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1.
Indian J Microbiol ; 64(3): 1278-1289, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39282159

RESUMEN

Malaria is one of the most infectious disease that affects lives of million people throughout the world. Recently, there are several reports which indicate Plasmodium vivax (P. vivax) causing severe disease in infected patients from different parts of the world. For P. vivax disease severity, the data related to immunological and inflammatory status in human host is very limited. In the present study clinical parameters, cytokine profile and integrin gene were analyzed in P. vivax clinical patients. A total of 169 P. vivax samples were collected and categorized into severe vivax malaria (SVM; n = 106) and non-severe vivax malaria (NSVM; n = 63) according to WHO severity criteria. We measured host biomarker levels of interferon (IFN-γ), superoxide dismutase (SOD-1), interleukins viz. (IL-6, IL-10), and tumor necrosis factor (TNF-α) in patient plasma samples by ELISA for pro- and anti-inflammatory cytokines in severe malaria. Host integrin gene was genotyped using PCR assay. In our study, thrombocytopenia and anemia were major symptoms in severe P. vivax patients. In analyzed SVM and NSVM groups a significant increase in cytokine levels (IL-10, IL-6, and TNF-α) and anti-oxidant enzyme SOD-1 was found. Our study results also showed a higher pro-inflammatory (TNF-α, IL-6 and IFN-γ) to anti-inflammatory (IL-10) cytokine ratio in severe vivax patients. Integrin gene showed no mutation with respect to thrombocytopenic patients among clinically defined groups. It was observed that severe vivax cases had increased cytokine levels irrespective of age and sex of the patients along with thrombocytopenia and other clinical manifestations. The results of current findings could serve as baseline data for evaluating severe malaria parameters during P. vivax infections and will help in developing an effective biomarker for diagnosis. Supplementary Information: The online version contains supplementary material available at 10.1007/s12088-024-01324-4.

2.
Parasites Hosts Dis ; 62(3): 313-322, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-39218630

RESUMEN

Plasmodium vivax variant interspersed repeats (vir) refer to the key protein used for escaping the host immune system. Knowledge in the genetic variation of vir genes can be used for the development of vaccines or diagnostic methods. Therefore, we evaluated the genetic diversity of the vir genes of P. vivax populations of several Asian countries, including Pakistan, which is a malaria-endemic country experiencing a significant rise in malaria cases in recent years. We analyzed the genetic diversity and population structure of 4 vir genes (vir 4, vir 12, vir 21, and vir 27) in the Pakistan P. vivax population and compared these features to those of the corresponding vir genes in other Asian countries. In Pakistan, vir 4 (S=198, H=9, Hd=0.889, Tajima's D value=1.12321) was the most genetically heterogenous, while the features of vir 21 (S=8, H=7, Hd=0.664, Tajima's D value =-0.63763) and vir 27 (S =25, H =11, Hd =0.682, Tajima's D value=-2.10836) were relatively conserved. Additionally, vir 4 was the most genetically diverse among Asian P. vivax populations, although within population diversity was low. Meanwhile, vir 21 and vir 27 among all Asian populations were closely related genetically. Our findings on the genetic diversity of vir genes and its relationships between populations in diverse geographical locations contribute toward a better understanding of the genetic characteristics of vir. The high level of genetic diversity of vir 4 suggests that this gene can be a useful genetic marker for understanding the P. vivax population structure. Longitudinal genetic diversity studies of vir genes in P. vivax isolates obtained from more diverse geographical areas are needed to better understand the function of vir genes and their use for the development of malaria control measures, such as vaccines.


Asunto(s)
Variación Genética , Malaria Vivax , Plasmodium vivax , Plasmodium vivax/genética , Pakistán/epidemiología , Variación Genética/genética , Humanos , Malaria Vivax/epidemiología , Malaria Vivax/parasitología , Malaria Vivax/genética , Genética de Población , Proteínas Protozoarias/genética
3.
Cureus ; 16(8): e66189, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-39233984

RESUMEN

Plasmodium vivax (P. vivax) malaria was long considered to have low mortality. Severe malaria was classically associated with Plasmodium falciparum (P. falciparum). However, there is growing evidence that severe and complicated forms of vivax malaria may be more widespread than previously assumed. We report a case of a 32-year-old female patient with acute respiratory distress syndrome (ARDS) as a complication of P. vivax malaria who has recovered completely following starting intravenous antimalarial medications and noninvasive ventilation (NIV).

