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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 -
Acta Dermatovenerologica Croatica : ADC Mar 2024Cutaneous leishmaniasis (CL) is common in the pediatric population, but there are only a limited number of studies focused on the clinical and epidemiological...
Cutaneous leishmaniasis (CL) is common in the pediatric population, but there are only a limited number of studies focused on the clinical and epidemiological characteristics of patients in this age group. In this study, our objective was to investigate the epidemiological and clinical characteristics of pediatric subjects diagnosed with CL. A total of 8047 patients who had been diagnosed with CL between 2010 and 2021 in an endemic region were included in this retrospective study. The clinical and demographic characteristics such as age, gender, number, size, duration, location, and type of lesions and the administered CL treatments were recorded. In order to better understand the epidemiological and clinical characteristics of patients with pediatric CL (PCL), the study patients were divided into three groups according to their age (0-6, 7-12, and 13-18 years) and the clinical and epidemiological characteristics of these groups were compared. When patients with PCL were compared according to age groups, it was found that the highest number of patients were in the 13-18 age group. It was determined that the patients in the 6-12 age group had fewer lesions, that and the size of the lesions was smaller than the other groups. The disease duration was the longest in the 0-5 age group. The highest rate of nodular, ulcerated, and recurrent lesions was in the 13-18 age group, and the highest rate of papular lesions was in the 6-12 age group. Systemic pentavalent antimony therapy (IM or IV) was administered to 438 patients with PCL (5.44%), while intralesional pentavalent antimony therapy (IL) was administered to 7447 patients (92.54%). Patients receiving systemic therapy had larger lesions compared with patients receiving IL therapy and no treatment. The lesion duration was longer in patients who received systemic treatment, and the number of lesions was higher than those who received IL treatment. The highest rate of systemic treatment was in the 13-18 age group (43.8%). In conclusion, our study found that the intragroup comparison of the age group with the highest CL rate displayed similar clinico-epidemiological characteristics reported in previous studies conducted in the same region.
Topics: Humans; Leishmaniasis, Cutaneous; Child; Retrospective Studies; Turkey; Adolescent; Male; Female; Child, Preschool; Infant; Infant, Newborn; Antiprotozoal Agents
PubMed: 38946187
DOI: No ID Found -
Nature Communications Jun 2024Children in malaria-endemic regions can experience repeated Plasmodium infections over short periods of time. Effects of re-infection on multiple co-existing CD4 T cell...
Children in malaria-endemic regions can experience repeated Plasmodium infections over short periods of time. Effects of re-infection on multiple co-existing CD4 T cell subsets remain unresolved. Here, we examine antigen-experienced CD4 T cells during re-infection in mice, using scRNA-seq/TCR-seq and spatial transcriptomics. TCR transgenic T cells initiate rapid Th1/Tr1 recall responses prior to proliferating, while GC Tfh counterparts are refractory, with T/Tfh-like cells exhibiting modest non-proliferative responses. Th1-recall is a partial facsimile of primary Th1-responses, with no upregulated effector-associated genes being unique to recall. Polyclonal, TCR-diverse, CD4 T cells exhibit similar recall dynamics, with individual clones giving rise to multiple effectors including highly proliferative Th1/Tr1 cells, as well as GC Tfh and Tfh-like cells lacking proliferative capacity. Thus, we show substantial diversity in recall responses mounted by multiple co-existing CD4 T cell subsets in the spleen, and present graphical user interfaces for studying gene expression dynamics and clonal relationships during re-infection.
Topics: Animals; Malaria; CD4-Positive T-Lymphocytes; Mice; Reinfection; Th1 Cells; Mice, Inbred C57BL; Spleen; Receptors, Antigen, T-Cell; Mice, Transgenic; Female; Immunologic Memory
PubMed: 38944658
DOI: 10.1038/s41467-024-49879-6 -
Malaria Journal Jun 2024Microscopic detection of malaria parasites is labour-intensive, time-consuming, and expertise-demanding. Moreover, the slide interpretation is highly dependent on the...
BACKGROUND
Microscopic detection of malaria parasites is labour-intensive, time-consuming, and expertise-demanding. Moreover, the slide interpretation is highly dependent on the staining technique and the technician's expertise. Therefore, there is a growing interest in next-generation, fully- or semi-integrated microscopes that can improve slide preparation and examination. This study aimed to evaluate the clinical performance of miLab™ (Noul Inc., Republic of Korea), a fully-integrated automated microscopy device for the detection of malaria parasites in symptomatic patients at point-of-care in Sudan.
