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Parasites & Vectors Jul 2024Application of numerous malaria control interventions has led to reduction in clinical malaria cases and deaths but also the realisation that asymptomatic parasite...
BACKGROUND
Application of numerous malaria control interventions has led to reduction in clinical malaria cases and deaths but also the realisation that asymptomatic parasite carriers play a key role in sustaining transmission. This study assessed the effectiveness of using the Ultra-sensitive NxTek eliminate RDT (uRDT) and conventional SD Bioline HRP2 RDT (cRDT) in diagnosing asymptomatic parasitaemia while measuring the impact of mass testing, treatment and tracking (MTTT) on the prevalence of asymptomatic malaria over a 1-year period in Ghana.
METHODS
A total of 4000 targeted participants from two towns, Obom and Kofi Kwei, with their surrounding villages, were tested for asymptomatic malaria four times over the study period using uRDT (intervention) and the cRDT (control) respectively. Participants carrying malaria parasites were followed by home visit and phone calls for compliance to treatment, and filter paper blood blots collected from participants were used to determine true parasite carriage by PET-PCR. A mathematical model of the study site was developed and used to test the impact of test sensitivity and mass migration on the effect of MTTT.
RESULTS
The start and end point sensitivities of the cRDT were 48.8% and 41.7% and those for the uRDT were 52.9% and 59.9% respectively. After a year of MTTTs, asymptomatic parasite prevalence, as determined by PCR, did not differ statistically in the control site (40.6% to 40.1%, P = 0.730) but decreased at the intervention site (55.9% to 46.4%, P < 0.0001). Parasite prevalence by RDT, however, indicated statistical reduction in the control site (25.3% to 22.3%, P = 0.017) and no change in the intervention site (35.1% to 36.0%, P = 0.614). The model predicted a mild effect of both diagnostic sensitivity and human movement in diminishing the impact of MTTT in the study sites.
CONCLUSIONS
Asymptomatic parasite prevalence at the molecular level reduced significantly in the site where the uRDT was used but not where the cRDT was used. Overall, the uRDT exhibited higher sensitivity relative to the cRDT. Highly sensitive molecular techniques such as PET-PCR should be included in parasite prevalence estimation during MTTT exercises.
Topics: Ghana; Humans; Female; Male; Sensitivity and Specificity; Adult; Adolescent; Child, Preschool; Young Adult; Child; Diagnostic Tests, Routine; Parasitemia; Malaria, Falciparum; Middle Aged; Malaria; Plasmodium falciparum; Prevalence; Mass Screening; Infant
PubMed: 38951912
DOI: 10.1186/s13071-024-06354-x -
Journal of Orthopaedic Surgery and... Jul 2024Bone defects, resulting from substantial bone loss that exceeds the natural self-healing capacity, pose significant challenges to current therapeutic approaches due to...
BACKGROUND
Bone defects, resulting from substantial bone loss that exceeds the natural self-healing capacity, pose significant challenges to current therapeutic approaches due to various limitations. In the quest for alternative therapeutic strategies, bone tissue engineering has emerged as a promising avenue. Notably, excretory proteins from Toxoplasma gondii (TgEP), recognized for their immunogenicity and broad spectrum of biological activities secreted or excreted during the parasite's lifecycle, have been identified as potential facilitators of osteogenic differentiation in human bone marrow mesenchymal stem cells (hBMSCs). Building on our previous findings that TgEP can enhance osteogenic differentiation, this study investigated the molecular mechanisms underlying this effect and assessed its therapeutic potential in vivo.
METHODS
We determined the optimum concentration of TgEP through cell cytotoxicity and cell proliferation assays. Subsequently, hBMSCs were treated with the appropriate concentration of TgEP. We assessed osteogenic protein markers, including alkaline phosphatase (ALP), Runx2, and Osx, as well as components of the BMP/Smad signaling pathway using quantitative real-time PCR (qRT-PCR), siRNA interference of hBMSCs, Western blot analysis, and other methods. Furthermore, we created a bone defect model in Sprague-Dawley (SD) male rats and filled the defect areas with the GelMa hydrogel, with or without TgEP. Microcomputed tomography (micro-CT) was employed to analyze the bone parameters of defect sites. H&E, Masson and immunohistochemical staining were used to assess the repair conditions of the defect area.
