The malaria system microApp: A new, mobile device-based tool for malaria diagnosis

Background: Malaria is a public health problem that affects remote areas worldwide. Climate change has contributed to the problem by allowing for the survival of Anopheles in previously uninhabited areas. As such, several groups have made developing news systems for the automated diagnosis of malaria a priority. Objective: The objective of this study was to develop a new, automated, mobile device-based diagnostic system for malaria. The system uses Giemsa-stained peripheral blood samples combined with light microscopy to identify the Plasmodium falciparum species in the ring stage of development. Methods: The system uses image processing and artificial intelligence techniques as well as a known face detection algorithm to identify Plasmodium parasites. The algorithm is based on integral image and haar-like features concepts, and makes use of weak classifiers with adaptive boosting learning. The search scope of the learning algorithm is reduced in the preprocessing step by removing the background around blood cells. Results: As a proof of concept experiment, the tool was used on 555 malaria-positive and 777 malaria-negative previously-made slides. The accuracy of the system was, on average, 91%, meaning that for every 100 parasite-infected samples, 91 were identified correctly. Conclusions: Accessibility barriers of low-resource countries can be addressed with low-cost diagnostic tools. Our system, developed for mobile devices (mobile phones and tablets), addresses this by enabling access to health centers in remote communities, and importantly, not depending on extensive malaria expertise or expensive diagnostic detection equipment.Peer ReviewedPostprint (published version

First field and laboratory evaluation of LAMP assay for malaria diagnosis in Cubal, Angola

Angola; MalariaAngola; MalariaAngola; MalàriaBackground Malaria is a globally distributed infectious disease. According to the World Health Organization, Angola is one of the six countries that account for over half the global malaria burden in terms of both malaria cases and deaths. Diagnosis of malaria still depends on microscopic examination of thin and thick blood smears and rapid diagnostic tests (RDTs), which often lack analytical and clinical sensitivity. Molecular methods could overcome these disadvantages. The aim of this study was to evaluate, for the first time to our knowledge, the performance of a loop-mediated isothermal amplification (LAMP) for the diagnosis of malaria in an endemic area in Cubal, Angola, and to assess the reproducibility at a reference laboratory. Methods A total of 200 blood samples from patients attended at Hospital Nossa Senhora da Paz, Cubal, Angola, were analysed for Plasmodium spp. detection by microscopy, RDTs, and LAMP. LAMP assay was easily performed in a portable heating block, and the results were visualized by a simple colour change. Subsequently, the samples were sent to a reference laboratory in Spain to be reanalysed by the same colorimetric LAMP assay and also in real-time LAMP format. Results In field tests, a total of 67/200 (33.5%) blood samples were microscopy-positive for Plasmodium spp., 98/200 RDT positive, and 112/200 (56%) LAMP positive. Using microscopy as reference standard, field LAMP detected more microscopy-positive samples than RDTs (66/67; 98% vs. 62/67; 92.5%). When samples were reanalysed at a reference laboratory in Spain using both colorimetric and real-time assays, the overall reproducibility achieved 84.5%. Conclusions This is the first study to our knowledge in which LAMP has been clinically evaluated on blood samples in a resource-poor malaria-endemic area. The colorimetric LAMP proved to be more sensitive than microscopy and RDTs for malaria diagnosis in field conditions. Furthermore, LAMP showed an acceptable level of reproducibility in a reference laboratory. The possibility to use LAMP in a real-time format in a portable device reinforces the reliability of the assay for molecular diagnosis of malaria in resource-poor laboratories in endemic areas.The work was supported by the Institute of Health Carlos III, ISCIII, Spain (www.isciii.es) grant number PI22/01721 (PFS), European Union cofinancing by FEDER (Fondo Europeo de Desarrollo Regional) ‘Una manera de hacer Europa’. We also acknowledge support by the Predoctoral Fellowship Program of Junta de Castilla y León cofounded by Fondo Social Europeo: (BDNS Identif.: 422058, BFS) and (BDNS Identif: 487971, BCV)

Neurological Short-Term Outcomes of a Cohort of Children Born to Zika Virus-Infected Mothers in Barcelona

