SciELO - Scientific Electronic Library Online

 
vol.52Descriptive study of suspected congenital Zika syndrome cases during the 2015-2016 epidemic in BrazilThe use of meta-analysis in infectious disease surveillance: Is it a relevant tool? author indexsubject indexarticles search
Home Pagealphabetic serial listing  

Services on Demand

Journal

Article

Indicators

Related links

Share


Revista da Sociedade Brasileira de Medicina Tropical

Print version ISSN 0037-8682On-line version ISSN 1678-9849

Rev. Soc. Bras. Med. Trop. vol.52  Uberaba  2019  Epub Aug 01, 2019

http://dx.doi.org/10.1590/0037-8682-0146-2019 

Major Article

Seroprevalence of Trypanosoma cruzi infection among blood donors in the state of Bahia, Brazil

Diego Lopes Paim Miranda1  2 

Gilmar Ribeiro Jr2 

Fernanda Cardoso Lanza2 

Fred Luciano Neves Santos2 

Renato Barbosa Reis2 

Deborah Bittencourt Mothé Fraga2 

Luciano Kalabric Silva2 

Marinho Marques da Silva Neto3 

Iraildes de Jesus Santana3 

Mitermayer Galvão dos Reis1  2  4 
http://orcid.org/0000-0002-3051-9060

1Faculdade de Medicina, Universidade Federal da Bahia, Salvador, BA, Brasil.

2Laboratório de Patologia e Biologia Molecular, Instituto Gonçalo Moniz, Fundação Oswaldo Cruz, Salvador, BA, Brasil.

3Fundação de Hematologia e Hemoterapia da Bahia, Salvador, BA, Brasil.

4Yale University, New Haven, Connecticut, USA.

Abstract

INTRODUCTION:

Chagas disease (CD) affects 5.7-7.0 million individuals worldwide, and its prevalence reached 25.1% in the state of Bahia, Brazil. There is an association between the prevalence of CD, the socioeconomic status of the population, and the risk of re-emergence due to non-vectorial transmission, such as blood transfusion. This study determined the seroprevalence of T. cruzi infection among blood donors in the state of Bahia, located in northeastern Brazil, and their epidemiological profile during a 10-year period.

METHODS:

We performed a descriptive cross-sectional study involving a database review. Data were collected from patients with non-negative results for T. cruzi infection during a 10-year period.

RESULTS:

A total of 3,084 (0.62%) samples were non-negative for T. cruzi infection in an initial serological screening, and 810 (0.16%) samples were non-negative in the second screening. The correlation between infection and age (30 years or older) and between infection and lower educational level (12 years or less) in the first and second screening was statistically significant. The seroprevalence of T. cruzi infection was higher in men in the first screening. In addition, 99.52% of the municipalities of Bahia had at least one case of CD. Livramento de Nossa Senhora and Salvador presented the highest disease prevalence and recurrence, respectively.

CONCLUSIONS:

The seroprevalence of T. cruzi infection in these populations was lower than that found in other studies in Brazil but was comparatively higher in densely-populated areas. The demographic characteristics of our population agreed with previous studies.

Keywords: disease; Blood donor; Seroepidemiological studies

INTRODUCTION

Human Chagas disease (CD), also known as American trypanosomiasis, is a vector-borne tropical disease caused by the protozoan hemoflagellate Trypanosoma cruzi. CD was discovered and initially described by Dr. Carlos Chagas in 1909, at Lassance, Minas Gerais, Brazil1.

In Latin American countries, CD causes 12,000 to 14,000 deaths annually2 and affects 5.7 to 7.0 million people3. More affordable traveling conditions from Latin America to non-endemic areas and increasing international migration flows have increased T. cruzi infection beyond the borders of Latin America, and CD reached Europe, North America, and Oceania countries4-6.

The seroprevalence of T. cruzi infection decreased in Latin America (from 6.49% to 1.28%) and Brazil (from 6.96% to 0.21%) between 1970 and 20067 as a consequence of control campaigns in endemic countries, which helped reduce vectorial and transfusion transmission. Despite this decreasing trend in endemic areas, neglected regions have a higher number of cases and infected individuals.