METHODS
This was a prospective, case-control diagnostic accuracy study conducted in primary health care facilities in rural Khartoum, Sudan in 2020. According to the outcomes of routine on-site microscopy testing, 100 malaria-positive and 90 malaria-negative patients who presented at the health facility and were 5 years of age or older were enrolled consecutively. All consenting patients underwent miLab™ testing and received a negative or suspected result. For the primary analysis, the suspected results were regarded as positive (automated mode). For the secondary analysis, the operator reviewed the suspected results and categorized them as either negative or positive (corrected mode). Nested polymerase chain reaction (PCR) was used as the reference standard, and expert light microscopy as the comparator.
RESULTS
Out of the 190 patients, malaria diagnosis was confirmed by PCR in 112 and excluded in 78. The sensitivity of miLab™ was 91.1% (95% confidence interval [CI] 84.2-95.6%) and the specificity was 66.7% (95% Cl 55.1-67.7%) in the automated mode. The specificity increased to 96.2% (95% Cl 89.6-99.2%), with operator intervention in the corrected mode. Concordance of miLab with expert microscopy was substantial (kappa 0.65 [95% CI 0.54-0.76]) in the automated mode, but almost perfect (kappa 0.97 [95% CI 0.95-0.99]) in the corrected mode. A mean difference of 0.359 was found in the Bland-Altman analysis of the agreement between expert microscopy and miLab™ for quantifying parasite counts.
CONCLUSION
When used in a clinical context, miLab™ demonstrated high sensitivity but low specificity. Expert intervention was shown to be required to improve the device's specificity in its current version. miLab™ in the corrected mode performed similar to expert microscopy. Before clinical application, more refinement is needed to ensure full workflow automation and eliminate human intervention. Trial registration ClinicalTrials.gov: NCT04558515.
Topics: Sudan; Microscopy; Humans; Case-Control Studies; Prospective Studies; Point-of-Care Systems; Female; Male; Sensitivity and Specificity; Child; Child, Preschool; Adult; Adolescent; Malaria; Young Adult; Middle Aged
PubMed: 38943203
DOI: 10.1186/s12936-024-05029-3 -
Parasites & Vectors Jun 2024Chicken coccidiosis is a protozoan disease that leads to considerable economic losses in the poultry industry. Live oocyst vaccination is currently the most effective...
Oral vaccination with a recombinant Lactobacillus plantarum expressing the Eimeria tenella rhoptry neck 2 protein elicits protective immunity in broiler chickens infected with Eimeria tenella.
BACKGROUND
Chicken coccidiosis is a protozoan disease that leads to considerable economic losses in the poultry industry. Live oocyst vaccination is currently the most effective measure for the prevention of coccidiosis. However, it provides limited protection with several drawbacks, such as poor immunological protection and potential reversion to virulence. Therefore, the development of effective and safe vaccines against chicken coccidiosis is still urgently needed.
METHODS
In this study, a novel oral vaccine against Eimeria tenella was developed by constructing a recombinant Lactobacillus plantarum (NC8) strain expressing the E. tenella RON2 protein. We administered recombinant L. plantarum orally at 3, 4 and 5 days of age and again at 17, 18 and 19 days of age. Meanwhile, each chick in the commercial vaccine group was immunized with 3 × 10 live oocysts of coccidia. A total of 5 × 10 sporulated oocysts of E. tenella were inoculated in each chicken at 30 days. Then, the immunoprotection effect was evaluated after E. tenella infection.
RESULTS
The results showed that the proportion of CD4 and CD8 T cells, the proliferative ability of spleen lymphocytes, inflammatory cytokine levels and specific antibody titers of chicks immunized with recombinant L. plantarum were significantly increased (P < 0.05). The relative body weight gains were increased and the number of oocysts per gram (OPG) was decreased after E. tenella challenge. Moreover, the lesion scores and histopathological cecum sections showed that recombinant L. plantarum can significantly relieve pathological damage in the cecum. The ACI was 170.89 in the recombinant L. plantarum group, which was higher than the 150.14 in the commercial vaccine group.
CONCLUSIONS
These above results indicate that L. plantarum expressing RON2 improved humoral and cellular immunity and enhanced immunoprotection against E. tenella. The protective efficacy was superior to that of vaccination with the commercial live oocyst vaccine. This study suggests that recombinant L. plantarum expressing the RON2 protein provides a promising strategy for vaccine development against coccidiosis.
Topics: Animals; Eimeria tenella; Chickens; Coccidiosis; Poultry Diseases; Protozoan Vaccines; Lactobacillus plantarum; Administration, Oral; Protozoan Proteins; Vaccination; Antibodies, Protozoan; Vaccines, Synthetic
PubMed: 38943202
DOI: 10.1186/s13071-024-06355-w -
Malaria Journal Jun 2024The Dual-Active Ingredient long-lasting insecticidal nets (Dual-AI LLIN) have been developed to counteract the reduced efficacy of pyrethroid (PY)-only nets due to... (Randomized Controlled Trial)
Randomized Controlled Trial
Will a lack of fabric durability be their downfall? Impact of textile durability on the efficacy of three types of dual-active-ingredient long-lasting insecticidal nets: a secondary analysis on malaria prevalence and incidence from a cluster-randomized trial in north-west Tanzania.
