Severe COVID-19 and long COVID are associated with high expression of STING, cGAS and IFN-α.

The cGAS-STING pathway appears to contribute to dysregulated inflammation during coronavirus disease 2019 (COVID-19); however, inflammatory factors related to long COVID are still being investigated. In the present study, we evaluated the association of cGAS and STING gene expression levels and plasma IFN-α, TNF-α and IL-6 levels with COVID-19 severity in acute infection and long COVID, based on analysis of blood samples from 148 individuals, 87 with acute COVID-19 and 61 in the post-COVID-19 period. Quantification of gene expression was performed by real-time PCR, and cytokine levels were quantified by ELISA and flow cytometry. In acute COVID-19, cGAS, STING, IFN-α, TNF-α, and IL-6 levels were higher in patients with severe disease than in those with nonsevere manifestations (p < 0.05). Long COVID was associated with elevated cGAS, STING and IFN-α levels (p < 0.05). Activation of the cGAS-STING pathway may contribute to an intense systemic inflammatory state in severe COVID-19 and, after infection resolution, induce an autoinflammatory disease in some tissues, resulting in long COVID.

Betacoronavirus Infection Outbreak, São Paulo, Brazil, Fall 2023.

We report a human coronavirus OC43 infection outbreak in hospitalized patients and healthcare workers in São Paulo, Brazil, occurring after SARS-CoV-2 cases disappeared. Infection was associated with healthcare workers in 5 (29.4%) patients. Routine surveillance including a respiratory virus panel can improve coronavirus detection in both healthcare professionals and patients.

Comparative analysis of Respiratory Syncytial Virus frequency rates and viral load in different patient cohorts in a University Hospital in São Paulo, Brazil, over an eight-year period (2005-2013).

Respiratory Syncytial Virus (RSV) poses a global health concern, particularly affecting young children, the elderly, and immunosuppressed individuals. RSV viral load is essential for understanding transmission, disease severity, prevention, and treatment. This retrospective study aimed to analyze the frequency rates and viral loads of RSV infections in different patient cohorts and age groups over an eight-year period in a university hospital in São Paulo, Brazil. This study analyzed 1380 Immunocompetent (IC) and Immunosuppressed (IS) patients with acute respiratory tract infections. IC included patients with chronic Heart Disease (HD), Primary Care service recipients (PC), and a subgroup suspected of having Severe Acute Respiratory Syndrome caused by Influenza A (H1N1)pdm09 virus (SARS H1N1). IS comprised transplant patients and those with HIV infection. Respiratory samples were collected between February 2005 and October 2013, with RSV detection and viral load quantification (Log10 copies of RNA/mL) using RT-qPCR. Overall RSV infection rate was 17.3 %, with higher rates in children (23.9 %) than in adults (12.9 %), particularly in children under two years of age (28.2 %). Children in the SARS H1N1 and PC subgroups had higher infection rates (16.4 % and 34.9 %, respectively), with the highest rate in PC children aged 1 to < 2 years (45.45 %). Adults with HD had a significantly higher frequency rate (27.83 %) than those in the SARS H1N1 (2.65 %) and IS (15.16 %) subgroups and higher hospitalization rate among adults under 65 years. RSV viral load ranged from 2.43 to 10.15 Log10 RNA copies/mL (mean ± SD 5.82 ± 2.19), with hospitalized patients exhibiting significantly higher viral loads (7.34 ± 1.9) than outpatients (4.38 ± 1.89). Elderly bone marrow transplant patients also had significantly higher viral loads (7.57 ± 2.41) than younger adults (5.12 ± 1.87). This study provides insights into the RSV infection patterns in different patient cohorts in Brazil. Further investigations are needed to understand susceptibility and risk factors associated with RSV infection. In conclusion, high RSV viral load among hospitalized patients could serve as a surrogate marker of disease severity. Additionally, patients with chronic heart disease deserve greater attention regarding complications associated with RSV infection.

Polymorphisms in the MBL2 gene are associated with the plasma levels of MBL and the cytokines IL-6 and TNF-α in severe COVID-19.