In Brazil, the overall prevalence of T. cruzi infection reached 4.2% between 2000 and 2002 in the northeast, and the infection rate was higher than 5%8,9. More recently, micro-outbreaks of CD occurred via oral transmission in municipalities in the interior of the states of Santa Catarina and Bahia10.

Vectorial transmission is more common in endemic areas, in which the parasite is transmitted by contact with feces or urine of infected blood-sucking triatomine bugs (Hemiptera, Reduviidae). Other transmission routes include the consumption of contaminated foods or beverages, tissue and organ transplantation, mother-to-child transmission during pregnancy, laboratory accidents, induced or criminal infection, and blood transfusion. The transmission of T. cruzi via blood transfusion has increased because of urbanization and modernization of medicine11 and is the predominant route of transmission in both endemic and non-endemic areas12, especially in countries in which screening tests for CD are not mandatory in blood banks. Furthermore, T. cruzi tolerates extreme conditions, such as low temperatures (-80 to 4°C), and freezing and thawing13, indicating that the parasite can be transmitted in all blood components, including granulocytes, red blood cells, and plasma.

T. cruzi infection occurs predominantly in individuals living in rural areas8. However, the epidemiological status of CD has changed as a consequence of migration flows from rural areas to the periphery of large cities, where the presence of forest remnants increases the risk of disease transmission14-17.

Human CD is classified as a neglected transmitted disease, primarily affecting communities with higher social vulnerability, characterized by low income, poor housing and hygiene conditions, and low levels of schooling. For this reason, among parasitic diseases, CD is the most strongly associated with population vulnerability, in which the majority of seropositive individuals have these risk factors18.

Studies on CD should assess ecological, biological, social, and economic parameters to identify risk factors associated with disease development and progression. Furthermore, these studies reduce the risk of infection by producing knowledge for scientific and technological innovations.

Technologies capable of reducing the risk of transmitting infectious diseases through transfusion are critical to prevent the spread of contagious agents and ensure the quality of blood for transfusion19. Studies of discarded serological tests are capable of creating relevant technologies to improve the quality of blood transfusion. Serological screening has been used in several countries to improve public health programs. However, this type of testing is facing ethical, operational, and financial difficulties20.

Training the teams responsible for collecting pre-donation information is critical, given that adequately collected epidemiological data may help avoid transmission and decrease costs in the public health system.

In addition to avoiding transmission, identifying individuals with suspected disease allows researchers to identify regions with a higher risk of transmission and the most relevant epidemiological characteristics associated with seropositivity. Moreover, identifying places of birth and residence with higher prevalence may help characterize areas with a higher risk of transmission in the state of Bahia.

Previous studies with blood donors reported that the percentage of non-negative results was higher among married individuals, people in stable relationships7, and subjects with lower education levels21. The percentage of infection was higher in men22-25, although one study found that the rate was higher in women21. The number of cases was higher in older age groups, especially in individuals older than 30 years7,22,23,25,26. Moreover, the percentage of infection between men and women differed according to age group22.

The objective of this study was to determine the seroprevalence of T. cruzi infection and describe the epidemiological profile of blood donors from the Hematology and Hemotherapy Foundation of Bahia (HEMOBA) with non-negative results for T. cruzi infection detected by screening tests during a 10-year period (February 2008 to February 2018) in the state of Bahia. The specific objectives were to determine the most relevant epidemiological characteristics of blood donors with non-negative results for CD and identify the municipalities of origin of this population.

METHODS

Study design: Descriptive cross-sectional study involving a database review.