Zika virus infection; Microcephaly; NeonateInfección por el virus Zika; Microcefalia; NeonatoInfecció pel virus Zika; Microcefàlia; NounatZika virus (ZIKV) is a vector-borne flavivirus with a known teratogenic effect, yet the full spectrum has not been delineated. Studies on endemic areas tried to characterize the clinical outcomes of ZIKV intrauterine exposure. We aimed to describe early neurodevelopmental outcomes on prenatally ZIKV-exposed children in a non-endemic ZIKV area. This is a prospective observational cohort study conducted from May 2016 to December 2021 at Hospital Universitari Vall d’Hebron in Barcelona, Catalonia, Spain. We monitored for up to 24 months 152 children extracted from a pregnant women cohort with suspected ZIKV infection; eleven women (11/150; 7.3%) fulfilled the criteria for a confirmed ZIKV infection. Among the 152 children included, we describe two cases of congenital ZIKV syndrome (CZS) born from women with a confirmed ZIKV infection. Additionally, we describe five cases of other potentially ZIKV-related outcomes (OPZROs), all with normal birth cranial circumference and born to women with probable ZIKV infection. The low exposed prevalence of adverse outcomes in asymptomatic children at birth in a non-endemic area suggests that close follow-up should be addressed by primary care pediatricians instead of pediatric specialists. Further studies are needed to assess the effects of ZIKV intrauterine exposure beyond two years of life.European Union’s Horizon 2020 research and innovation program under grant agreement No. 734857 (ZIKAction)

Zika Virus Infection in Tourists Travelling to Thailand : Case Series Report

Thailand is a popular tourist destination where Zika virus (ZIKV) transmission is currently active. To our knowledge, there are no reports of ZIKV infection imported from Thailand and affecting children. Here, we describe the clinical and microbiological findings in three cases of vector-borne ZIKV infection: An 11-year-old boy, a 2-year-old girl, and her pregnant mother, this last case leading to the prenatal exposure of her second baby to ZIKV in the second trimester of pregnancy. All patients were diagnosed after traveling to Thailand between September 2019 and January 2020. No complications were detected in any patient at follow-up, and the prenatally exposed fetus showed no abnormalities during intensive antenatal health care monitoring. On postnatal study, there were no clinical signs or microbiological findings of mother-to-child ZIKV transmission. ZIKV IgG was initially positive, but seroreversion occurred at 4 months of life. This report describes the clinical and serological evolution of vector-borne ZIKV infection occurring in dengue-naïve tourists returning from Thailand. The World Health Organization currently recommends that pre-travel advice to prevent arbovirus infection should be maintained in travelers to Southeast Asia

First field and laboratory evaluation of LAMP assay for malaria diagnosis in Cubal, Angola

[EN]Malaria is a globally distributed infectious disease. According to the World Health Organization, Angola is one of the six countries that account for over half the global malaria burden in terms of both malaria cases and deaths. Diagnosis of malaria still depends on microscopic examination of thin and thick blood smears and rapid diagnostic tests (RDTs), which often lack analytical and clinical sensitivity. Molecular methods could overcome these disadvantages. The aim of this study was to evaluate, for the first time to our knowledge, the performance of a loop-mediated isothermal amplification (LAMP) for the diagnosis of malaria in an endemic area in Cubal, Angola, and to assess the reproducibility at a reference laboratory

Changes in the microbiological diagnosis and epidemiology of cutaneous leishmaniasis in real-time PCR era: A six-year experience in a referral center in Barcelona

