Ester C. Sabino

WHO comparative evaluation of serologic assays for Chagas disease

BACKGROUND: Evaluation of commercially available test kits for Chagas disease for use in blood bank screening is difficult due to a lack of large and well‐characterized specimen panels. This study presents a collaborative effort of Latin American blood centers and the World Health Organization (WHO) to establish such a panel.

Dengue viremia in blood donors from Honduras, Brazil, and Australia.

BACKGROUND: Dengue fever and hemorrhagic disease are caused by four dengue virus (DENV) serotypes (DENV‐1 to ‐4), mosquito‐borne flaviviruses with increasing incidence, and expanding global distributions. Documented transfusion transmission of West Nile virus raised concern regarding transfusion‐transmitted DENV.

Establishment and cryptic transmission of Zika virus in Brazil and the Americas

Transmission of Zika virus (ZIKV) in the Americas was first confirmed in May 2015 in northeast Brazil. Brazil has had the highest number of reported ZIKV cases worldwide (more than 200,000 by 24 December 2016) and the most cases associated with microcephaly and other birth defects (2,366 confirmed by 31 December 2016). Since the initial detection of ZIKV in Brazil, more than 45 countries in the Americas have reported local ZIKV transmission, with 24 of these reporting severe ZIKV-associated disease. However, the origin and epidemic history of ZIKV in Brazil and the Americas remain poorly understood, despite the value of this information for interpreting observed trends in reported microcephaly. Here we address this issue by generating 54 complete or partial ZIKV genomes, mostly from Brazil, and reporting data generated by a mobile genomics laboratory that travelled across northeast Brazil in 2016. One sequence represents the earliest confirmed ZIKV infection in Brazil. Analyses of viral genomes with ecological and epidemiological data yield an estimate that ZIKV was present in northeast Brazil by February 2014 and is likely to have disseminated from there, nationally and internationally, before the first detection of ZIKV in the Americas. Estimated dates for the international spread of ZIKV from Brazil indicate the duration of pre-detection cryptic transmission in recipient regions. The role of northeast Brazil in the establishment of ZIKV in the Americas is further supported by geographic analysis of ZIKV transmission potential and by estimates of the basic reproduction number of the virus.

distribution of Hiv-1 subtypes seen in an Aids clinic in Sao Paulo City, Brazil

Objective: To determine the distribution of HIV‐1 subtypes in Sao Paulo, Brazil. Methods: Samples were obtained from 80 consecutive HIV‐1‐infected individuals attending the Immunodeficiency Clinic at the University of Sao Paulo in 1993. Peripheral blood mononuclear cells (PBMC) were separated by Ficoll‐Hypaque gradient and a portion was used for routine CD4 counts; the remainder were frozen. PBMC were proteinase‐K‐digested and DNA‐purified by organic extraction. Samples were amplified for the env region of HIV, and envelope sequence subtypes determined by heteroduplex mobility analysis using prototypic subtypes as references. A subset of these were also sequenced through the C2‐V3 region of env. Results: A total 69 of 80 samples yielded env polymerase chain reaction product enabling subtype determination; samples that did not amplify were those with low DNA yields. Among 12 injecting drug users (IDU) or sexual partners of IDU, four were typed as clade F and eight as clade B. Forty‐three homosexual men or female sexual partners of bisexual men were typed as clade B. The 14 additional cases without known risk factors were typed as clade B. Conclusion: These data suggest that subtype F is related to injecting drug use in Brazil.

Sequence Variability of Human Erythroviruses Present in Bone Marrow of Brazilian Patients with Various Parvovirus B19-Related Hematological Symptoms

ABSTRACT The presence of erythrovirus infections was investigated by PCR with bone marrow samples of patients with various parvovirus B19-related hematological symptoms. Erythrovirus DNA was found in 17.3% (12/69) of patients. Phylogenetic analysis revealed that five strains cluster with genotype 1, one clusters with genotype 2, and six cluster with genotype 3. Our study is the first to document the presence of the three erythrovirus genotypes in Brazil.

HTLV in the Americas: challenges and perspectives

The first description of the human T-lymphotropic virus type 1 (HTLV-1) was made in 1980, followed closely by the discovery of HTLV-2, in 1982. Since then, the main characteristics of these viruses, commonly referred to as HTLV-1/2, have been thoroughly studied. Central and South America and the Caribbean are areas of high prevalence of HTLV-1 and HTVL-2 and have clusters of infected people. The major modes of transmission have been through sexual contact, blood, and mother to child via breast-feeding. HTLV-1 is associated with adult T-cell leukemia/lymphoma (ATL), HTLV-associated myelopathy/tropical spastic paraparesis (HAM/TSP), and HTLV-associated uveitis as well as infectious dermatitis of children. More clarification is needed in the possible role of HTLV in rheumatologic, psychiatric, and infectious diseases. Since cures for ATL and HAM/TSP are lacking and no vaccine is available to prevent HTLV-1 and HTLV-2 transmission, these illnesses impose enormous social and financial costs on infected individuals, their families, and health care systems. For this reason, public health interventions aimed at counseling and educating high-risk individuals and populations are of vital importance. In the Americas this is especially important in the areas of high prevalence.

Trends in antiretroviral drug resistance and clade distributions among HIV-1--infected blood donors in Sao Paulo, Brazil.

