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Parasites & Vectors Jun 2024Reliance on praziquantel for the treatment and control of schistosomiasis is likely to facilitate the emergence of drug resistance. Combination therapy targeting adult... (Randomized Controlled Trial)
Randomized Controlled Trial
Efficacy and safety of single-dose artesunate plus sulfalene/pyrimethamine combined with praziquantel for the treatment of children with Schistosoma mansoni or Schistosoma haematobium in western Kenya: a randomised, open-label controlled trial.
BACKGROUND
Reliance on praziquantel for the treatment and control of schistosomiasis is likely to facilitate the emergence of drug resistance. Combination therapy targeting adult and juvenile schistosome worms is urgently needed to improve praziquantel efficacy and delay the potential development of drug resistance. We assessed the efficacy and safety of single-dose praziquantel combined with single-dose artesunate plus sulfalene-pyrimethamine in the treatment of Kenyan children with schistosomiasis.
METHODS
This was an open-label, randomised clinical trial involving 426 school-aged children (7-15 years old) diagnosed with Schistosoma mansoni (by Kato-Katz) or S. haematobium (by urine filtration). They were randomly assigned (1:1:1) to receive a single dose of praziquantel (40 mg/kg), a single dose of artesunate plus sulfalene-pyrimethamine (12 mg/kg artesunate) or combination therapy using a single dose of praziquantel (40 mg/kg) combined with a single dose of artesunate plus sulfalene-pyrimethamine (12 mg/kg artesunate). The primary outcome was cure and egg reduction rates at 6 weeks post-treatment in the available case population. Adverse events were assessed within 3 h after treatment.
RESULTS
Of the 426 children enrolled, 135 received praziquantel, 150 received artesunate plus sulfalene-pyrimethamine, and 141 received combination therapy. Outcome data were available for 348 (81.7%) children. For S. mansoni-infected children (n = 335), the cure rates were 75.6%, 60.7%, and 77.8%, and the egg reduction rates were 80.1%, 85.0%, and 88.4% for praziquantel, artesunate plus sulfalene-pyrimethamine, and combination therapy, respectively. For S. haematobium-infected children (n = 145), the corresponding cure rates were 81.4%, 71.1%, and 82.2%, and the egg reduction rates were 95.6%, 97.1%, and 97.7%, respectively. Seventy-one (16.7%) children reported mild-intensity adverse events. The drugs were well tolerated and no serious adverse events were reported.
CONCLUSIONS
A single oral dose of praziquantel combined with artesunate plus sulfalene-pyrimethamine cured a high proportion of children with S. haematobium but did not significantly improve the treatment efficacy for either urinary or intestinal schistosomiasis. Sequential administration of praziquantel and artesunate plus sulfalene-pyrimethamine may enhance the efficacy and safety outcomes.
Topics: Humans; Child; Praziquantel; Pyrimethamine; Animals; Adolescent; Artesunate; Female; Male; Schistosomiasis mansoni; Schistosoma haematobium; Schistosomiasis haematobia; Schistosoma mansoni; Drug Therapy, Combination; Kenya; Artemisinins; Treatment Outcome; Anthelmintics; Sulfalene; Drug Combinations; Parasite Egg Count
PubMed: 38943214
DOI: 10.1186/s13071-024-06359-6 -
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 -
Scientific Reports Jun 2024Helminth infections lead to an overdispersion of the parasites in humans as well as in animals. We asked whether early immune responses against migrating Ascaris larvae...
Helminth infections lead to an overdispersion of the parasites in humans as well as in animals. We asked whether early immune responses against migrating Ascaris larvae are responsible for the unequal distribution of worms in natural host populations and thus investigated a susceptible versus a resistant mouse strain. In mice, the roundworm larvae develop until the lung stage and thus early anti-Ascaris immune responses against the migrating larvae in the liver and lung can be deciphered. Our data show that susceptible C57BL/6 mice respond to Ascaris larval migration significantly stronger compared to resistant CBA mice and the anti-parasite reactivity is associated with pathology. Increased eosinophil recruitment was detected in the liver and lungs, but also in the spleen and peritoneal cavity of susceptible mice on day 8 post infection compared to resistant mice. In serum, eosinophil peroxidase levels were significantly higher only in the susceptible mice, indicating functional activity of the recruited eosinophils. This effect was associated with an increased IL-5/IL-13 production by innate lymphoid cells and CD4 T cells and a pronounced type 2 macrophage polarization in the lungs of susceptible mice. Furthermore, a comparison of wildtype BALB/c and eosinophil-deficient dblGATA-1 BALB/c mice showed that eosinophils were not essential for the early control of migrating Ascaris larvae. In conclusion, in primary infection, a strong local and systemic type 2 immune response during hepato-tracheal helminth larval migration is associated with pathology rather than protection.