Introduction: Mannose-binding lectin (MBL) promotes opsonization, favoring phagocytosis and activation of the complement system in response to different microorganisms, and may influence the synthesis of inflammatory cytokines. This study investigated the association of MBL2 gene polymorphisms with the plasma levels of MBL and inflammatory cytokines in COVID-19. Methods: Blood samples from 385 individuals (208 with acute COVID-19 and 117 post-COVID-19) were subjected to real-time PCR genotyping. Plasma measurements of MBL and cytokines were performed by enzyme-linked immunosorbent assay and flow cytometry, respectively. Results: The frequencies of the polymorphic MBL2 genotype (OO) and allele (O) were higher in patients with severe COVID-19 (p< 0.05). The polymorphic genotypes (AO and OO) were associated with lower MBL levels (p< 0.05). IL-6 and TNF-α were higher in patients with low MBL and severe COVID-19 (p< 0.05). No association of polymorphisms, MBL levels, or cytokine levels with long COVID was observed. Discussion: The results suggest that, besides MBL2 polymorphisms promoting a reduction in MBL levels and therefore in its function, they may also contribute to the development of a more intense inflammatory process responsible for the severity of COVID-19.

Antibody Response to the SARS-CoV-2 Spike and Nucleocapsid Proteins in Patients with Different COVID-19 Clinical Profiles.

The first case of coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), in Brazil was diagnosed on February 26, 2020. Due to the important epidemiological impact of COVID-19, the present study aimed to analyze the specificity of IgG antibody responses to the S1, S2 and N proteins of SARS-CoV-2 in different COVID-19 clinical profiles. This study enrolled 136 individuals who were diagnosed with or without COVID-19 based on clinical findings and laboratory results and classified as asymptomatic or as having mild, moderate or severe disease. Data collection was performed through a semistructured questionnaire to obtain demographic information and main clinical manifestations. IgG antibody responses to the S1 and S2 subunits of the spike (S) protein and the nucleocapsid (N) protein were evaluated using an enzyme-linked immunosorbent assay (ELISA) according to the manufacturer's instructions. The results showed that among the participants, 87.5% (119/136) exhibited IgG responses to the S1 subunit and 88.25% (120/136) to N. Conversely, only 14.44% of the subjects (21/136) displayed S2 subunit responses. When analyzing the IgG antibody response while considering the different proteins of the virus, patients with severe disease had significantly higher antibody responses to N and S1 than asymptomatic individuals (p ≤ 0.0001), whereas most of the participants had low antibody titers against the S2 subunit. In addition, individuals with long COVID-19 showed a greater IgG response profile than those with symptomatology of a short duration. Based on the results of this study, it is concluded that levels of IgG antibodies may be related to the clinical evolution of COVID-19, with high levels of IgG antibodies against S1 and N in severe cases and in individuals with long COVID-19.

Comparative analysis of Respiratory Syncytial Virus frequency rates and viral load in different patient cohorts in a University Hospital in São Paulo, Brazil, over an eight-year period (2005-2013)

Abstract Respiratory Syncytial Virus (RSV) poses a global health concern, particularly affecting young children, the elderly, and immunosuppressed individuals. RSV viral load is essential for understanding transmission, disease severity, prevention, and treatment. This retrospective study aimed to analyze the frequency rates and viral loads of RSV infections in different patient cohorts and age groups over an eight-year period in a university hospital in São Paulo, Brazil. This study analyzed 1380 Immunocompetent (IC) and Immunosuppressed (IS) patients with acute respiratory tract infections. IC included patients with chronic Heart Disease (HD), Primary Care service recipients (PC), and a subgroup suspected of having Severe Acute Respiratory Syndrome caused by Influenza A (H1N1)pdm09 virus (SARS H1N1). IS comprised transplant patients and those with HIV infection. Respiratory samples were collected between February 2005 and October 2013, with RSV detection and viral load quantification (Log10 copies of RNA/mL) using RT-qPCR. Overall RSV infection rate was 17.3 %, with higher rates in children (23.9 %) than in adults (12.9 %), particularly in children under two years of age (28.2 %). Children in the SARS H1N1 and PC subgroups had higher infection rates (16.4 % and 34.9 %, respectively), with the highest rate in PC children aged 1 to < 2 years (45.45 %). Adults with HD had a significantly higher frequency rate (27.83 %) than those in the SARS H1N1 (2.65 %) and IS (15.16 %) subgroups and higher hospitalization rate among adults under 65 years. RSV viral load ranged from 2.43 to 10.15 Log10 RNA copies/mL (mean ± SD 5.82 ± 2.19), with hospitalized patients exhibiting significantly higher viral loads (7.34 ± 1.9) than outpatients (4.38 ± 1.89). Elderly bone marrow transplant patients also had significantly higher viral loads (7.57 ± 2.41) than younger adults (5.12 ± 1.87). This study provides insights into the RSV infection patterns in different patient cohorts in Brazil. Further investigations are needed to understand susceptibility and risk factors associated with RSV infection. In conclusion, high RSV viral load among hospitalized patients could serve as a surrogate marker of disease severity. Additionally, patients with chronic heart disease deserve greater attention regarding complications associated with RSV infection.

