Genomic DNA extraction and amplification of Leishmania donovani using polymerase chain reaction (PCR) from archived, Giemsa- stained slides

In Sri Lanka, diagnosis of cutaneous leishmaniasis (CL) is usually based on clinical features and direct microscopy examinations. Polymerase chain reaction (PCR) for Leishmania is usually performed on tissue samples. In this study, we extracted DNA from archived Giemsa-stained slides which were prepared from cutaneous lesions. A total number of 85 Giemsa-stained slides fixed between 2008-2017 were selected. All the slides were examined using light microscopy and the number of amastigotes in positive smears was recorded. A nested PCR was carried out to amplify the 385 bp fragment of L. donovani kinetoplast mini-circle sequence. All 40 positive slides had only 1-2 amastigotes per slide. Of these, only 20% were PCR positive. Of the 45 negative slides, only one gave positive PCR result. Further studies are required to confirm the efficacy of PCR on Giemsa-stained smears in our setting.</p

A preliminary study on Naegleria species in water bodies of Kurunegala district, Sri Lanka

Introduction and Objective: Species belonging to the genus Naegleria are free-living ubiquitous protozoa. They have been isolated from most regions of the world. N. fowleri causes an acute, fulminant and rapidly fatal infection involving the central nervous system (CNS) in humans. It is known as primary amoebic meningoencephalitis (PAM). Infection is generally acquired while swimming, diving and total submersion for bathing in freshwater-lakes and ponds. Many inland fresh water bodies are present in Sri Lanka. These water bodies are frequently used by people for their daily needs. However, studies have not yet been conducted to determine the prevalence of Naegleria species occurring in local water bodies. The present study was therefore, carried out to isolate Naegleria species from selected water bodies located in four Divisional Secretariat (DS) divisions in the Kurunegala district, Sri Lanka.Methods: Two different sites (clear and turbid water) of each tank were selected for sampling. Two water samples (surface water and deep water) were collected from each site (4 samples from one tank). Altogether, eighty water samples were collected from 20 tanks. Culture, enflagellation test and staining were done to detect Naegleria species. ArcGIS 10.3 and MINITAB (14) software were used for the data analysis.Results: Flagella transformation was observed in 19 (47.5%) surface water samples and 11 (27.5%) deep water samples. Of 20 tanks, 10 were positive for Naegleria species.Conclusions: Findings of the present study suggest that more specific genotyping studies are needed to confirm the presence of pathogenic N. fowleri in the study area.</p

Prevalence of canine tick-borne haemoparasites in three Divisional Secretariat Divisions (Rambewa, Tirappane, and Galenbidunuwewa) in the Anuradhapura district, Sri Lanka

Introduction and Objectives: Ticks act as the vector for transmission of many parasitic pathogens. Several tick-borne haemoparasite infections are widespread among canines in tropical countries. However, information is scarce regarding canine tick-borne infections in Sri Lanka. The present study was therefore carried out to identify the canine tick-borne haemoparasite species and thereby assess their prevalence in three Divisional Secretariat divisions in the Anuradhapura district.Materials and methods: Blood samples were collected from dogs in three Divisional Secretariat (DS) divisions namely, Rambewa, Tirappane, and Galenbindunuwewa in the Anuradhapura district, Sri Lanka. From each blood sample, two thin smears were prepared and stained with Giemsa. Stained slides were subsequently examined with a light microscope to detect haemoparasites.Results: Out of 319 blood samples, 139 were positive for haemoparasites. Of the positives, 51.61% were from Rambewa, 40.47% were from Galenbindunuwewa and 38.88% were from Tirappane. Three haemoprotozoan species, Hepatozoon canis, Babesia gibsoni, Babesia canis and one bacterial species, Ehrlichia canis were morphologically identified in the present study.Conclusions: Comparatively, the prevalence of ehrlichiosis (20.06%) and babesiosis (16.29%) were high in three DS divisions compared to the prevalence of H. canis infection (1.56%). The prevalence of the haemoprotozoan infections was significantly different among thee DS divisions (P&lt;0.01). Co-infections among dogs suggest that the same vector may be involved in transmitting different infections.</p

Soil-transmitted helminth infections, associated factors and nutritional status in an estate community in Sri Lanka

