fell from 4.7% to 2.8%13 It is, however, similar to that observed in a study carried out in maternity hospitals registered in the National Program for STD/AIDS in 1999-2000 (1.7%)8 and to the results of a sentinel study carried out in 2004 (1.6%).d The data found suggest the prevalence of syphilis in pregnancy in Rio de Janeiro is declining, growing closer to values observed in other parts of the country. Increasing work on preventing STDs/AIDS and greater access to treatment for syphilis may be possible explanations for the data observed.

The incidence of congenital syphilis (6/1,000 births) is high and is six times higher than the Ministry of Health's goal to eliminate the disease.e

The rate of transmission found, higher than 30%; the serious form of the disease in cases of congenital syphilis, with three cases proving fatal and the high levels of premature births and low birth weight; allied to the deficiencies in care observed, such as starting antenatal care late, breaks in the continuity of the care due to changing health care centers, difficulties in diagnosing syphilis in pregnancy (absent in 25% of the congenital syphilis cases), deficiencies in treatment and, especially in treatment for sexual partners, and lack of counselling and information about the disease and about using condoms, indicate that the quality and effectiveness of antenatal care in reducing vertical transmission is low. It is noteworthy that the number of newborns born premature or with low birth weights was much higher than that observed in a set of newborns born in the city of RJ in 2007, with values of 8.9% and 9.7% respectively.f,g

The lack of counselling resulted in some women not even knowing the results of the test, even those women with positive results. Syphilis requires treatment by injection, changes in behavior and a series of tests to control the cure, which may well culminate in the woman not following the treatment, especially if she is unaware of what disease she has.

Studies carried out in other contexts indicate deficiencies in managing cases of syphilis in pregnancy, with the majority of cases of congenital syphilis considered to be avoidable.15 However, cases which are unavoidable regardless of the good antenatal care provided by health care professionals, due to treatment failure, delayed infection or reinfection,15 were reported, something which was not observed in this study.

After the 1999/2000 campaign to eliminate syphilis in the city of Rio de Janeiro, there was a 29% reduction in the number of deaths from congenital syphilis in 2000 and 2001, explained by the effects of the campaign.11 However, the following years saw a return to the previous situation with an annual incidence of above 10/1,000 between 2004 and 2006a and perinatal deaths due to congenital syphilis at a steady rate of 1/1,000. Similar data were found in this study, showing that the epidemiological situation of congenital syphilis was practically unaltered in the last few years.

Although syphilis is a disease for which simple and low cost diagnostic and therapeutic resources exist, controlling it in pregnancy has proven to be a challenge for health professionals and managers. This is because of the limited interval of the pregnancy in which to carry out diagnosis and treatment; to the difficulty of approaching sexually transmitted diseases, especially during pregnancy; and probably due to the lack of awareness on the part of both the population and health professionals of the magnitude of this health problem and the damage it can cause to the health of mother and child.

The fact that the highest prevalence of syphilis in pregnancy was found in women from poor socio-economic conditions, those with an obstetric history of risk and those with worse access to health services highlights the greater social and reproductive vulnerability of these women, results also found in other studies,8,10,11,15 and which make the challenge of controlling syphilis in this population more complex.

The attempt to reconstruct the care pathways of the women diagnosed with syphilis in pregnancy based on the data of a cross-sectional study and from data sought in the SUS information systems is a limitation of this study. By their very nature, cross-sectional studies capture the information available at the moment in which the research is carried out. Interviewing women at the start of their pregnancies may have led to the loss of important data on antenatal care. On the other hand, the records in the information systems consulted did not contain all of the data relevant to the objective of this study, as well as the quality with which they were filled out varying, often being incomplete, as has been described in previous studies.10,12

The limits for calculating the prevalence of syphilis in pregnancy and the incidence of congenital syphilis are related to problems in the coverage of the information systems, SIH being the system which performed worst for congenital syphilis. Moreover, it was not possible to obtain SIH data for 2007, which may have meant the loss of cases of congenital syphilis not reported in other systems for this year. The criteria used to identify cases, excluding any in which a doubt existed, may also have resulted in the search being less sensitive. For these reasons, the results should be viewed as conservative, the possibility exists that they underestimate the true seriousness of the situation of incidence of congenital syphilis, rate of vertical transmission and cases of death found.

Innovative strategies are necessary to: ensure pregnant women are caught early so antenatal care can begin in the first trimester; guarantee diagnosis of the disease during the pregnancy as early as possible, so treatment can begin before the 24th-28th week, when it is most effective for the fetus;2 and the adequate clinical management of the woman and her sexual partner(s), including counselling and information on the disease and forms of prevention. Thus, treatment may be more likely to be followed and the vulnerability of the women and their partners to this STD reduced.

