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Journal of Global Health Jun 2024Malaria infection during pregnancy is associated with an increased risk of maternal death, as well as adverse birth outcomes. Intermittent preventive treatment in...
BACKGROUND
Malaria infection during pregnancy is associated with an increased risk of maternal death, as well as adverse birth outcomes. Intermittent preventive treatment in pregnancy with sulfadoxine-pyrimethamine (IPTp-SP) is known to improve pregnancy outcomes. However, the coverage of IPTp-SP in antenatal care (ANC) in sub-Saharan Africa remains well below the target. This study aims to estimate to what extent malaria service readiness affects the uptake of IPTp-SP during ANC visits in sub-Saharan African countries.
METHODS
This study included 3267 pregnant women attending ANC for the first time and 2797 pregnant women who had attended ANC more than a month ago in six sub-Saharan African countries. The readiness of malaria services at each institution includes four indicators: the presence of IPTp-SP guidelines, SP availability, integration of IPTp-SP service into ANC, and provider training on IPTp-SP. The outcome variable indicates whether a pregnant woman received IPTp-SP at her current ANC visit. A modified Poisson regression model estimated the associations between malaria service readiness and IPTp-SP uptake for women eligible for the first and subsequent doses.
RESULTS
For women eligible for their first dose, visiting an institution with available SP was associated with an increased probability of receiving IPTp-SP (risk ratio (RR) = 1.43; 95% confidence interval (CI) = 1.22 to 1.67, P < 0.001). For women who were eligible for their next dose, the availability of SP (RR = 1.17; 95% CI = 1.04 to 1.32, P = 0.008) and integration of IPTp-SP service into ANC (RR = 1.82; 95% CI = 1.21 to 2.74, P = 0.004) in the institution were associated with increased likelihood of IPTp-SP uptake. Counterfactual predictions indicated that enhanced provider training could boost IPTp-SP uptake in high-uptake countries, while better SP availability and IPTp-SP integration into ANC would significantly impact low-uptake countries.
CONCLUSIONS
For better IPTp-SP coverage, strategies should be customised. High uptake countries should focus on provider training, while low uptake ones should ensure IPTp-SP availability and service integration.
Topics: Humans; Female; Pregnancy; Antimalarials; Africa South of the Sahara; Pyrimethamine; Sulfadoxine; Malaria; Pregnancy Complications, Parasitic; Adult; Drug Combinations; Prenatal Care; Young Adult; Adolescent; Patient Acceptance of Health Care
PubMed: 38939971
DOI: 10.7189/jogh.14.04112 -
Journal of Extracellular Biology Oct 2023Parasites are responsible for the most neglected tropical diseases, affecting over a billion people worldwide (WHO, 2015) and accounting for billions of cases a year and...
Parasites are responsible for the most neglected tropical diseases, affecting over a billion people worldwide (WHO, 2015) and accounting for billions of cases a year and responsible for several millions of deaths. Research on extracellular vesicles (EVs) has increased in recent years and demonstrated that EVs shed by pathogenic parasites interact with host cells playing an important role in the parasite's survival, such as facilitation of infection, immunomodulation, parasite adaptation to the host environment and the transfer of drug resistance factors. Thus, EVs released by parasites mediate parasite-parasite and parasite-host intercellular communication. In addition, they are being explored as biomarkers of asymptomatic infections and disease prognosis after drug treatment. However, most current protocols used for the isolation, size determination, quantification and characterization of molecular cargo of EVs lack greater rigor, standardization, and adequate quality controls to certify the enrichment or purity of the ensuing bioproducts. We are now initiating major guidelines based on the evolution of collective knowledge in recent years. The main points covered in this position paper are methods for the isolation and molecular characterization of EVs obtained from parasite-infected cell cultures, experimental animals, and patients. The guideline also includes a discussion of suggested protocols and functional assays in host cells.
PubMed: 38939734
DOI: 10.1002/jex2.117 -
Frontiers in Immunology 2024
Topics: Biomarkers; Animals; Humans; Host-Parasite Interactions; Trypanosomiasis; Trypanosomatina; Trypanosoma
PubMed: 38938579
DOI: 10.3389/fimmu.2024.1422067 -
Parasites & Vectors Jun 2024Indoor residual spraying (IRS) has been implemented to prevent malaria in Zambia for several decades, but its effectiveness has not been evaluated long term and in Vubwi...
