Trend and spatial distribution of infectious diseases in pregnant women in the state of Paraná-Brazil*

Objective to analyze the trend and spatial distribution of some diseases that require compulsory notification in pregnant women. Method ecological study, with data from the National Notifiable Diseases Surveillance System, of the incidence of the six most frequent diseases that, require compulsory notification, in pregnant women. The Prais-Winsten model was used to analyze the trend classified as stable, decreasing and increasing, according to macro-regions. For the spatial analysis, the incidences distributed in percentiles, in choropleth maps, by Health Regions were calculated. Results the most frequent infections were syphilis, dengue, Human Immunodeficiency Virus, influenza, hepatitis and toxoplasmosis. Incidence increased by 30.8%, 30.4%, 15.4% and 2.6%, on average, for syphilis, toxoplasmosis, dengue and Human Immunodeficiency Virus, respectively. On average, the incidence of syphilis increased by 40.5% in Macro-regional North and 38% in Macro-regional Northwest. The spatial analysis showed, in the last four years, high incidence of dengue, syphilis and infection by Human Immunodeficiency Virus, which reached 180.2, 141.7 and 100.8 cases per 10,000 live births, respectively. Conclusion there were increased incidences of infection in pregnant women due to syphilis, toxoplasmosis and Human Immunodeficiency Virus, with differences in their spatial distribution, indicating that these diseases should be a priority in the care of pregnant women in more affected regions.


Introduction
Decree 204, dated February 17, 2016, of the Ministry of Health (MH), establishes the diseases and aggravations of compulsory notification in Brazil and, among them, infectious diseases (1) , which are still part of the epidemiological profile of the population and, when they affect women during pregnancy, may compromise their health and that of the newborn.

Compulsory notification infectious diseases
range from ancient diseases such as syphilis, dengue, Human Immunodeficiency Virus (HIV), Acquired Immunodeficiency Syndrome (Aids) and hepatitis, to recent infections, such as the Zika virus. The occurrence of infectious diseases may vary by region. Developing countries aggregate the majority of cases (2)(3)(4) and in some regions of the world such as India, Africa and the Middle East, these diseases are still considered the leading cause of maternal death (3) .
A study with a population of pregnant women in a rural area of Ghana found a high prevalence of hepatitis B (16.7%) and malaria (10.6%) (2) . In the United States, the incidence of congenital syphilis increased from 8.4 per 100,000 in 2012 to 11.6 per 100,000 live births in 2014, reflecting the increase in disease among pregnant women (5) . In a municipality in Gabon, a country in the African continent, a study with 973 pregnant women found a prevalence of 2.5% for syphilis, 4.0% for HIV infection and 57.3% for toxoplasmosis (6) .
In Brazil, a cross-sectional study, which analyzed the rapid test records in pregnant women performed during prenatal care in the city of Maceió, identified a prevalence of 2.8% syphilis, 0.3% HIV infection and 0.4% Hepatitis B (7) . In the city of Niterói-RJ, a study carried out, also with serological tests records of pregnant women attended at a university hospital, found a prevalence of 1.5% for syphilis, 0.9% and 1.6% for hepatitis B and C respectively, and 5.8% for HIV infection (8) .
These studies show the profile of infectious diseases in gestation, especially those that are part of prenatal screening protocols, such as syphilis, HIV infection, toxoplasmosis and hepatitis B, recorded in the patient's medical records or documents (7)(8)(9) . However, it can be seen, that the studies are not enough to present the joint analysis of the infectious diseases of compulsory notification occurred in pregnant women, mainly with the analysis of trend in recent period. It is also necessary to know the spatial distribution of infectious diseases to trigger preventive actions in identified geographical areas.
Studies of the behavior of these diseases over time and in the geographical space can contribute to the evaluation of public policies and control of infectious diseases in pregnant women. Thus, the objective of this study was to analyze the trend and spatial distribution of some infectious diseases of compulsory notification in pregnant women in the state of Paraná.

Method
Ecological study (10) (11) . The Human Development Index (HDI), released in the 2010 Census, was 0.749, the fifth highest among the states of the country (11) . The state of Paraná is divided into 22 Regions and four Macro-regions of Health (Central East, West, North and Northwest) responsible for health care management ( Figure 1).
The study was carried out, with data from the   Northwest Macro-regional, syphilis rates increased, on average, by 40.7% and 38%, respectively.