Níveis séricos de vitamina D e alterações hepáticas em pacientes com malária na região Amazônica / Serum levels of vitamin d and hepatic changes in patients with malaria in the Amazon region / Niveles séricos de vitamina d y alteraciones hepáticas en pacientes con malaria en la Amazonia

Vários estudos sugerem a importância da vitamina D ­ 25(OH)D ­ na evolução clínica dos pacientes com malária. Entretanto, a prevalência de deficiência de 25(OH)D na população amazônica é pouco conhecida, havendo também poucos estudos com pacientes diagnosticados com malária. Assim, o objetivo deste estudo foi avaliar os níveis séricos de 25(OH)D em pacientes com malária e sua relação com dados epidemiológicos, parasitológico e provas de função hepática. Para tanto, foi realizado um estudo transversal analítico com um grupo de pacientes com malária e um grupo controle no município de Itaituba (PA), Brasil, no período de janeiro de 2018 a outubro de 2019. Elaborou-se um protocolo para avaliação dos dados sociodemográficos, parasitológicos e laboratoriais, adotando-se o nível de significância de 5%. A prevalência de deficiência de 25(OH)D foi observada nos pacientes com malária (28,5%) e no grupo controle (24,6%), sem diferença estatística; porém, entre os residentes no garimpo, os níveis séricos foram estatisticamente menores nos pacientes com malária. Os níveis séricos de transaminase glutâmico-pirúvica (TGP) apresentaram correlação inversa com os de 25(OH)D. As provas de função hepática foram significativamente maiores no grupo com malária. Dessa forma, este estudo evidenciou a deficiência de 25(OH)D em Itaituba. Alterações hepáticas pela infecção plasmodial podem ter contribuído para a correlação inversa observada entre os níveis de TGP e 25(OH)D.

Several studies suggest the importance of vitamin D ­ 25(OH)D ­ in the clinical evolution of patients with malaria. However, the prevalence of 25(OH)D deficiency in the Amazonian population is little known, and studies with patients diagnosed with malaria are scarce. Thus the objective of this study is to evaluate the serum levels of 25(OH)D in patients with malaria and its relationship with epidemiological and parasitological data and liver function tests. To that end, an analytical cross-sectional study was carried out with a group of patients with malaria and a control group in the municipality of Itaituba (PA), Brazil, from January 2018 to October 2019. A protocol was elaborated for the evaluation of sociodemographic, parasitological, and laboratory data, adopting a significance level of 5%. Results: The prevalence of 25(OH)D deficiency was observed in patients with malaria (28.5%) and in the control group (24.6%), with no statistical difference; however, among residents in the mining, serum levels were statistically lower in patients with malaria. The glutamic-pyruvic transaminase (GPT) serum levels showed an inverse correlation with 25(OH)D levels. Liver function tests were significantly higher in the malaria group. Thus, this study evidenced 25(OH)D deficiency in Itaituba. Hepatic changes due to plasmodial infection may have contributed to the inverse correlation observed between GPT and 25(OH)D levels.

Diversos estudios sugieren la importancia de la vitamina D ­[25(OH)D]­ en la evolución clínica de pacientes con malaria. Sin embargo, la prevalencia de la deficiencia de 25(OH)D en la población amazónica es poco conocida y existen pocos estudios en pacientes con malaria. Ante esto, el objetivo de este estudio fue evaluar los niveles séricos de 25(OH)D en pacientes con malaria y su relación con datos epidemiológicos, parasitológicos y pruebas de función hepática. Para ello, se realizó un estudio transversal analítico en el grupo de pacientes con malaria y en un grupo control en el municipio de Itaituba (PA), Brasil, de enero de 2018 a octubre de 2019. Se elaboró un protocolo para la evaluación de datos sociodemográficos, parasitológicos y de laboratorio, adoptando un nivel de significancia del 5%. La prevalencia de deficiencia de 25(OH)D se observó en pacientes con malaria (28,5%) y en el grupo control (24,6%), sin diferencia estadística; sin embargo, entre los residentes en la minería, los niveles séricos fueron estadísticamente inferiores en pacientes con malaria. Los niveles séricos de transaminasa glutámico pirúvica (TGP) mostraron una correlación inversa con los niveles de 25(OH)D. Las pruebas de función hepática fueron significativamente más altas en el grupo de malaria. De esta manera, se evidenció deficiencia de 25(OH)D en la población de Itaituba. Los cambios hepáticos debido a la infección plasmodial pueden haber contribuido a la correlación inversa observada entre los niveles de TGP y 25(OH)D.

