Aspartate aminotransferase-to-platelet ratio index (APRI): A potential marker for diagnosis in patients at risk of severe malaria caused by Plasmodium vivax.

Acute infection with Plasmodium vivax, classically associated with benign disease, has been presenting as serious and even fatal disease in recent years. Severe disease is mainly due to biochemical and hematological alterations during the acute phase of infection. In the present cross-sectional study, the aspartate aminotransferase-to-platelet ratio index (APRI) was evaluated as a method for identifying patients at risk of severe vivax malaria. This retrospective study included 130 patients with confirmed P. vivax infection between June 2006 and January 2018. Clinical-epidemiological data were obtained from medical records. Hematological and biochemical parameters were determined using automated equipment. The criteria of severity for infection by Plasmodium falciparum, established by the World Health Organization (WHO), were adapted to classify patients with danger signs of severe vivax malaria. Of the 130 patient's records evaluated, 19 (14.6%) had one or more signs and symptoms of severe malaria. The mean APRI values among patients with and without severe malaria were 2.11 and 1.09, respectively (p = 0.044). Among those with severe disease, the proportion with an APRI value above 1.50 was 30% compared to the 10% among those without severe disease (p = 0.007). The area under the receiver operating characteristic curve (95% CI), calculated to assess the accuracy of the APRI in discriminating between patients with and without severe disease, was 0.645 (0.494; 0.795). An APRI cutoff of 0.74 resulted in sensitivity of 74.0%, specificity of 56.0%, and accuracy of 65.0%. This study shows that the APRI is elevated in patients with evidence of infection by P. vivax. Based on the good sensitivity found in this study, we conclude that this simple index can serve as a diagnostic biomarker to identify patients at risk of severe disease during the acute phase of P. vivax infection

Submicroscopic malaria parasite carriage: how reproducible are polymerase chain reaction-based methods?

Submitted by Nuzia Santos ([email protected]) on 2015-02-02T11:09:58Z No. of bitstreams: 1 2014_013.pdf: 612202 bytes, checksum: 0b0dfc01b7f9ecdf1fd8f04eac043720 (MD5)Approved for entry into archive by Nuzia Santos ([email protected]) on 2015-02-02T11:10:06Z (GMT) No. of bitstreams: 1 2014_013.pdf: 612202 bytes, checksum: 0b0dfc01b7f9ecdf1fd8f04eac043720 (MD5)Approved for entry into archive by Nuzia Santos ([email protected]) on 2015-02-02T11:15:52Z (GMT) No. of bitstreams: 1 2014_013.pdf: 612202 bytes, checksum: 0b0dfc01b7f9ecdf1fd8f04eac043720 (MD5)Made available in DSpace on 2015-02-02T11:15:52Z (GMT). No. of bitstreams: 1 2014_013.pdf: 612202 bytes, checksum: 0b0dfc01b7f9ecdf1fd8f04eac043720 (MD5) Previous issue date: 2014Fundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Belo Horizonte, MG, BrasilUniversidade Federal de São João Del Rei. Departamento de Bioengenharia. São João Del Rey, MG, BrasilFundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Belo Horizonte, MG, BrasilUniversidade Federal de Mato Grosso. Cuiabá, MT, BrasilUniversidade Federal de Mato Grosso. Cuiabá, MT, BrasilUniversidade Federal de Mato Grosso. Cuiabá, MT, BrasilCentro de Controle de Zoonoses de Uberlândia. Uberlândia, MG, BrasilFundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Belo Horizonte, MG, BrasilFundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Belo Horizonte, MG, BrasilThe polymerase chain reaction (PCR)-based methods for the diagnosis of malaria infection are expected to accurately identify submicroscopic parasite carriers. Although a significant number of PCR protocols have been described, few studies have addressed the performance of PCR amplification in cases of field samples with submicroscopic malaria infection. Here, the reproducibility of two well-established PCR protocols (nested-PCR and real-time PCR for the Plasmodium 18 small subunit rRNA gene) were evaluated in a panel of 34 blood field samples from individuals that are potential reservoirs of malaria infection, but were negative for malaria by optical microscopy. Regardless of the PCR protocol, a large variation between the PCR replicates was observed, leading to alternating positive and negative results in 38% (13 out of 34) of the samples. These findings were quite different from those obtained from the microscopy-positive patients or the unexposed individuals; the diagnosis of these individuals could be confirmed based on the high reproducibility and specificity of the PCR-based protocols. The limitation of PCR amplification was restricted to the field samples with very low levels of parasitaemia because titrations of the DNA templates were able to detect < 3 parasites/µL in the blood. In conclusion, conventional PCR protocols require careful interpretation in cases of submicroscopic malaria infection, as inconsistent and false-negative results can occur

