[Serologic screening of infectious diseases in blood banks as an indicator of morbidity in the population]

Prevalence and trends in transfusion-transmissible infections among blood donors in Brazil from 2010 to 2016

Background

Assessing trends in the rate of transfusion-transmissible infections (TTIs) in blood donors is critical to the monitoring of the blood supply safety and the donor screening effectiveness. The objective of this study was to conduct a trend analysis of TTIs and associated demographic factors of donors at a public blood bank in the central Brazil.

Methods

A retrospective analysis (2010–2016) of blood donation data was performed to determine the prevalence of markers for TTIs. Multinomial and multivariate logistic regression were used to verify the association between the explanatory variables and TTIs. The trend was evaluated with the Prais Winsten’s regression analysis.

Results

The prevalence of TTIs was 4.04% (5,553 donors) among 137,209 donors, with a steady trend in the analyzed period. The seroprevalence for the hepatitis B virus (HBV), syphilis, hepatitis C virus (HCV), human immunodeficiency virus (HIV), Chagas disease, and human T-lymphotropic virus (HTLV) were 1.63%, 0.87%, 0.46%, 0.21%, 0.21% and 0.09%, respectively. The prevalence of HBV decreased (b = −0.021, p <  0.001), while syphilis increased (b = 0.112; p =  0.001), during the period investigated. The probability for a positive test for TTI was higher among donors with a low level of education, aged ≥30 years old, without stable marital status, and first-time donors.

Conclusions

Even with the reduction in HBV, the increased rate of syphilis may have contributed to the fact that the overall rate of TTIs did not decrease in the evaluated period.

Path of infectious diseases in Brazil in the last 50 years: an ongoing challenge

In this article, we comment on the main features of infectious diseases in Brazil in the last 50 years, highlighting how much of this path Revista de Saúde Pública could portray. From 1967 to 2016, 1,335 articles focusing on infectious diseases were published in Revista de Saúde Pública. Although the proportion of articles on the topic have decreased from about 50.0% to 15.0%, its notability remained and reflected the growing complexity of the research required for its control. It is noteworthy that studies design and analysis strategies progressively became more sophisticated, following the great development of epidemiology in Brazil in the recent decades. Thus, the journal has followed the success of public health interventions that permitted to control or eliminate numerous infectious diseases - which were responsible, in the past, for high rates of morbidity and mortality -, and also followed the reemergence of diseases already controlled and the emergence of until then unknown diseases, with a strong impact on the Brazilian population, establishing a little predictable and very challenging path. RESUMO Neste artigo, comentamos as principais características das doenças infecciosas no Brasil, nos últimos 50 anos, destacando o quanto a Revista de Saúde Pública conseguiu capturar essa trajetória. De 1967 a 2016, foram publicados 1.335 artigos na Revista de Saúde Pública com foco em doenças infecciosas. Ainda que a proporção de artigos sobre esse tema tenha declinado de cerca de 50,0% para 15,0%, seu destaque se manteve e refletiu a crescente complexidade das pesquisas necessárias para o seu controle. Nota-se que os desenhos dos estudos e as estratégias de análise ganharam progressivamente maior sofisticação, acompanhando o grande desenvolvimento da epidemiologia no Brasil, nas últimas décadas. Assim, foi registrado não apenas o sucesso de intervenções de saúde pública que permitiram o controle ou a eliminação de inúmeras doenças infecciosas responsáveis, no passado, por elevadas taxas de morbimortalidade, como também a reemergência de males já controlados e o surgimento de doenças até então desconhecidas, com forte impacto na população brasileira, desenhando uma trajetória pouco previsível e muito desafiadora.

Blood discard rate in a blood center in Curitiba - Brazil. Ten years of study

INTRODUCTION

Development of technologies to reduce transfusion risks of infectious diseases is a major characteristic of hemotherapy. Thus, each donation undergoes clinical and serological screening tests to ensure the donated blood do not offer risks to the receiver.

OBJECTIVE

Evaluate the prevalence of positive serology in blood donations rejected by Hemobanco (Curitiba - PR) in the period ranging from January 2003 to December 2012.

METHODOLOGY

During the period studied, we observed the total number of donations and its division according to gender. We also analyzed the number of rejected donations due to seropositivity, considering the diseases investigated routinely in blood banks in Brazil, and the frequency of discards according to age groups.