Association between vitamin D serum levels and clinical, laboratory, and parasitological parameters in patients with malaria from an endemic area of the Amazon.

BACKGROUND: Some studies have suggested the importance of vitamin D [25(OH)D] in malaria clinical practice. The prevalence of 25(OH)D deficiency in the Amazon population is not well known, and there are few studies in patients with malaria. This study aimed to evaluate 25(OH)D serum levels in patients with malaria and determine their relationships with epidemiological, clinical, laboratory, and parasitemia data. METHODS: An analytical cross-sectional study of 123 patients with malaria and 122 individuals without malaria was performed in Itaituba, Pará, Brazil, from January 2018 to October 2019, by evaluating sociodemographic, clinical-epidemiological, parasitological, and laboratory data and adopting a 5% significance level. Parametric tests (Student's t-test), non-parametric tests (Mann-Whitney U), and Spearman's correlation ([rs], for non-parametric variables) were used according to the nature of the distribution of the variables. For the qualitative variables, Pearson's chi-square test, Fisher's exact test, and the G test were used. Spearman's correlation was used to compare the results of the 25(OH)D levels and blood counts performed among patients and the control group. RESULTS: Malaria patients residing in a mining area had 25(OH)D serum levels that were significantly lower than those in the control group residing in the mining area, though both were within normal levels. Red blood cell counts had an inverse correlation with parasitemia (Plasmodium falciparum), and platelet levels had an inverse correlation with parasitemia (Plasmodium vivax). 25(OH)D deficiency was evidenced in Itaituba, in the state of Pará, which is an endemic area of malaria in the Amazon region.

Analysis of malaria clinical-epidemiological predictors in individuals from Brazilian Amazon.

This research aims to determine whether the combination of epidemiological and clinical features can predict malaria. Diagnostic investigation detected 22.3% of individuals with Plasmodium vivax (P. vivax) malaria, with significant predominance of the male gender. The malaria triad (fever, chills and headache) had a more expressive frequency (81.1%) in individuals with positive thick blood than those with negative thick blood smear (65.1%), although there was no statistical significance. Among the variables analysed as predictive for positive thick blood smear, it was observed that personal history of travel to an endemic malaria area and past malaria infection (PMI) were significantly associated with malaria, even in multiple logistic regression. Fever had the higher sensitivity (94.6%) and past malaria history had the greater specificity (68.2%), with accuracy of 23.5% and 67.5%, respectively. In combined analysis, fever with chills had the highest sensitivity (91.9%), but low accuracy (38.5%). High specificity (91.5%) was found in the association of malaria triad, PMI and history of travel to endemic malaria area (which along with anorexia, was higher 94.6%), with good accuracy (80.7%), suggesting that the screening of patients for performing thick blood smear can be based on these data. The epidemiological features and the malaria triad (fever, chills and headache) can be predictors for identification of malaria patients, concurring to precocious diagnosis and immediate treatment of individuals with malaria.

Análise clínico-epidemiológica dos atendimentos em um centro de referência em imunobiológicos especiais na amazônia / Análisis clínico-epidemiológico de la atención en un centro de referencia em inmunobiológicos especiales em la amazonia / Clinical-epidemiological analysis of the care services at a special immunobiological reference center in the amazon

RESUMO Objetivo: descrever o perfil clínico-epidemiológico do atendimento no Centro de Referência em Imunobiológicos Especiais de Hospital na Amazônia. Método: descritivo de abordagem quantitativa e analisado por meio da estatística descritiva e inferencial. O Sistema de Informação do Centro de Referência para Imunobiológicos Especiais (antigo) e Sistema de Informação do Programa Nacional de Imunização (atual) foram as bases utilizadas, entre 2006 e 2016. Resultados: foram administradas 77.077 doses de imunobiológicos; 25,2% corresponderam à vacina influenza inativada; insuficiência renal crônica foi a principal indicação (19%). O sistema atual registrou 18.267 doses de imunobiológicos administrados entre os anos de 2014 a 2016; sendo 37,8% correspondente à vacina influenza inativada; não foram informadas 42,5% das indicações, sendo HIV/AIDS 18,2%. Infectologia foi a especialidade que mais encaminhou para vacinação (18,3%). Conclusão: a acurácia dos dados foi comprometida pela falta de completude nos sistemas de informação. Observou-se subutilização do serviço pela população local.