4.
Artículo en Inglés | MEDLINE | ID: mdl-39291304

RESUMEN

Plasmodium vivax is a major cause of malaria, which poses an increased health burden on approximately one third of the world's population due to climate change. Primaquine, the preferred treatment for P. vivax malaria, is contraindicated in individuals with glucose-6-phosphate dehydrogenase (G6PD) deficiency, a common genetic cause of hemolytic anemia, that affects ∼2.5% of the world's population and ∼8% of the population in areas of the world where P. vivax malaria is endemic. The Seattle Structural Genomics Center for Infectious Disease (SSGCID) conducted a structure-function analysis of P. vivax N-myristoyltransferase (PvNMT) as part of efforts to develop alternative malaria drugs. PvNMT catalyzes the attachment of myristate to the N-terminal glycine of many proteins, and this critical post-translational modification is required for the survival of P. vivax. The first step is the formation of a PvNMT-myristoyl-CoA binary complex that can bind to peptides. Understanding how inhibitors prevent protein binding will facilitate the development of PvNMT as a viable drug target. NMTs are secreted in all life stages of malarial parasites, making them attractive targets, unlike current antimalarials that are only effective during the plasmodial erythrocytic stages. The 2.3 Šresolution crystal structure of the ternary complex of PvNMT with myristoyl-CoA and a novel inhibitor is reported. One asymmetric unit contains two monomers. The structure reveals notable differences between the PvNMT and human enzymes and similarities to other plasmodial NMTs that can be exploited to develop new antimalarials.

5.
Microbiol Resour Announc ; : e0059024, 2024 Sep 16.
Artículo en Inglés | MEDLINE | ID: mdl-39283158

RESUMEN

Plasmodium vivax causes ~20% of malaria cases in Ethiopia. Here, we report a long-read genome assembly generated from an individual collected in 2022. P. vivax is genetically diverse across endemic regions; thus, the genome assembly of an African isolate is an important resource for the malaria research community.

6.
EMBO Mol Med ; 2024 Sep 16.
Artículo en Inglés | MEDLINE | ID: mdl-39284948

RESUMEN

The malaria vaccination landscape has seen significant advancements with the recent endorsement of RTS,S/AS01 and R21/Matrix-M vaccines, which target the pre-erythrocytic stages of Plasmodium falciparum (Pf) infection. However, several challenges remain to be addressed, including the incomplete protection afforded by these vaccines, their dependence on a single Pf antigen, and the fact that they were not designed to protect against P. vivax (Pv) malaria. Injectable formulations of whole-sporozoite (WSpz) malaria vaccines offer a promising alternative to existing subunit vaccines, with recent developments including genetically engineered parasites and optimized administration regimens. Clinical evaluations demonstrate varying efficacy, influenced by factors, such as immune status, prior exposure to malaria, and age. Despite significant progress, a few hurdles persist in vaccine production, deployment, and efficacy in malaria-endemic regions, particularly in children. Concurrently, transgenic parasites expressing Pv antigens emerge as potential solutions for PvWSpz vaccine development. Ongoing clinical studies and advancements in vaccine technology, including the recently described PfSPZ-LARC2 candidate, signify a hopeful future for WSpz malaria vaccines, which hold great promise in the global fight against malaria.

7.
Epidemics ; 48: 100789, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39255654

RESUMEN

Plasmodium vivax is the most geographically widespread malaria parasite. P. vivax has the ability to remain dormant (as a hypnozoite) in the human liver and subsequently reactivate, which makes control efforts more difficult. Given the majority of P. vivax infections are due to hypnozoite reactivation, targeting the hypnozoite reservoir with a radical cure is crucial for achieving P. vivax elimination. Stochastic effects can strongly influence dynamics when disease prevalence is low or when the population size is small. Hence, it is important to account for this when modelling malaria elimination. We use a stochastic multiscale model of P. vivax transmission to study the impacts of multiple rounds of mass drug administration (MDA) with a radical cure, accounting for superinfection and hypnozoite dynamics. Our results indicate multiple rounds of MDA with a high-efficacy drug are needed to achieve a substantial probability of elimination. This work has the potential to help guide P. vivax elimination strategies by quantifying elimination probabilities for an MDA approach.


