Alterations in angiogenic proteins play a role in newborn growth potential, and they have been widely studied, but not further explored in malaria research. We aimed to identify maternal peripheral proteins that are associated with newborn growth parameters in the context of malaria in pregnancy. We analysed data and biological samples collected from 386 pregnant women with and without malaria selected from previous cohort study in the Amazon region, Brazil, between 2013 and 2015. ELISAs were used to quantify Ang-1, Ang-2, Tie2, VEGF, sFlt1, VEGFR2, PlGF, sENG, and leptin in peripheral plasma at time of delivery. We generated receiver operating characteristic curves and multivariable logistic regression models to assess the associations of maternal peripheral protein levels with the anthropometric profiles of newborns. Tie2, sFlt1, sENG and leptin were associated to growth parameters in newborns of mothers who had malaria during pregnancy. sFlt1 levels were associated with newborn weight and length, and sENG was associated with newborn length in Plasmodium vivax-infected women. Tie2, sFlt1 and leptin levels were associated with newborn length in Plasmodium falciparum-infected women. Identifying maternal peripheral proteins associated with newborn outcomes might help in understanding biological dynamics of malaria in pregnancy in areas of low transmission, improving future health interventions, and encourage further studies with angiogenic proteins.

Abstract Background B-lines by lung ultrasound (LUS) are associated with left ventricular (LV) dysfunction and may be useful for diagnostics in resource-limited settings. Purpose To assess the incidence of LV dysfunction in the general population of the Amazon Basin and to evaluate the diagnostic potential of LUS. We defined LV dysfunction as LV ejection fraction <45% and LUS was assessed across eight chest zones. B-lines were calculated as the sum of all zones. Methods and results We conducted echocardiography and LUS in 514 individuals from a population sample in the Amazon Basin (mean age 41 years, 40% men). No patients had known heart failure, renal insufficiency or lung disease. A total of 14 individuals (3%) had LV dysfunction, corresponding to an incidence of 27.2 per 1,000 individuals. The mean number of B-lines in the general population was 0.2 (range 0 to 17 B-lines). Individuals with LV dysfunction presented with a significantly higher number of B-lines (P=0.006) and more frequently had >=3 B-lines (8% vs 2%, P=0.018) compared to those with normal LV function. Identification of >=3 B-lines yielded a sensitivity of 58% and specificity of 93% (AUC 0.72, negative predictive value 99%, positive predictive value 19%) for detecting LV dysfunction. Per 1 unit increase in B-lines, LV ejection fraction decreased by 9% (95%CI: -15% to -3%, P=0.010) and the relationship persisted to be significant after adjusting for age, sex, body mass index, heart rate and creatinine (-8%, 95%CI: -15% to -2%, P=0.016). Conclusion The incidence of LV dysfunction in the Amazon Basin was 27.2/1,000 individuals and B-lines by LUS was able to detect LV dysfunction with reasonable diagnostic accuracy. Moreover, a higher number of B-lines was associated with decreasing LV ejection fraction. Our findings indicate that LUS may supplement conventional cardiac diagnostics for assessing LV function, especially in rural environments with restricted access to imaging tools.B-lines and LV ejection fraction

Background Plasmodium vivax infection, when it occurs during pregnancy, has often been associated with serious adverse pregnancy outcomes. However, immunological alterations in pregnancy and their consequences have been little explored. We characterized the humoral immune response in pregnant women exposed to malaria by P. vivax antigens and its association with the maternal inflammatory profile and poor pregnancy outcomes. Methods An observational cohort study in the Brazilian Amazon was conducted between 2013 and 2015. After applying exclusion criteria, 242 mother-child pairs were included in the analysis. Data on maternal infection, gestational outcomes, and inflammatory factors were evaluated in the maternal peripheral plasma. In samples from the first infection, the presence of total IgG and its subclasses in plasma against PvMSP119 protein were also quantified. Results Previous exposure to malaria, observed by anti-total IgG antibodies to the PvMSP119 antigen, increased the inflammatory response to infection when the pregnant woman had malaria during pregnancy. IL-6 and IL-10 levels were positively correlated with parasitemia and with total IgG levels; but they were negatively correlated with the gestational age at delivery from Pv-infected woman. In multivariate linear regression analyses, IgG 1, 2 and 4 was negatively and positively associated with cytokines IL-6 and IL-10, respectively, in P. vivax-infection. Conclusions An association between the humoral immune response and the peripheral inflammatory cytokine profile with the adverse outcomes in malaria in pregnancy by P. vivax was observed. Previous exposure to the parasite can influence the IL-6 and IL-10 response, which is associated with increased parasitemia, reduced maternal weight gain and premature delivery.

