There are limited treatment options for
Trypanosoma cruzei
infection, or Chagas' disease. Preclinical data had suggested that posaconazole might be an effective therapy. In this randomized trial, ...posaconazole monotherapy was found not to be effective.
Chagas' disease, a chronic parasitic infection caused by the protozoan
Trypanosoma cruzi,
is considered to be one of the neglected tropical diseases.
1
Although Chagas' disease was identified more than 100 years ago, current therapeutic options for this condition are limited mainly to benznidazole and nifurtimox. The phase of the disease is one of the factors that determine the success of treatment. Cure rates of 65 to 80% have been documented when treatment is administered in the acute phase of the disease, with rates reaching almost 100% in cases of congenitally acquired infection that is treated during the first years of . . .
Prolonged Zika Virus Viremia during Pregnancy Suy, Anna; Sulleiro, Elena; Rodó, Carlota ...
New England journal of medicine/The New England journal of medicine,
12/2016, Letnik:
375, Številka:
26
Journal Article
Recenzirano
Odprti dostop
The presence of Zika virus in the blood may be prolonged during pregnancy. In this letter, Zika virus remained detectable for more than 3 months in a pregnant woman.
To the Editor:
We describe a case ...of Zika virus (ZIKV) infection during pregnancy in a Colombian woman. She was infected in December 2015 while she was visiting her home country. At 9 weeks’ gestation, she had a self-limited maculopapular, nonconfluent rash for 3 days that affected her trunk, arms, and legs; she had no fever or other concurrent symptoms. She was screened for ZIKV and other flaviviruses.
A reverse-transcriptase–polymerase-chain-reaction (RT-PCR) assay (RealStar Zika Virus RT-PCR Kit 1.0, Altona Diagnostics) of a serum sample was positive for ZIKV, and testing remained positive for 89 days (or 107 days after the . . .
Malaria, a parasitic infection caused by Plasmodium parasites and transmitted through the bite of infected female Anopheles mosquitos, is one of the main causes of mortality in many developing ...countries. Over 200 million new infections and nearly half a million deaths are reported each year, and more than three billion people are at risk of acquiring malaria worldwide. Nevertheless, most malaria cases could be cured if detected early. Malaria eradication is a top priority of the World Health Organisation. However, achieving this goal will require mass population screening and treatment, which will be hard to accomplish with current diagnostic tools.
We report an electrochemical point-of-care device for the fast, simple and quantitative detection of Plasmodiumfalciparum lactate dehydrogenase (PfLDH) in whole blood samples. Sample analysis includes 5-min lysis to release intracellular parasites, and stirring for 5 more min with immuno-modified magnetic beads (MB) along with an immuno-modified signal amplifier. The rest of the magneto-immunoassay, including sample filtration, MB washing and electrochemical detection, is performed at a disposable paper electrode microfluidic device. The sensor provides PfLDH quantitation down to 2.47 ng mL−1 in spiked samples and for 0.006–1.5% parasitemias in Plasmodium-infected cultured red blood cells, and discrimination between healthy individuals and malaria patients presenting parasitemias >0.3%. Quantitative malaria diagnosis is attained with little user intervention, which is not achieved by other diagnostic methods.
•Electrochemical POC for fast simple and quantitative malaria detection in whole blood.•Single-step magneto-immunoassay for Plasmodiumfalciparum lactate dehydrogenase (PfLDH).•Paper microfluidic electrode for magneto-assay operation with little user intervention.•Quantitation in lysed whole blood in <20 min.
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.
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%).