RESULTS
Our results indicate that TgEP promotes the expression of key osteogenic markers, including ALP, Runx2, and Osx, as well as the activation of Smad1, BMP2, and phosphorylated Smad1/5-crucial elements of the BMP/Smad signaling pathway. Furthermore, in vivo experiments using a bone defect model in rats demonstrated that TgEP markedly promoted bone defect repair.
CONCLUSION
Our results provide compelling evidence that TgEP facilitates hBMSC osteogenic differentiation through the BMP/Smad signaling pathway, highlighting its potential as a therapeutic approach for bone tissue engineering for bone defect healing.
Topics: Mesenchymal Stem Cells; Osteogenesis; Humans; Animals; Signal Transduction; Cell Differentiation; Rats, Sprague-Dawley; Male; Toxoplasma; Rats; Smad Proteins; Protozoan Proteins; Bone Morphogenetic Proteins; Cells, Cultured
PubMed: 38951811
DOI: 10.1186/s13018-024-04839-0 -
BMJ Open Jul 2024Toxoplasmosis is a zoonotic parasitic disease caused by . It has a wide host range and is capable of vertical transmission in pregnant women, which may lead to...
BACKGROUND
Toxoplasmosis is a zoonotic parasitic disease caused by . It has a wide host range and is capable of vertical transmission in pregnant women, which may lead to undesirable pregnancy outcomes such as congenital malformations, miscarriage, premature birth and stillbirth. This study investigated the seroprevalence of infection among pregnant women attending the antenatal clinic at Namwala District Hospital in Southern Zambia.
METHODS
This was a cross-sectional study where blood was collected, and the serum was tested for IgG and IgM. A questionnaire was administered to participants on demographic characteristics and risk factors. Data were entered in Microsoft Excel and exported to STATA version 14 for analysis.
RESULTS
A total of 401 women were enrolled in the study from 3 March to 5 August 2021. The seroprevalence of IgG was 4.2% (n=17), while the seroprevalence of IgM was 0.7% (n=3). The median age was 27 (IQR: 24-30) years, and a larger proportion had primary-level education (n=223, 55.6%). The majority (81.6%) of the women were married. None of the risk factors investigated in this study were significant for infection.
CONCLUSION
There was a low seroprevalence of infection among pregnant women in the Namwala district of Southern Province, Zambia, and regular screening may not be warranted in this population. Continued research on toxoplasmosis is recommended to understand its epidemiology across Zambia.
Topics: Humans; Female; Zambia; Cross-Sectional Studies; Seroepidemiologic Studies; Adult; Pregnancy; Toxoplasmosis; Risk Factors; Toxoplasma; Young Adult; Immunoglobulin M; Antibodies, Protozoan; Pregnancy Complications, Parasitic; Immunoglobulin G; Prenatal Care
PubMed: 38950992
DOI: 10.1136/bmjopen-2024-084582 -
PloS One 2024Toxoplasma gondii can cause symptomatic toxoplasmosis in immunodeficient hosts, including in people living with human immunodeficiency virus (PLWH), mainly because of...
INTRODUCTION
Toxoplasma gondii can cause symptomatic toxoplasmosis in immunodeficient hosts, including in people living with human immunodeficiency virus (PLWH), mainly because of the reactivation of latent infection. We assessed the prevalence of toxoplasmosis and its associated risk factors in PLWH in the Asia-Pacific region using data from the TREAT Asia Human Immunodeficiency Virus (HIV) Observational Database (TAHOD) of the International Epidemiology Databases to Evaluate AIDS (IeDEA) Asia-Pacific.
METHODS
This study included both retrospective and prospective cases of toxoplasmosis reported between 1997 and 2020. A matched case-control method was employed, where PLWH diagnosed with toxoplasmosis (cases) were each matched to two PLWH without a toxoplasmosis diagnosis (controls) from the same site. Sites without toxoplasmosis were excluded. Risk factors for toxoplasmosis were analyzed using conditional logistic regression.