We hypothesized that adults with uncomplicated malaria have lower left ventricular contractile function compared to the general population and that this improves after antimalarial treatment. We examined uncomplicated malaria and the general population from the Western part of the Brazilian Amazon Basin. All persons underwent an echocardiographic examination and peripheral blood smears. Left ventricular function was assessed by speckle tracking analysis of global longitudinal strain (GLS). Logistic regression models were used to assess the association between malaria status (yes/no) and GLS and improvement in GLS by follow-up was assessed using a paired T-test. We enrolled 99 adults with uncomplicated malaria (mean age 40 years, 46% female) of whom 75 had Plasmodium vivax , 22 Plasmodium falciparum and two had both species [median 1595 (528 to 6585) parasites/mm 3 ]. Seventy adults completed a follow-up examination after standard malaria treatment (median 31 days). We examined 486 from the general population (mean age 41 years, 63% female). In persons with malaria at baseline, GLS was lower compared to the general population (18.7% vs. 19.4%, P = 0.002) and GLS improved at follow-up (19.2%, P = 0.032). In multivariable models adjusted for clinical, socioeconomic and echocardiographic confounders, baseline GLS remained significantly associated with malaria status [odds ratio 2.45 (95%CI 1.00 to 7.25), P = 0.023 per 1% increase]. Parasite density was associated with worsening in GLS [+ 16% (+ 0% to + 34%), P = 0.047 per 1 unit increase in GLS]. Adults with uncomplicated malaria had lower GLS compared to the general population and this improved after completed antimalarial treatment. Our results suggest that malaria infection may affect left ventricular contractile function, however, further studies are needed to fully elucidate such a relationship.

Objective Prior studies have suggested that self-rated health may be a useful indicator of cardiovascular disease. Consequently, we aimed to assess the relationship between self-rated health, cardiovascular risk factors and subclinical cardiac disease in the Amazon Basin. Design Cross-sectional study. Setting, participants and interventions In participants from the Amazon Basin of Brazil we obtained self-rated health according to a Visual Analogue Scale, ranging from 0 (poor) to 100 (excellent). We performed questionnaires, physical examination and echocardiography. Logistic and linear regression models were applied to assess self-rated health, cardiac risk factors and cardiac disease by echocardiography. Multivariable models were mutually adjusted for other cardiovascular risk factors, clinical and socioeconomic data, and known cardiac disease. Outcome measures Cardiovascular risk factors and subclincial cardiac disease by echocardiography. Results A total of 574 participants (mean age 41 years, 61% female) provided information on self-rated health (mean 75±21 (IQR 60–90) points). Self-rated health (per 10-point increase) was negatively associated with hypertension (OR 0.87 (95% CI 0.78 to 0.97), p=0.01), hypercholesterolaemia (OR 0.89 (95%CI 0.80 to 0.99), p=0.04) and positively with healthy diet (OR 1.13 (95%CI 1.04 to 1.24), p=0.004). Sex modified these associations (p-interaction <0.05) such that higher self-rated health was associated with healthy diet and physical activity in men, and lower odds of hypertension and hypercholesterolaemia in women. No relationship was found with left ventricular ejection fraction <45% (OR 0.97 (95% CI 0.77 to 1.23), p=0.8), left ventricular hypertrophy (OR 0.97 (95% CI 0.76 to 1.24), p=0.81) or diastolic dysfunction (OR 1.09 (95% CI 0.85 to 1.40), p=0.51). Conclusion Self-rated health was positively associated with health parameters in the Amazon Basin, but not with subclinical cardiac disease by echocardiography. Our findings are of hypothesis generating nature and future studies should aim to determine whether assessment of self-rated health may be useful for screening related to policy-making or lifestyle interventions. Trial registration number Clinicaltrials.gov: NCT04445103; Post-results