Leishmania; Reacción en cadena de la polimerasa; EspañaLeishmania; Polymerase chain reaction; SpainLeishmania; Reacció en cadena de la polimerasa; EspanyaBackground Leishmaniasis is a neglected disease caused by different species of the protozoa Leishmania spp. Cutaneous lesions are the most common clinical manifestation. This disease is prevalent in tropical and subtropical areas, including the Mediterranean basin. In Spain, Leishmania (L.) infantum is the only endemic species, but imported cases are often diagnosed. Different classical parasitological methods can be performed for cutaneous leishmaniasis (CL) diagnosis; but currently molecular techniques serve as a relevant tool for the detection and characterization of Leishmania parasites. We aimed to evaluate clinical and epidemiological characteristics of CL diagnosed patients by real-time PCR in a tertiary hospital over a six-year period. Methodology/Principal findings Clinical, epidemiological and microbiological data were retrospectively collected and analyzed. In our study, CL was confirmed in 59 (31.4%) out of 188 patients by real-time PCR, showing an increase over recent years: 11 cases of CL between 2014 and 2016 and 48 between 2017 and 2019. Real-time PCR was performed on skin swabs and/or biopsies samples, with a positivity of 38.5% and 26.5%, respectively. Results were 100% concordant when biopsy and skin swab were performed simultaneously. L. (L.) infantum was the most frequent species detected (50%), followed by L. (L.) major (45%) and Viannia subgenus (5%), which were detected only in imported cases. L. (L.) major was almost entirely detected in travelers/migrants from Morocco. Multiple and atypical skin lesions were more common in imported cases than in autochthonous cases (44.4% vs. 21.8%). Conclusions/Significance An increase in both autochthonous and imported CL cases has been observed in past years in our hospital. Molecular techniques assist in improving CL diagnosis and characterization of the Leishmania species, mainly in imported cases.The author(s) received no specific funding for this work

Analytical Evaluation of Dried Blood Spot and Rapid Diagnostic Test as a New Strategy for Serological Community Screening for Chronic Chagas Disease

Trypanosoma cruzi; Mancha de sangre seca (DBS); Cribado serológicoTrypanosoma cruzi; Taca de sang seca (DBS); Cribratge serològicTrypanosoma cruzi; Dried blood spot (DBS); Serological screeningBackground: Chagas disease is a public health problem not only in Latin America, but also in other regions, including Spain, due to migration movements. Conventional serological diagnosis requires an invasive sample (plasma or serum) and a well-equipped laboratory. To circumvent those limitations, blood samples dried on filter paper (DBS) or Rapid Diagnostic Test (RDT) could be a practical alternative to reference protocol for serological screening in epidemiological studies. We evaluated the usefulness of dried blood sampling and a rapid diagnostic test (Trypanosoma Detect™) for the detection of antibodies against T. cruzi for their use in community-based screening. Methodology/Principal Findings: A total of 162 stored paired whole-blood and serum samples from Latin American migrants and 25 negative-control blood samples were included. Diagnosis of chronic Chagas disease was performed in serum according to WHO algorithms. Blood samples were retrospectively collected as dried spots and then analyzed using two different serological techniques, enzyme-linked immunosorbent assay (ELISA) and electrochemiluminescence immunoassay (E-CLIA). Whole-blood samples were also used to evaluate a rapid diagnostic test based on immunochromatography. A better correlation with conventional serum was observed in dried blood elutes using E-CLIA than ELISA (97% vs. 77% sensitivity, respectively). Both assays reported 100% specificity. The median cut-off index values of E-CLIA for dried blood were significantly lower than those for serum (138.1 vs. 243.3, P<0.05). The Trypanosoma Detect™ test presented a sensitivity and specificity of 89.6% and 100%, respectively. Conclusions: The detection of antibodies against T. cruzi in dried blood samples shows a higher sensitivity when using E-CLIA compared with ELISA. Trypanosoma Detect™ is easier to use but has a lower sensitivity. Hence, we propose a sequential strategy based on performing the rapid test first, and a negative result will be confirmed by DBS-ECLIA for use in community Chagas disease screening programs.This work has been supported by the Fundació la Marató TV3 (project number 20182610)

Risk of SARS-CoV-2 Infection in Previously Infected and Non-Infected Cohorts of Health Workers at High Risk of Exposure