Target population: All blood donors from HEMOBA in the state of Bahia, Brazil, examined during the study period. HEMOBA is the official blood service in Bahia, and its units cover all health macro-regions in the state;

Diagnostic criteria: Non-negative results for T. cruzi infection;

Selection criteria:

  • Inclusion: Donors with non-negative results for T. cruzi infection detected in serological screening tests performed at HEMOBA;

  • Exclusion: Donors with negative serology in the second screening;

Variables: Gender, age, place of residence, place of birth, education level, racial group, marital status, number of annual blood donations, and test results in the first and second screening;

Clinical selection of candidates and release of blood bags: To minimize the risk of T. cruzi infection via blood transmission, the Brazilian Ministry of Health has issue several ordinances, the most recent being Ordinance 5, which was published in the Official Gazette of the Union on September 28, 201727 and lists the criteria for the clinical selection of candidates for blood donation. HEMOBA created a standard computerized questionnaire (Hemovida System) following these criteria and disclosed the data for the study. The methodology used for the release of blood bags followed the recommendation of the Ministry of Health according to Ordinance 5.

Serological screening: High sensitivity tests are mandatory. Between January 1991 and January 2015, screening tests for CD among blood donors at HEMOBA used anti-T. cruzi antibodies and ELISA from MUREX (FRA) and BIOMÉRIEUX (FRA). Since February 2015, HEMOBA adopted serological screening by chemiluminescence using IgG and IgM class antibodies. These antibodies were purchased from ABBOTT (IL, USA) until February 25, 2016, and from DIASORIN (ITA) since then to date. HEMOBA uses the same serological test in donors in the second screening and sends them to a referral unit in case of positivity.

Statistical analysis: Descriptive analyses were performed using the statistical package Epi Info 2000 (CDC, Atlanta, GE, USA). The X2 test was used to compare proportions, and a level of significance of 5% (p<0.05) and a confidence interval of 95% were adopted in all tests. Qualitative variables were expressed as absolute numbers and relative frequency.

Georeferencing: The information was georeferenced using the software Qgis version 20.0 to identify groups with high rates of non-negative results for T. cruzi infection according to the place of residence. The natural breaks method with five class intervals was used because the variables were discrete.

Ethics

The adopted procedures were in accordance with the ethical standards of the Research Ethics Committee of the Gonçalo Moniz Institute (FIOCRUZ, Bahia, Brazil) and with the Helsinki Declaration of 1964, revised in 1975, 1983, 1989, 1996, and 2000. The consent form was waived because the analysis was based on a database. However, no personal identification data were used to ensure the complete anonymity of blood donors. The research did not cause any physical, psychic, moral, intellectual, social, cultural, or religious risk to blood donors.

RESULTS

During the 10-year study period (February 22, 2008 to February 21, 2018), 494,010 donors and 816,346 blood samples were examined at HEMOBA. In a preliminary analysis, 3,084 (0.62%) non-negative samples were identified. All samples reactive for T. cruzi are considered non-negative by HEMOBA. Patients whose test results were non-negative or inconclusive were advised to return to HEMOBA to undergo a second screening. This orientation follows a protocol in which the blood center sends up to three letters to the donor’s registered address, with an interval of 30 days between each of them. A total of 1,486 patients returned to the blood center for a second screening, of whom 810 (0.16%) were considered non-negative for T. cruzi infection.

Among the non-negative samples, 1,334 (43.26%) were analyzed by chemiluminescence using IgG and IgM antibodies and 1,750 (56.74%) by ELISA using anti-T. cruzi antibodies in the first screening, whereas 671 (45.15%) samples were analyzed by chemiluminescence using IgG and IgM antibodies and 815 (54.85%) by ELISA using anti-T. cruzi antibodies in the second screening.

The group of individuals non-negative for T. cruzi infection in the first and second screening (810) was analyzed by gender, age, racial group, marital status, educational level, place of residence, and place of birth.

In the first screening, the prevalence of non-negative results for T. cruzi infection was 0.62% (3048 samples) and was higher in men (PR, 1.0919; 95% CI, 1.02-1.17) and in blood donors aged 30 years or older (PR, 1.5863; 95% CI, 1.4676-1.7147). The prevalence of non-negative results in donors with less than 12 years of schooling was 32% (PR, 1.3236; 95% CI, 1.2040-1.4550) when compared with those with at least 12 years of education. There was no statistically significant association between the place of birth and residence and the prevalence of non-negative serology in this population (Table 1).