RESULTS
A total of 269/9576 (2.8%) PLWH were diagnosed with toxoplasmosis in 19 TAHOD sites. Of these, 227 (84%) were reported retrospectively and 42 (16%) were prospective diagnoses after cohort enrollment. At the time of toxoplasmosis diagnosis, the median age was 33 years (interquartile range 28-38), and 80% participants were male, 75% were not on antiretroviral therapy (ART). Excluding 63 out of 269 people without CD4 values, 192 (93.2%) had CD4 ≤200 cells/μL and 162 (78.6%) had CD4 ≤100 cells/μL. By employing 538 matched controls, we found that factors associated with toxoplasmosis included abstaining from ART (odds ratio [OR] 3.62, 95% CI 1.81-7.24), in comparison to receiving nucleoside reverse transcriptase inhibitors plus non-nucleoside reverse transcriptase inhibitors, HIV exposure through injection drug use (OR 2.27, 95% CI 1.15-4.47) as opposed to engaging in heterosexual intercourse and testing positive for hepatitis B virus surface antigen (OR 3.19, 95% CI 1.41-7.21). Toxoplasmosis was less likely with increasing CD4 counts (51-100 cells/μL: OR 0.41, 95% CI 0.18-0.96; 101-200 cells/μL: OR 0.14, 95% CI 0.06-0.34; >200 cells/μL: OR 0.02, 95% CI 0.01-0.06), when compared to CD4 ≤50 cells/μL. Moreover, the use of prophylactic cotrimoxazole was not associated with toxoplasmosis.
CONCLUSIONS
Symptomatic toxoplasmosis is rare but still occurs in PLWH in the Asia-Pacific region, especially in the context of delayed diagnosis, causing advanced HIV disease. Immune reconstitution through early diagnosis and ART administration remains a priority in Asian PLWH.
Topics: Humans; Male; Risk Factors; Adult; Female; Toxoplasmosis; HIV Infections; Asia; Retrospective Studies; Case-Control Studies; Middle Aged; Prevalence; Prospective Studies; Toxoplasma
PubMed: 38950027
DOI: 10.1371/journal.pone.0306245 -
PloS One 2024Co-infections are a common reality but understanding how the immune system responds in this context is complex and can be unpredictable. Heligmosomoides bakeri...
Heligmosomoides bakeri and Toxoplasma gondii co-infection leads to increased mortality associated with changes in immune resistance in the lymphoid compartment and disease pathology.
Co-infections are a common reality but understanding how the immune system responds in this context is complex and can be unpredictable. Heligmosomoides bakeri (parasitic roundworm, previously Heligmosomoides polygyrus) and Toxoplasma gondii (protozoan parasite) are well studied organisms that stimulate a characteristic Th2 and Th1 response, respectively. Several studies have demonstrated reduced inflammatory cytokine responses in animals co-infected with such organisms. However, while general cytokine signatures have been examined, the impact of the different cytokine producing lymphocytes on parasite control/clearance is not fully understood. We investigated five different lymphocyte populations (NK, NKT, γδ T, CD4+ T and CD8+ T cells), five organs (small intestine, Peyer's patches, mesenteric lymph nodes, spleen and liver), and 4 cytokines (IFN©, IL-4, IL-10 and IL-13) at two different time points (days 5 and 10 post T. gondii infection). We found that co-infected animals had significantly higher mortality than either single infection. This was accompanied by transient and local changes in parasite loads and cytokine profiles. Despite the early changes in lymphocyte and cytokine profiles, severe intestinal pathology in co-infected mice likely contributed to early mortality due to significant damage by both parasites in the small intestine. Our work demonstrates the importance of taking a broad view during infection research, studying multiple cell types, organs/tissues and time points to link and/or uncouple immunological from pathological findings. Our results provide insights into how co-infection with parasites stimulating different arms of the immune system can lead to drastic changes in infection dynamics.
Topics: Animals; Coinfection; Toxoplasma; Mice; Cytokines; Nematospiroides dubius; Strongylida Infections; Toxoplasmosis; Female; Toxoplasmosis, Animal; Spleen; Parasite Load; Lymphoid Tissue
PubMed: 38950025
DOI: 10.1371/journal.pone.0292408 -
PloS One 2024Although the overall burden of malaria is decreasing in Ethiopia, a recent report of an unpredictable increased incidence may be related to the presence of...