Coronavirus SARS-CoV-2; COVID-19; 2019-nCoV; Immunitat natural; ReinfeccióCoronavirus SARS-CoV-2; COVID-19; 2019-nCoV; Inmunidad natural; ReinfecciónCoronavirus SARS-CoV-2; COVID-19; 2019-nCoV; Natural immunity; ReinfectionThe objective of this study is to assess the risk of newly acquired RNA detection-proven SARS-CoV-2 infection after previous SARS-CoV-2 infection. This is a prospective study conducted from March to September 2020 in Barcelona, Spain. Healthcare workers caring for SARS-CoV-2 infected patients were divided in two cohorts: (a) previously RNA-proven SARS-CoV-2 infected cohort with mild symptoms (IC) and (b) healthy cohort (HC). Weekly SARS-CoV-2 RNA detection assays from nasopharyngeal swabs were performed. Serology status was assessed at the beginning and at the end of the study. Twenty participants were included in each group. The median age was 30 (IQR 27–34.75) years, and 55% were female. The median time of follow up was 49 (IQR 49–51) days. Fifteen out of 246 (6%) nasopharyngeal swab samples were positive for SARS-CoV-2, all in the IC. The percentage of participants in the IC with a probable newly acquired SARS-CoV-2 RNA-proven infection was 20% (95% IC 5.7–43.6%) at the end of the 7-week follow up period. The incidence reinfection rate was 28.6 (95% IC 7.8–73.2) cases per 1000 person-week. Despite detectable IgG antibodies against SARS-CoV-2 participants highly exposed to SARS-CoV-2 may develop a newly acquired SARS-CoV-2 RNA detection episode during the first months after the initial infection.ASM is supported by a postdoctoral grant “Juan Rodés” (JE18/00022) from Instituto de Salud Carlos III trough the Ministry of Economy and Competitiveness, Spain

Opportunistic Community Screening of Chronic Chagas Disease Using a Rapid Diagnosis Test in Pharmacies in Barcelona (Catalonia, Spain): Study Protocol and Pilot Phase Results

Chagas disease; Community pharmacies; Rapid testEnfermedad de Chagas; Farmacias comunitarias; Test rapidoMalaltia de Chagas; Farmàcies comunitàries; Prova ràpidaObjectives: This study aimed to report the protocol and results from the pilot phase of an opportunistic CP-based CD screening program in Barcelona, Spain. Methods: Three strategies according to recruitment approach were designed: passive, active and active-community. The study process consisted of signing the informed consent form, recording the patient’s data in a web-based database system, and performing the rapid test and blood collection on dry paper. Results: Nineteen pharmacies participated and 64 patients were included during the pilot phase of the study. The rapid diagnostic test (RDT) was positive in 2/64 (3.13%) cases. Of the 49 DBS samples that arrived at the laboratory, 22 (45%) were collected incorrectly. After quantitative and qualitative assessment of the program, the dry paper sample and passive strategy were ruled out. Conclusion: DBS sampling and the passive strategy are not suitable for CD screening in community pharmacies. There is a need to expand the number of participating pharmacies and individuals to determine whether conducting a RDT in community pharmacies is an effective screening method to increase access to CD diagnosis in a non-endemic area.This work has been supported by the Fundació la Marató TV3 (project number 481/U/2018)

Treatment of Complex Cutaneous Leishmaniasis with Liposomal Amphotericin B

Leishmania; Anfotericina B liposomal; Terapia sistémicaLeishmania; Liposomal amphotericin B; Systemic therapyLeishmania; Amfotericina B liposomal; Teràpia sistèmicaBackground: There is no consensus for the best treatment of complex cutaneous leishmaniasis (CL). We aimed to describe a cohort of CL, focusing on liposomal amphotericin B (L-AmB) treatment outcome. Methods: We performed a retrospective study in Vall d’Hebron University Hospital (Barcelona, Spain). All patients with parasitologically proven CL diagnosed from 2012 to 2018 were included. Results: The analysis included 41 patients with CL. The median age was 39 years (IQR 12- 66); 12 (29%) were children, and 29 (71%) were men. Regarding treatment, 24 (59%) received local treatment, whereas 17 (41%) had complex CL and were offered intravenous systemic treatment. Sixteen patients received L-AmB; eight (50%) had adverse events, and three (19%) discontinued treatment for safety reasons. All cases were considered cured within the first year post-treatment. Conclusions: L-AmB for complex CL showed no treatment failures, offering an alternative treatment option for patients with complex CL. Clinicians should pay close attention to the potential adverse events of L-AmB and adopt an active drug safety surveillance scheme to rapidly detect reversible side effects.This research received no external funding