Objectives: To determine the prevalence, intensity, and risk factors associated with soil transmitted helminth (STH) infections and to explore the association between STH infections and nutritional status of an estate community.Methods: A cross-sectional study was conducted in Hanthana Tea Estate (HTE) in Kandy, Sri Lanka, from September 2013 to November 2014. Demographic data were obtained using an interviewer-administrated structured questionnaire. Haemoglobin and serum albumin concentrations were measured in children. Faecal samples were analyzed by direct smears in saline and iodine and Kato-Katz technique using single-stool samples. Anthropometric measurements were obtained to calculate weight-for-age (WAZ), height-for-age (HAZ), and body-mass-index-for-age (BAZ) to evaluate underweight, stunting and wasting, respectively.Results: A total of 233 children (50% female, aged between 1 and 12 years, mean age 6.2±3.4) and 98 parents (93% female, aged between 20 and 52 years, mean age 33±6.2 years) participated in this study. The prevalence of STH infections in children and adults were 27.4% and 14.3% respectively. Ascaris lumbricoides was found in children and adult populations predominantly (26.6% and 14.3% respectively) followed by Trichuris trichiura (0.8% and 1%).Of the infected group, 57.8% of children and 92.8% of adults had a light infection. Moderate infection was found in 40.6% of the children, and 7.2% of the adults. Only one child had a heavy egg count (≥ 50000). The prevalence of STH infections was significantly higher among children than adults (p = 0.014). Not hand washing before a meal (p = 0.002) and after defecation (p &lt; 0.001), greater de-worming period (p &lt; 0.001), use of shared latrine facilities (p = 0.023) and lower levels of mother`s education (p= 0.035) were significantly associated with STH infections. Children with and without STH infection had comparable levels of nutritional indicators. However, 17.6% (n=41) of stunted, 19.3% (n=45) of wasted and 39.5% (n=92) of underweight children were identified in the present study. In addition, 20.2% (n=47) of the children had a low serum albumin level and 15.9% (n=27) had anaemia.Conclusions: Prevalence of STH infections was notably high in both children (27.4%) and their parents (14.3%), indicating a high level of morbidity among the study population. Therefore, a coordinated control and prevention programme considering the diverse socio-demographic characteristics of estate communities is needed to eliminate STH infections in the study population.</p

The first documentation of the immune response to cutaneous leishmaniasis caused by Leishmania donovani in Sri Lanka.

Introduction and Objectives: The predominant form of leishmaniasis seen in Sri Lanka is cutaneous leishmaniasis (CL) caused by Leishmania donovani, a species commonly causing visceral disease. The objective of this study was to explore the human host immune response to CL in Sri Lanka. Methods: A descriptive comparative study was carried out on nine CL patients referred to the Department of Parasitology, Faculty of Medicine, University of Peradeniya, Sri Lanka, during 2011-2013. mRNA was extracted from the skin biopsy samples and reverse transcribed to cDNA and tested for Th1 and Th2 cytokines by using specific primers for IFN-γ, IL-2 (Th1 cytokines) and IL-4, IL-10 (Th2 cytokines). The results were compared with different characteristics of the lesion (number, duration, size and type of lesion). Results: This study revealed that the majority of CL patients (5/9) elicited a Th1 response whereas a Th2 response was not detected in any of the patients. Of the Th1 cytokine positive patients, majority had single lesions, with a shorter duration and smaller sized lesions which were of the plaque type. Of those which exhibited a negative Th1 response, the majority were larger lesions with a longer duration and were of the papular-nodular type. Conclusions: The study suggests that the predominant immune response to CL caused by L. donovani in Sri Lanka, is a Th1 type of response which may explain the localization of L. donovani which is usually a viscerotropic species, to skin tissue. Limitations of study: This study was done only in nine patients due to resource limitations. A continuation of this study is indicated to validate these results.</p