Background:Malaria in pregnancy (MiP) is a public health problem in the Brazilian Amazon region that requires special attention due to associated serious adverse consequences, such as low birth weight, increased prematurity and spontaneous abortion rates. In Brazil, there have been no comprehensive epidemiological studies of MiP. In this study, we aimed to explore the spatial and spatiotemporal patterns of MiP in Brazil and epidemiologically characterize this population of pregnant women over a period of 15 years. Methods:We performed a national-scale ecological analysis using a Bayesian space-time hierarchical model to estimate the incidence rates of MiP between 1 January 2004 and 31 December 2018. We mapped the high-incidence clusters among pregnant women aged 10-49 years old using a Poisson model, and we characterized the population based on data from the Epidemiological Surveillance Information System for Malaria (SIVEP-Malaria). Findings:We consolidated the data of 61,833 women with MiP in Brazil. Our results showed a reduction of 50·1% (95% CI: 47·3 to 52·9) in the number of malaria cases over the period analysed, with Plasmodium vivax malaria having the highest incidence. MiP was widely distributed throughout the Amazon region, and spatial and spatiotemporal analyses revealed statistically significant clusters in some municipalities of Amazonas, Acre, Rondônia and Pará. In addition, we observed that younger pregnant women had a higher risk of infection, and the administration of appropriate treatment requires more attention. Interpretation:This nationwide study provides robust evidence that, despite the reduction in the number of MiP cases in the country, it remains a serious public health problem, especially for young pregnant women. Our analyses highlight focus areas for strengthening interventions to control and eliminate MiP. Funding:FAPESP and CNPq - Brazil.

Background: Rheumatic heart disease (RHD) continues to be a burden in low- and middle-income countries and prevalence estimates are lacking from South America. We aimed to determine the prevalence of RHD in the Brazilian Amazon Basin. Methods: We examined a random sample of adults (>= 18 years) from the general population, who underwent echocardiographic image acquisition by a medical doctor. All images were analyzed according to (i) the 2012 World Heart Federation criteria and (ii) a simplified algorithm for RHD from a previously validated risk score (categories: low-, medium-, high-risk) which involved assessment of the mitral valve (leaflet thickening and excessive motion, regurgitation jet length) and aortic valve (thickening and any regurgitation).Results: A total of 488 adults were screened (mean age 40 +/- 15 years, 38% men). The prevalence of RHD was 39/ 1000 adults (n = 17 definite and n = 2 borderline). Fourteen (74%) had pathological mitral regurgitation, four (21%) mitral stenosis, 0 (0%) pathological aortic regurgitation and six (32%) both mitral and aortic valve disease. None had a prior diagnosis of RHD, 10 (53%) had positive cardiac auscultation and two (11%) reported a history of rheumatic fever. The simplified algorithm identified four (21%) adults as low-risk, six (32%) as intermediate, and nine (47%) as high-risk. Conclusions: The prevalence of RHD was 39/1000 in adults from the Brazilian Amazon Basin, indicating the need for screening programs in remote areas. A simplified model was only able to categorize every second case of RHD as high-risk. External validation of simplified screening models to increase feasibility in clinical practice are encouraged.

ABSTRACT. Malaria patients are at risk of cardiopulmonary complications but diagnosis and management can be difficult in resource-limited settings. B-lines on lung ultrasound (LUS) mark changes in lung density; however, little is known about their role in malaria. We aimed to examine the prevalence of B-lines in adults with malaria at baseline and follow-up compared with controls in the Amazon Basin. We also examined the relationship between B-lines and left ventricular ejection fraction. We performed eight-zone LUS, echocardiography, and blood smears in 94 adults (mean age 40 years, 54% men) with uncomplicated malaria and 449 controls without heart failure, renal insufficiency or lung disease (mean age 41 years, 38% men). Examinations of adults with malaria were repeated after antimalarial treatment, corresponding to a median of 30 days (interquartile range [IQR] 27–39). Adults with malaria suffered from Plasmodium vivax (N = 70, median 2,823 [IQR 598–7,698] parasites/μL) or P. falciparum (N = 24, median 1,148 [IQR 480–3,128] parasites/μL). At baseline, adults with malaria more frequently had ≥ 3 B-lines (summed across eight zones) compared with controls (30% versus 2%, P value < 0.001), indicating higher lung density. When examinations were repeated, only 6% of adults with malaria had ≥ 3 B-lines at follow-up, which was significant lower compared with baseline (median reduction 3 B-lines; P value < 0.001). B-lines were not significantly associated with left ventricular ejection fraction in adults with malaria. In conclusion, B-lines detected by LUS were more frequent in adults with uncomplicated malaria compared with controls and decreased after completed antimalarial treatment.

