Spread of Gamma (P.1) Sub-Lineages Carrying Spike Mutations Close to the Furin Cleavage Site and Deletions in the N-Terminal Domain Drives Ongoing Transmission of SARS-CoV-2 in Amazonas, Brazil.

The Amazonas was one of the most heavily affected Brazilian states by the COVID-19 epidemic. Despite a large number of infected people, particularly during the second wave associated with the spread of the Variant of Concern (VOC) Gamma (lineage P.1), SARS-CoV-2 continues to circulate in the Amazonas.

Increased platelet distribution width and reduced IL-2 and IL-12 are associated with thrombocytopenia in Plasmodium vivax malaria.

Background: Thrombocytopenia in malaria involves platelet destruction and consumption; however, the cellular response underlying this phenomenon has still not been elucidated.

Objective: To find associations between platelet indices and unbalanced Th1/Th2/Th17 cytokines as a response to thrombocytopenia in Plasmodium vivax infected (Pv-MAL) patients.

Methods: Platelet counts and quantification of Th1/Th2/Th17 cytokine levels were compared in 77 patients with uncomplicated P.

Unusual clinical manifestations of dengue disease - Real or imagined?

The disease caused by each of the four serotypes of dengue virus (DENV) have plagued humans since last century. Symptoms of dengue virus (DENV) infection range from asymptomatic to dengue fever (DF) to severe dengue disease (SDD). One third of the world's population lives in regions with active urban DENV transmission, and thousands of serologically naïve travelers visit these areas annually, making a significant portion of the human population at risk of being infected.

Malaria impact on cognitive function of children in a peri-urban community in the Brazilian Amazon.

Background: In Latin America, where Plasmodium vivax malaria is more prevalent, it is known that this species plays an important role in the sustainability of transmission, and can have an impact on morbidity in terms of anaemia, nutritional status, and cognitive development in children.

Methods: The present study aimed to assess the impact of malaria infection on cognition of children in a peri-urban community in the Brazilian Amazon with moderate endemicity by applying Home Inventory and WPPSI-IV. A non-concurrent cohort study was designed and the cognitive, haematological, and nutritional profiles of the children were assessed.

Divergent cerebrospinal fluid cytokine network induced by non-viral and different viral infections on the central nervous system.

Background: Meningoencephalitis is one of the most common disorders of the central nervous system (CNS) worldwide. Viral meningoencephalitis differs from bacterial meningitis in several aspects. In some developing countries, bacterial meningitis has appropriate clinical management and chemotherapy is available.

Unravelling the patterns of host immune responses in Plasmodium vivax malaria and dengue co-infection.

Background: Concurrent malaria and dengue infection is frequently diagnosed in endemic countries, but its immunopathology remains largely unknown. In the present study, a large panel of cytokines/chemokines and clinical laboratory markers were measured in patients with Plasmodium vivax and dengue co-infection as well as in individuals with malaria or dengue mono-infections in order to identify biosignatures of each clinical condition.

Methods: Individuals from the Brazilian Amazon were recruited between 2009 and 2013 and classified in three groups: vivax malaria (n = 52), dengue (n = 30) and vivax malaria and dengue co-infection (n = 30).

Epidemiology of infectious meningitis in the State of Amazonas, Brazil.

Introduction: In the State of Amazonas, particularly in the capital Manaus, meningitis has affected populations of different cultures and social strata over the years. Bacterial meningitis is caused by several different species and represents a major issue of public health importance. The present study reports the meningitis case numbers with different etiologies in Amazonas from January 1976 to December 2012.

Arboviral diseases in the Western Brazilian Amazon: a perspective and analysis from a tertiary health & research center in Manaus, State of Amazonas.

The Fundação de Medicina Tropical Dr. Heitor Vieira Dourado (FMT-HVD), located in Manaus, the capital of the State of Amazonas (Western Brazilian Amazon), is a pioneering institution in this region regarding the syndromic surveillance of acute febrile illness, including arboviral infections. Based on the data from patients at the FMT-HVD, we have detected recurrent outbreaks in Manaus by the four dengue serotypes in the past 15 years, with increasing severity of the disease.

Malaria in the State of Amazonas: a typical Brazilian tropical disease influenced by waves of economic development.

In Brazil, more than 99% of malaria cases are reported in the Amazon, and the State of Amazonas accounts for 40% of this total. However, the accumulated experience and challenges in controlling malaria in this region in recent decades have not been reported. Throughout the first economic cycle during the rubber boom (1879 to 1912), malaria was recorded in the entire state, with the highest incidence in the villages near the Madeira River in the Southern part of the State of Amazonas.

Characterization of Plasmodium vivax-associated admissions to reference hospitals in Brazil and India.

Background: The benign character formerly attributed to Plasmodium vivax infection has been dismantled by the increasing number of reports of severe disease associated with infection with this parasite, prompting the need for more thorough and comprehensive characterization of the spectrum of resulting clinical complications. Endemic areas exhibit wide variations regarding severe disease frequency. This study, conducted simultaneously in Brazil and India, constitutes, to our knowledge, the first multisite study focused on clinical characterization of P.

P. vivax malaria and dengue fever co-infection: a cross-sectional study in the Brazilian Amazon.

Background: Malaria and dengue are the most prevalent vector-borne diseases worldwide and represent major public health problems. Both are endemic in tropical regions, propitiating co-infection. Only few co-infection cases have been reported around the world, with insufficient data so far to enhance the understanding of the effects of co-infection in the clinical presentation and severity.

Influence of age on the haemoglobin concentration of malaria-infected patients in a reference centre in the Brazilian Amazon.

