Molecular landscape of the JAK2 gene in chronic myeloproliferative neoplasm patients from the state of Amazonas, Brazil.

JAK2V617F (dbSNP: rs77375493) is the most frequent and most-studied variant in BCR::ABL1 negative myeloproliferative neoplasms and in the JAK2 gene. The present study aimed to molecularly characterize variants in the complete coding region of the JAK2 gene in patients with BCR::ABL1 negative chronic myeloproliferative neoplasms. The study included 97 patients with BCR::ABL1 negative myeloproliferative neoplasms, including polycythemia vera (n=38), essential thrombocythemia (n=55), and myelofibrosis (n=04). Molecular evaluation was performed using conventional PCR and Sanger sequencing to detect variants in the complete coding region of the JAK2 gene. The presence of missense variants in the JAK2 gene including rs907414891, rs2230723, rs77375493 (JAK2V617F), and rs41316003 were identified. The coexistence of variants was detected in polycythemia vera and essential thrombocythemia. Thus, individuals with high JAK2V617F variant allele frequency (≥50% VAF) presented more thrombo-hemorrhagic events and manifestations of splenomegaly compared with those with low JAK2V617F variant allele frequency (<50% VAF). In conclusion, individuals with BCR::ABL1 negative neoplasms can display >1 variant in the JAK2 gene, especially rs2230722, rs2230724, and rs77375493 variants, and those with high JAK2V617F VAF show alterations in the clinical-laboratory profile compared with those with low JAK2V617F VAF.

Reinfection by the SARS-CoV-2 Gamma variant in blood donors in Manaus, Brazil.

BACKGROUND: The city of Manaus, north Brazil, was stricken by a second epidemic wave of SARS-CoV-2 despite high seroprevalence estimates, coinciding with the emergence of the Gamma (P.1) variant. Reinfections were postulated as a partial explanation for the second surge. However, accurate calculation of reinfection rates is difficult when stringent criteria as two time-separated RT-PCR tests and/or genome sequencing are required. To estimate the proportion of reinfections caused by Gamma during the second wave in Manaus and the protection conferred by previous infection, we identified anti-SARS-CoV-2 antibody boosting in repeat blood donors as a mean to infer reinfection. METHODS: We tested serial blood samples from unvaccinated repeat blood donors in Manaus for the presence of anti-SARS-CoV-2 IgG antibodies using two assays that display waning in early convalescence, enabling the detection of reinfection-induced boosting. Donors were required to have three or more donations, being at least one during each epidemic wave. We propose a strict serological definition of reinfection (reactivity boosting following waning like a V-shaped curve in both assays or three spaced boostings), probable (two separate boosting events) and possible (reinfection detected by only one assay) reinfections. The serial samples were used to divide donors into six groups defined based on the inferred sequence of infection and reinfection with non-Gamma and Gamma variants. RESULTS: From 3655 repeat blood donors, 238 met all inclusion criteria, and 223 had enough residual sample volume to perform both serological assays. We found 13.6% (95% CI 7.0-24.5%) of all presumed Gamma infections that were observed in 2021 were reinfections. If we also include cases of probable or possible reinfections, these percentages increase respectively to 22.7% (95% CI 14.3-34.2%) and 39.3% (95% CI 29.5-50.0%). Previous infection conferred a protection against reinfection of 85.3% (95% CI 71.3-92.7%), decreasing to respectively 72.5% (95% CI 54.7-83.6%) and 39.5% (95% CI 14.1-57.8%) if probable and possible reinfections are included. CONCLUSIONS: Reinfection by Gamma is common and may play a significant role in epidemics where Gamma is prevalent, highlighting the continued threat variants of concern pose even to settings previously hit by substantial epidemics.

Three-quarters attack rate of SARS-CoV-2 in the Brazilian Amazon during a largely unmitigated epidemic.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spread rapidly in Manaus, the capital of Amazonas state in northern Brazil. The attack rate there is an estimate of the final size of the largely unmitigated epidemic that occurred in Manaus. We use a convenience sample of blood donors to show that by June 2020, 1 month after the epidemic peak in Manaus, 44% of the population had detectable immunoglobulin G (IgG) antibodies. Correcting for cases without a detectable antibody response and for antibody waning, we estimate a 66% attack rate in June, rising to 76% in October. This is higher than in São Paulo, in southeastern Brazil, where the estimated attack rate in October was 29%. These results confirm that when poorly controlled, COVID-19 can infect a large proportion of the population, causing high mortality.

High rate of seromarkers for HIV, HBV and syphilis among blood donors using confidential unit exclusion, before and after HIV-NAT implementation at a major public blood bank in the Brazilian Amazon.