BACKGROUND:Dengue virus can affect the cardiovascular system and men may be at higher risk of severe complications than women. We hypothesized that clinical dengue virus (DENV) infection could induce myocardial alterations of the left ventricle (LV) and that these changes could be detected by transthoracic echocardiography. METHODOLOGY/PRINCIPAL FINDINGS:We examined individuals from Acre in the Amazon Basin of Brazil in 2020 as part of the Malaria Heart Study. By questionnaires we collected information on self-reported prior dengue infection. All individuals underwent transthoracic echocardiography, analysis of left ventricular ejection fraction (LVEF) and global longitudinal strain (GLS). We included 521 persons (mean age 40±15 years, 39% men, 50% urban areas) of which 253 (49%) had a history of dengue infection. In multivariable models adjusted for clinical and sociodemographic data, a history of self-reported dengue was significantly associated with lower LVEF (β = -2.37, P < 0.01) and lower GLS (β = 1.08, P < 0.01) in men, whereas no significant associations were found in women (P > 0.05). In line with these findings, men with a history of dengue had higher rates of LV systolic dysfunction (LVEF < 50% = 20%; GLS < 16% = 17%) than those without a history of dengue (LVEF < 50% = 7%; GLS < 16% = 8%; P < 0.01 and 0.06, respectively). CONCLUSIONS/SIGNIFICANCE:The findings of this study suggest that a clinical infection by dengue virus could induce myocardial alterations, mainly in men and in the LV, which could be detected by conventional transthoracic echocardiography. Hence, these results highlight a potential role of echocardiography for screening LV dysfunction in participants with a history of dengue infection. Further larger studies are warranted to validate the findings of this study.

Background Information on cardiopulmonary complications in clinical malaria is sparse and diagnosis may be difficult in resource-limited areas due to lack of proper diagnostic tools and access to medical care. A case of pericardial effusion and pulmonary alterations assessed by ultrasound in a patient with uncomplicated mixed malaria infection is described. Case presentation A previously healthy 23-year-old male from the Amazon Basin was diagnosed with mixed infection of Plasmodium vivax and Plasmodium falciparum by peripheral blood smear. The patient presented with mild malaria symptoms without signs of severe malaria, but reported moderate chest pain and shortness of breath. Laboratory analyses revealed thrombocytopenia and anemia. The electrocardiogram had PR depressions and bedside ultrasound of the cardiopulmonary system showed pericardial effusion (18 mm) accompanied by multiple B-lines in the lungs, identified as vertical artifacts extending from the pleural line. Cardiac biomarkers were normal. The patient was treated according to national guidelines for malaria and suspected pericarditis, respectively. At follow-up on day 5, the pericardial effusion (9mm) and B-lines had markedly decreased. By day 21 the patient was asymptomatic, had completed the treatment, and the electrocardiogram and ultrasound findings had normalized. Conclusions This case report highlight the usefulness of bedside ultrasound to identify cardiopulmonary involvement in patients with uncomplicated malaria and relevant symptoms.

Background: Studies have shown that infection with dengue virus may affect the heart in the acute phase, and that men possibly have a higher risk of severe dengue complications. No studies have investigated if dengue infection also may affect long-term cardiovascular function. Hypothesis: We hypothesized that adults from the general population with a self-reported history of dengue infection had lower myocardial strain compared to controls. Furthermore, that strain could be even lower in men with a history of dengue. Methods: We enrolled individuals from the general population in the Amazon Basin. History of self-reported dengue infection and cardiovascular risk factors were collected by questionnaires. All persons underwent physical examination and bedside echocardiography. We analyzed global longitudinal strain (GLS) and circumferential strain (GCS). Results: We included 529 individuals (mean age 39±15 years, 39% men) of which 49% (n=259) had a history of dengue infection. A history of dengue infection was not associated with lower GLS (Figure A). However, when stratifying the population by sex, dengue infection in men was significantly associated with lower GLS (OR 1.13 per 1% decrease [95%CI 1.02 to 1.24], P=0.014) and GCS (OR 1.06 per 1% decrease [95%CI 1.01 to 1.12], P=0.030), whereas no relationship was found for women (Figure A). In multivariable models adjusted for age, blood pressure, heart rate, creatinine, smoking habits, diabetes and income, the association with GLS (OR 1.13 [95%CI 1.02 to 1.25], P=0.016) and GCS (OR 1.07 [95%CI 1.01 to 1.14], P=0.015) remained significant in men (Figure B and C). We found no significant relationship with left ventricular ejection fraction. Conclusion: Dengue may potentially have long term effects on left ventricular systolic function as measured by strain in men. This calls for further studies to assess long-term cardiac sequelae and subclinical myocardial impairment in individuals with a history of dengue.

