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PLoS Pathogens Jul 2024The regulation of inflammatory responses and pulmonary disease during SARS-CoV-2 infection is incompletely understood. Here we examine the roles of the prototypic pro-...
The regulation of inflammatory responses and pulmonary disease during SARS-CoV-2 infection is incompletely understood. Here we examine the roles of the prototypic pro- and anti-inflammatory cytokines IFNγ and IL-10 using the rhesus macaque model of mild COVID-19. We find that IFNγ drives the development of 18fluorodeoxyglucose (FDG)-avid lesions in the lungs as measured by PET/CT imaging but is not required for suppression of viral replication. In contrast, IL-10 limits the duration of acute pulmonary lesions, serum markers of inflammation and the magnitude of virus-specific T cell expansion but does not impair viral clearance. We also show that IL-10 induces the subsequent differentiation of virus-specific effector T cells into CD69+CD103+ tissue resident memory cells (Trm) in the airways and maintains Trm cells in nasal mucosal surfaces, highlighting an unexpected role for IL-10 in promoting airway memory T cells during SARS-CoV-2 infection of macaques.
PubMed: 38950078
DOI: 10.1371/journal.ppat.1012339 -
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) 2024Myxidium rhodei Léger, 1905 (Cnidaria: Myxozoa) is a kidney-infecting myxosporean that was originally described from the European bitterling Rhodeus amarus....
Myxidium rhodei Léger, 1905 (Cnidaria: Myxozoa) is a kidney-infecting myxosporean that was originally described from the European bitterling Rhodeus amarus. Subsequently, it has been documented based on spore morphology in more than 40 other cypriniform species, with the roach Rutilus rutilus being the most commonly reported host. This study introduces the first comprehensive data assessment of M. rhodei, conducted through morphological, ecological and molecular methods. The morphological and phylogenetic analyses of SSU rDNA sequences of Myxidium isolates obtained from European bitterling and roach did not support parasite conspecificity from these fish. In fact, the roach-infecting isolates represent three distinct parasite species. The first two, M. rutili n. sp. and M. rutilusi n. sp., are closely related cryptic species clustering with other myxosporeans in the freshwater urinary clade, sharing the same tissue tropism. The third one, M. batuevae n. sp., previously assigned to M. cf. rhodei, clustered in the hepatic biliary clade sister to bitterling-infecting M. rhodei. Our examination of diverse cypriniform fishes, coupled with molecular and morphological analyses, allowed us to untangle the cryptic species nature of M. rhodei and discover the existence of novel species. This underscores the largely undiscovered range of myxozoan diversity and highlights the need to incorporate sequence data in diagnosing novel species.
Topics: Animals; Myxozoa; Phylogeny; Parasitic Diseases, Animal; Fish Diseases; Host Specificity; Cypriniformes; DNA, Ribosomal; Kidney; Cyprinidae
PubMed: 38949637
DOI: 10.1051/parasite/2024030 -
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 Maritime Health 2024The World Health Organization (WHO) reported an estimated 249 million malaria cases globally in 2023, of which 94% were reported from Africa. Tanzania, a Sub-Saharan...
BACKGROUND
The World Health Organization (WHO) reported an estimated 249 million malaria cases globally in 2023, of which 94% were reported from Africa. Tanzania, a Sub-Saharan African country, has an exceptionally high malaria prevalence (3.6 million in 2023). The aim of the present study was to assess malaria prevalence rates in the Arusha Region, northern Tanzania. This region is famous for its national parks and wildlife reserves, and it is visited by thousands of tourists from all over the world each year. The assessment of malaria prevalence in the region is important in the context of the necessity to administer antimalarial chemoprophylaxis to international travellers.
MATERIAL AND METHODS
The study group consisted of 101 people, residents of the Karatu District in the Arusha Region, aged between 1 and 73 years, who volunteered to participate in the screening. Phase I of the study was conducted in July 2022 in the Karatu Lutheran Hospital in Karatu Town (located close to the Ngorongoro Conservation Area and the Serengeti National Park). During this phase a venous blood sample was collected from each patient. The samples were tested for malaria using a rapid diagnostic test (mRDT); the same samples were also used to measure haemoglobin concentration and next they were applied onto the Whatman FTA micro cards for further molecular diagnostics in Poland (phase II).