Toxoplasma, Toxocara and Tuberculosis co-infection in a four year old child

<p>Abstract</p> <p>Background</p> <p>Tuberculosis. toxocariasis and toxoplasmosis are among the common infectious causes of lymphadenitis in children. Cases of <it>Toxoplasma gondii </it>and <it>Toxocara spp </it>co-infection have been reported.</p> <p>Case Presentation</p> <p>This case report describes a co-infection of <it>Toxoplasma gondii</it>, <it>Toxocara </it>spp and tuberculosis in a child with chronic lymphadenopathy and eosinophilia.</p> <p>Conclusion</p> <p>The case report highlights two important points. First is the diagnostic challenges that are encountered by clinicians in tropical countries such as Sri Lanka, where lymphadenopathy and eosinophilia with a positive serology commonly point towards a parasitic infection. Secondly the importance of proper history taking and performing the Mantoux test as a first line investigation in a country where the incidence of tuberculosis is low, even in the absence of a positive contact history.</p

Computational pathology of pre-treatment biopsies identifies lymphocyte density as a predictor of response to neoadjuvant chemotherapy in breast cancer.

BACKGROUND: There is a need to improve prediction of response to chemotherapy in breast cancer in order to improve clinical management and this may be achieved by harnessing computational metrics of tissue pathology. We investigated the association between quantitative image metrics derived from computational analysis of digital pathology slides and response to chemotherapy in women with breast cancer who received neoadjuvant chemotherapy. METHODS: We digitised tissue sections of both diagnostic and surgical samples of breast tumours from 768 patients enrolled in the Neo-tAnGo randomized controlled trial. We subjected digital images to systematic analysis optimised for detection of single cells. Machine-learning methods were used to classify cells as cancer, stromal or lymphocyte and we computed estimates of absolute numbers, relative fractions and cell densities using these data. Pathological complete response (pCR), a histological indicator of chemotherapy response, was the primary endpoint. Fifteen image metrics were tested for their association with pCR using univariate and multivariate logistic regression. RESULTS: Median lymphocyte density proved most strongly associated with pCR on univariate analysis (OR 4.46, 95 % CI 2.34-8.50, p < 0.0001; observations = 614) and on multivariate analysis (OR 2.42, 95 % CI 1.08-5.40, p = 0.03; observations = 406) after adjustment for clinical factors. Further exploratory analyses revealed that in approximately one quarter of cases there was an increase in lymphocyte density in the tumour removed at surgery compared to diagnostic biopsies. A reduction in lymphocyte density at surgery was strongly associated with pCR (OR 0.28, 95 % CI 0.17-0.47, p < 0.0001; observations = 553). CONCLUSIONS: A data-driven analysis of computational pathology reveals lymphocyte density as an independent predictor of pCR. Paradoxically an increase in lymphocyte density, following exposure to chemotherapy, is associated with a lack of pCR. Computational pathology can provide objective, quantitative and reproducible tissue metrics and represents a viable means of outcome prediction in breast cancer. TRIAL REGISTRATION: ClinicalTrials.gov NCT00070278 ; 03/10/2003.We acknowledge funding from Cancer Research UK and NIHR Cambridge Biomedical Research Centre. HRA is an NIHR Academic Clinical Lecturer supported by a Career Development Fellowship from the Pathological Society of Great Britain and Northern Ireland and a Starter Grant for Clinical Lecturers from the Academy of Medical Sciences.This is the final version of the article. It first appeared from BioMed Central via https://doi.org 10.1186/s13058-016-0682-

Frequency of eosinophilia and risk factors and their association with Toxocara infection in schoolchildren during a health survey in the north of Lima, Peru

During a health survey in a primary school from the district of Carabayllo (North of Lima, Peru), 200 schoolchildren (96 male and 104 female between five to 12 years old) were randomly selected and divided in two groups (as positive or negative group), according to the serologic result of the Toxocara ELISA test from a total population of 646 schoolchildren. All children were analyzed by hematologic tests to determinate the frequency of eosinophilia and leukocytosis. Additionally, all clinical and epidemiological data were also analyzed to determine their association with toxocariasis. From group of children with positive serology, 40% had some type of eosinophilia in contrast to 19% of children with negative serology, and their association was statistically significant (OR = 2.84, p < 0.001). From all signs and symptoms evaluated, only 'dry cough' was more frequent and statistically significant in the positive serology group (OR = 2.79, p < 0.001). Almost all risk factors evaluated were highly frequent and statistically associated to the positive serology. In conclusion, the presence of eosinophilia and the risk factors evaluated in this population were frequently associated to human toxocariasis