60 research outputs found

    Waterborne protozoan pathogens in environmental aquatic biofilms: implications for water quality assessment strategies

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    Biofilms containing pathogenic organisms from the water supply are a potential source of protozoan parasite outbreaks and a general public health concern. The aim of the present study was to demonstrate the simultaneous and multispatial occurrence of waterborne protozoan pathogens (WBPP) in substrate-associated biofilms (SAB) and compare it to surface water (SW) and sediments with bottom water (BW) counterparts using manual filtration and elution from low-volume samples. For scenario purposes, simulated environmental biofilm contamination was created from in-situ grown one-month-old SAB (OM-SAB) that were spiked with Cryptosporidium parvum oocysts. Samples were collected from the largest freshwater reservoirs in Luzon, Philippines and a University Lake in Thailand. A total of 69 samples (23 SAB, 23 SW, and 23 BW) were evaluated using traditional staining techniques for Cryptosporidium, and immunofluorescence staining for the simultaneous detection of Cryptosporidium and Giardia. In the present study, WBPP was found in 43% SAB, 39% SW, and 39% BW samples tested with SAB results reflecting SW and BW results. Further, the potential and advantages of using low-volume sampling for the detection of parasite (oo)cysts in aquatic matrices were also demonstrated. Scanning electron microscopy of OM-SAB revealed a naturally-associated testate amoeba shell, while Cryptosporidium oocysts spiked samples provided a visual profile of what can be expected from naturally contaminated biofilms. This study provides the first evidence for the simultaneous and multi-spatial occurrence of waterborne protozoan pathogens in low-volume environmental aquatic matrices and warrants SAB testing along with SW and BW matrices for improved water quality assessment strategies (iWQAS)

    First report of Cryptosporidium hominis in a freshwater sponge

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    Identification of Cryptosporidium oocyst is essential in ensuring water quality fit for human use, consumption, and recreation.This communication proposes the supplemental analysis of substrateassociated biofilms, in particular, freshwater sponges in improving case finding of waterborne-protozoan pathogens (WBPP) in environmental aquatic samples. In this study, a small portion of a mature freshwater sponge under the Genus Radiospongilla was subjected to microscopic and molecular analysis to identify the presence of Cryptosporidium. Microscopic screening with modified Kinyoun's staining (MK) and microscopic confirmation using direct antibody fluorescent testing (IFT) returned with Cryptosporidium spp. positive findings. Molecular investigation resulted in the confirmation of Cryptosporidium hominis upon sequencing of PCR products and phylogenetic analysis. This is the first report of a pathogenic protozoan, C. hominis isolated from a freshwater sponge. The results of this study provide evidence of the value of expanding water quality assessment strategies to the analysis of substrate-associated biofilms and sponges in improving case finding of WBPP in natural aquatic environments

    Immunoproteomics to identify species-specific antigens in Neospora caninum recognised by infected bovine sera

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    Bovine neosporosis is a disease of concern due to its global distribution and significant economic impact through massive losses in the dairy and meat industries. To date, there is no effective chemotherapeutic drug or vaccine to prevent neosporosis. Control of this disease is therefore dependent on efficient detection tests that may affect treatment management strategies. This study was conducted to identify the specific immunoreactive proteins of Neospora caninum tachyzoites recognised by sera from cattle infected with N. caninum, Toxoplasma gondii, Cryptosporidium parvum, Babesia bovis and B. bigemina, and by sera from uninfected cattle using two-DE dimensional gel electrophoresis (2-DE) combined with immunoblot and mass spectrometry (LC-MS/MS). Among 70 protein spots that reacted with all infected sera, 20 specific antigenic spots corresponding to 14 different antigenic proteins were recognised by N. caninum-positive sera. Of these immunoreactive antigens, proteins involved in cell proliferation and invasion process were highly immunogenic, including HSP90-like protein, putative microneme 4 (MIC4), actin, elongation factor 1-alpha and armadillo/beta-catenin-like repeat-containing protein. Interestingly, we discovered an unnamed protein product, rhoptry protein (ROP1), possessing strong immunoreactivity against N. caninum but with no data on function available. Moreover, we identified cross-reactive antigens among these apicomplexan parasites, especially N. caninum, T. gondii and C. parvum. Neospora caninum-specific immunodominant proteins were identified for immunodiagnosis and vaccine development. The cross-reactive antigens could be evaluated as potential common vaccine candidates or drug targets to control the diseases caused by these apicomplexan protozoan parasites

    Impact of Weekly Climatic Variables on Weekly Malaria Incidence throughout Thailand: A Country-Based Six-Year Retrospective Study