TABLE 1: Factors associated with T. Cruzi infection in the first and second screening. 

Characteristics Seroprevalence of T. cruzi infection (2008-2018)
First screening Second screening
Total %* PR (95% CI) p Total %* PR (95% CI) p
Total 3084 0.62 810 0.16
Sex
Male 1908 0.65 1.0919 (1.0150-1.1733) p < 0.05 470 0.16 0.9298 (0.8088-1.0689) ns
Female 1176 0.59 1 340 0.17 1
Age, years
≥ 30 2196 0.44 1.5863 (1.4676-1.7147) p < 0.001† 683 0.14 3.4497 (2.8547-4.1689) p<0.001†
< 30 888 0.28 1 127 0.40 1
Place of residence is located in Bahia
Yes 3049 0.38 1.2657 (0.9075-1.7653) ns 803 0.10 1.6667 (0.7922-3.5066) ns
No 35 0.30 1 7 0.06 1
Place of birth is located in Bahia
Yes 2832 0.38 1.0743 (0.9447-1.2218) ns 753 0.10 1.2629 (0.9649-1.6529) ns
No 252 0.35 1 57 0.08 1
Years of education
≤ 12 2573 0.66 1.3236 (1.2040-1.4550) p < 0.001† 738 0.19 2.6943 (2.1154-3.4317) p<0.001†
> 12 511 0.50 1 72 0.07 1

*% of total blood donors that belong to this category between 2008 and 2018. CI, confidence interval; ns, not significant. † Significant in a multivariate logistic regression analysis. PR: Prevalence Rate.

The analysis of data from the second screening indicated that the prevalence of non-negative results for T. cruzi infection was 0.15% (810 samples). The prevalence was higher in blood donors aged 30 years or older (PR, 3.4497; 95% CI, 2.8547-4.1689) and donors with 12 years of schooling or less (PR, 2.6943; 95% CI, 2.1154-3.4317). There was no statistically significant association between non-negative serology, gender, and the place of birth and residence in Bahia (Table 1).

The data on the prevalence of non-negative results according to the marital status and racial group are shown in Table 2. Given the high miscegenation of the population in Bahia, it is difficult to classify the study sample into racial groups. Notwithstanding, there was no significant association between prevalence rates and racial groups.

TABLE 2: Seroprevalence distribution according to marital status and racial group. 

Characteristics Seroprevalence of T. cruzi infection (2008-2018)
Sample 1 Sample 2
Total %* Total %*
Total 3084 0.62 810 0.16
Marital status
Married 1299 0.75 373 0.22
Separated 10 0.89 4 0.36
Divorced 57 0.62 20 0.22
Judicially separated 10 0.71 2 0.14
Single 1634 0.55 386 0.13
Widow 41 1.29 17 0.01
Others 33 0.50 8 0.12
Racial group
Caucasian 172 0.59 45 0.15
Brazilian Caucasian 1069 0.60 277 0.16
Indian 4 0.27 1 0.07
Mixed 1422 0.66 400 0.18
Black 417 0.60 87 0.13
Asian 0 0 0 0

*% of total blood donors that belong to this category between 2008 and 2018.

The data on the place of residence of blood donors with non-negative results for T. cruzi infection were georeferenced and summarized in cartographic representations. The prevalence rates during the 10-year period in the first and second screening performed at HEMOBA is shown in Figure 1.

FIGURE 1: Seroprevalence of Trypanosoma cruzi infection in the state of Bahia in the first screening (left) and second screening (right) between 2008 and 2018. 

During the study period, 415 municipalities of Bahia were identified as places of residence of blood donors who presented at HEMOBA. Only the municipalities of Almadina and Jiquiriçá were not represented in the samples in this period. In addition, 608 cities outside of Bahia were identified as places of residence, with 11,656 donors (1.43%); however, these donors were not included in the geographical representations because these cities were outside the cartographic limit of the state.

