BackgroundPregnancy poses specific challenges for the diagnosis of Plasmodium falciparum infection due to parasite sequestration in the placenta, which translates in low circulation levels in peripheral blood. The aim of this study is to assess the performance of a new highly sensitive rapid diagnostic test (HS-RDT) for the detection of malaria in peripheral and placental blood samples from pregnant women in Colombia.MethodsThis is a retrospective study using 737 peripheral and placental specimens collected from pregnant women in Colombian malaria-endemic regions. Light microscopy (LM), conventional rapid diagnostic tests (Pf/Pv RDT and Pf RDT), and HS-RDT testing were performed. Diagnostic accuracy endpoints of LM, HS-RDT and RDTs were compared with nested polymerase chain reaction (nPCR) as the reference test.ResultsIn comparison with nPCR, the sensitivity of HS-RDT, Pf RDT, Pf/Pv RDT and LM to detect infection in peripheral samples was 85.7% (95% CI = 70.6–93.7), 82.8% (95% CI = 67.3–91.9), 77.1% (95% CI = 61.0–87.9) and 77.1% (95% CI = 61.0–87.9) respectively. The sensitivity to detect malaria in asymptomatic women, was higher with HS-RDT, where LM and Pf/Pv RDT missed half of infections detected by nPCR, but differences were not significant. Overall, specificity was similar for all tests (>99.0%). In placental blood, the prevalence of infection by P. falciparum by nPCR was 2.8% (8/286), by HS-RDT was 1% and by conventional RDTs (Pf RDT and Pf/Pv RDT) and LM was 0.7%. The HS-RDT detected placental infections in peripheral blood that were negative by LM and Pf/Pv RDT, however the number of positive placentas was low.ConclusionsThe sensitivity of HS-RDT to detect P. falciparum infections in peripheral and placental samples from pregnant women was slightly better compared to routinely used tests during ANC visits and at delivery. Although further studies are needed to guide recommendations on the use of the HS-RDT for malaria case management in pregnancy, this study shows the potential value of this test to diagnose malaria in pregnancy in low-transmission settings.

Background: In low transmission settings early diagnosis is the main strategy to reduce adverse outcomes of malaria in pregnancy; however, microscopy and rapid diagnostic tests (RDTs) are inadequate for detecting lowdensity infections. We studied the performance of the highly sensitive-RDT (hsRDT) and the loop mediated isothermal DNA amplification (LAMP) for the detection of P. falciparum in pregnant women. Methods: A cross-sectional study was conducted in two malaria-endemic municipalities in Colombia. We screened pregnant women in the context of an antenatal care program in health facilities and evaluated five tests (microscopy, conventional RDT, hsRDT, LAMP and nested polymerase chain reaction-PCR) for the detection of P. falciparum in peripheral blood, using a quantitative reverse transcription PCR (qRT-PCR) as the reference standard. Diagnostic performance of hsRDT and LAMP were compared with routine testing. Results: The prevalence of P. falciparum was 4.5% by qRT-PCR, half of those infections were subpatent. The sensitivity of the hsRDT (64.1%) was slightly better compared to microscopy and cRDT (59 and 53.8% respectively). LAMP had the highest sensitivity (89.7%) for detecting P. falciparum and the ability to detect very low-density infections (minimum parasite density detected 0.08 p/μL). Conclusions: There is an underestimation of Plasmodium spp. infections by tests routinely used in pregnant women attending antenatal care visits. LAMP methodology can be successfully implemented at local hospitals in malaria-endemic areas. The relevance of detecting and treating this sub-patent P. falciparum infections in pregnant women should be evaluated.