BACKGROUND
Indoor residual spraying (IRS) has been implemented to prevent malaria in Zambia for several decades, but its effectiveness has not been evaluated long term and in Vubwi District yet. This study aimed to assess the association between IRS and the malaria burden in Zambia and Vubwi District and to explore the factors associated with refusing IRS.
METHODS
A retrospective study was used to analyze the association between IRS and malaria incidence in Zambia in 2001-2020 and in Vubwi District in 2014-2020 by Spearman correlation analysis. A case-control study was used to explore the factors associated with IRS refusals by households in Vubwi District in 2021. A logistic regression model was performed to identify factors associated with IRS refusals.
RESULTS
The malaria incidence reached its peak (391/1000) in 2001 and dropped to the lowest (154/1000) in 2019. The annual percentage change in 2001-2003, 2003-2008, 2008-2014, 2014-2018 and 2018-2020 was - 6.54%, - 13.24%, 5.04%, - 10.28% and 18.61%, respectively. A significantly negative correlation between the percentage of population protected by the IRS against the total population in Zambia (coverage) and the average malaria incidence in the whole population was observed in 2005-2020 (r = - 0.685, P = 0.003) and 2005-2019 (r = - 0.818, P < 0.001). Among 264 participants (59 in the refuser group and 205 in the acceptor group), participants with specific occupations (self-employed: OR 0.089, 95% CI 0.022-0.364; gold panning: OR 0.113, 95% CI 0.022-0.574; housewives: OR 0.129, 95% CI 0.026-0.628 and farmers: OR 0.135, 95% CI 0.030-0.608 compared to employees) and no malaria case among household members (OR 0.167; 95% CI 0.071-0.394) had a lower risk of refusing IRS implementation, while those with a secondary education level (OR 3.690, 95% CI 1.245-10.989) had a higher risk of refusing IRS implementation compared to those who had never been to school.
CONCLUSIONS
Increasing coverage with IRS was associated with decreasing incidence of malaria in Zambia, though this was not observed in Vubwi District, possibly because of the special geographical location of Vubwi District. Interpersonal communication and targeted health education should be implemented at full scale to ensure household awareness and gain community trust.
Topics: Zambia; Humans; Case-Control Studies; Malaria; Mosquito Control; Incidence; Retrospective Studies; Insecticides; Female; Male; Animals; Adult; Child, Preschool; Child; Adolescent
PubMed: 38937791
DOI: 10.1186/s13071-024-06328-z -
Journal of Medicinal Food Jun 2024Malaria impedes the ability of primary cells of the immune system to generate an efficacious inflammatory and immune response. Black seed () is a core dietary supplement...
Malaria impedes the ability of primary cells of the immune system to generate an efficacious inflammatory and immune response. Black seed () is a core dietary supplement and food additive in folklore. This study investigated the antioxidant, immunomodulatory, and anti-inflammatory effects of cookies in -infected mice. Aqueous extract of black seed was prepared, and the total phenol and flavonoid contents were determined. The mice were infected with standard inoculum of the strain NK65 . The mice weight and behavioral changes were observed. The mice were fed with the cookies (2.5%, 5%, and 10%) and 10 mg/kg chloroquine for 5 consecutive days after the infection was established. The reactive oxygen species (ROS), malondialdehyde (MDA), superoxide dismutase, catalase, and hematological parameters (red cell indices, leukocytes, and its differentials) in the infected mice were determined. The inflammatory mediators, C-reactive protein (CRP), and myeloperoxidase (MPO) were also assayed. The result revealed that black seed had a total phenol content of 18.73 mgGAE/g and total flavonoid content of 0.36 mgQUE/g. The infected mice treated with cookies showed significantly decreased parasitaemia, MDA, and ROS levels. Furthermore, the results showed significant suppression in proinflammatory mediators (CRP and MPO) levels and enhanced antioxidant status of infected mice treated with . The study suggests that could function as nutraceuticals in the management of infection associated with inflammatory and immunomodulatory disorders.