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.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Malaria is an infectious disease caused by parasites of the genus
Plasmodium
spp. It is transmitted to humans by the bite of an infected female
Anopheles
mosquito. It is the most common disease in ...resource-poor settings, with 241 million malaria cases reported in 2020 according to the World Health Organization. Optical microscopy examination of blood smears is the gold standard technique for malaria diagnosis; however, it is a time-consuming method and a well-trained microscopist is needed to perform the microbiological diagnosis. New techniques based on digital imaging analysis by deep learning and artificial intelligence methods are a challenging alternative tool for the diagnosis of infectious diseases. In particular, systems based on Convolutional Neural Networks for image detection of the malaria parasites emulate the microscopy visualization of an expert. Microscope automation provides a fast and low-cost diagnosis, requiring less supervision. Smartphones are a suitable option for microscopic diagnosis, allowing image capture and software identification of parasites. In addition, image analysis techniques could be a fast and optimal solution for the diagnosis of malaria, tuberculosis, or Neglected Tropical Diseases in endemic areas with low resources. The implementation of automated diagnosis by using smartphone applications and new digital imaging technologies in low-income areas is a challenge to achieve. Moreover, automating the movement of the microscope slide and image autofocusing of the samples by hardware implementation would systemize the procedure. These new diagnostic tools would join the global effort to fight against pandemic malaria and other infectious and poverty-related diseases.
Soil-transmitted helminth (STH) infections inflict disability worldwide, especially in the poorest communities. Current therapeutic options against STHs show limited efficacy, particularly against
...Trichuris trichiura
. The empirical management of patients coming from high-prevalence areas has been suggested for non-endemic areas. This study aimed to describe the management of STH infections in a non-endemic setting using an individualised approach. We performed a retrospective, descriptive study of all patients up to 16 years of age with STH infections attended at an international health unit in a non-endemic area (2014–2018), including all
T. trichiura
,
Necator americanus
,
Ancylostoma duodenale
, and
Ascaris lumbricoides
infections diagnosed using a formol-ether concentration technique and direct visualisation. Patients were treated according to current international guidelines. Sixty-one stool samples from 48 patients testing positive for STHs were collected, with 96% (46/48) reporting a previous long-term stay in endemic areas. Cure rates with 3-day benzimidazole regimens were 72% for
T. trichiura
, 40% for hookworms, and 83% for
A. lumbricoides
. The results were not influenced by any reinfection risk due to the study being performed in a non-endemic area. Patients coming from STH-endemic areas should be evaluated with appropriate diagnostic tools and followed up until cure control results. Cure rates in our cohort were moderate to low, similar to those published in studies in endemic areas. The efficacy of current treatment options is insufficient to recommend a specific empirical approach in high-income countries’ healthcare systems.
The World Health Organization (WHO) estimates that over three billion people are at risk of acquiring malaria, a parasitic infection that produces more than 200 million new infections and nearly half ...a million deaths each year. Expanding the access to early diagnosis and treatment is one of the most effective ways to prevent disease complications, reduce patient mortality, and curb the community transmission. However, none of the diagnostic methods used currently for malaria detection, including light microscopy, polymerase chain reaction (PCR), and rapid diagnostic tests (RDTs), can provide simultaneously fast results, high sensitivity, and parasitaemia quantitation with minimal user intervention. Here, we present a magneto-immunoassay that, based on the unique combination of magnetic beads (MB), an enzymatic signal amplifier (Poly-HRP), and chemiluminescence detection, provides fast, sensitive, and quantitative malaria diagnosis with easy user manipulation. This assay quantifies Plasmodium falciparum lactate dehydrogenase (PfLDH) in lysed whole blood samples in <15 min, exhibiting a limit of detection (LOD) of 0.02 ng mL–1 and providing patient stratification consistent with the reference methods. These figures of merit surpass the performance of the magneto-immunoassays reported previously for Plasmodium detection and demonstrate for the first time that the proposed combination of MB, Poly-HRP, and chemiluminescence detection produces extremely fast, simple, and efficient assays that approach the requirements of point-of-care (POC) malaria surveillance.
Amoebic colitis is the most frequent clinical manifestation of invasive intestinal infection due to Entamoeba histolytica and a common cause of diarrhoea worldwide. Since higher transmission rates ...are usually related to poor health and exposure to unhygienic conditions, cases reported in Europe usually involve immigrants and international travellers. The goal of this study was to characterise both the clinical and the epidemiological features of a European population diagnosed with amoebic colitis and then to evaluate the diagnostic tools and therapeutic options applied.