BACKGROUND: Confidential unit exclusion (CUE) was introduced in the 1980's as an additional layer to blood safety, before highly specific and sensitive nucleic acid tests (NAT) for HIV were implemented. The utility of CUE-use in settings that have implemented NAT should be evaluated over time. STUDY DESIGN, METHODS: Cross-sectional retrospective study carried out from June 2010-November 2015, at Manaus Hemocenter (HEMOAM), Amazonas, Brazil that implemented HIV-NAT in 2012. The HIV, HCV, HBV, HTLV, Chagas disease, and syphilis rates were compared among CUE and non-CUE blood donors, before and after HIV-NAT implementation. RESULTS: Among 287,588 donations, 2,154 (0.75%) were associated with CUE, mainly voluntary donations (64.2%), by repeat donors (58.4%) from young (median age = 31 years), males (84.4%), unmarried (63.1%). CUE-users compared to non-CUE donors (n = 285,434) had higher seropositivity rates to HIV (OR = 6.09, 95% CI: 3.68-10.07, p < 0.001), HBV (anti-HBc OR = 1.81 95% CI: 1.24-2.64, p = 0.004; HBsAg OR = 5.68, 95% CI: 1.78-18.07, p = 0.017), and syphilis (OR = 1.78, 95% CI: 1.05-3.04, p = 0.030). Most (97.2%) discarded blood units associated to CUE was seronegative for all pathogens. Most donations (73.4%) were tested by HIV-NAT and showed four window period donations, positive by HIV-NAT only among non-CUE donors. CONCLUSION: A high rate of transfusion transmissible infections/TTIs was observed at HEMOAM especially in CUE-users. CUE-use offered an additional layer of blood safety by its association with anti-HBc/HBsAg and syphilis that are not covered by NAT. For blood banks in highly endemic areas for HIV and TTI, as HEMOAM, the identification of at risk donors, and the orientation to be tested at proper sites remain a great challenge.

Detection of Mansonella ozzardi among blood donors from highly endemic interior cities of Amazonas state, northern Brazil.

BACKGROUND: In the Brazilian Amazon, the filarial nematode Mansonella ozzardi co-exists with malaria parasites and thick blood smear microscopy is considered the diagnostic gold standard. Transfusion of M. ozzardi microfilariae does not establish new infections, however microfilariae can survive approximately 2 years in blood-recipients with unknown risk of pathology. Data on transfusion-transmitted filariasis are lacking. This study investigated M. ozzardi parasitemias in blood donors from decentralized centers of "Fundação Hematologia e Hemoterapia do Estado do Amazonas/HEMOAM," Northern Brazil. STUDY DESIGN AND METHODS: Cross-sectional investigation employing blood smear microscopy (n = 356) and qualitative nested-M. ozzardi-PCR (227 out of 356) in donor candidates from 19 hemocenters in interior/rural municipalities of Amazonas state. FINDINGS: Participants were mostly young males. Positivity by microscopy was 7.9% (28 out of 356) and 23.8% by M. ozzardi-PCR (54 out of 227). Parasitaemias were found in 16 out of 19 municipalities. In 54 M. ozzardi-positives, 24 were ineligible; among 30 that donated, 27 were interdicted by seropositivity (22 anti-HBc, 3 anti-HBc + HBsAg, 1 Chagas+malaria, 1 VDRL). Seropositivty was higher in M. ozzardi-PCR-positives vs M. ozzardi-PCR-negatives (OR = 15.8, 95% CI 4.5-56.1, p < 0.0001). Three M. ozzardi contaminated blood units were transfused, but no follow-up information on the recipients is available. MAIN CONCLUSIONS: Our study provides important baseline data on M. ozzardi among blood donors from the Brazilian Amazon. Further investigations in endemic areas are necessary to clarify possible association between M. ozzardi and other infections and also to elucidate whether there is any significant clinical effect upon transfusion of contaminated blood.

Alternative transmission routes in the malaria elimination era: an overview of transfusion-transmitted malaria in the Americas.

BACKGROUND: Transfusion-transmitted (TT) malaria is an alternative infection route that has gained little attention from authorities, despite representing a life-threatening condition. There has been no systematic review of this health problem in American countries. The aim of this study was to describe the clinical and epidemiological characteristics of TT malaria in the Americas and identify factors associated with lethality based on the studies published in the literature. METHODS: Potentially relevant papers in all languages were retrieved from MEDLINE and LILACS. Additional articles were obtained from reviews and original papers. Publications on screening of candidate blood donors and on surveillance of TT malaria cases were included. Odds ratios with respective 95% confidence intervals (95% CI) were calculated. Epidemiological characteristics of blood donors of TT malaria cases, including a pooled positivity of different tests for malaria diagnosis, were retrieved. RESULTS: A total of 63 publications regarding TT malaria from seven countries were included, from 1971 to 2016. A total of 422 cases of TT malaria were recorded. Most TT malaria cases were in females (62.0%) and 39.5% were in the ≥61 years-old age group. About half of all cases were from Mexico (50.7%), 40.3% from the United States of America (USA) and 6.6% from Brazil. Gyneco-obstetrical conditions (67.3%), surgical procedures (20.6%) and complications from neoplasias (6.1%) were the most common indications of transfusion. Packed red blood cells (RBCs) (50.7%) and whole blood (43.3%) were the blood products mostly associated with TT malaria. Cases were mostly caused by Plasmodium malariae (58.4%), followed by Plasmodium vivax (20.7%) and Plasmodium falciparum (17.9%). A total of 66.6% of cases were diagnosed by microscopy. Incubation period of 2-3 weeks was the most commonly observed (28.6%). Lethality was seen in 5.3% of cases and was associated with living in non-endemic countries, P. falciparum infection and concomitant neoplastic diseases. CONCLUSION: There is an important research and knowledge gap regarding the TT malaria burden in Latin American countries where malaria remains endemic. No screening method that is practical, affordable and suitably sensitive is available at blood banks in Latin American countries, where infections with low parasitaemia contribute greatly to transmission. Lethality from TT malaria was not negligible. TT malaria needs to be acknowledged and addressed in areas moving toward elimination.