Although the overall burden of malaria is decreasing in Ethiopia, a recent report of an unpredictable increased incidence may be related to the presence of community-wide gametocyte-carrier individuals and a high proportion of infected vectors. This study aimed to reveal the current prevalence of gametocyte-carriage and the sporozoite infectivity rate of Anopheles vectors for Plasmodium parasites. A community-based cross-sectional study was conducted from May 01 to June 30/2019. A total of 53 households were selected using systematic random sampling and a 242 study participants were recruited. Additionally,515 adult female Anopheles mosquitoes were collected using Center for Diseases Control and Prevention (CDC) light traps and mouth aspirators. Parasite gametocytemia was determined using giemsa stain microscopy, while sporozoite infection was determined by giemsa staining microscopy and enzyme linked immunosorbent assay (ELISA). Among the total 242 study participants, 5.4% (95%, CI = 2.9-8.3) of them were positive for any of the Plasmodium species gametocyte. Furthermore, being female [AOR = 15.5(95%, CI = 1.71-140.39)], age group between 15-29 years old [AOR = 16.914 (95%, CI = 1.781-160.63)], no ITNs utilization [AOR = 16.7(95%, CI = 1.902 -146.727)], and high asexual parasite density [(95%, CI = 0.057-0.176, P = 0.001, F = 18.402)] were identified as statistically significant factors for gametocyte carriage. Whereas sporozoite infection rate was 11.6% (95%, CI = 8.2-15.5) and 12.7% (95%, CI = 9.6-16.3) by microscopy and ELISA, respectively. Overall, this study indicated that malaria remains to be an important public health problem in Gondar Zuria district where high gametocyte carriage rate and sporozoite infection rate could sustain its transmission and burden. Therefore, in Ethiopia, where malaria elimination program is underway, frequent, and active community-based surveillance of gametocytemia and sporozoite infection rate is important.
Topics: Animals; Ethiopia; Humans; Anopheles; Female; Adult; Sporozoites; Adolescent; Young Adult; Male; Cross-Sectional Studies; Mosquito Vectors; Child; Child, Preschool; Malaria; Middle Aged; Plasmodium; Infant; Plasmodium falciparum; Prevalence
PubMed: 38950022
DOI: 10.1371/journal.pone.0306289 -
Parasite (Paris, France) 2024Wild rodents serve as reservoirs for Cryptosporidium and are overpopulated globally. However, genetic data regarding Cryptosporidium in these animals from China are...
Wild rodents serve as reservoirs for Cryptosporidium and are overpopulated globally. However, genetic data regarding Cryptosporidium in these animals from China are limited. Here, we have determined the prevalence and genetic characteristics of Cryptosporidium among 370 wild rodents captured from three distinct locations in the southern region of Zhejiang Province, China. Fresh feces were collected from the rectum of each rodent, and DNA was extracted from them. The rodent species was identified by PCR amplifying the vertebrate cytochrome b gene. Cryptosporidium was detected by PCR amplification and amplicon sequencing the small subunit of ribosomal RNA gene. Positive samples of C. viatorum and C. parvum were further subtyped by analyzing the 60-kDa glycoprotein gene. A positive Cryptosporidium result was found in 7% (26/370) of samples, involving five rodent species: Apodemus agrarius (36), Niviventer niviventer (75), Rattus losea (18), R. norvegicus (155), and R. tanezumi (86). Their respective Cryptosporidium positive rates were 8.3%, 5.3%, 11.1%, 7.1%, and 7.0%. Sequence analysis confirmed the presence of three Cryptosporidium species: C. parvum (4), C. viatorum (1), and C. muris (1), and two genotypes: Cryptosporidium rat genotype IV (16) and C. mortiferum-like (4). Additionally, two subtypes of C. parvum (IIdA15G1 and IIpA19) and one subtype of C. viatorum (XVdA3) were detected. These results demonstrate that various wild rodent species in Zhejiang were concurrently infected with rodent-adapted and zoonotic species/genotypes of Cryptosporidium, indicating that these rodents can play a role in maintaining and dispersing this parasite into the environment and other hosts, including humans.
Topics: Animals; Cryptosporidiosis; China; Cryptosporidium; Feces; Rodent Diseases; Animals, Wild; Rats; Rodentia; Prevalence; Public Health; Disease Reservoirs; Phylogeny; Humans; DNA, Protozoan; Murinae; Polymerase Chain Reaction; Zoonoses; Genotype
PubMed: 38949636
DOI: 10.1051/parasite/2024033 -
International Journal For Parasitology.... Aug 2024Reduncin bovids of spp. (Bovidae: Reduncini) are natively distributed in sub-Saharan Africa, although some populations have been introduced into parks and zoos around...