Topics: Animals; Plasmodium berghei; Malaria; Oxidative Stress; Mice; Nigella sativa; Seeds; Plant Extracts; Male; Antioxidants; Disease Models, Animal; Reactive Oxygen Species; Malondialdehyde; Inflammation; Anti-Inflammatory Agents; Food, Fortified; C-Reactive Protein; Superoxide Dismutase; Humans; Flavonoids; Peroxidase
PubMed: 38935918
DOI: 10.1089/jmf.2023.0181 -
PLoS Pathogens Jun 2024
Review
Topics: Malaria Vaccines; Humans; Vaccine Development; Malaria; Animals; Plasmodium falciparum; Malaria, Falciparum
PubMed: 38935630
DOI: 10.1371/journal.ppat.1012309 -
ELife Jun 2024The Zanzibar archipelago of Tanzania has become a low-transmission area for . Despite being considered an area of pre-elimination for years, achieving elimination has...
BACKGROUND
The Zanzibar archipelago of Tanzania has become a low-transmission area for . Despite being considered an area of pre-elimination for years, achieving elimination has been difficult, likely due to a combination of imported infections from mainland Tanzania and continued local transmission.
METHODS
To shed light on these sources of transmission, we applied highly multiplexed genotyping utilizing molecular inversion probes to characterize the genetic relatedness of 282 isolates collected across Zanzibar and in Bagamoyo district on the coastal mainland from 2016 to 2018.
RESULTS
Overall, parasite populations on the coastal mainland and Zanzibar archipelago remain highly related. However, parasite isolates from Zanzibar exhibit population microstructure due to the rapid decay of parasite relatedness over very short distances. This, along with highly related pairs within , suggests ongoing low-level local transmission. We also identified highly related parasites across that reflect human mobility on the main island of Unguja and identified a cluster of highly related parasites, suggestive of an outbreak, in the Micheweni district on Pemba island. Parasites in asymptomatic infections demonstrated higher complexity of infection than those in symptomatic infections, but have similar core genomes.
CONCLUSIONS
Our data support importation as a main source of genetic diversity and contribution to the parasite population in Zanzibar, but they also show local outbreak clusters where targeted interventions are essential to block local transmission. These results highlight the need for preventive measures against imported malaria and enhanced control measures in areas that remain receptive to malaria reemergence due to susceptible hosts and competent vectors.
FUNDING
This research was funded by the National Institutes of Health, grants R01AI121558, R01AI137395, R01AI155730, F30AI143172, and K24AI134990. Funding was also contributed from the Swedish Research Council, Erling-Persson Family Foundation, and the Yang Fund. RV acknowledges funding from the MRC Centre for Global Infectious Disease Analysis (reference MR/R015600/1), jointly funded by the UK Medical Research Council (MRC) and the UK Foreign, Commonwealth & Development Office (FCDO), under the MRC/FCDO Concordat agreement and is also part of the EDCTP2 program supported by the European Union. RV also acknowledges funding by Community Jameel.
Topics: Tanzania; Plasmodium falciparum; Malaria, Falciparum; Humans; Genotype
PubMed: 38935423
DOI: 10.7554/eLife.90173 -
Parasitology Research Jun 2024Cutaneous leishmaniasis (CL), a neglected tropical disease, is a major public health concern in Yemen, with Leishmania tropica identified as the main causative agent....
First report of Leishmania tropica in domestic and wild animal hosts in hyperendemic areas of human cutaneous leishmaniasis in western Yemen: a neglected tropical disease needing One Health approach.
Cutaneous leishmaniasis (CL), a neglected tropical disease, is a major public health concern in Yemen, with Leishmania tropica identified as the main causative agent. This study aims to investigate the occurrence and distribution of Leishmania parasites in domestic and wild animals in CL endemic areas in the western highlands of Yemen. A cross-sectional study was conducted in the Utmah District of western Yemen. Blood and skin scraping specimens were collected from 122 domestic and wild animals and tested for the Leishmania DNA using internal transcribed spacer 1 (ITS1) nested polymerase chain reaction. Phylogenetic analyses were performed on 20 L. tropica sequences obtained from animals in this study and 34 sequences from human isolates (collected concurrently from the same study area) retrieved from the GenBank. Overall, L. tropica was detected in 16.4% (20/122) of the examined animals, including 11 goats, two dogs, two bulls, one cow, one donkey, one rabbit, one rat and one bat. None of the examined cats and sheep was positive. The animal sequences were segregated into four different L. tropica haplotypes, with the majority of the animal (15/20) and human (32/34) sequences composed of one dominant haplotype/genotype. These findings represent the first confirmed evidence of natural L. tropica infections in different kinds of domestic and wild animals in western Yemen, suggesting these animals potentially have a role in the transmission of CL in Yemen. Therefore, a One Health approach is required for the effective prevention and control of this devastating disease among endemic populations.