RESULTS

Within the period studied, 399,280 donations were performed. 62.0% donors were male. Comparing 2003 to 2012, we noticed a significant decrease of discards, from 10.2% to 5.0%, respectively. There was a reduction of seropositivity for HIV, HBsAg and anti-HBc and an increase for Chagas Disease, hepatitis C, syphilis and HTLV. The age group with the highest prevalence for discards changed: it used to be the 40-59 years old group in 2003, and became the 20-39 years old group in 2012.

CONCLUSION

There was an increase in the number of donations in Hemobanco and a decrease in total discards due to seropositive donations. Most donors were male. The most prevalent cause of discards only amongst seropositive donation discards is seropositivity for anti-HBc. There was a significant increase of donors aged between 20 and 39 years old.

[Syphilis detection using ELISA and VDRL tests on blood donors at the blood center of Guarapuava, State of Paraná]

The aim of this study was to evaluate the syphilis seroprevalence among 5,752 blood donors who were attended at the blood center of Guarapuava, State of Paraná, in 2006. The seropositivity rates were 2.1% for enzyme Linked Immuno Sorbent Assay and 0.2% for Veneral Disease Research Laboratory, thus showing low prevalence of syphilis among the individuals who came to this blood bank.

HIV and infections of similar transmission patterns in a drug injectors community of Santos, Brazil

To study the prevalence of HIV and infections with related transmission patterns, we interviewed and obtained blood samples from 220 injecting drug users (IDUs), sampled by snowballing, from the city of Santos in the state of São Paulo, Brazil, where the estimated number of IDUs (10,000) comprises approximately 2% of the entire population. Seroprevalence of HIV, hepatitis B and C, syphilis, and HTLV (1 and 2) was assessed and compared with that in 197 blood donors from the same city, matched for age and gender. Risk behavior related to HIV was assessed by a standard questionnaire applied to the IDU sample. Univariate and multivariate analyses of the risk factors were performed. Seroprevalences found were 62% for HIV, 75% for HCV, 75% for HBV, 34% for syphilis, and 25% for HTLV (1 and 2) among IDUs, which compare with 0.0%, 2%, 23%, 12%, and 1% for blood donors, respectively. The risk for parenterally transmitted infections in this IDU community was higher than that for sexually transmitted infections (odds ratio for syphilis, 3.57; hepatitis B, 10.0; and hepatitis C, 100). The results of the mutivariate risk analysis showed that daily rate of ID use >5 times/day (OR = 6.73), not changing behavior to avoid AIDS (OR= 3.28), ID use >15 days/month (OR = 2.72), and ID use in the last 2 months (OR = 2.23) were the risk behaviors significantly associated with HIV infection.

Changing patterns of HIV-1 transmission in southern Brazil 1985-1991

In order to describe the changing patterns of risk factors for HIV-1 transmission of patients using hospital services at an AIDS referral centre in Porto Alegre, southern Brazil, data on demographic characteristics, referral patterns and risk factors at time of first presentation were collected prospectively on 405 patients between October 1985 and September 1991. Overall HIV-related patient workload increased during the study period, as did the proportion of infected female patients seen (P < 0.05). Of all patients, 147 (36%) presented with symptomatic HIV disease and 77 (19%) presented with an AIDS defining condition; men were more likely to present with symptomatic disease than women. Approximately 156 (44%) of men were self-referred compared with 4 (8%) of the women (P < 0.0001). Of the 357 infected men, 82 (23%) were bisexuals; of the 26 heterosexually infected women, 7 (24%) had bisexual male partners. These data suggest the increasing importance of heterosexual HIV transmission in this hitherto 'low' prevalence area, with male bisexuals constituting an important route through which heterosexual females are being infected in this area. The data also suggest that heterosexual women in Southern Brazil do not perceive themselves to be at risk for HIV-1 infection.

[Alcoholism and syphilis: prevalence and clinical and hepatic biochemical changes]

The prevalence of syphilis in chronic alcoholics and the hepatic clinical and biochemical alterations were evaluated in patients with both entities. The prevalence of syphilis in patients with other psychiatric diagnosis was taken as control. The patients were asymptomatic or oligosymptomatic with respect to hepatic alcoholic dysfunction or to any manifestation of the three clinical stages of syphilis. Alcoholics (206 patients) and patients with other psychiatric conditions (228 patients) were submitted to clinical examination and to quantitative serology for syphilis (Wasserman and VDRL), yielding 6.3% and 3.1% of seropositivity, respectively. No statistically significant difference was observed between alcoholics of the seropositive or seronegative groups, as to the frequencies of clinical or biochemical alterations which would indicate hepatic alterations.