Discussion
This study is innovative because it described the main infectious diseases in pregnant women reported in SINAN, identified and analyzed the trend and the spatial distribution of the six most frequent diseases in a period of ten years. The most frequent notifiable infectious diseases in pregnant women were: syphilis, dengue, HIV / AIDS, influenza, viral hepatitis and toxoplasmosis.
Trend analysis showed increased rates of syphilis, HIV infection and toxoplasmosis, and the thematic maps illustrate this behavior by presenting rates in the first triennium and the last quadrennial.
Syphilis continues to be a public health problem for pregnant women worldwide, with serious consequences such as prematurity, fetal death and neonatal, which can be prevented with early diagnosis and treatment (14) .
Recent studies on syphilis in pregnant women and newborns indicate that control measures are not sufficient and need to be intensified (14)(15)(16) . For quality prenatal care, special attention should be paid to all pregnant women, especially adolescents, those with 35 years of age or older, low schooling, race / black color, late onset or low number of visits of prenatal care (15,17) .
Improving health care for pregnant women is a priority in several regions of the world, however, a study conducted in a Health Regional Hospital in Brazil, through annual reports, identified that almost 70% of pregnant women in the public network did not have seven or more prenatal consultations, and only 49% and 50% had performed rapid syphilis and HIV tests, respectively (18) . These findings, complemented by those such as syphilis, HIV and toxoplasmosis (19) .  (20) . It reinforces the role of the nurse, who is trained to guide the team on the necessary behaviors in relation to infectious diseases during pregnancy.
Although with lower rates, the constant and significant increase in the notifications of HIV infection in pregnant women was noticed, a result that agrees with that of other authors (21) . Analysis of AIDS cases in Brazil showed an increase in incidence, especially in the Southeast, South and Mid-West regions (21) . Factors associated with HIV infection include income, inadequate prenatal care, multiplicity of sexual partners, race/ color black, homosexuality, unprotected sex, injecting drug use, blood transfusion, and accidents with sharp objects in health professionals (22)(23) . In addition to these factors, women of reproductive age and, consequently, women in the gestational period, with a threat to the health of the newborn are also at risk for HIV infection, as identified in a study in Mozambique where children from infected mothers had a higher risk of prematurity, malnutrition, hospitalizations and death (24) .
In prenatal care, it is recommended to perform the rapid test at the first visit for all pregnant women: one in the third trimester and the other at the time of admission to labor (25) . This technology is one of the actions that help to reduce the vertical transmission of HIV infection, which has a target to be reached with an incidence of up to 50 cases per 100,000 live births (26) .
Thus, it is necessary to intensify early prevention, diagnosis and treatment (27) , especially in regions with a greater number of cases identified in this study.
An important infection, which also presented a growing trend, was toxoplasmosis, which is part of the recommendations of the guide network of the Paranaense Mother Network program through the screening of all pregnant women in the first consultation or in the first trimester of pregnancy (25) . Because it is a disease that can cause intrauterine growth restriction, fetal death, prematurity, ocular and brain injuries, all pregnant women should be informed about prevention, which mainly involves care in handling food and contact with animal feces (28) .
In this study, other infections were reported, in pregnant women and, although they did not present an increasing tendency in the analyses, they deserve to be highlighted, such as influenza, which, when it occurs in pregnant women, can be serious and lead to hospitalization (29) . The pandemic, which occurred in 2009, showed that pregnant women are at increased risk for complications, and 5% of all deaths caused by infection worldwide occurred in women during gestation (30) . In Brazil, a study conducted in the state of Rio Grande do Sul during the pandemic identified 24 deaths of pregnant women due to influenza, in addition to eight fetal deaths (31) . In this study, it was clear that were still cases, ranging from 5.0 to 21.8 per 10,000 live births and also differences in their distribution space.
Severe cases of influenza still occur, as shown in a study in the state of California -United States, where 88% of pregnant women with severe influenza were hospitalized, 53% required mechanical ventilation, and 29% died (32) . As of 2009, the benefits of influenza vaccination were observed not only for pregnant women, but also for newborns during the first six months of life (30) . Therefore, in Brazil, the vaccination schedule of pregnant women includes the influenza vaccine and it must be offered during prenatal care (25) .
In this study, the highest incidence of dengue in pregnant women occurred from 2013 to 2015, a result similar to that found by other authors for the southern region of Brazil (33) . A study on dengue in Brazil showed a nearly four-fold increased risk for pregnant women when compared to non-pregnant women (33) .