Topics: Animals; Ascariasis; Larva; Mice; Th2 Cells; Mice, Inbred BALB C; Lung; Ascaris; Eosinophils; Mice, Inbred C57BL; Mice, Inbred CBA; Liver; Female
PubMed: 38942904
DOI: 10.1038/s41598-024-65281-0 -
BMJ Paediatrics Open Jun 2024To determine the prevalence and associated factors of scabies among the children living in the Madrasahs (Islamic religious educational institution) of Bangladesh was...
INTRODUCTION
To determine the prevalence and associated factors of scabies among the children living in the Madrasahs (Islamic religious educational institution) of Bangladesh was the objective of the study.
METHODS
This cross-sectional study was conducted in eight selected Madrasahs from May to October 2023 among male and female children aged between 3 and 18 years. Children were screened for scabies according to criteria developed by the International Alliance for the Control of Scabies.
RESULTS
It was found that overall prevalence of scabies among the children living in Madrasahs was almost 34% (mild 73.5%, moderate 24.9% and severe 1.6%). Prevalence of scabies among male was higher than female (39.4% vs 28.4%). Male gender (aOR 2.09, 95% CI 1.27 to 3.47, p=0.004) and age (aOR 0.95, 95% CI 0.91 to 0.99, p=0.017) were two significant predictors of scabies among children. Besides, living in Madrasahs having more boarders (aOR 1.37, 95% CI 1.06 to 1.69, p=0.025), shared bedding, clothes or toilet stuffs with other children (aOR 1.46, 95% CI 1.03 to 2.09, p=0.036) and history of pruritus in the close entourage (aOR 4.19, 95% CI 3.07 to 5.73, p<0.001) were associated with a higher chance of being infected by scabies.
CONCLUSION
Almost one-third of the children living in the Islamic boarding schools in Bangladesh are suffering from scabies, more prevalence in male and younger children. Accommodation of higher number of boarders, sharing personal staffs and pruritus in close contacts increase the risk of scabies in these children.
Topics: Humans; Scabies; Male; Bangladesh; Female; Cross-Sectional Studies; Child; Prevalence; Adolescent; Risk Factors; Child, Preschool; Islam; Schools
PubMed: 38942588
DOI: 10.1136/bmjpo-2023-002421 -
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 -
PLoS Pathogens Jun 2024Plasmodium vivax serological exposure markers (SEMs) have emerged as promising tools for the actionable surveillance and implementation of targeted interventions to...
Plasmodium vivax serological exposure markers (SEMs) have emerged as promising tools for the actionable surveillance and implementation of targeted interventions to accelerate malaria elimination. To determine the dynamic profiles of SEMs in current and past P. vivax infections, we screened and selected 11 P. vivax proteins from 210 putative proteins using protein arrays, with a set of serum samples obtained from patients with acute P. vivax and documented past P. vivax infections. Then we used a murine protein immune model to initially investigate the humoral and memory B cell response involved in the generation of long-lived antibodies. We show that of the 11 proteins, especially C-terminal 42-kDa region of P. vivax merozoite surface protein 1 (PvMSP1-42) induced longer-lasting long-lived antibodies, as these antibodies were detected in individuals infected with P. vivax in the 1960-1970s who were not re-infected until 2012. In addition, we provide a potential mechanism for the maintenance of long-lived antibodies after the induction of PvMSP1-42. The results indicate that PvMSP1-42 induces more CD73+CD80+ memory B cells (MBCs) compared to P. vivax GPI-anchored micronemal antigen (PvGAMA), allowing IgG anti-PvMSP1-42 antibodies to be maintained for a long time.