Abstract Background Several studies have indicated that self-perception of health is related to cardiovascular disease. Despite cardiovascular disease is the leading cause of mortality in South America, the relationship between patient reported health and cardiovascular risk is sparsely explored, specifically in indigenous areas. Purpose We assessed if self-rated health is associated with cardiovascular risk factors in a remote area in South America. Methods We included participants by cluster-randomization of community health care clinics from June to December 2020. Sociodemographic variables and information on cardiovascular risk factors were collected by questionnaires and physical examination. All participants rated their present health status according to the validated EQ5D-VAS instrument, ranging from 0 (worst) to 100 (best). Results A total of 492 participants (mean age 41±15 years; 38% men) were included. The mean value of self-rated health was 80 (range 0 to 100) and the prevalence of cardiovascular risk factors were: Hypertension (19%), hypercholesterolemia (15%), smoking (37%), low intake of vegetables (defined as <3 times per week; 54%), no sport activity (62%), diabetes (6%) and obesity (24%). In logistic regression models adjusted for sex, age and socioeconomic status, higher self-rated health was significantly associated with lower risk of hypertension, hypercholesterolemia, smoking, obesity and greater vegetable intake (P<0.05; Figure 1). No association was found with sport activity or diabetes. The total number of cardiovascular risk factors increased with lower self-rated health (beta = 0.100 [0.04 to 0.15], P<0.001 per 10 decrease in self-reported health). Conclusion Self-rated health was significantly associated with a greater burden of cardiovascular risk factors and may influence ideal cardiovascular health. Future studies should assess if patient reported health status constitutes an independent risk factor for heart disease in this specific population, and studies elucidating gaps on self-perception of cardiovascular health are encouraged. Funding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): The Independent Research Fund Denmark

Introduction: Rheumatic heart disease (RHD) remains a significant cause of morbidity and mortality in middle- and low-income countries. However, the prevalence of RHD is often underestimated in resource limited areas due to lack of proper screening programs. Purpose: We aimed to determine the prevalence of clinical and subclinical RHD among adults in the Northwestern part of the Amazon Basin, Brazil. In addition, we evaluated the diagnostic yield of a history of self-reported rheumatic fever (RF) and cardiac auscultation Methods: We included a probability sample of adults from the general population in the Amazon Basin. Participants underwent questionnaire on medical history, cardiac auscultation and echocardiography. Participants were assessed according to the 2012 World Heart Federation (WHF) Criteria for echocardiographic diagnosis of RHD (Figure A) Results: We included a total of 591 participants (mean age 41+/-15 years, 60% women, 5% <20 years old). 3% (n=19) had definite RHD (age 50 [IQR 29-70] years, 53% women) and <1% (n=2) had borderline RHD. The distribution of definite RHD according to the WHF Criteria 2012 was: A (n=8), B (n=3), C (n=0), D (n=8). Valve pathologies are displayed in Figure B. Among definite RHD cases, 16% (n=3) were considered clinical (prevalence ~1%) and 84% (n=16) were subclinical (prevalence ~3%). A self-reported history of RF had a sensitivity of 3% and a specificity of 92% (PPV 2%/ NPV 95%) to detect RHD, whereas cardiac auscultation had a sensitivity of 38% and a specificity of 80% (PPV 5%/ NPV 97%). When combining a self-reported history of RF with cardiac auscultation, this yielded a sensitivity of 3% and a specificity of 98% (PPV 10%/ NPV 96%) Conclusions: By applying the 2012 WHF Criteria, the prevalence of clinical and subclinical RHD in adults from the Northwestern part of the Amazon Basin was 1% and 3%, respectively. A combination of a self-reported history of RF and cardiac auscultation provided low sensitivity but high specificity for RHD.