Submicroscopic malaria parasite carriage: how reproducible are polymerase chain reaction-based methods?

The polymerase chain reaction (PCR)-based methods for the diagnosis of malaria infection are expected to accurately identify submicroscopic parasite carriers. Although a significant number of PCR protocols have been described, few studies have addressed the performance of PCR amplification in cases of field samples with submicroscopic malaria infection. Here, the reproducibility of two well-established PCR protocols (nested-PCR and real-time PCR for the Plasmodium 18 small subunit rRNA gene) were evaluated in a panel of 34 blood field samples from individuals that are potential reservoirs of malaria infection, but were negative for malaria by optical microscopy. Regardless of the PCR protocol, a large variation between the PCR replicates was observed, leading to alternating positive and negative results in 38% (13 out of 34) of the samples. These findings were quite different from those obtained from the microscopy-positive patients or the unexposed individuals; the diagnosis of these individuals could be confirmed based on the high reproducibility and specificity of the PCR-based protocols. The limitation of PCR amplification was restricted to the field samples with very low levels of parasitaemia because titrations of the DNA templates were able to detect < 3 parasites/µL in the blood. In conclusion, conventional PCR protocols require careful interpretation in cases of submicroscopic malaria infection, as inconsistent and false-negative results can occur

Susceptibility to Plasmodium vivax malaria associated with DARC (Duffy antigen) polymorphisms is influenced by the time of exposure to malaria