According to the data from the first screening, the municipalities with the highest prevalence were Livramento de Nossa Senhora, located in the center-south of the state (n=2, 100%), Cotegipe (n=14, 6.31%), Wanderley (n=17, 6.69%), Sebastião Laranjeiras (n=5, 7.25%), Mulungu do Morro (n=8, 7.92%), Jaborandi (n=4, 8.33%), and Lajedinho (n=1, 10%). In the second screening, the municipalities with the highest prevalence were Livramento de Nossa Senhora (n=2, 100%), Boa Vista do Tupim (n=1, 3.85%), Wanderley (n=11, 4.33%), Botuporã (n=1, 4.7%), and Lajedinho (n=1, 10%).

The places of residence with at least one non-negative result per year between February 2008 and February 2018 in the second screening are shown in Figure 2.

FIGURE 2: Recurrence of Trypanosoma cruzi infection (second sample) per year by municipality in the state of Bahia, Brazil, between 2008 and 2018. 

The municipalities with the highest number of recurrences was Salvador (state capital) (11 out of 11 years), Feira de Santana (located in the north-central region of the state) (9 out of 11 years), Barreiras (8 out of 11 years), and Santo Antônio de Jesus (8 out of 11 years).

DISCUSSION

Human CD is endemic in Brazil, despite the success of government initiatives adopted in the past few decades. Measures for eradicating vectorial transmission are constantly debated. However, much remains to be done because the disease is transmitted by other routes, including blood transfusion, which has gained importance in the epidemiological literature. Studies investigating the prevalence of CD in blood donors can provide quantitative epidemiological data and guide interventions in high-risk areas and population groups.

Among a population of 494,010 donors and 816,346 blood donations during the 10-year period, 3,084 (0.62%) samples were non-negative in the first screening. Among 1,486 donors, 810 (0.16%) samples were non-negative in the second screening. These rates may be underestimated because, despite strong guidance on the importance of second screening, many donors did not return to the blood units and therefore were not included in the analysis.

The prevalence rates were lower than those found in other studies conducted in Brazil but were relatively higher in densely-populated regions. Dias et al. (2000) found that the seropositivity for T. cruzi infection between 1987 and 1994 ranged from 0.77% to 2.22% in Bahia and from 0.69% to 0.88% in the northeast region of Brazil. Dias (1998) reported that the seropositivity between 1988 and 1990 in Brazil was 0.97% and decreased in the following years: 0.7-1.1% in 1991, 0.7% in 1993, and 0.75% in 1994; the seropositivity in the northeast of Brazil was 0.36% in 1994. In contrast, Monich (2016) found that the discard rate of donated blood in Curitiba between 2003 and 2012 varied from 0.6% to 0.9%, whereas Slavov et al. (2016) indicated that the discard rate in the state of São Paulo between 2012 and 2014 was 0.1%. It is worth mentioning that the methodology used in some studies did not involve second screening, and prevalence was calculated using donors with positive serology in the first screening. The prevalence in the present study using this approach was 0.62% (3,084 individuals).

The seroprevalence of T. cruzi infection was higher in individuals aged 30 years or older and individuals with 12 years or less of education in the first and second screening, and seroprevalence was significantly higher in men in the first screening. These results agree with previous studies21-25. Data on seroprevalence rates according to marital status and racial group are summarized in Table 1.

With respect to the geographical distribution of the places of residence, 99.52% (415) of the municipalities of the state of Bahia and 608 municipalities outside the state borders had at least one diagnosed case of CD during the 10-years study period. Georeferencing was performed according to the place of residence rather than the place of birth because maternities are unavailable in many cities in the interior of the state. Moreover, the place of residence is a more reliable parameter because it represents, in most cases, the place where individuals are most exposed to infection throughout life.

Georeferencing enabled the identification of municipalities with higher seroprevalence (Figure 1). Increased access to blood transfusion services is a contributing factor for higher recurrence. Salvador, the state capital, is home to the HEMOBA headquarter and has the highest number of blood donors and donations, which may explain the higher rate of recurrence in this city. In addition, HEMOBA’s blood collection stations were being implemented in municipalities of the state throughout the study period, which might have increased the number of blood donations.