RESULTS
mRDT detected two (2.0%) infections caused by Plasmodium (the etiological factor of malaria), the molecular tests (RT-PCR) confirmed the two positive results by mRDT but also detected infections in six other samples (7.9% in total). The study found that six patients were infected with the Plasmodium falciparum species, while two other subjects had co-infections (P. falciparum + P. ovale, P. falciparum + P. vivax + P. malariae).
CONCLUSIONS
The study findings confirm the prevalence of malaria in areas located close to national parks in northern Tanzania and support the use of antimalarial chemoprophylaxis in international travellers visiting the area. The present study found co-infections caused by four different species of Plasmodium species which supports the prevalence of different parasitic species in Sub-Saharan Africa and is in line with CDC reports but contrary to WHO reports which estimate that 100% of malaria cases in Sub-Saharan Africa are caused by P. falciparum.
Topics: Humans; Tanzania; Prevalence; Adult; Middle Aged; Adolescent; Male; Female; Child; Aged; Young Adult; Child, Preschool; Malaria; Infant; Antimalarials
PubMed: 38949218
DOI: 10.5603/imh.100440 -
F1000Research 2024This scoping review will identify existing literature regarding contextual factors relevant to vector-control interventions to prevent malaria. We will use the findings... (Review)
Review
OBJECTIVE
This scoping review will identify existing literature regarding contextual factors relevant to vector-control interventions to prevent malaria. We will use the findings of the scoping review to produce an interactive evidence and gap map. The map will assist in the priority setting, development, and conduct of targeted systematic reviews. These systematic reviews seek to assist the Vector Control and Insecticide Resistance Unit of the World Health Organization's Global Malaria Programme by informing recommendation development by their Guidelines Development Group.
INTRODUCTION
Malaria contributes substantially to the global burden of disease, with an estimated 247 million cases and 619,000 deaths in 2021. Vector-control is key in reducing malaria transmission. Vector-control interventions directly target the mosquito, reducing the potential for parasite infections. These interventions commonly include insecticides used in indoor residual spraying or insecticide-treated nets and larval source management. Several new vector-control interventions are under evaluation to complement these. In addition to estimating the effects of interventions on health outcomes, it is critical to understand how populations at risk of malaria consider them in terms of their feasibility, acceptability, and values.
INCLUSION CRITERIA
Eligible studies will have assessed the contextual factors of feasibility or acceptability of the interventions of interest, or the valuation of the outcomes of interests. These assessments will be from the perspective of people who receive (residents) or deliver (workers or technicians) the vector-control intervention for the purpose of preventing malaria.
METHODS
We will conduct this scoping review in accordance with the JBI methodology for scoping reviews and report in line with the Preferred Reporting Items for Systematic Reviews and Meta-analyses extension for Scoping Reviews (PRISMA-ScR). We will construct the evidence and gap map following guidance from the Campbell Collaboration.
Topics: Malaria; Humans; Mosquito Control; Animals; Insecticides; Mosquito Vectors
PubMed: 38948349
DOI: 10.12688/f1000research.144661.1 -
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 -
Cureus May 2024Omalizumab, a humanized anti-IgE monoclonal antibody, is commonly employed in the treatment of antihistamine-refractory chronic spontaneous urticaria (CSU), where it...
Omalizumab, a humanized anti-IgE monoclonal antibody, is commonly employed in the treatment of antihistamine-refractory chronic spontaneous urticaria (CSU), where it significantly reduces free IgE levels, minimizing histamine release from basophils and mast cells. Despite its efficacy, there are concerns regarding its effect on parasitic defense due to IgE's role in combating parasitic infestations. We present a case of a 28-year-old female agriculturist with a six-month history of CSU who experienced a paradoxical exacerbation of her symptoms following an increase in the omalizumab treatment dose. This deterioration coincided with a serologically confirmed parasitic infection with and . Despite normal eosinophil counts and IgE levels, which are typically used to identify parasitic infections, the patient's clinical worsening prompted further investigation that led to the identification of the parasitic infection. Treatment with albendazole and omalizumab discontinuation led to the resolution of her CSU, suggesting that the parasitic infection was contributing to the symptom exacerbation. This case highlights the need for careful screening for parasitic infections before initiating omalizumab in antihistamine-refractory CSU patients from endemic regions, or patients who deteriorate clinically on omalizumab, especially when other indicators such as eosinophil count and IgE levels might not suggest infection. It also underscores the importance of considering a tailored approach to managing CSU that balances effective treatment with the potential for adverse effects related to immunomodulation.
PubMed: 38947573
DOI: 10.7759/cureus.61453