If the disease is to be better controlled, it is fundamental to broaden the reporting of cases of syphilis in pregnancy in Sinam, to search systematically for cases of congenital syphilis in all of the information systems and to improve the completion of the reporting records. Obligatory investigation of congenital syphilis as a sentinel event, foreseen since the first list drawn up by Rutstein in 19769 and established by the Ministry of Health in 1986, seems to us to be an integral part of epidemiological monitoring

 

REFERENCES

1. Barros FC, Bhutta ZA, Batra M, Hansen TN, Victora CG, Rubens CE. Global report on preterm and stillbirth (3 of 7): evidence for effectiveness of interventions. BMC Pregnancy Childbirth. 2010;10(Suppl 1):S3. DOI:10.1186/1471-2393-10-S1-S3        [ Links ]

2. Blencowe H, Cousens S, Kamb M, Berman S, Lawn JE. Lives Saved Tool supplement detection and treatment of syphilis in pregnancy to reduce syphilis related stillbirths and neonatal mortality. BMC Public Health. 2011;11(Suppl 3):S9. DOI:10.1186/1471-2458-11-S3-S9        [ Links ]

3. Camargo Jr KR, Coeli CM. Reclink: aplicativo para o relacionamento de banco de dados implementando o método Probabilistic Record Linkage. Cad Saude Publica. 2000;16(2):439-47. DOI:10.1590/S0102-311X2000000200014        [ Links ]

4. Carroli G, Rooney C, Villar J. How effective is antenatal care in preventing maternal mortality and serious morbidity? An overview of the evidence. Paediatr Perinat Epidemiol. 2001;15(Suppl 1):1-42. DOI:10.1046/j.1365-3016.2001.0150s1001.x        [ Links ]

5. Hartz ZMA, Champagne F, Leal MC, Contandriopoulos AP. Mortalidade infantil "evitável" em duas cidades do Nordeste do Brasil: indicador de qualidade do sistema local de saúde. Rev Saude Publica. 1996;30(4):310-8. DOI:10.1590/S0034-89101996000400004        [ Links ]

6. Leal MC, Gama SGN, Campos MR, Cavalini LT, Garbayo LS, Brasil CLP, et al. Fatores associados à morbi-mortalidade perinatal em uma amostra de maternidades públicas e privadas do Município do Rio de Janeiro, 1999-2001. Cad Saude Publica. 2004;20(Supl 1):S20-33. DOI:10.1590/S0102-311X2004000700003        [ Links ]

7. Malta DC, Duarte EC, Almeida MF, Dias MAS, Morais Neto OL, Moura L, et al. Lista de causas de mortes evitáveis por intervenções do Sistema Único de Saúde do Brasil. Epidemiol Serv Saude. 2007;16(4):233-44. DOI:10.5123/S1679-49742007000400002        [ Links ]

8. Rodrigues CS, Guimarães MDC; Grupo Nacional de Estudos sobre Sífilis Congênita. Positividade para sífilis em puérperas: ainda um desafio para o Brasil. Rev Panam Salud Publica. 2004;16(3):168-75. DOI:10.1590/S1020-49892004000900003        [ Links ]

9. Rutstein DD, Berenberg W, Chalmers TC, Child CG 3rd, Fishman AP, Perrin EB. Measuring the quality of medical care: a clinical method. N Engl J Med. 1976;294(11):582-8. DOI:10.1056/NEJM197603112941104        [ Links ]

10. Saraceni V, Leal MC. Avaliação da efetividade das campanhas para eliminação da sífilis congênita na redução da morbi-mortalidade perinatal. Município do Rio de Janeiro, 1999-2000. Cad Saude Publica. 2003;19(5):1341-9. DOI:10.1590/S0102-311X2003000500012        [ Links ]

11. Saraceni V, Guimarães MHSF, Theme Filha MM, Leal MC. Mortalidade perinatal por sífilis congênita: indicador da qualidade da atenção à mulher e à criança. Cad Saude Publica. 2005;21(4):1244-50. DOI:10.1590/S0102-311X2005000400027        [ Links ]

12. Saraceni V, Vellozo V, Leal MC, Hartz ZMA. Estudo de confiabilidade do SINAN a partir das campanhas para a eliminação da sífilis congênita no Município do Rio de Janeiro. Rev Bras Epidemiol. 2005;8(4):419-24. DOI:10.1590/S1415-790X2005000400010        [ Links ]

13. Saraceni V, Domingues RMSM, Vellozo V, Lauria LM, Dias MAB, Ratto KMN, et al. Vigilância da sífilis na gravidez. Epidemiol Serv Saude. 2007;16(2):103-11. DOI:10.5123/S1679-49742007000200005        [ Links ]

14. Szwarcwald CL, Damacena GN. Amostras complexas em inquéritos populacionais: planejamento e implicações na análise estatística dos dados. Rev Bras Epidemiol. 2008;11(Supl 1):38-45. DOI:10.1590/S1415-790X2008000500004        [ Links ]

15. Warner L, Rochat RW, Fichtner RR, Stoll BJ, Nathan L, Toomey KE. Missed opportunities for congenital syphilis prevention in an urban southeastern hospital. Sex Transm Dis. 2001;28(2):92-8.         [ Links ]

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