Asymptomatic and Submicroscopic Plasmodium Infections in an Area Before and During Integrated Vector Control in Homa Bay, Western Kenya

Background Long lasting insecticidal bednets (LLINs) have been the primary vector control strategy until indoor residual spraying (IRS) was added in Homa Bay and Migori Counties in western Kenya. The objective of this study was to evaluate the impact of LLINs integrated with organophosphate-based (Actellic 300 CS) IRS on the prevalence of asymptomatic and submicroscopic Plasmodium species infections in Homa Bay County. Methods Four consecutive community cross-sectional surveys for Plasmodium species infection were conducted in residents of Homa Bay County, Kenya commencing immediately before and 2 years after introduction of annual IRS. Finger-prick blood samples were obtained to prepare thick and thin smears for microscopic determination and qPCR diagnosis of Plasmodium genus, P. falciparum, P. malariae and P. ovale infection. Results Plasmodium spp. infection prevalence by microscopy was 18.5% before IRS and 14.2%, 3.3% and 1.3% after two annual rounds of IRS (χ²= 186.9, df = 3, p < 0.0001). Submicroscopic (blood smear negative, qPCR positive) parasitemia was 50.4% before IRS and 43.2%, 68.0% and 80.7% after IRS (χ²= 31.98, df = 3, p < 0.0001). Geometric mean density of P. falciparum parasitemia decreased over the 2-year study period (ANOVA, F = 28.95, df = 3, 243, p < 0.0001). The proportion of blood smear positive asymptomatic infections that included P. falciparum did not significantly change over the study period. In contrast, the proportion of asymptomatic submicroscopic P. falciparum infections trended upward following introduction of IRS (pre-IRS 48.2% versus post-IRS 41.6%, 61.3% and 75.4%; (χ²= 24.00, df = 3, p = 0.0002). Conclusions These data suggest that two annual rounds of IRS integrated with LLIN significantly reduced the prevalence of Plasmodium parasitemia, whereas the proportion of submicroscopic infections that included P. falciparum parasite increases. Strategies that aim at reducing the number of asymptomatic submicroscopic infections should be considered to diminish cryptic P. falciparum transmission and enhance malaria control.

Automated Detection Model in Classification of B-Lymphoblast Cells from Normal B-Lymphoid Precursors in Blood Smear Microscopic Images Based on the Majority Voting Technique

Introduction. Acute lymphoblastic leukemia (ALL) is the most common type of leukemia, a deadly white blood cell disease that impacts the human bone marrow. ALL detection in its early stages has always been riddled with complexity and difficulty. Peripheral blood smear (PBS) examination, a common method applied at the outset of ALL diagnosis, is a time-consuming and tedious process that largely depends on the specialist’s experience. Materials and Methods. Herein, a fast, efficient, and comprehensive model based on deep learning (DL) was proposed by implementing eight well-known convolutional neural network (CNN) models for feature extraction on all images and classification of B-ALL lymphoblast and normal cells. After evaluating their performance, four best-performing CNN models were selected to compose an ensemble classifier by combining each classifier’s pretrained model capabilities. Results. Due to the close similarity of the nuclei of cancerous and normal cells, CNN models alone had low sensitivity and poor performance in diagnosing these two classes. The proposed model based on the majority voting technique was adopted to combine the CNN models. The resulting model achieved a sensitivity of 99.4, specificity of 96.7, AUC of 98.3, and accuracy of 98.5. Conclusion. In classifying cancerous blood cells from normal cells, the proposed method can achieve high accuracy without the operator’s intervention in cell feature determination. It can thus be recommended as an extraordinary tool for the analysis of blood samples in digital laboratory equipment to assist laboratory specialists.

Systematic segmentation method based on PCA of image hue features for white blood cell counting

Leukocyte (white blood cell, WBC) count is an essential factor that physicians use to diagnose infections and provide adequate treatment. Currently, WBC count is determined manually or semi-automatically, which often leads to miscounting. In this paper, we propose an automated method that uses a bioinspired segmentation mimicking the human perception of color. It is based on the claim that a person can locate WBCs in a blood smear image via the high chromatic contrast. First, by applying principal component analysis over RGB, HSV, and L*a*b* spaces, with specific combinations, pixels of leukocytes present high chromatic variance; this results in increased contrast with the average hue of the other blood smear elements. Second, chromaticity is processed as a feature, without separating hue components; this is different to most of the current automation that perform mathematical operations between hue components in an intuitive way. As a result of this systematic method, WBC recognition is computationally efficient, overlapping WBCs are separated, and the final count is more precise. In experiments with the ALL-IDB benchmark, the performance of the proposed segmentation was assessed by comparing the WBC from the processed images with the ground truth. Compared with previous methods, the proposed method achieved similar results in sensitivity and precision and approximately 0.2% higher specificity and 0.3% higher accuracy for pixel classification in the segmentation stage; as well, the counting results are similar to previous works.

HALLAZGO DE MÓRULAS COMPATIBLES CON ANAPLASMA PLATYS EN UN CANINO DE LA CIUDAD DE ESPERANZA

Anaplasma platys is a Gram-negative, intracellular obligate bacterium that is transmitted by Rhipicephalus sanguineus ticks and has been identified in most of the country. It is the causative agent of canine infectious cyclic thrombocytopenia. The objective of this work is to report the finding of morulae compatible with A. platys in the blood smear of a 10-year-old male Weimaraner canine who was treated at the Hospital de Salud Animal of the Facultad de Ciencias Veterinarias of the Universidad Nacional del Litoral, in the city of Esperanza. The case could not be followed up, because the patient died a few days after his first consultation. The detection of obligate intracellular pathogens in blood smears has low sensitivity and specificity, therefore confirmation of the causative agent must be performed using PCR. Due to the severity of the condition presented in this case, it is necessary to differentiate the presence of Ehrliquia canis and confirm the finding of A. platys using PCR. Current scientific evidence reveals that the zoonotic potential of A. platys is very low or nil.

A CLINICOPATHOLOGICAL STUDY OF ACUTE AND CHRONIC LEUKEMIA IN A TERTIARY CARE HOSPITAL

Introduction: Leukemias are neoplastic proliferations of haematopoietic stem cells and form a major proportion of haematopoietic neoplasms that are diagnosed worldwide. Typing of leukemia is essential for effective therapy because prognosis and survival rate are different for each type and sub-type Aims: this study was carried out to determine the frequency of acute and chronic leukemias and to evaluate their clinicopathological features. Methods: It was a hospital based cross sectional study of 60 patients carried out in the department of Pathology, JMCH, Assam over a period of one year between February 2018 and January 2019. Diagnosis was based on peripheral blood count, peripheral blood smear and bone marrow examination (as on when available marrow sample) for morphology along with cytochemical study whenever possible. Results: In the present study, commonest leukemia was Acute myeloid leukemia (AML, 50%) followed by Acute lymphoblastic leukemia (ALL 26.6%), chronic myeloid leukemia (CML, 16.7%) and chronic lymphocytic leukemia (CLL, 6.7%). Out of total 60 cases, 36 were male and 24 were female with Male:Female ratio of 1.5:1. Acute lymphoblastic leukemia was the most common type of leukemia in the children and adolescents. Acute Myeloid leukemia was more prevalent in adults. Peripheral blood smear and bone Conclusion: marrow aspiration study still remains the important tool along with cytochemistry, immunophenotyping and cytogenetic study in the diagnosis and management of leukemia.