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    Purpose. This study aimed to evaluate climatic data, including mean temperature, relative humidity, and rainfall, and their association with malaria incidence throughout Thailand from 2012 to 2017. The correlation of climatic parameters including temperature, relative humidity, and rainfall in each province and the weekly malaria incidence was analyzed using Spearman’s rank correlation. The results showed that the mean temperature correlated with malaria incidence (p value < 0.05) in 44 provinces in Thailand. These correlations were frequently found in the western and southern parts of Thailand. Relative humidity correlated with malaria incidence (p value < 0.05) in 35 provinces. These correlations were frequently found in the northern and northeastern parts of Thailand. Rainfall correlated with malaria incidence (p value < 0.05) in 38 provinces. These correlations were frequently found in the northern parts and some western parts of Thailand. The impacts of the mean temperature, relative humidity, and rainfall were observed frequently in specific provinces, including Chiang Mai, Chiang Rai, Trat, Kanchanaburi, Ubonratchathani, and Si Sa Ket. This is the first study to report areas where climatic data are associated with malaria incidence throughout Thailand from 2012 to 2017. These results can map out the climatic change process over time and across the country, which is the foundation for effective early warning systems for malaria, public health awareness campaigns, and the adoption of proper adaption measures that will help in malaria detection, diagnosis, and treatment

    Diet and risk of breast cancer

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    Diet may play a role in both promoting and inhibiting human breast cancer development. In this review, nutritional risk factors such as consumption of dietary fat, meat, fiber, and alcohol, and intake of phytoestrogen, vitamin D, iron, and folate associated with breast cancer are reviewed. These nutritional factors have a variety of associations with breast cancer risk. Type of fat consumed has different effects on risk of breast cancer: consumption of meat is associated with heterocyclic amine (HCA) exposure; different types of plant fiber have various effects on breast cancer risk; alcohol consumption may increase the risk of breast cancer by producing acetaldehyde and reactive oxygen species (ROS); intake of phytoestrogen may reduce risk of breast cancer through genomic and non-genomic action; vitamin D can reduce the risk of breast cancer by inhibiting the process of cancer invasion and metastasis; intake of dietary iron may lead to oxidative stress, DNA damage, and lipid peroxidation; and lower intake of folate may be linked to a higher risk of breast cancer

    Prevalence of Malaria and Chikungunya Co-Infection in Febrile Patients: A Systematic Review and Meta-Analysis

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    Background: Co-infection with malaria and chikungunya could exert a significant public health impact with infection misdiagnosis. Therefore, this study aimed to collect qualitative and quantitative evidence of malaria and chikungunya co-infection among febrile patients. Methods: Potentially relevant studies were identified using PubMed, Web of Science, and Scopus. The bias risk of the included studies was assessed using the checklist for analytical cross-sectional studies developed by the Joanna Briggs Institute. The pooled prevalence of malaria and chikungunya co-infection among febrile patients and the pooled prevalence of chikungunya virus (CHIKV) infection among malaria patients were estimated with the random effect model. The odds of malaria and chikungunya co-infection among febrile patients were also estimated using a random effect model that presumed the heterogeneity of the outcomes of the included studies. The heterogeneity among the included studies was assessed using the Cochran Q test and I2 statistics. Publication bias was assessed using the funnel plot and Egger’s test. Results: Of the 1924 studies that were identified from the three databases, 10 fulfilled the eligibility criteria and were included in our study. The pooled prevalence of malaria and chikungunya co-infection (182 cases) among febrile patients (16,787 cases), stratified by diagnostic tests for CHIKV infection, was 10% (95% confidence interval (CI): 8–11%, I2: 99.5%) using RDT (IgM), 7% (95% CI: 4–10%) using the plaque reduction neutralization test (PRNT), 1% (95% CI: 0–2%, I2: 41.5%) using IgM and IgG ELISA, and 4% (95% CI: 2–6%) using real-time RT-PCR. When the prevalence was stratified by country, the prevalence of co-infection was 7% (95% CI: 5–10%, I2: 99.5%) in Nigeria, 1% (95% CI: 0–2%, I2: 99.5%) in Tanzania, 10% (95% CI: 8–11%) in Sierra Leone, 1% (95% CI: 0–4%) in Mozambique, and 4% (95% CI: 2–6%) in Kenya. The pooled prevalence of CHIKV infection (182 cases) among malaria patients (8317 cases), stratified by diagnostic tests for CHIKV infection, was 39% (95% CI: 34–44%, I2: 99.7%) using RDT (IgM), 43% (95% CI: 30–57%) using PRNT, 5% (95% CI: 3–7%, I2: 5.18%) using IgM and IgG ELISA, and 9% (95% CI: 6–15%) using real-time RT-PCR. The meta-analysis showed that malaria and chikungunya co-infection occurred by chance (p: 0.59, OR: 0.32, 95% CI: 0.6–1.07, I2: 78.5%). Conclusions: The prevalence of malaria and chikungunya co-infection varied from 0% to 10% as per the diagnostic test for CHIKV infection or the country where the co-infection was reported. Hence, the clinicians who diagnose patients with malaria infections in areas where two diseases are endemic should further investigate for chikungunya co-infection to prevent misdiagnosis or delayed treatment of concurrent infection

