Molecular screening of Plasmodium sp. asymptomatic carriers among transfusion centers from Brazilian Amazon region

The transmission of malaria in Brazil is heterogeneous throughout endemic areas and the presence of asymptomatic Plasmodium sp. carriers (APCs) in the Brazilian Amazon has already been demonstrated. Malaria screening in blood banks is based on the selection of donors in respect to possible risks associated with travel or residence, clinical evidence and/or inaccurate diagnostic methods thereby increasing the probability of transfusion-transmitted infection. We evaluated the frequency of APCs in four blood services in distinct areas of the Brazilian Amazon region. DNA was obtained from 400 human blood samples for testing using the phenol-chloroform method followed by a nested-PCR protocol with species-specific primers. The positivity rate varied from 1 to 3% of blood donors from the four areas with an average of 2.3%. All positive individuals had mixed infections for Plasmodium vivax and Plasmodium falciparum. No significant differences in the results were detected among these areas; the majority of cases originated from the transfusion centres of Porto Velho, Rondônia State and Macapá, Amapá State. Although it is still unclear whether APC individuals may act as reservoirs of the parasite, efficient screening of APCs and malaria patients in Brazilian blood services from endemic areas needs to be improved.

Download Full-text

Evaluation of Histidine-Rich Proteins 2 and 3 Gene Deletions in Plasmodium falciparum in Endemic Areas of the Brazilian Amazon

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18010123 ◽

2020 ◽

Vol 18 (1) ◽

pp. 123

Author(s):

Leandro Góes ◽

Nathália Chamma-Siqueira ◽

José Mário Peres ◽

José Maria Nascimento ◽

Suiane Valle ◽

...

Keyword(s):

Plasmodium Falciparum ◽

Gene Deletion ◽

Brazilian Amazon ◽

Amazon Region ◽

The State ◽

Molecular Surveillance ◽

Gene Deletions ◽

Exon 2 ◽

Brazilian Amazon Region ◽

Endemic Areas

Histidine-rich proteins 2 and 3 gene (pfhrp2 and pfhrp3) deletions affect the efficacy of rapid diagnostic tests (RDTs) based on the histidine-rich protein 2 (HRP2), compromising the correct identification of the Plasmodium falciparum species. Therefore, molecular surveillance is necessary for the investigation of the actual prevalence of this phenomenon and the extent of the disappearance of these genes in these areas and other South American countries, thus guiding national malaria control programs on the appropriate use of RDTs. This study aimed to evaluate the pfhrp2 and pfhrp3 gene deletion in P. falciparum in endemic areas of the Brazilian Amazon. Aliquots of DNA from the biorepository of the Laboratory of Basic Research in Malaria, Evandro Chagas Institute, with a positive diagnosis for P. falciparum infection as determined by microscopy and molecular assays, were included. Monoinfection was confirmed by nested-polymerase chain reaction assay, and DNA quality was assessed by amplification of the merozoite surface protein-2 gene (msp2). The pfhrp2 and pfhrp3 genes were amplified using primers for the region between exons 1 and 2 and for all extension of exon 2. Aliquots of DNA from 192 P. falciparum isolates were included in the study, with 68.7% (132/192) from the municipality of Cruzeiro do Sul (Acre) and 31.3% (60/192) from Manaus (Amazonas). Of this total, 82.8% (159/192) of the samples were considered of good quality. In the state of Acre, 71.7% (71/99) showed pfhrp2 gene deletion and 94.9% (94/99) showed pfhrp3 gene deletion, while in the state of Amazonas, 100.0% (60/60) of the samples showed pfhrp2 gene deletion and 98.3% (59/60) showed pfhrp3 gene deletion. Moreover, 79.8% (127/159) of isolates displayed gene deletion. Our findings confirm the presence of a parasite population with high frequencies of pfhrp2 and pfhrp3 gene deletions in the Brazilian Amazon region. This suggests reconsidering the use of HRP2-based RDTs in the Acre and Amazonas states and calls attention to the importance of molecular surveillance and mapping of pfhrp2/pfhrp3 deletions in this area and in other locations in the Amazon region to guarantee appropriate patient care, control and ultimately contribute to achieving P. falciparum malaria elimination.

Download Full-text

Sensitivity of diagnostic methods for Mansonella ozzardi microfilariae detection in the Brazilian Amazon Region

Memórias do Instituto Oswaldo Cruz ◽

10.1590/0074-02760170321 ◽

2018 ◽

Vol 113 (3) ◽

pp. 173-177 ◽

Cited By ~ 3

Author(s):

Jansen Fernandes Medeiros ◽

Gilberto Fontes ◽

Vilma Lopes do Nascimento ◽

Moreno Rodrigues ◽

Jacob Cohen ◽

...

Keyword(s):

Brazilian Amazon ◽

Amazon Region ◽

Diagnostic Methods ◽

Brazilian Amazon Region

Download Full-text

CYP2D6 Allele Frequency in Five Malaria Vivax Endemic Areas From Brazilian Amazon Region

Frontiers in Pharmacology ◽

10.3389/fphar.2021.542342 ◽

2021 ◽

Vol 12 ◽

Author(s):

Paula Ferreira Salles ◽

Daiana Souza Perce-da-Silva ◽

Atila Duque Rossi ◽

Luisa Riehl Raposo ◽

Aina Danaisa Ramirez Ramirez ◽

...