Background: We analyzed rates of drug resistance mutations in antiretroviral-naive São Paulo blood donors with recently acquired or established HIV-1 infections and characterized clade diversity in this population. Methods: Six hundred forty-eight seropositive blood donor specimens were identified at the Blood Center of São Paulo between July 1998 and March 2002. To discriminate recent infections, samples were subjected to the standardized testing algorithm for recent HIV seroconversion (less-sensitive enzyme immunoassay) testing algorithm. There were 531 samples with a sufficient volume of serum to attempt polymerase chain reaction (PCR) and viral sequencing; 341 (64%) samples yielded a PCR product that could be sequenced for the reverse transcriptase and protease genes. Mutations were analyzed using the 2005 International AIDS Society mutation list. Results: Of 341 specimens successfully analyzed, 21 (6.3%; 95% confidence interval [CI]: 3.9% to 9.3%) had drug-resistant mutations. The proportion of resistant strains was 12.7% (95% CI: 5.2% to 24.5%) among recently infected individuals compared with 5.0% (95% CI: 2.8% to 8.2%) among those with long-standing infections (P = 0.03). No change in the proportion of drug-resistant strains was observed among recently infected donor samples from the first half of the study period (4 of 32 samples) as compared with the second half (3 of 23 samples; P = 0.95). Of the 341 samples, 277 (81.2%) were classified as subtype B, 25 (7.3%) as subtype F1, 13 (3.8%) as subtype C, and 26 (7.6%) as recombinant strains. The distribution of HIV-1 subtypes was similar among recent and long-standing infected individuals and over time. Conclusions: The prevalence of drug-resistant mutations among newly diagnosed persons in São Paulo city is low and similar to what has been described in Europe and the United States. Although HIV-1 subtype B remains predominant, subtypes F and C and recombinant forms are present in substantial proportions in infected donors.

Ten-Year Incidence of Chagas Cardiomyopathy Among Asymptomatic Trypanosoma cruzi–Seropositive Former Blood Donors

Background— Very few studies have measured disease penetrance and prognostic factors of Chagas cardiomyopathy among asymptomatic Trypanosoma cruzi–infected persons. Methods and Results— We performed a retrospective cohort study among initially healthy blood donors with an index T cruzi–seropositive donation and age-, sex-, and period-matched seronegatives in 1996 to 2002 in the Brazilian cities of São Paulo and Montes Claros. In 2008 to 2010, all subjects underwent medical history, physical examination, ECGs, and echocardiograms. ECG and echocardiogram results were classified by blinded core laboratories, and records with abnormal results were reviewed by a blinded panel of 3 cardiologists who adjudicated the outcome of Chagas cardiomyopathy. Associations with Chagas cardiomyopathy were tested with multivariate logistic regression. Mean follow-up time between index donation and outcome assessment was 10.5 years for the seropositives and 11.1 years for the seronegatives. Among 499 T cruzi seropositives, 120 (24%) had definite Chagas cardiomyopathy, and among 488 T cruzi seronegatives, 24 (5%) had cardiomyopathy, for an incidence difference of 1.85 per 100 person-years attributable to T cruzi infection. Of the 120 seropositives classified as having Chagas cardiomyopathy, only 31 (26%) presented with ejection fraction <50%, and only 11 (9%) were classified as New York Heart Association class II or higher. Chagas cardiomyopathy was associated (P<0.01) with male sex, a history of abnormal ECG, and the presence of an S3 heart sound. Conclusions— There is a substantial annual incidence of Chagas cardiomyopathy among initially asymptomatic T cruzi–seropositive blood donors, although disease was mild at diagnosis.

Prevalence, incidence, and residual risk of human immunodeficiency virus among community and replacement first-time blood donors in São Paulo, Brazil

BACKGROUND:  Concerted efforts have been directed toward recruitment of community rather than replacement donors in Brazil. Time trends and demographic correlates of human immunodeficiency (HIV) prevalence and incidence among first‐time (FT) donors in Brazil were examined by donation type. HIV residual risk from FT‐donor transfusions, and projected yield of p24 antigen and nucleic acid test (NAT) screening were estimated.

Descarte de bolsas de sangue e prevalência de doenças infecciosas em doadores de sangue da Fundação Pró-Sangue/Hemocentro de São Paulo

OBJETIVO: Analisar a evolucao, de 1991 a 2001, do descarte sorologico na Fundacao Pro-Sangue/Hemocentro de Sao Paulo, o maior banco de sangue da America Latina, e verificar a prevalencia de doencas infecciosas entre doadores dessa instituicao no ano de 2001. METODOS: Foram compilados os dados de descarte sorologico relativos aos anos de 1991 a 2001. Para determinar a prevalencia de doencas infecciosas, foram analisadas 9 942 amostras triadas em novembro de 2001, sendo as amostras reativas submetidas a testes confirmatorios. RESULTADOS: Foi encontrada uma diminuicao percentual significativa de descarte, de 20% em 1991 para 9% em 2001. A prevalencia de doencas infecciosas entre doadores em 2001 foi de 0,04% para virus da imunodeficiencia humana (VIH); 0,21% para virus da hepatite C (VHC); 0,06% para virus T-linfotropico humano (HTLV); para virus da hepatite B (VHB), as prevalencias foram de 0,14% para anti-HBc + HBsAg, 1,68% para anti-HBc + anti-HBs e 1,67% para anti-HBc isolado; 1,10% para sifilis; e 0,14% para doenca de Chagas. CONCLUSAO: A diminuicao no descarte e a prevalencia de doencas infecciosas entre doadores da Fundacao Pro-Sangue/Hemocentro de Sao Paulo em 2001 refletem o aumento na porcentagem de doadores de repeticao nesse banco de sangue.