Seroprevalence analysis of CD can accurately assess the risk of transfusion-related CD and the rate of disease transmission28. This study identified high-prevalence regions in Bahia, allowing performing serological and epidemiological surveys in these areas and collecting epidemiological data to formulate health policies.

ACKNOWLEDGMENTS

We are grateful to The School of Medicine of the Federal University of Bahia, Oswaldo Cruz Foundation, and Foundation of Hematology and Hemotherapy of Bahia for the technical support.

REFERENCES

1. Chagas C. Nova tripanozomiaze humana: estudos sobre a morfologia e o ciclo evolutivo do Schizotrypanum cruzi n. gen., n. sp., ajente etiolojico de nova entidade morbida do homem. Mem Inst Oswaldo Cruz. 1909. [ Links ]

2. Hotez PJ, Dumonteil E, Woc-Colburn L, Serpa JA, Bezek S, Edwards MS, et al. Chagas disease: “The New HIV/AIDS of the Americas”. PLOS Negl Trop Dis. 2012;6(5):4-7. [ Links ]

3. World Health Organization (WHO). Chagas disease (American Trypanosomiasis). Technical Report Series. Geneva: WHO, 2015; 2. [ Links ]

4. Schmunis GA, Yadon ZE. Chagas disease: a Latin American health problem becoming a world health problem. Acta Trop. 2010;115(1-2):14-21. [ Links ]

5. Manne-Goehler J, Reich MR, Wirtz VJ. Access to care for Chagas disease in the United States: a health systems analysis. Am J Trop Med Hyg. 2015;93(1):108-13. [ Links ]

6. Conners EE, Vinetz JM, Weeks JR, Brouwer KC. A global systematic review of Chagas disease prevalence among migrants. Acta Trop . 2016;156:68-78. [ Links ]

7. Lima LM, Alves NP, Barbosa VF, Pimenta GA, Moraes-Souza H, Martins PRJ. Prevalence of Chagas disease in blood donors at the Uberaba Regional Blood Center, Brazil, from 1995 to 2009. Rev Soc Bras Med Trop. 2012;45(6):723-6. [ Links ]

8. Dias JCP, Machado EM, Fernandes AL, Vinhaes MC. General Situation and perspectives of Chagas disease in Northeastern Region, Brazil. Cad Saude Publica. 2000;16(Suppl 2):13-34. [ Links ]

9. Aras R, Velga M, Gomes I, Mota I, Rodrigues B, Rabelo R, et al. Prevalence of Chagas’ Disease in Mulungu do Morro Northeastern Brazil. Arq Bras Cardiol 2002;78(5):441-3. [ Links ]

10. Dias JP, Bastos C, Araújo E, Mascarenhas AV, Netto EM, Grassi F, et al. Acute Chagas disease outbreak associated with oral transmittion. Rev Soc Bras Med Trop . 2008;41(3):296-300. [ Links ]

11. Rassi A, Rassi Jr A, Rezende JM. American Trypanosomiasis (Chagas Disease). Infect Dis Clin. 2012;25:275-91. [ Links ]

12. Wendel S. Transfusion transmitted Chagas disease: Is it really under control? Acta Trop . 2010;115(1-2):28-34. [ Links ]

13. Goodhew B, Czaicki N, Forster K, Rajbhandary S, Hunter S, Brubaker AS. Trypanosoma cruzi Survival following Cold Storage: Possible Implications for Tissue Banking. PLoS One. 2014;9(12). [ Links ]

14. Antonio F, Maegawa B, Damerau EF, Beltrame-botelho IT, Lopes A, Emmanuelle-machado P, et al. Autochthonous Chagas disease in Santa Catarina State, Brazil: report of the first case of digestive tract involvement. Rev Soc Bras Med Trop . 2003;36(5):609-12. [ Links ]

15. Noya BA, Diaz-Bello Z, Colmenares C, Ruiz-guevara R, Mauriello L, Zavala-jaspe R, et al. Large Urban Outbreak of Orally Acquired Acute Chagas Disease at a Achool in Caracas, Venezuela. J Infect Dis. 2010;201(9):1308-15. [ Links ]