Anaemia is amongst the major complications of malaria, a major public health problem in the Amazon Region in Latin America. We examined the haemoglobin (Hb) concentrations of malaria-infected patients and compared it to that of malaria-negative febrile patients and afebrile controls. The haematological parameters of febrile patients who had a thick-blood-smear performed at an infectious diseases reference centre of the Brazilian Amazon between December 2009-January 2012 were retrieved together with clinical data.

Clinical and virological descriptive study in the 2011 outbreak of dengue in the Amazonas, Brazil.

Background: Dengue is a vector-borne disease in the tropical and subtropical region of the world and is transmitted by the mosquito Aedes aegypti. In the state of Amazonas, Brazil during the 2011 outbreak of dengue all the four Dengue virus (DENV) serotypes circulating simultaneously were observed. The aim of the study was to describe the clinical epidemiology of dengue in Manaus, the capital city of the state of the Amazonas, where all the four DENV serotypes were co-circulating simultaneously.

Detection of Herpesvirus, Enterovirus, and Arbovirus infection in patients with suspected central nervous system viral infection in the Western Brazilian Amazon.

Acute infections of the central nervous system (CNS) can be caused by various pathogens. In this study, the presence of herpesviruses (HHV), enteroviruses (EVs), and arboviruses were investigated in CSF samples from 165 patients with suspected CNS viral infection through polymerase chain reaction (PCR) and reverse transcriptase PCR. The genomes of one or more viral agents were detected in 29.

Evaluation of the WHO classification of dengue disease severity during an epidemic in 2011 in the state of Ceará, Brazil.

In 2009, the World Health Organization (WHO) issued a new guideline that stratifies dengue-affected patients into severe (SD) and non-severe dengue (NSD) (with or without warning signs). To evaluate the new recommendations, we completed a retrospective cross-sectional study of the dengue haemorrhagic fever (DHF) cases reported during an outbreak in 2011 in northeastern Brazil. We investigated 84 suspected DHF patients, including 45 (53.

Identification of dengue viruses in naturally infected Aedes aegypti females captured with BioGents (BG)-Sentinel traps in Manaus, Amazonas, Brazil.

Introduction: In Manaus, the first autochthonous cases of dengue fever were registered in 1998. Since then, dengue cases were diagnosed by the isolation of viruses 1, 2, 3, and 4.

Methods: One hundred eighty-seven mosquitoes were collected with BioGents (BG)-Sentinel traps in 15 urban residential areas in the Northern Zone of Manaus and processed by molecular tests.

Clinical profile of concurrent dengue fever and Plasmodium vivax malaria in the Brazilian Amazon: case series of 11 hospitalized patients.

Malaria and dengue fever are the most prevalent vector-borne diseases worldwide. This study aims to describe the clinical profile of patients with molecular diagnosis of concurrent malaria and dengue fever in a tropical-endemic area. Eleven patients with concurrent dengue virus (DENV) and Plasmodium vivax infection are reported.

Postmortem characterization of patients with clinical diagnosis of Plasmodium vivax malaria: to what extent does this parasite kill?

Background: Severe disease attributable to Plasmodium vivax infection is already well described worldwide; however, autopsies in these patients are scarce.

Methods: From 1996 to 2010, 19 patient deaths with a clinical diagnosis of P. vivax infection occurred in a tertiary care center in the Brazilian Amazon.

Simultaneous circulation of all four dengue serotypes in Manaus, State of Amazonas, Brazil in 2011.

Introduction: Manaus, the capital city of the state of Amazon with nearly 2 million inhabitants, is located in the middle of the Amazon rain forest and has suffered dengue outbreaks since 1998.

Methods: In this study, blood samples were investigated using reverse transcriptase-polymerase chain reaction (RT-PCR), aimed at identifying dengue virus serotypes.

Results: Acute phase sera from 432 patients were tested for the presence of dengue virus.

Identification of Oropouche Orthobunyavirus in the cerebrospinal fluid of three patients in the Amazonas, Brazil.

Oropouche fever is the second most frequent arboviral infection in Brazil, surpassed only by dengue. Oropouche virus (OROV) causes large and explosive outbreaks of acute febrile illness in cities and villages in the Amazon and Central-Plateau regions. Cerebrospinal fluid (CSF) samples from 110 meningoencephalitis patients were analyzed.

Serological evidence of hantavirus infection in rural and urban regions in the state of Amazonas, Brazil.

Hantavirus disease is caused by the hantavirus, which is an RNA virus belonging to the family Bunyaviridae. Hantavirus disease is an anthropozoonotic infection transmitted through the inhalation of aerosols from the excreta of hantavirus-infected rodents. In the county of Itacoatiara in the state of Amazonas (AM), Brazil, the first human cases of hantavirus pulmonary and cardiovascular syndrome were described in July 2004.

Understanding the clinical spectrum of complicated Plasmodium vivax malaria: a systematic review on the contributions of the Brazilian literature.

The resurgence of the malaria eradication agenda and the increasing number of severe manifestation reports has contributed to a renewed interested in the Plasmodium vivax infection. It is the most geographically widespread parasite causing human malaria, with around 2.85 billion people living under risk of infection.

Co-infection of Dengue virus by serotypes 3 and 4 in patients from Amazonas, Brazil.

The natural co-infection with dengue virus can occur in highly endemic areas where different serotypes have been observed for many years. We report here four cases of DENV-3/DENV-4 co-infection detected by serological and molecular tests among 674 patients with acute undifferentiated fever from the tropical medicine reference center of Manaus City, Brazil, between 2005 and 2010. Analysis of the sequences obtained indicated the presence of genotype 3 and 1 for DENV-3 and DENV-4 respectively.