Remarks on spp. (Apicomplexa: Eimeriidae) from spp. (Bovidae: Reduncini), with supplementary morphological data of Ricci-Bitti et al., 1973 from a new host subspecies, the common waterbuck (Ogilbyi, 1833).
Reduncin bovids of spp. (Bovidae: Reduncini) are natively distributed in sub-Saharan Africa, although some populations have been introduced into parks and zoos around the world. The majority of the species has declining populations, being categorized as threatened by the International Union for Conservation of Nature and Natural Resources; therefore, protective measures for the conservation of spp. are necessary, including the study of their parasites, such as the eimeriid coccidians (Apicomplexa: Eimeriidae). In this context, the aim of the current study was to brings together the taxonomic data from the descriptions and reports of spp. from reduncin bovids, based on the detailed morphological identification of Ricci-Bitti, Pampiglione & Kabala, 1973 from a new host subspecies, the common waterbuck (Ogilbyi, 1833), in a safari park of Portugal. Five spp. are recorded from reduncin bovids, in addition to six more reports identified generically as sp., which were compared and taxonomically rearranged. The oocysts identified as in the current study were compatible with the original description and were supplemented for some taxonomic characters not originally included, such as: Stieda body flattened to nipplelike, sub-Stieda body rounded to trapezoidal, sporocyst residuum granular and membrane-bound, in addition to greater details of the micropyle, among others. Finally, the current study highlights the importance of studying the coccidians of reduncin bovids for the conservation of spp. due to the possibility of these spp. are extra-intestinal parasites, which can potentially cause severe coccidiosis associated with increased morbidity and mortality in certain threatened populations of spp.
PubMed: 38948237
DOI: 10.1016/j.ijppaw.2024.100952 -
PeerJ 2024The integration of diagnostic methods holds promise for advancing the surveillance of malaria transmission in both endemic and non-endemic regions. Serological assays...
BACKGROUND
The integration of diagnostic methods holds promise for advancing the surveillance of malaria transmission in both endemic and non-endemic regions. Serological assays emerge as valuable tools to identify and delimit malaria transmission, serving as a complementary method to rapid diagnostic tests (RDT) and thick smear microscopy. Here, we evaluate the potential of antibodies directed against peptides encompassing the entire amino acid sequence of the MSP-1 Sal-I strain as viable serological biomarkers for exposure.
METHODS
We screened peptides encompassing the complete amino acid sequence of the Merozoite Surface Protein 1 (MSP-1) Sal-I strain as potential biomarkers for exposure. Here, immunodominant peptides specifically recognized by antibodies from individuals infected with were identified using the SPOT-synthesis technique followed by immunoblotting. Two 15-mer peptides were selected based on their higher and specific reactivity in immunoblotting assays. Subsequently, peptides p70 and p314 were synthesized in soluble form using SPPS (Solid Phase Peptide Synthesis) and tested by ELISA (IgG, and subclasses).
RESULTS
This study unveils the presence of IgG antibodies against the peptide p314 in most -infected individuals from the Brazilian Amazon region. B-cell epitope prediction further supports the utilization of p314 as a potential biomarker for evaluating malaria transmission, strengthened by its amino acid sequence being part of a conserved block of MSP-1. Indeed, compared to patients infected with and uninfected individuals never exposed to malaria, -infected patients have a notably higher recognition of p314 by IgG1 and IgG3.
Topics: Humans; Malaria, Vivax; Merozoite Surface Protein 1; Plasmodium vivax; Biomarkers; Antibodies, Protozoan; Immunoglobulin G; Adult; Female; Male; Middle Aged; Peptides; Enzyme-Linked Immunosorbent Assay; Young Adult; Adolescent; Amino Acid Sequence
PubMed: 38948214
DOI: 10.7717/peerj.17632 -
Trends in Parasitology Jun 2024Gamete development is a precisely programmed process in Cryptosporidium parvum, a leading cause of diarrheal disease worldwide. Nava et al. recently described the...
Gamete development is a precisely programmed process in Cryptosporidium parvum, a leading cause of diarrheal disease worldwide. Nava et al. recently described the developmentally regulated expression of CDPK5 during male gametogenesis. Here we discuss their main findings, posing this protein kinase as a promising target for antiparasitic interventions.
PubMed: 38944561
DOI: 10.1016/j.pt.2024.06.007