Topics: Animals; Leishmania tropica; Leishmaniasis, Cutaneous; Yemen; Humans; Cross-Sectional Studies; Animals, Wild; Animals, Domestic; Phylogeny; One Health; DNA, Protozoan; Neglected Diseases; Endemic Diseases; DNA, Ribosomal Spacer; Polymerase Chain Reaction; Sequence Analysis, DNA; Male
PubMed: 38935203
DOI: 10.1007/s00436-024-08273-3 -
Systematic Parasitology Jun 2024Eight Eimeria spp. (Apicomplexa: Eimeriidae) have been isolated from the ring-necked pheasant (Phasianus colchicus Linnaeus), native to the temperate zone of Asia and...
Eight Eimeria spp. (Apicomplexa: Eimeriidae) have been isolated from the ring-necked pheasant (Phasianus colchicus Linnaeus), native to the temperate zone of Asia and eastern regions of Europe. Enteric coccidiosis has become a major issue associated with the breeding of farmed pheasants for game bird release or meat production. In this study, 35 fecal samples were collected from two-to-three-month-old ring-necked pheasants from four pheasant-rearing farms in Ehime Prefecture, Japan. Microscopic examination using a saturated sugar solution technique detected numerous subspherical oocysts from the samples of one farm and ellipsoidal Eimeria phasiani Tyzzer, 1929 oocysts from the three other farms. The subspherical oocysts were artificially sporulated and measured 18.6 µm by 15.7 µm with a 1.18 shape index (n = 150). Each oocyst contained four 10.7 µm × 5.8 µm sporocysts (n = 30) and one coarse refractile polar granule; no micropyle or residua were detected. Each sporocysts contained two sporozoites with one large and one small refractile body and sparsely distributed residua. The complete, 1,443-bp cytochrome c oxidase subunit I gene (cox1) of this isolate exhibited low sequence identity with published Eimeria spp. sequences including E. phasiani that was previously recorded in the same area. Meanwhile, the oocyst morphology most closely resembled that of Eimeria tetartooimia Wacha, 1973, but with distinct refractile polar granules and sporocyst residua. The available GenBank cox1 sequence of E. tetartooimia exhibited a sequence identity of < 94.5% with the study isolate. Here, the coccidian isolate identified in this study represents a new Eimeria iyoensis n. sp. capable of infecting ring-necked pheasant.
Topics: Animals; Eimeria; Galliformes; Japan; Phylogeny; Oocysts; Species Specificity; Feces; Coccidiosis
PubMed: 38935159
DOI: 10.1007/s11230-024-10171-2 -
Molecules (Basel, Switzerland) Jun 2024The development of new compounds to treat Chagas disease is imperative due to the adverse effects of current drugs and their low efficacy in the chronic phase. This...
The development of new compounds to treat Chagas disease is imperative due to the adverse effects of current drugs and their low efficacy in the chronic phase. This study aims to investigate nitroisoxazole derivatives that produce oxidative stress while modifying the compounds' lipophilicity, affecting their ability to fight trypanosomes. The results indicate that these compounds are more effective against the epimastigote form of , with a 52 ± 4% trypanocidal effect for compound . However, they are less effective against the trypomastigote form, with a 15 ± 3% trypanocidal effect. Additionally, compound interacts with a higher number of amino acid residues within the active site of the enzyme cruzipain. Furthermore, it was also found that the presence of a nitro group allows for the generation of free radicals; likewise, the large size of the compound enables increased interaction with aminoacidic residues in the active site of cruzipain, contributing to trypanocidal activity. This activity depends on the size and lipophilicity of the compounds. The study recommends exploring new compounds based on the nitroisoxazole skeleton, with larger substituents and lipophilicity to enhance their trypanocidal activity.
Topics: Trypanosoma cruzi; Trypanocidal Agents; Isoxazoles; Protozoan Proteins; Structure-Activity Relationship; Chagas Disease; Cysteine Endopeptidases; Animals; Catalytic Domain; Molecular Structure
PubMed: 38930828
DOI: 10.3390/molecules29122762