RESUMEN: Objetivo: describir el perfil clínico-epidemiológico de la atención brindada por el Centro de Referencia para Inmunobiológicos Especiales de un Hospital de la Amazonía. Método: descriptivo con enfoque cuantitativo y analizado mediante estadística descriptiva e inferencial. El Sistema de Información del Centro de Referencia para Inmunobiológicos Especiales (antiguo) y el Sistema de Información del Programa Nacional de Inmunización (actual) se utilizaron como base de datos entre 2006 y 2016. Resultados: se administraron 77,077 dosis de inmunobiológicos; el 25,2% correspondió a la vacuna inactivada contra la influenza; La insuficiencia renal crónica fue la indicación principal (19%). El sistema actual registró 18.267 dosis de inmunobiológicos administradas entre los años 2014 y 2016; siendo que el 37,8% correspondió a la vacuna inactivada contra la influenza; El 42,5% de las indicaciones no fueron informadas, y el porcentaje informado de VIH / SIDA fue de 18,2%. La especialidad que más derivaciones realizó para vacunación fue la de infectología (18,3%). Conclusión: la precisión de los datos se vio comprometida por la falta de integridad en los sistemas de información. Se observó la subutilización del servicio por la población local.

ABSTRACT Objective: to describe the clinical-epidemiological profile of the care service at the Reference Center for Special Immunobiologicals of Hospital in the Amazon. Method: a descriptive study, of a quantitative approach and analyzed by means of the descriptive and inferential statistics. The Information System of the Reference Center for Special Immunobiologicals (former) and the Information System of the National Immunization Program (current) were the databases used, between 2006 and 2016. Results: 77,077 doses of immunobiological vaccines were administered; 25.2% corresponded to the inactivated influenza vaccine; chronic renal failure was the main indication (19%). The current system recorded 18,267 doses of immunobiological vaccines administered between the years 2014 to 2016; 37.8% of which were inactivated influenza vaccines; 42.5% of the indications were not reported, with HIV/AIDS being 18.2%. Infectologia foi a especialidade que mais encaminhou para vacinação (18,3%). Conclusion: the data accuracy has been compromised by the incompleteness in the information systems. We observed underutilization of the service by the local population.

Pre-travel malaria chemoprophylaxis counselling in a public travel medicine clinic in São Paulo, Brazil.

BACKGROUND: Malaria is one of the most prevalent parasitic diseases in the world and represents a threat to travellers visiting endemic areas. Chemoprophylaxis is the prevention measure used in travel medicine, avoiding clinical manifestations and protecting against the development of severe disease and death. METHODS: Retrospective and descriptive analysis of malaria prevention data in travellers was recorded from a travel medicine clinic in São Paulo, Brazil, between January 2006 and December 2010. All the medical records of travellers, who had travelled to areas with risk of disease transmission, including Brazil, were analysed. Demographic characteristics of travellers, travel details and recommendations for preventing malaria were also seen. RESULTS: During the study period, 2836 pre-travel consultations were carried out on 2744 individuals (92 were consulted twice). The most common reasons for travelling were tourism and work. The most common destinations were Africa (24.5%), Europe (21.2%), Asia (16.6%) and locations within Brazil (14.9%). In general prophylaxis against malaria was recommended in 10.3% of all the consultations. African destinations vs Asian, Brazilian and other destinations and length of stay ≤30 days were independently associated with the higher odds of chemoprophylaxis recommendation after the logistic regression. CONCLUSION: The prophylaxis against malaria was recommended in 10.3% of the consultations. The authors believe that a coherent measure of malaria prevention in Brazil and for international travellers would be to recommend for all parts of the North Brazil, avoidance of mosquito bites and immediate consultation of a physician in case of fever during or after the journey is recommended.