Recent studies have suggested that malaria may affect the cardiovascular system. The aim of this systematic review and meta-analysis was to determine the prevalence of cardiovascular complications in symptomatic malaria patients. We searched databases such as Pubmed, Embase, Cochrane, and Web of Science (January 1950-April 2020) for studies reporting on cardiovascular complications in adults and children with malaria. Cardiovascular complications were defined as abnormalities in electrocardiogram (ECG), cardiac biomarkers, and echocardiography on admission or during outpatient examination. Studies of patients with known heart disease or cardiovascular evaluation performed after the start of intravenous antimalarial medication were excluded. The study was registered in International Prospective Register of Systematic Reviews (PROSPERO) (No.: CRD42020167672). The literature search yielded 1,243 studies, and a total of 43 studies with symptomatic malaria patients were included. Clinical studies (n = 12 adults; n = 5 children) comprised 3,117 patients, of which a majority had Plasmodium falciparum (n = 15) and were diagnosed with severe malaria (n = 13). In random-effects models of adults, the pooled prevalence estimate for any cardiovascular complication was 7% (95% CI: 5-9). No meta-analysis was conducted in children, but the range of abnormal ECG was 0-8%, cardiac biomarkers 0-57%, and echocardiography 4-9%. We analyzed 33 cases (n =10 postmortem), in which the most common cardiovascular pathologies were myocarditis and acute coronary syndrome. All histopathological studies found evidence of parasitized red blood cells in the myocardium. Cardiovascular complications are not uncommon in symptomatic adults and children with malaria. Additional studies investigating malaria and cardiovascular disease are encouraged.

Drug resistance in Mycobacterium tuberculosis , the causative agent of tuberculosis disease, arises from genetic mutations in genes coding for drug-targets or drug-converting enzymes. SNPs linked to drug resistance have been extensively studied and form the basis of molecular diagnostics and sequencing-based resistance profiling. However, alternative forms of functional variation such as large deletions and other loss of function (LOF) mutations have received much less attention, but if incorporated into diagnostics they are likely to improve their predictive performance. Our work aimed to characterize the contribution of LOF mutations found in 42 established drug resistance genes linked to 19 anti-tuberculous drugs across 32689 sequenced clinical isolates. The analysed LOF mutations included large deletions (n=586), frameshifts (n=4764) and premature stop codons (n=826). We found LOF mutations in genes strongly linked to pyrazinamide (pncA), isoniazid (katG), capreomycin (tlyA), streptomycin (e.g. gid) and ethionamide (ethA, mshA) (P<10−5), but also in some loci linked to drugs where relatively less phenotypic data is available [e.g. cycloserine, delaminid, bedaquiline, para-aminosalicylic acid (PAS), and clofazimine]. This study reports that large deletions (median size 1115 bp) account for a significant portion of resistance variants found for PAS (+7.1% of phenotypic resistance percentage explained), pyrazinamide (+3.5%) and streptomycin (+2.6%) drugs, and can be used to improve the prediction of cryptic resistance. Overall, our work highlights the importance of including LOF mutations (e.g. large deletions) in predicting genotypic drug resistance, thereby informing tuberculosis infection control and clinical decision-making.