This was a retrospective observational study in which data from all patients diagnosed with amoebic colitis attending at the International Health Units of two tertiary referral hospitals, Germans Trias i Pujol University Hospital (Badalona, North Barcelona Metropolitan Area) and Vall d'Hebron University Hospital (Barcelona city) between 2007 and 2017 were analysed. During the study period 50 patients were diagnosed with amoebic colitis. Thirty-six (72%) were men, and immigrants accounted for 46% of all cases. Antecedents of any international travel were reported for 28 (56%), the most frequent destinations having been the Indian subcontinent, South and Central America and sub-Saharan Africa. Preexisting pathological conditions or any kind of immunosuppression were identified in 29 (58%) patients; of these, 13 (26%) had HIV infection-all of them men who have sex with men-and 5 (10%) had inflammatory bowel disease. Diarrhoea, abdominal pain and dysentery were the most frequently recorded symptoms of invasive amoebae. Diagnosis was made through microbiological study in 45 (90%) and/or histological identification of amoebae in colon biopsies in 10 (20%). After treatment with metronidazole (82%) or tinidazole (8%), all patients had good outcomes. Post-acute intraluminal treatment was indicated in 28 (56%).
Amoebic colitis should be suspected in patients with diarrhoea and compatible epidemiological risk factors (immigration, travelling abroad or men who have sex with men), especially if some degree of immunosuppression concurs. These risk factors must be taken into account in any diagnostic approach to inflammatory bowel disease (IBD), and active searches for stool parasites should be performed in such cases to rule out misdiagnosis or simultaneous amoebic infection. Treatment should include intraluminal anti-amoebic treatment in order to avoid relapse and prevent further spread of the disease.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
In a clinical context, conventional optical microscopy is commonly used for the visualization of biological samples for diagnosis. However, the availability of molecular techniques and rapid ...diagnostic tests are reducing the use of conventional microscopy, and consequently the number of experienced professionals starts to decrease. Moreover, the continuous visualization during long periods of time through an optical microscope could affect the final diagnosis results due to induced human errors and fatigue. Therefore, microscopy automation is a challenge to be achieved and address this problem. The aim of the study is to develop a low-cost automated system for the visualization of microbiological/parasitological samples by using a conventional optical microscope, and specially designed for its implementation in resource-poor settings laboratories. A 3D-prototype to automate the majority of conventional optical microscopes was designed. Pieces were built with 3D-printing technology and polylactic acid biodegradable material with Tinkercad/Ultimaker Cura 5.1 slicing softwares. The system’s components were divided into three subgroups: microscope stage pieces, storage/autofocus-pieces, and smartphone pieces. The prototype is based on servo motors, controlled by Arduino open-source electronic platform, to emulate the X-Y and auto-focus (Z) movements of the microscope. An average time of 27.00 ± 2.58 seconds is required to auto-focus a single FoV. Auto-focus evaluation demonstrates a mean average maximum Laplacian value of 11.83 with tested images. The whole automation process is controlled by a smartphone device, which is responsible for acquiring images for further diagnosis via convolutional neural networks. The prototype is specially designed for resource-poor settings, where microscopy diagnosis is still a routine process. The coalescence between convolutional neural network predictive models and the automation of the movements of a conventional optical microscope confer the system a wide range of image-based diagnosis applications. The accessibility of the system could help improve diagnostics and provide new tools to laboratories worldwide.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Currently available drugs against Trypanosoma cruzi infection, which causes 12000 deaths annually, have limitations in their efficacy, safety and tolerability. The evaluation of therapeutic responses ...to available and new compounds is based on parasite detection in the bloodstream but remains challenging because a substantial proportion of infected individuals have undetectable parasitemia even when using diagnostic tools with the highest accuracy. We characterize parasite dynamics which might impact drug efficacy assessments in chronic Chagas by analyzing pre- and post-treatment quantitative-PCR data obtained from blood samples collected regularly over a year. We show that parasitemia remains at a steady-state independently of the diagnostic sensitivity. This steady-state can be probabilistically quantified and robustly predicted at an individual level. Furthermore, individuals can be assigned to categories with distinct parasitological status, allowing a more detailed evaluation of the efficacy outcomes and adjustment for potential biases. Our analysis improves understanding of parasite dynamics and provides a novel background for optimizing future drug efficacy trials in Chagas disease. Trial Registration: original trial registered with ClinicalTrials.gov, number NCT01489228.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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