16. Suárez J, Suárez CB, Alarcon de Noya B, Espinosa R, Chiurillo MA, Villaroel PA, et al. Enfermedad de Chagas sistémico en fase aguda por transmisión oral: diagnóstico integral de un caso autopsiado. Gac Med Caracas. 2010;118(3):212-22. [ Links ]

17. Sangenis LH, De Sousa AS, Sperandio da Silva GM, Xavier SS, Machado CR, Brasil P, et al. First report of acute Chagas disease by vector transmission in Rio de Janeiro State, Brazil. Rev Inst Med Trop Sao Paulo. 2015;57(4):361-4. [ Links ]

18. World Health Organization (WHO). Control of Chagas Disease: second report of the WHO expert committee. Technical Report Series. Geneva: WHO , 2002; 63. [ Links ]

19. Carrazzone CF, Brito AM, Gomes YM. Importância da avaliação sorológica pré-transfusional em receptores de sangue. Rev Bras Hematol Hemoter. 2004;26(2):93-8. [ Links ]

20. Monich AG, Dantas TW, Favero KB, Almeida PTR, Maluf EC, Capeletto CM, et al. Blood discard rate in a blood center in Curitiba - Brazil, Ten years of study. Transfusion Apher Sci. 2016;1353. [ Links ]

21. Araújo AB, Vianna EES, Berne MEA. Anti-Trypanosoma cruzi Antibody Detection in Blood Donors in the Southern Brazil. Braz J Infect Dis . 2008;12(6):480-2. [ Links ]

22. Reiche EMV, Inouye MMZ, Pontello R, Morimoto HK, Jankevicius SI, Matsuo T, et al. Seropositivity for anti-trypanosoma cruzi antibodies among blood donors of the “Hospital Universitário Regional do Norte do Paraná”, Londrina, Brazil. Rev Inst Med Trop Sao Paulo . 1996;38(3):223-40. [ Links ]

23. Sobreira AC, Gomes FV, Silva MA, Oliveira MF. Prevalência de infecção chagásica em doadores de sangue do Hemocentro Regional de Iguatu, CE. Rev Soc Bras Med Trop . 2001;34(2):193-6. [ Links ]

24. Silveira H, Mozart O, Norberg A, Pile E. Prevalência e formas clínicas de Trypanosoma cruzi em candidatos a doadores de sangue no Brasil. Rev Saude Publica. 2003;37(6):807-9. [ Links ]

25. Slavov SN, Otaguiri KK, Pinto MT, Valente VB, Ubiali EMA, Covas DT, et al. Prevalence of Trypanosoma Cruzi antibodies in blood donors from the São Paulo State, Brazil, between 2012 and 2014. J Infect Dev Ctries. 2017;11(03):277-81. [ Links ]

26. Sabino EC, Goncalez TT, Salles NA, Silva GR, Chamone DF. Trends in the prevalence of Chagas’ disease among first-time blood donors in São Paulo, Brazil. Transfusion. 2003;43(7):853-6. [ Links ]

27. Ministério da Saúde (MS). Secretaria de Vigilância em Saúde. Sistema Nacional de Vigilância em Saúde - Portaria de consolidação nº.5. Consolidação das normas sobre as ações e os serviços de saúde do Sistema Único de Saúde. Brasília: MS; 2017. [ Links ]

28. Dias JCP, Schofield CJ. Controle da transmissão transfusional da doença de Chagas na Iniciativa do Cone Sul. Rev Soc Bras Med Trop . 1998;31(4):373-83. [ Links ]

Financial Support: Fundação de Amparo à Pesquisa do Estado da Bahia (Project No. 0023/2013).

Received: March 27, 2019; Accepted: May 31, 2019

Corresponding author: Dr. Mitermayer Galvão dos Reis. e-mail:miter@bahia.fiocruz.br

Conflicts of Interests: The authors declare that there are no conflicts of interest associated with this study.

Creative Commons License This is an open-access article distributed under the terms of the Creative Commons Attribution License