O ser com AIDS em sua dimensão existencial

A inquietação sobre o significado de estar com AIDS, sob a perspectiva da pessoa que vivência a doença, levou as autoras a uma pesquisa que as norteie para uma assistência de enfermagem que contemple o doente em sua dimensão existencial. Desta forma, utilizando os passos de uma investigação fenomenológica, puderam, a partir dos discursos das pessoas sobre as suas experiências vividas de um ser com AIDS, desvelar facetas que integram a essência desse vivenciar e que o afetam enquanto um ser histórico. O momento crítico de revelação do diagnóstico, o conviver com a doença e com os sintomas a ela inerentes, a perspectiva de finitude próxima, a configuração de seu horizonte existencial face ao que lhes está acontecendo, foram facetas que emergiram e que são analisadas. Esses resultados contribuem, efetivamente, para uma assistência de enfermagem que assegure aos doentes o exercício de sua condição primordial de ser humano: a sua dimensão existencial.

[Methodological considerations in the interpretation of serologic screening for hepatitis B virus among blood donors]

Between October 1988 and February 1989, 1,033 voluntary first-time blood donors were screened for hepatitis B infection in five blood banks in Goiâna, Central Brazil. The survey was part of a major study designed to estimate seroprevalence of HBsAg and anti-HBs and to discuss methodological issues related to prevalence estimation based on data from blood banks. Donors were interviewed and blood samples were collected and tested for HBsAg and anti-HBs by ELISA tests. Prevalences of 1.9% and 10.9% were obtained for HBsAg and anti-HBs, respectively, and no statistical difference was found between the sexes. Prevalence of anti-HBs increased with age (X2 for trend = 7.9 p = 0.004). The positive predictive value and sensitivity of history of jaundice or hepatitis reported in the interview in detecting seropositives were 13.6% and 2.2%, respectively. The methodological issues, including internal and external validity of HBV prevalence estimated among blood donors are discussed. The potential usefulness of blood banks as a source of morbidity information for surveillance for Hepatitis B virus infection is stressed.

[Positive serology of syphilis, toxoplasmosis and Chagas' disease in pregnant women in their first visit to health centers in a metropolitan area, Brazil]

The diagnosis of some infectious diseases contracted during pregnancy is very important, as these diseases can be transmitted to the fetus. Four hundred and eighty-one pregnant women were studied, of an average 24.5 years of age (from 14 to 46), during their first prenatal visit to the State of S. Paulo's Health Care Centres in the subdistrict of Paz (Butantan), City of S. Paulo, Brazil, between April and October, 1988. Classified by trimester of pregnancy, 230 patients (47.8%) fell into the first, 203 (42.2%) into the second and 48 (10%) into the third trimester. Of the 474 patients that declared their income, 309 (65.2%) earned 1 MSPC (minimum salary per capita) per month, which gives some indication of the low socioeconomic status of our patients is. The serologic tests for syphilis, toxoplasmosis and Chagas' disease were analysed for each patient, more than one technique being used for each. The results were as follows: 25 patients (5.2%) had a positive test for syphilis; in 67 patients (13.9%) active toxoplasmosis was diagnosed (Presence of IgM antibodies in 6); 14 patients (2.9%) were positive for Chagas' disease, among which 10 (71.4%) came from the States of Bahia and Minas Gerais, where this disease has a high prevalence.