BACKGROUND
The Dual-Active Ingredient long-lasting insecticidal nets (Dual-AI LLIN) have been developed to counteract the reduced efficacy of pyrethroid (PY)-only nets due to widespread pyrethroid insecticide resistance in malaria vector mosquitoes. They constitute half of the nets distributed in sub-Saharan Africa between 2022 and 2024. However, their effectiveness once they develop holes is unclear, particularly in pyrethroid-resistant settings. This study evaluates the textile integrity of three dual- AI LLINs compared to standard PY LLN, over 3 years of use in a community in Tanzania and the associated impact on malaria prevalence and incidence.
METHODS
A secondary analysis of data from a randomized controlled trial (RCT) in North-western Tanzania was conducted to evaluate the effectiveness of α-cypermethrin only; pyriproxyfen and α-cypermethrin (PPF-PY); chlorfenapyr and α-cypermethrin (chlorfenapyr-PY); and the synergist piperonyl butoxide and permethrin (PBO-PY) LLINs on malaria infection prevalence and case incidence. The association between the net textile condition and 1/malaria prevalence over 3 years of use between 2019 and 2022, and 2/malaria case incidence in a cohort of children over 2 years of follow-up was assessed between 2019 and 2021.
RESULTS
There was no significant association between damaged (OR 0.98, 95% CI 0.71-1.37, p-value = 0.655) and too-torn (OR 1.07, 95% CI 0.77-1.47, p-value = 0.694) compared to intact nets on malaria prevalence for all net types. However, there were reduced rates of malaria case incidence in children sleeping under a net in good condition compared to too-torn nets (incidence rate ratio (IRR) 0.76 [95% CI 0.63-0.92], p = 0.005). Malaria incidence was also consistently lower in too-torn PBO-PY LLIN (IRR = 0.37 [95% CI 0.19-0.72], p = 0.003) and chlorfenapyr-PY LLIN (IRR = 0.45 [95% CI 0.33-0.97], p = 0.053) compared to an intact PY-only LLIN during the first year of follow up. In year 2, the incidence was only significantly lower in intact chlorfenapyr-PY LLIN (IRR = 0.49 [95% CI 0.29-0.81], p = 0.006) compared to intact PY LLIN.
CONCLUSION
The study confirmed that sleeping under a chlorfenapyr-PY LLIN or PBO-PY LLIN offered superior protection to pyrethroid-only nets even when torn. Preventing the development of holes is essential as they impact the level of protection offered against malaria infection.
TRIAL REGISTRATION
ClinicalTrials.gov, number (NCT03554616).
Topics: Insecticide-Treated Bednets; Tanzania; Malaria; Textiles; Incidence; Prevalence; Insecticides; Pyrethrins; Humans; Mosquito Control; Piperonyl Butoxide; Permethrin; Child, Preschool; Insecticide Resistance
PubMed: 38943155
DOI: 10.1186/s12936-024-05020-y -
Progress in Molecular Biology and... 2024Protozoan parasites are major hazards to human health, society, and the economy, especially in equatorial regions of the globe. Parasitic diseases, including... (Review)
Review
Protozoan parasites are major hazards to human health, society, and the economy, especially in equatorial regions of the globe. Parasitic diseases, including leishmaniasis, malaria, and others, contribute towards majority of morbidity and mortality. Around 1.1 million people die from these diseases annually. The lack of licensed vaccinations worsens the worldwide impact of these diseases, highlighting the importance of safe and effective medications for their prevention and treatment. However, the appearance of drug resistance in parasites continuously affects the availability of medications. The demand for novel drugs motivates global antiparasitic drug discovery research, necessitating the implementation of many innovative ways to maintain a continuous supply of promising molecules. Drug repurposing has come out as a compelling tool for drug development, offering a cost-effective and efficient alternative to standard de novo approaches. A thorough examination of drug repositioning candidates revealed that certain drugs may not benefit significantly from their original indications. Still, they may exhibit more pronounced effects in other disorders. Furthermore, certain medications can produce a synergistic effect, resulting in enhanced therapeutic effectiveness when given together. In this chapter, we outline the approaches employed in drug repurposing (sometimes referred to as drug repositioning), propose novel strategies to overcome these hurdles and fully exploit the promise of drug repurposing. We highlight a few major human protozoan diseases and a range of exemplary drugs repurposed for various protozoan infections, providing excellent outcomes for each disease.
Topics: Drug Repositioning; Humans; Animals; Protozoan Infections; Antiprotozoal Agents
PubMed: 38942539
DOI: 10.1016/bs.pmbts.2024.05.001