    Evidence of malarial chemoprophylaxis among travellers who died from malaria: a systematic review and meta-analysis

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    Abstract Background Chemoprophylaxis is a prevention method for malaria during travel in malaria-endemic countries. This study aimed to collate and synthesize the evidence of malarial chemoprophylaxis among malaria death cases. Methods Studies documenting malarial chemoprophylaxis related to malaria deaths were searched in PubMed, Scopus, MEDLINE, Embase, and CENTRAL until 3 July 2022. The pooled proportion of malarial chemoprophylaxis among death cases was synthesized using logit transformation and back transformation to a proportion performed using generalized linear mixed models. The pooled log odds ratio (log-OR) with a 95% confidence interval (CI) of malarial chemoprophylaxis in death cases compared to survivors were synthesized. Results Fifty-eight studies were included in the systematic review and the meta-analysis. Of 602 pooled malaria death cases, the number of patients who took chemoprophylaxis was 187 (30%) (95% CI 22–40, P < 0.01, 58 studies), and those who took adequate chemoprophylaxis were 24 (5%) (95% CI 2–13, P < 0.01, 42 studies). A comparable log-OR of underwent chemoprophylaxis was observed between malaria death cases and survivors (P = 0.94, pooled log-OR: − 0.02, 95% CI − 0.46–0.42, I2: 0%, 17 studies). Similarly, a comparable log-OR of adequate chemoprophylaxis was identified between malaria death cases and survivors (P = 0.15, pooled log-OR: 0.83, 95% CI − 0.30–1.97, I2: 47.08%, 11 studies). Conclusions Among the studies where malarial chemoprophylaxis was reported, approximately 30% of malaria death cases had taken such prophylaxis. Notably, only 5% of these cases adhered fully or adequately to the recommended chemoprophylactic regimen. However, the analysis did not reveal a significant difference in the odds of malarial chemoprophylaxis between malaria death cases and survivors

    Differences in catalase levels between malaria-infected individuals and uninfected controls: a systematic review and meta-analysis

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    Abstract Inconsistent catalase (CAT) research necessitates a comprehensive review of CAT levels among patients with malaria to achieve better therapeutic strategies. This study aimed to systematically review and meta-analyze available literature on CAT levels in nonpregnant and pregnant individuals with malaria compared with those in uninfected controls, with the goal of providing a robust evidence base for future research and potential interventions. Following PRISMA guidelines, a systematic literature search across six databases was conducted to examine CAT levels in patients with malaria. Data was extracted independently by two reviewers, and study quality was assessed using the Joanna Briggs Institute (JBI) critical appraisal checklist. The standardized mean difference of CAT levels was calculated with heterogeneity assessment. Subgroup and sensitivity analyses were conducted to explore heterogeneity and assess the robustness of the findings. Publication bias was visually and statistically assessed and corrected, if necessary. Statistical analyses were performed using Stata software, with a significance level set at P < 0.05. Nineteen studies were included in the review. These studies, published from before 2000 to 2023, primarily from Africa and Asia, focused on different Plasmodium species and age groups. Results of qualitative synthesis among nonpregnant individuals consistently showed lower CAT levels in malaria-infected individuals, although some studies reported higher levels. No significant differences in CAT levels were found between malaria-infected and uninfected individuals, as demonstrated by a meta-analysis overall (P = 0.05, Hedges’ g: − 0.78, 95% confidence interval (CI): (− 1.56)–0.01, I2: 98.47, 15 studies), but subgroup analyses showed significant differences in CAT levels in studies conducted in Africa (P = 0.02, Hedges’ g: − 0.57, 95% CI: − 1.02–(0.11), I2: 91.81, 7 studies), and in studies that specifically focused on children (P = 0.03, Hedges’ g: − 0.57, 95% CI: − 1.07–(− 0.07), I2: 87.52, 4 studies). Pregnant women showed variations in CAT levels across trimesters. This study provides valuable insights into the association between malaria infection and CAT enzyme levels, particularly in nonpregnant individuals. Furthermore, well-designed studies are essential to decoding the intricacies of this relationship, which could have significant implications for understanding disease processes and improving patient care
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