Abstract Background Patients with acute malaria are at risk of pericarditis and may benefit from timely identification of pericardial effusion. However, diagnostic imaging tools, such as echocardiography, are not always available in malaria endemic regions. Purpose The aim of this study is to examine the diagnostic yield of pathology in electrocardiograms (ECG) to identify pericardial effusion in acute malaria. Methods We enrolled adult acute malaria patients in community healthcare clinics in a remote area in South America. All patients underwent ECG, echocardiography, and peripheral blood smears. We excluded patients on anti-malarial medication, suspected concomitant infection and pregnant women. All ECGs were examined for the following criteria: (i) PR-depression >0.5mm and/or ST-elevation 0.5–1mm (I, II, aVL, aVF, V2–6) (ii) PR-elevation >0.5mm (only aVR), (iii) ST/T-ratio >0.25 (only V6), (v) low voltage, defined as QRS amplitude <5 mm in limb leads or <10 mm in precordial leads, and (vi) Spodick's sign (all leads). A criterion was positive when present in ≥2 leads. Information on shortness of breath and/or chest pain was also collected. Pericardial effusion was diagnosed by echocardiography and had to be ≥0.5cm in width. Results We included 99 non-severe malaria patients (age 40±15 years, 55% men, median parasite density 1517/mm3, [interquartile range 528 to 6,585/mm3]) who suffered from Plasmodium vivax (n=75), falciparum (n=22 falciparum) and mixed vivax/falciparum (n=2). The ECGs showed a mean frequency of 78±16bpm, PR-interval 147±20ms, QRS 88±11ms and QT-interval 376±34ms. A total of 11 patients displayed pericardial effusion (mean width 0.9±0.3cm, n=7 vivax, n=2 falciparum, n=2 mixed). Patients with effusion were older (mean age 39 vs 53 years, P=0.003), but displayed no difference in sex, parasite density or parasite species compared to patients without pericardial effusion (P>0.05). Distribution of ECG findings and symptoms are displayed in figure 1A. PR-depression had a sensitivity and specificity for diagnosing pericardial effusion of 73% and 90%, respectively. The sensitivity and specificity for other ECG findings and clinical symptoms are displayed in Figure 1B. Conclusion ECG findings may aid in identifying pericardial effusion in acute malaria, specifically PR depression which had a diagnostic yield of 73% sensitivity and 90% specificity. Based on this, ECG in acute malaria may improve treatment and risk stratification when echocardiography is not an option. Funding Acknowledgement Type of funding sources: Foundation. Main funding source(s): Novo Nordisk Foundation, Independent Research Fund Denmark ECG findings in malaria patients

Country- and ethnicity-specific reference values for echocardiographic parameters are necessary for decision making. No prior studies have examined reference values in adults from the Amazon Basin of Brazil. We performed echocardiographic examinations in 290 healthy adults (mean age 37 ± 14 years, 40% male) from the Brazilian Amazon. Left ventricular (LV) dimensions and volumes were obtained and indexed to body surface area. We also assessed systolic (LV ejection fraction [LVEF] and global longitudinal strain [GLS]) and diastolic function. LV dimensions and volumes were larger in males compared to females, but after indexation only volumes remained larger (P < 0.001 for all). Parameters of systolic function, were significantly greater in females (LVEF 50 to 68%, GLS − 17 to − 24%) than in males (LVEF 50 to 67%, GLS − 15 to − 23%, P < 0.05). Upper limits of normality for cardiac dimensions (indexed and non-indexed) were markedly higher compared to contemporary guidelines (American Society of Echocardiography) and the Brazilian subgroup in the World Alliance Society of Echocardiography (WASE). Lower limit of normality for LVEF (both sex 50%) and upper limit of normality for the left atrial volume index (LAVI) (male: 31 mL/m2, female: 25 mL/m2) were within normal range but slightly lower compared to guidelines and the WASE study. Other diastolic parameters, including E/A-ratio, E/e’ ratio and peak tricuspid regurgitation velocity were compatible with present recommendations. Normal reference ranges of echocardiographic parameters in healthy adults from the Brazilian Amazon Basin may be different compared to international guidelines and data from other regions of Brazil. This applies specifically for LVEF and LAVI.

Although infectious diseases have been associated with cardiovascular conditions, little is known about tropical disease burden and hypertension. We hypothesized that a history of tropical infections was associated with hypertension. We examined participants from outpatient clinics in the Amazon Basin who were interviewed about prior exposure to tropical diseases, including dengue, malaria hospitalization, and leishmaniasis. Hypertension was defined as a prior physician diagnosis of hypertension, treatment with anti-hypertensive medication, or a systolic blood pressure ≥140 mmHg and/or a diastolic blood pressure ≥90 mmHg. We used logistic regression models to examine the relationship between tropical infectious disease and hypertension. We included 556 participants (mean age 41 ± 15 years, 61% women) of whom 214 (38%) had hypertension and 354 (64%) had a history of tropical infectious disease. The distribution of tropical diseases was: dengue 270 (76%), malaria hospitalization 104 (29%) and leishmaniasis 48 (14%). Any prior tropical infection was significantly associated with prevalent hypertension (odds ratio 1.76 [95% CI 1.22–2.54], P = 0.003) and the association remained significant after adjusting for age, sex, body mass index, diabetes, hypercholesterolemia, socioeconomic status, smoking, vegetable intake and serum creatinine. Persons with a history of ≥2 tropical infections (n = 64) had the greatest risk of hypertension (odds ratio 2.04 [95% CI 1.15–3.63], P = 0.015). In adjusted models, prior infection with dengue was associated with hypertension (P = 0.006), but no associations were found with malaria hospitalization (P = 0.39) or leishmaniasis (P = 0.98). In conclusion, a history of tropical infectious disease was associated with hypertension. This finding supports the idea that pathogen burden may be related to cardiovascular conditions.