Pre-travel malaria chemoprophylaxis counselling in a public travel medicine clinic in São Paulo, Brazil

BACKGROUND: Malaria is one of the most prevalent parasitic diseases in the world and represents a threat to travellers visiting endemic areas. Chemoprophylaxis is the prevention measure used in travel medicine, avoiding clinical manifestations and protecting against the development of severe disease and death. METHODS: Retrospective and descriptive analysis of malaria prevention data in travellers was recorded from a travel medicine clinic in São Paulo, Brazil, between January 2006 and December 2010. All the medical records of travellers, who had travelled to areas with risk of disease transmission, including Brazil, were analysed. Demographic characteristics of travellers, travel details and recommendations for preventing malaria were also seen. RESULTS: During the study period, 2836 pre-travel consultations were carried out on 2744 individuals (92 were consulted twice). The most common reasons for travelling were tourism and work. The most common destinations were Africa (24.5%), Europe (21.2%), Asia (16.6%) and locations within Brazil (14.9%). In general prophylaxis against malaria was recommended in 10.3% of all the consultations. African destinations vs Asian, Brazilian and other destinations and length of stay ≤30 days were independently associated with the higher odds of chemoprophylaxis recommendation after the logistic regression. CONCLUSION: The prophylaxis against malaria was recommended in 10.3% of the consultations. The authors believe that a coherent measure of malaria prevention in Brazil and for international travellers would be to recommend for all parts of the North Brazil, avoidance of mosquito bites and immediate consultation of a physician in case of fever during or after the journey is recommended

Basic sanitation, socioeconomic conditions, and degree of risk for the presence and maintenance of malaria in a low-transmission area in the Brazilian Amazon.

INTRODUCTION: This study aimed to evaluate basic sanitation and socioeconomic indicators, reported cases of malaria, and risk of contracting malaria in the Ananindeua municipality, State of Pará. METHODS: Data on basic sanitation and socioeconomic dimensions were taken from the Brazilian Institute of Geography and Statistics [ Instituto Brasileiro de Geografia e Estatística (IBGE)] 2010 census. Epidemiological malaria information was taken from the Epidemiological Malaria Surveillance Information System [ Sistema de Informação de Vigilância Epidemiológica de Malária (SIVEP/Malaria)], between 2003 and 2013 of the Ministry of Health and from the SIVEP/Malaria forms of the municipality's Endemic Diseases Unit for 2,013 cases. RESULTS: Our data do not confirm the correlation among indicators of basic sanitation, socioeconomic conditions, and water supply with malaria cases. Of the 1,557 cases evaluated, most were caused by Plasmodium vivax , with rare cases of Plasmodium falciparum and mixed infections. There were 756 notifications in 2003. The number of reported cases was sharply reduced between 2006 and 2012, but a 142-case outbreak occurred in 2013. Ananindeua municipality's Annual Parasite Index indicated low risk in 2003 and no risk in other years, and the 2,013 cases were predominantly male individuals aged ≥40 years. CONCLUSIONS: Our data confirm the non-endemicity of malaria in the Ananindeua municipality, as the Annual Parasite Indices described for the years 2004-2013 classify it as a risk-free area. However, the 2013 outbreak indicates the need to strengthen prevention, surveillance, and control activities to reduce the risk of new outbreaks and consequent economic and social impacts on the population.

Basic sanitation, socioeconomic conditions, and degree of risk for the presence and maintenance of malaria in a low-transmission area in the Brazilian Amazon

ABSTRACTINTRODUCTION:This study aimed to evaluate basic sanitation and socioeconomic indicators, reported cases of malaria, and risk of contracting malaria in the Ananindeua municipality, State of Pará.METHODS:Data on basic sanitation and socioeconomic dimensions were taken from the Brazilian Institute of Geography and Statistics [ Instituto Brasileiro de Geografia e Estatística (IBGE)] 2010 census. Epidemiological malaria information was taken from the Epidemiological Malaria Surveillance Information System [ Sistema de Informação de Vigilância Epidemiológica de Malária (SIVEP/Malaria)], between 2003 and 2013 of the Ministry of Health and from the SIVEP/Malaria forms of the municipality's Endemic Diseases Unit for 2,013 cases.RESULTS:Our data do not confirm the correlation among indicators of basic sanitation, socioeconomic conditions, and water supply with malaria cases. Of the 1,557 cases evaluated, most were caused by Plasmodium vivax , with rare cases of Plasmodium falciparum and mixed infections. There were 756 notifications in 2003. The number of reported cases was sharply reduced between 2006 and 2012, but a 142-case outbreak occurred in 2013. Ananindeua municipality's Annual Parasite Index indicated low risk in 2003 and no risk in other years, and the 2,013 cases were predominantly male individuals aged ≥40 years.CONCLUSIONS:Our data confirm the non-endemicity of malaria in the Ananindeua municipality, as the Annual Parasite Indices described for the years 2004-2013 classify it as a risk-free area. However, the 2013 outbreak indicates the need to strengthen prevention, surveillance, and control activities to reduce the risk of new outbreaks and consequent economic and social impacts on the population.