Submitted by Nuzia Santos ([email protected]) on 2019-06-24T16:13:41Z No. of bitstreams: 1 Susceptibility to Plasmodium vivax malaria.pdf: 1166943 bytes, checksum: 8c68739c4ccbf3121183fed31318881b (MD5)Approved for entry into archive by Nuzia Santos ([email protected]) on 2019-06-24T16:24:09Z (GMT) No. of bitstreams: 1 Susceptibility to Plasmodium vivax malaria.pdf: 1166943 bytes, checksum: 8c68739c4ccbf3121183fed31318881b (MD5)Made available in DSpace on 2019-06-24T16:24:09Z (GMT). No. of bitstreams: 1 Susceptibility to Plasmodium vivax malaria.pdf: 1166943 bytes, checksum: 8c68739c4ccbf3121183fed31318881b (MD5) Previous issue date: 2018Fundação Oswaldo Cruz. Instituto Rene Rachou. Biologia Molecular e Imunologia da Malária. Belo Horizonte, MG, Brasil.Fundação Oswaldo Cruz. Instituto Rene Rachou. Biologia Molecular e Imunologia da Malária. Belo Horizonte, MG, Brasil.Fundação Oswaldo Cruz. Instituto Rene Rachou. Biologia Molecular e Imunologia da Malária. Belo Horizonte, MG, Brasil.Universidade Federal de Minas Gerais. Departamento de Engenharia de Produção. Belo Horizonte, MG, Brasil.Fundação Oswaldo Cruz. Instituto Rene Rachou. Biologia Molecular e Imunologia da Malária. Belo Horizonte, MG, Brasil.Universidade Federal de Mato Grosso. Cuiabá, MT, Brasil.Universidade Federal de Mato Grosso. Hospital Julio Muller. Cuiabá, MT, Brazil.Universidade de São Paulo. Faculdade de Ciências Farmacêuticas. Departamento de Análises Clínicas e Toxicológicas. São Paulo, SP, Brazil.Fundação Oswaldo Cruz. Instituto Rene Rachou. Biologia Molecular e Imunologia da Malária. Belo Horizonte, MG, Brasil.Fundação Oswaldo Cruz. Instituto Rene Rachou. Biologia Molecular e Imunologia da Malária. Belo Horizonte, MG, Brasil.Fundação Oswaldo Cruz. Instituto Rene Rachou. Biologia Molecular e Imunologia da Malária. Belo Horizonte, MG, Brasil.Malaria has provided a major selective pressure and has modulated the genetic diversity of the human genome. The variants of the Duffy Antigen/Receptor for Chemokines (DARC) gene have probably been selected by malaria parasites, particularly the FY*O allele, which is fixed in sub-Saharan Africa and confers resistance to Plasmodium vivax infection. Here, we showed the influence of genomic ancestry on the distribution of DARC genotypes in a highly admixed Brazilian population and confirmed the decreased susceptibility of the FY*A/FY*O genotype to clinical P. vivax malaria. FY*B/FY*O individuals were associated with a greater risk of developing clinical malaria. A remarkable difference among DARC variants concerning the susceptibility to clinical malaria was more evident for individuals who were less exposed to malaria, as measured by the time of residence in the endemic area. Additionally, we found that DARC-negative and FY*A/FY*O individuals had a greater chance of acquiring high levels of antibodies against the 19-kDa C-terminal region of the P. vivax merozoite surface protein-1. Altogether, our results provide evidence that DARC polymorphisms modulate the susceptibility to clinical P. vivax malaria and influence the naturally-acquired humoral immune response to malaria blood antigens, which may interfere with the efficacy of a future vaccine against malaria

Evaluation of a quality improvement intervention to reduce anastomotic leak following right colectomy (EAGLE): pragmatic, batched stepped-wedge, cluster-randomized trial in 64 countries

Background Anastomotic leak affects 8 per cent of patients after right colectomy with a 10-fold increased risk of postoperative death. The EAGLE study aimed to develop and test whether an international, standardized quality improvement intervention could reduce anastomotic leaks. Methods The internationally intended protocol, iteratively co-developed by a multistage Delphi process, comprised an online educational module introducing risk stratification, an intraoperative checklist, and harmonized surgical techniques. Clusters (hospital teams) were randomized to one of three arms with varied sequences of intervention/data collection by a derived stepped-wedge batch design (at least 18 hospital teams per batch). Patients were blinded to the study allocation. Low- and middle-income country enrolment was encouraged. The primary outcome (assessed by intention to treat) was anastomotic leak rate, and subgroup analyses by module completion (at least 80 per cent of surgeons, high engagement; less than 50 per cent, low engagement) were preplanned. Results A total 355 hospital teams registered, with 332 from 64 countries (39.2 per cent low and middle income) included in the final analysis. The online modules were completed by half of the surgeons (2143 of 4411). The primary analysis included 3039 of the 3268 patients recruited (206 patients had no anastomosis and 23 were lost to follow-up), with anastomotic leaks arising before and after the intervention in 10.1 and 9.6 per cent respectively (adjusted OR 0.87, 95 per cent c.i. 0.59 to 1.30; P = 0.498). The proportion of surgeons completing the educational modules was an influence: the leak rate decreased from 12.2 per cent (61 of 500) before intervention to 5.1 per cent (24 of 473) after intervention in high-engagement centres (adjusted OR 0.36, 0.20 to 0.64; P &lt; 0.001), but this was not observed in low-engagement hospitals (8.3 per cent (59 of 714) and 13.8 per cent (61 of 443) respectively; adjusted OR 2.09, 1.31 to 3.31). Conclusion Completion of globally available digital training by engaged teams can alter anastomotic leak rates. Registration number: NCT04270721 (http://www.clinicaltrials.gov)