Fish consumption, mercury exposure and serum antinuclear antibody in Amazonians.

Exposure to intrinsic Hg in fish was studied in Amazon populations with high prevalence of malaria disease. High fish-eater riverines were compared to urban (Manaus residents) low fish-eater riverines in regards to Hg exposure (hair-Hg) and serum antinuclear antibodies (ANA). Most riverines (99.0%) ate fish daily compared to only 3% of controls. Fish species high in MeHg was consumed more frequently (45.5%) by riverines than controls (18.8%). Mean hair-Hg (34.5 ppm) of riverines was significantly higher than controls (1.0 ppm). Although positive serum ANA was more frequently observed in riverine fish-eaters (12.4%) than controls (2.9%), there was no significant association between hair-Hg and ANA. High prevalence of malaria reporting among riverines was neither associated with Hg exposure nor with serum ANA. An autoimmune dysfunction is unlikely to occur as a result of MMHg exposure due to fish consumption.

Prevalência de marcadores sorológicos e moleculares do vírus da hepatite B em gestantes do Estado do Amazonas, Brasil / Prevalence of serologic and molecular markers of hepatitis B virus infectio among pregnant women in Amazonas State, Brazil

A infecção pelo vírus da hepatite B (VHB) constitui um importante problema de Saúde Pública na Amazônia brasileira, onde a exposição precoce, durante a infância, ocorre em áreas de maior endemicidade. Com a finalidade de contribuir para as políticas regionais de controle do VHB na região, foi conduzido um inquérito de prevalência de marcadores sorológicos e moleculares do VHB entre 1.460 gestantes atendidas pelo Programa Pré-Natal, nas nove sub-regiões do Estado do Amazonas, Brasil. Entre essas subregiões, a prevalência do antígeno de superfície (HBsAg) variou de 0 por cento a 8,7 por cento; dos anticorpos anti-core (anti-HBc), de 5,3 a 75,9 por cento;e de anticorpos anti-superfície (anti-HBs), de 10,6 a 73,4 por cento. Entre as 46 gestantes reativas para o HBsAg, 36 (78,3 por cento) foram positivas para VHB-DNA na reação em cadeia da polimerase (PCR). A carga viral de VHB-DNA foi menor que 1x103 cópias/ml em 73,9 por cento das gestantes HBsAg-reativas; porém, 8,7 por cento apresentavam níveis superiores a 1x105 cópias/ml, indicando infecção ativa. Os resultados encontrados mostram sub-regiões do Amazonas com elevada prevalência de VHB entre mulheres grávidas e, embora a maioria apresente baixa viremia, algumas podem representar risco potencial de transmissão mãe-filho, devido à elevada carga viral

Métodos de triagem para malária, em doadores de sangue de área endêmica / Screening methods for malaria, in blood donors in endemic area

Relizou-se um estudo controlado para comparar a presença parasitemiaa e anticorpos antiplasmódios em doadores expostos ao risco de infecçäo malárica, segundo os critérios fixados nas Normas Técnicas em Hemoterapia, do Miníterio da Saúde. Eles estabelecem a rejeiçäo dos candidatos à doaçäo que apresentaram quadro febril há 30 dias e malária há 12 meses, ou que frequentaram área de malária há 6 meses. Foram estudados 395 candidatos incluídos nos critérios de rejeiçäo (expostos) e 383 candidatos aptos (controles), selecionados na triagem de doadores do Hemocentro de Manaus (AM). Em ambos os grupos, realizou-se a gota espessa e o teste da laranja acridina (QBC) para o diagnóstico parasitológico e a imunofluorescência indireta para a pesquisa de anticorpos IgM e IgG ao Plamodium vivax e falciparum. Observou-se diferença significante entre expostos e controles em relaçäo à presença de parasitemia, porém mäo para a presença de anticorpos antiplasmódios (P<0.05). O QBC foi mais sensível do que a gota espessa para detectar parasitemia e a concordância entre ambos foi de 0.66 ao Indice Kappa