PubMed: 38941356
DOI: 10.1371/journal.ppat.1012334 -
Parasitology Research Jun 2024As ecosystem disruptors and intermediate hosts for various parasites, freshwater snails have significant socioeconomic impacts on human health, livestock production, and... (Review)
Review
As ecosystem disruptors and intermediate hosts for various parasites, freshwater snails have significant socioeconomic impacts on human health, livestock production, and aquaculture. Although traditional molluscicides have been widely used to mitigate these effects, their environmental impact has encouraged research into alternative, biologically based strategies to create safer, more effective molluscicides and diminish the susceptibility of snails to parasites. This review focuses on alterations in glucose metabolism in snails under the multifaceted stressors of parasitic infections, drug exposure, and environmental changes and proposes a novel approach for snail management. Key enzymes within the glycolytic pathway, such as hexokinase and pyruvate kinase; tricarboxylic acid (TCA) cycle; and electron transport chains, such as succinate dehydrogenase and cytochrome c oxidase, are innovative targets for molluscicide development. These targets can affect both snails and parasites and provide an important direction for parasitic disease prevention research. For the first time, this review summarises the reverse TCA cycle and alternative oxidase pathway, which are unique metabolic bypasses in invertebrates that have emerged as suitable targets for the formulation of low-toxicity molluscicides. Additionally, it highlights the importance of other metabolic pathways, including lactate, alanine, glycogenolysis, and pentose phosphate pathways, in snail energy supply, antioxidant stress responses, and drug evasion mechanisms. By analysing the alterations in key metabolic enzymes and their products in stressed snails, this review deepens our understanding of glucose metabolic alterations in snails and provides valuable insights for identifying new pharmacological targets.
Topics: Animals; Molluscacides; Snails; Glucose; Fresh Water
PubMed: 38940835
DOI: 10.1007/s00436-024-08274-2 -
Parasitology Research Jun 2024Opisthorchis viverrini infection is a pressing health issue in rural Southeast Asia and is associated with the risk of cholangiocarcinoma. Despite control efforts, high...
Opisthorchis viverrini infection is a pressing health issue in rural Southeast Asia and is associated with the risk of cholangiocarcinoma. Despite control efforts, high infection rates persist, including evidence of reinfection post-treatment. This study aimed to address this public health concern through an integrated One-Health approach in endemic areas in rural Thailand over a 3-year period. The study included data from 3600 participants from Udon Thani Province, Thailand, during the years 2020 to 2022 and involved integrated epidemiological data collection and risk factor analysis to understand the impact of various interventions on disease transmission in the community. The efficacy of interventions was assessed by monitoring the incidence of O. viverrini reinfection in 2021 and 2022. In 2020, 218 cases of O. viverrini infection (6.0%) were identified. Significant risk factors included proximity to water bodies and consumption of raw fish. Variables contributing to infection risk among participants (P < 0.001) were education level, engagement in traditional ceremonies, poor sanitation, absence of ducks in nearby water bodies, self-medication for parasitic conditions, and multiple infections within a household. Dogs, cats, and cyprinoid fish showed prevalence rates of 5.4%, 6.3%, and 11.5%, respectively. Geographic analysis revealed clusters of infected households around water bodies. Interventions, including in-depth interviews, focus-group discussions, health education, anthelminthic treatment, and biological control using local free-range ducks, were implemented, resulting in no human reinfections in the second year and a minimal 0.3% prevalence rate in the third year. This study offers valuable insights into the dynamic changes in infection prevalence, making a significant contribution to effective disease control and community health promotion. This integrated One-Health approach proved to be an effective strategy for the prevention and control of opisthorchiasis.
Topics: Opisthorchiasis; Thailand; Humans; Animals; Opisthorchis; Rural Population; Male; Middle Aged; Adult; Female; Risk Factors; Prevalence; One Health; Aged; Young Adult; Adolescent; Cats; Child; Dogs; Incidence
PubMed: 38940830
DOI: 10.1007/s00436-024-08275-1