Keyword(s):

Plasmodium Vivax ◽

Enzyme Level ◽

Brazilian Amazon ◽

Amazon Region ◽

Nucleotide Polymorphisms ◽

Drug Dosing ◽

Homozygous Genotype ◽

Brazilian Amazon Region ◽

Optimal Drug ◽

Endemic Areas

Genetic variability was linked with individual responses to treatment and susceptibility to malaria by Plasmodium vivax. Polymorphisms in the CYP2D6 gene may modulate enzyme level and activity, thereby affecting individual responses to pharmacological treatment. The aim of the study was to investigate whether or not CYP2D6 single nucleotide polymorphisms rs1065852, rs38920-97, rs16947 and rs28371725 are unequally distributed in malaria by Plasmodium vivax individuals from the Brazilian Amazon region. The blood samples were collected from 220 unrelated Plasmodium vivax patients from five different endemic areas. Genotyping was performed using SNaPshot® and real-time polymerase chain reaction methods. In all five areas, the rs1065852 (CYP2D6*10, C.100C > T), rs3892097 (CYP2D6*4, 1846C > T) and rs16947 (CYP2D6*2, C.2850G > A), as a homozygous genotype, showed the lowest frequencies. The rs28371725 (CYP2D6*41, 2988G > A) homozygous genotype was not detected, while the allele A was found in a single patient from Macapá region. No deviations from Hardy-Weinberg equilibrium were found, although a borderline p-value was observed (p = 0.048) for the SNP rs3892097 in Goianésia do Pará, Pará state. No significant associations were detected in these frequencies among the five studied areas. For the SNP rs3892097, a higher frequency was observed for the C/T heterozygous genotype in the Plácido de Castro and Macapá, Acre and Amapá states, respectively. The distribution of the CYP2D6 alleles investigated in the different areas of the Brazilian Amazon is not homogeneous. Further investigations are necessary in order to determine which alleles might be informative to assure optimal drug dosing recommendations based on experimental pharmacogenetics.

Download Full-text

Surgical Site Infection Following Caesarean Section by Acinetobacter Species: A Report from a Hyperendemic Setting in the Brazilian Amazon Region

Microorganisms ◽

10.3390/microorganisms9040743 ◽

2021 ◽

Vol 9 (4) ◽

pp. 743

Author(s):

Blenda Gonçalves Cabral ◽

Danielle Murici Brasiliense ◽

Ismari Perini Furlaneto ◽

Yan Corrêa Rodrigues ◽

Karla Valéria Batista Lima

Keyword(s):

Caesarean Section ◽

Surgical Site Infection ◽

Carbapenem Resistance ◽

Brazilian Amazon ◽

Amazon Region ◽

Site Infection ◽

Acinetobacter Species ◽

Brazilian Amazon Region ◽

Acinetobacter Spp ◽

The Impact

Surgical site infection (SSI) following caesarean section is associated with increased morbidity, mortality, and significant health care costs. This study evaluated the epidemiological, clinical, and microbiological features of Acinetobacter spp. in women with SSIs who have undergone caesarean section at a referral hospital in the Brazilian Amazon region. This study included 69 women with post-caesarean SSI by Acinetobacter spp. admitted to the hospital between January 2012 and May 2015. The 69 Acinetobacter isolates were subjected to molecular species identification, antimicrobial susceptibility testing, detection of carbapenemase-encoding genes, and genotyping. The main complications of post-caesarean SSI by Acinetobacter were inadequate and prolonged antibiotic therapy, sepsis, prolonged hospitalization, and re-suture procedures. A. baumannii, A. nosocomialis and A. colistiniresistens species were identified among the isolates. Carbapenem resistance was associated with OXA-23-producing A. baumannii isolates and IMP-1-producing A. nosocomialis isolate. Patients with multidrug-resistant A. baumannii infection showed worse clinical courses. Dissemination of persistent epidemic clones was observed, and the main clonal complexes (CC) for A. baumannii were CC231 and CC236 (Oxford scheme) and CC1 and CC15 (Pasteur scheme). This is the first report of a long-term Acinetobacter spp. outbreak in women who underwent caesarean section at a Brazilian hospital. This study demonstrates the impact of multidrug resistance on the clinical course of post-caesarean infections.

Download Full-text

Inadequate management of natural ecosystem in the Brazilian Amazon region results in the emergence and reemergence of arboviruses

Cadernos de Saúde Pública ◽

10.1590/s0102-311x2001000700025 ◽

2001 ◽

Vol 17 (suppl) ◽

pp. S155-S164 ◽

Cited By ~ 81

Author(s):

Pedro F. C. Vasconcelos ◽

Amélia P. A. Travassos da Rosa ◽

Sueli G. Rodrigues ◽

Elizabeth S. Travassos da Rosa ◽

Nicolas Dégallier ◽

...

Keyword(s):

Environmental Changes ◽

Epidemiological Data ◽

Brazilian Amazon ◽

Host Population ◽

Amazon Region ◽

Laboratory Animals ◽

Natural Ecosystem ◽

Brazilian Amazon Region ◽

Mining Dam ◽

The Impact

A total of 187 different species of arboviruses and other viruses in vertebrates were identified at the Evandro Chagas Institute (IEC) from 1954 to 1998, among more than 10,000 arbovirus strains isolated from humans, hematophagous insects, and wild and sentinel vertebrates. Despite intensive studies in the Brazilian Amazon region, especially in Pará State, very little is known about most of these viruses, except for information on date, time, source, and method of isolation, as well as their capacity to infect laboratory animals. This paper reviews ecological and epidemiological data and analyzes the impact of vector and host population changes on various viruses as a result of profound changes in the natural environment. Deforestation, mining, dam and highway construction, human colonization, and urbanization were the main manmade environmental changes associated with the emergence and/or reemergence of relevant arboviruses, including some known pathogens for humans.

Download Full-text