Studies have proposed that malaria may lead to electrocardiographic (ECG) changes and pericardial inflammation. We aimed to investigate the frequency of ECG alterations, determined by ECG and Holter monitoring, and pericardial effusion in patients with malaria infection. We performed a prospective observational study of adult patients with uncomplicated malaria in Amazonas, Brazil. Peripheral blood smears, ECG, and bedside echocardiography were conducted before antimalarial treatment and repeated at follow-up after completed treatment. We evaluated the diagnostic value of PR-segment depression, PR-segment elevation, and Spodick's sign for detecting pericardial effusion. A subset of patients underwent Holter monitoring at baseline. Among 98 cases of uncomplicated malaria (55% men; mean age 40 years; median parasite density 1,774/µl), 75 had Plasmodium vivax, 22 Plasmodium falciparum, and 1 had mixed infection. At baseline, 17% (n = 17) had PR-segment depression, 12% (n = 12) PR-segment elevation, 3% (n = 2) Spodick's sign, and the prevalence of pericardial effusion was 9% (n = 9). ECG alterations had sensitivities of 22% to 89% and specificities of 88% to 100% for detecting pericardial effusion at baseline. PR-segment depression had the best accuracy (sensitivity 89%, specificity 90%). Of the 25 patients, 4 patients who did not have pericardial effusion, displayed nonsustained ventricular tachycardia, determined by Holter monitoring (median duration 43 hours). Follow-up examination data were obtained for 71 patients (median 31 days), for whom PR-segment depression, elevation, and pericardial effusion had reduced significantly (p <0.05). In conclusion, our findings suggest that ECG alterations may be useful to detect pericardial effusion in malaria and that these findings decrease after completed antimalarial treatment.

Abstract Background Malaria patients are at risk of cardiopulmonary complications, but diagnosis and management are difficult in resource limited environments. B-lines by lung ultrasonography (LUS) can identify pulmonary alterations, however, little is known about the usefulness in malaria. Purpose We aimed to investigate the occurrence of B-lines in acute malaria patients at baseline and at follow-up, and whether they are associated with shortness of breath and impaired left ventricular ejection fraction (LVEF). Methods Adult patients with non-severe acute malaria were prospectively enrolled from June to December 2020 in community healthcare clinics in a remote area. Patients were age- and sex-matched to controls without a prior history of malaria. We examined patients prior to anti-malaria treatment and at follow-up. Malaria treatment was administered according to national guidelines. Patients were excluded if they were pregnant, had concomitant infections or recent chest trauma. Patients underwent LUS (8-zones), echocardiography and peripheral blood smear. Measurements were blinded to clinical variables and outcomes. Results We included a total of 99 patients (median age 40±15 years, 55% men). Patients suffered from Plasmodium vivax (n=75), P. falciparum (n=22), and a mix of the two (n=2) and median parasite density was 1,595 parasites/mL (interquartile range [IQR] 528–6,585/mL). Follow-up was completed in 71 patients and the median follow-up time was 31 days (IQR 27–40 days). Patients with acute malaria had significantly more B-lines at baseline than matched controls (P-value<0.001) and fewer B-lines at follow-up (P-value<0.001) (Figure 1). In acute malaria patients, number of B-lines at baseline correlated significantly with shortness of breath (OR 1.20, [1.04 to 1.39], P-value=0.01) and with LVEF (adjusted for age and sex: +8% [+1% to +15%], P-value=0.016 per 1% decrease in LVEF). There was no correlation between number of B-lines and parasite density (+2% [−5% to +11%], P-value=0.53 per 1000 increase in parasite density). Conclusion B-lines detected by LUS are more frequent in patients with acute malaria than in age- and sex-matched controls and decrease in response to treatment. B-lines also correlate with shortness of breath and lower LVEF at baseline. Because LUS is a quick and accessible examination, it may potentially facilitate risk stratification and therapeutic decisions regarding cardiopulmonary complications in patients with acute malaria. Funding Acknowledgement Type of funding sources: Foundation. Main funding source(s): Danish Heart Association