Usefulness of real-time PCR for urogenital schistosomiasis diagnosis in preschool children in a high-prevalence area in Angola.

BACKGROUND: Urogenital schistosomiasis caused by Schistosoma haematobium is highly endemic in the municipality of Cubal in Angola. Currently, diagnosis is based on the observation of S. haematobium eggs in urine samples by microscopy but this method has low sensitivity. Few studies have been performed using molecular techniques in high-prevalence areas for the detection of S. haematobium. The objective of this study is to evaluate the usefulness of real-time PCR as a diagnostic technique for urogenital schistosomiasis among preschool-age children and its correlation with morbidity data. METHODS: A cross-sectional study was conducted in Cubal, Angola, involving 97 urine samples from preschool-age children analyzed by the dipstick test, microscopic examination of filtered urine, and real-time PCR. The diagnosis of urogenital schistosomiasis was based on microscopy and/or real-time PCR results. Clinical and ultrasonography evaluation was performed to rule out complications of schistosomiasis. RESULTS: We detected a total of 64.95% of samples positive by real-time PCR and 37.11% by microscopy. The sensitivity of parasitological diagnosis of urogenital schistosomiasis by real-time PCR and microscopy was 95.45% and 54.55%, respectively, and the sensitivity of real-time PCR compared with microscopy was 91.67%. A positive real-time PCR result was significantly related to older age (mean = 3.22 years), detection of eggs by microscopy, and abnormal urine dipstick results (18.56% with proteinuria, 31.96% with leukocyturia, and 31.96% with microhematuria) (p-value<0.05). Ultrasound analysis showed that 23.94% of children had urinary tract abnormalities, and it was significantly related to the real-time PCR diagnosis (p-value<0.05). CONCLUSIONS: Real-time PCR is a more sensitive technique than microscopy for urinary schistosomiasis diagnosis in preschool-age children in Cubal. This increase in sensitivity would allow earlier diagnosis and treatment, thus reducing the morbidity associated with schistosomiasis in its early stages.

Seroprevalence status of vaccine-preventable diseases in migrants living in shelter centers in Barcelona, Spain.

INTRODUCTION: Almost 281 million people were living in a foreign country in 2022, and more than 100 million were displaced because of war conflicts and human right violations. Vaccination coverage of infectious diseases in migrants from some disadvantaged settings could be lower than reception countries populations, consequently seroprevalence studies and better access to vaccination could contribute to reducing these differences. METHODS: A descriptive retrospective cross-sectional study was conducted including migrants, living ≤5 years in the reception country and ≥16 years old, who requested a medical exam between January 1st, 2020 and January 31st, 2021. Seroprevalence assessment was performed, and vaccination was offered to those individuals without immunity to hepatitis B, hepatitis A, varicella, measles, mumps, and rubella. RESULTS: A total of 315 migrants were attended during the study period. Immunity protection at arrival was 252/296 (85.1%) for measles, 274/295 (92.9%) for rubella, 257/296 (86.8%) for mumps, 264/295 (89.5%) for varicella, 267/313 (85.3%) for hepatitis A, and 104/300 (34.6%) for hepatitis B. The final immunity protection after full vaccination schedules was 278/296 (93.9%) for measles, 287/295 (97.3%) for rubella, 274/296 (92.6%) for mumps, 276/295 (93.6%) for varicella, 280/313 (89.5%) for hepatitis A, and 139/300 (46.3%) for hepatitis B. CONCLUSIONS: The vaccination intervention has increased immunity rates for the studied diseases in the attended migrants in our center, however, such interventions should be maintained to reach local population immunization levels. Moreover, the collaboration between shelter and reference specialized health centers is fundamental to implement such vaccination programs.

Development of a low-cost robotized 3D-prototype for automated optical microscopy diagnosis: An open-source system.

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.