Background:Polyarteritis nodosa (PAN) is the third most frequent vasculitis in pediatrics, Cutaneous PAN (CPAN) being more common that Systemic PAN (SPAN). CPAN is frequently described as a benign disease. In children, PAN onset is frequent between 9 and 11 years of age, with no sex differences, and its clinical features may be nonspecific.Objectives:To characterize pediatric patients who were diagnosed with CPAN and SPAN and to compare their clinical features, treatments, and outcome.Methods:A descriptive study was conducted in two centers from Medellin- Colombia, using retrospective data from January 2010 to December 2019. Patients under 18 years of age classified as PAN according to EULAR/PRINTO/PRES(1) criteria were included. CPAN patients were defined according to EULAR/PRES definition (2). Data from medical records were registered, and were expressed in median and ranges and mean and standard deviation (SD) according to their distribution. A univariate analysis was carried out by comparing signs, symptoms, and treatment between CPAN and SPAN, and ap-value < 0,05was considered as significant.Results:Twenty patients were included. The median age at diagnosis was ten years. 60% were boys. The median follow-up period was 27 months. CPAN was diagnosed in 11 (55%) and SPAN in 9 patients (45%). The most frequent symptoms were cutaneous manifestations (95%), fever (60%) and Calf Pain (55%). Mucosal ulcers were described in four patients; 3 of them were defined as CPAN. Lingual necrosis was present in two CPAN, and peripheral nervous system involvement was found in one SPAN and two CPAN patients in skin affected with lesions; even though, no significant statistical differences between CPAN and SPAN were found in constitutional, cutaneous, muscle-skeletal symptoms, and acute phase reactants. Arteriographic anomalies as hepatic and renal microaneurysms, carotidal aneurysms without aortic involvement, and renal infarction were found in one patient each. Skin Biopsy was performed in 18 patients, being compatible with PAN in 16. All PAN patients (CPAN and SPAN) required treatment with glucocorticoids. None of the patients died during the follow-up period.Conclusion:In this Colombian pediatric cohort of PAN patients, the disease was more common in boys than girls, and CPAN was more frequent than SPAN, as already been described. As is evident in this cohort, although CPAN has been considered a benign disease, these patients may be severely ill, requiring glucocorticoid treatment. Pediatric CPAN patients should be strictly followed with particular attention to identify systemic involvement, considering that constitutional, cutaneous, and muscle-skeletal features may be very similar between CPAN and SPAN.References:[1]Ozen S, Pistorio A, Iusan S, et al. EULAR/PRINTO/PRES criteria for Henoch-Schönlein purpura, childhood polyarteritis nodosa, childhood Wegener granulomatosis and childhood Takayasu arteritis: Ankara 2008. Part II: Final classification criteria. Ann Rheum Dis. 2010 May;69(5):798–806.[2]Ozen S, Ruperto N, Dillon M, et al. EULAR/PReS endorsed consensus criteria for the classification of childhood vasculitides. Ann Rheum Dis. 2006;65(7):936–41.Disclosure of Interests:None declared

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El absceso hepático amibiano (AHA) es la complicación extraintestinal másfrecuente de la amibiasis; su cuadro clínico es generalmente agudo y se lo considera una urgencia médica. Se manifiesta con síntomas generales, acompañado de dolor en hipocondrio derecho, que se puede irradiar al hombro; la hepatomegalia dolorosa es un signo sugestivo pero no diagnóstico; debe diferenciarse del absceso hepático piógeno y del hepatoma necrótico; para el enfoque diagnóstico se requieren ayudas imaginológicas y pruebas de laboratorio como las inmunológicas. En este estudio se puso a punto la prueba de ELISA para la determinación de anticuerpos antiamibianos en sueros controles de pacientes con AHA, estandarizada en el Instituto Nacional de Salud de Bogotá. Además se evaluaron 67 muestras de pacientes con sospecha clínica de AHA, procedentes del Hospital González Valencia de Bucaramanga y del Hospital Universitario San Vicente de Paúl de Medellín. El 70.2% de los sueros problema evaluados fueron positivos, con una tasa de positividad significativamente mayor en los procedentes de Bucaramanga.