[Seroprevalence and risk factors for hepatitis B virus infection by AgHBs and anti-HBs markers in prisoners and prime blood donors]

Two cross-sectional surveys on hepatitis B virus (HBV) infection were carried out among 1,033 volunteer first-time blood donors in five blood banks (3 private, 2 public) and among 201 prisoners in the Penitentiary Center of Industrial Activity, in Goiania, Central Brazil, between June 1988 and February 1989. Those surveys were part of a major study designed to estimate seroprevalence of HBsAg and anti-HBsAg markers by ELISA test, and to study risk factors associated with seropositivity. The presence of any serum marker was considered as previous exposure to HBV. A standard questionnaire was applied to both populations to evaluate previous blood transfusion, number of sexual partners, homo/bisexual activity, history of sexually transmitted diseases, drug abusers, use of parenteral medicine, acupuncture, tattooing and VDRL seropositivity. Seroprevalence varied from 12.8% to 26.4% in blood donors and prisoners, respectively, (p less than 0.05) and increased with age (X2 trend=14.0 p less than 0.05%). Prisoners had higher percentages of all risk factors investigated than blood donors, with the exception of number of sexual partners. Among all risk factors studied, age, imprisonment and tattooing were statistically associated with seropositivity, even after multivariate analysis controlling for age and reclusion. The paper discusses the methodologic issues related to this epidemiologic investigation.

Trends of T. cruzi infection based on data from blood bank screening

Between October 1988 and April 1989 a cross-sectional survey was carried out in six out of eight blood banks of Goiánia, Central Brazil. Subjects attending for first-time blood donation in the mornings of the study period (n = 1358) were interviewed and screened for T. cruzi infection as a part of a major study among blood donors. Tests to anti-T. cruzi antibodies were performed, simultaneously, by indirect hemagglutination test (IHA) and complement fixation test (CFT). A subject was considered seropositive when any one of the two tests showed a positive result. Information on age, sex, place of birth, migration and socio-economic level was recorded. Results from this survey were compared with seroprevalence rates obtained in previous studies in an attempt to analyse trend of T. cruzi infection in an endemic urban area. The overall seroprevalence of T. cruzi infection among first-time donors was found to be 3.5% (95% confidence interval 2.5%-4.5%). The seroprevalence rate increased with age up to 45 years and then decreased. Migrants from rural areas had higher seroprevalence rates than subjects from urban counties (1.8%-16.2% vs. 0%-3.6%). A four fold decrease in prevalence rates was observed when these rates were compared with those of fifteen years ago. Two possible hypotheses to explain this difference were suggested: 1. a cohort effect related with the decrease of transmission in rural areas and/or 2. a differential proportion of people of rural origin among blood donors between the two periods. The potential usefulness of blood banks as a source of epidemiological information to monitor trends of T. cruzi infection in an urban adult population was stressed.

Seroprevalence of Trypanosoma cruzi infection among unskilled urban workers in central Brazil

A cross-sectional survey of the prevalence of Trypanosoma cruzi infection was carried out among urban unskilled workers in an endemic area in central Brazil as part of a study to assess the health impact of Chagas disease and to identify risk factors for the evolution of cardiopathy. Blood samples from 5425 male and female workers, aged 15-61 years, from 5 public institutions, were screened by indirect immunofluorescence, enzyme-linked immunosorbent assay and indirect haemagglutination for antibodies to T. cruzi. Seroprevalence varied from 8.8% to 15.6% in the different institutions and increase with age up to 55 years. More stable jobs were associated with lower seroprevalence. Migrants from São Paulo and Minas Gerais presented higher prevalence and a relative risk associated with seropositivity in relation to workers from Goiás of 2.2 (95% confidence limits, 1.4-3.5) and 1.9 (1.6-2.3), respectively.

[Seroprevalence and risk factors for syphilis in prisoners in Goiás, Brazil]

A cross-sectional survey was carried-out among 299 prisoners in the Penitentiary Center of Industrial Activity of Goiás (CEPAIGO), to determine the seroprevalence to T. pallidum and to identify risk factors associated to seropositivity. The seropositivity criterion was a positive VDRL test at any titer. A questionnaire was applied to evaluate the following risk factors: time of imprisonment, clinical evidence of sexually transmitted diseases (STD), history of syphilis or others STD, homo/bisexuality and number of sexual partners. The positive (PPV) and negative (NPV) predictive values of the history of syphilis were calculated. Seroprevalence of 18.4% was found and no difference was detected in the different age groups. The PPV of history of syphilis was 26% indicating that 74% of the individuals who have reported syphilis in the past presented a negative VDRL test. Among all the risk factors studied, homo/bisexuality was the only one with statistically significant association with seropositivity (relative risks 5.7-95% CL1.2-26, p = 0.03). The paper discusses the methodological problems related with the investigation.