Asunto(s)
Antimaláricos , Erradicación de la Enfermedad , Malaria Vivax , Administración Masiva de Medicamentos , Plasmodium vivax , Humanos , Malaria Vivax/prevención & control , Malaria Vivax/tratamiento farmacológico , Malaria Vivax/epidemiología , Administración Masiva de Medicamentos/estadística & datos numéricos , Plasmodium vivax/efectos de los fármacos , Plasmodium vivax/fisiología , Erradicación de la Enfermedad/métodos , Erradicación de la Enfermedad/estadística & datos numéricos , Antimaláricos/uso terapéutico , Antimaláricos/administración & dosificación , Procesos Estocásticos , Simulación por Computador
8.
MSMR ; 31(8): 14-19, 2024 08 20.
Artículo en Inglés | MEDLINE | ID: mdl-39255515

RESUMEN

Australian Defence Force (ADF) personnel train and operate in malarious regions that include neighboring countries with high burden and species with latent hepatic parasites.1 We summarized longitudinal malaria case data, following a prior 10-year period review to 2007.2 Malaria case entries within the ADF Malaria and Infectious Diseases Institute (ADFMIDI)-managed Central Malaria Register (CMR) were examined. Data from cases confirmed between January 1, 2008 through December 31, 2022 were analyzed. Sixty ADF members were diagnosed with malaria, including 1 with a mixed Plasmodium falciparum and P. vivax infection. Of 61 malaria infections, 69% (42 of 61) were P. vivax. P. vivax infection resulted in delayed initial case presentation (more than 4 weeks after exposure) in at least 36% (15 of 42) of cases, and 5 personnel experienced further relapse. Most P. vivax infections were acquired in the U.S. Indo-Pacific Command (INDOPACOM) and P. falciparum in the U.S. Africa Command (AFRICOM) regions. The ADF experienced ongoing reduced malaria case incidence following high rates in the early 2000s. Maintenance of prophylactic vigilance, both for eradicating dormant hypnozoites and preventing P. vivax relapse, remains important, however.


Asunto(s)
Malaria Falciparum , Malaria Vivax , Personal Militar , Humanos , Personal Militar/estadística & datos numéricos , Australia/epidemiología , Masculino , Femenino , Adulto , Malaria Vivax/epidemiología , Malaria Falciparum/epidemiología , Adulto Joven , Incidencia , Persona de Mediana Edad , Plasmodium vivax/aislamiento & purificación , Malaria/epidemiología , Plasmodium falciparum/aislamiento & purificación , Sistema de Registros
9.
Vet Parasitol Reg Stud Reports ; 54: 101090, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39237241

RESUMEN

Trypanosoma vivax infections are endemic in Africa, where they provoke trypanosomosis against which some local taurine breeds are tolerant and are thus named trypanotolerant. In Latin America, T. vivax was imported in 1919, since when it has been responsible for periodic outbreaks of the disease. This study assessed whether a South American taurine breed resilient to several parasitic and infectious diseases (Curraleiro Pé-Duro-CPD) can meet trypanotolerant criteria (control parasite proliferation, prevent anemia, survive without treatment, and maintain productivity). Three groups were established, each consisting of six animals (Group 1: CPD-infected; Group 2: Holstein/Gyr-infected; Group 3: Holstein/Gyr-uninfected, negative control). Groups 1 and 2 were infected with T. vivax on Day 0 and evaluated until day 532. Throughout the experimental period, parasitological (Woo and Brener), molecular (cPCR), serological (enzyme-linked immunosorbent assay - ELISA, indirect fluorescent antibody test - IFAT, immunochromatographic assay - IA), and clinical (hemogram, fever, weight loss) aspects were evaluated. During the acute phase of the disease, T. vivax was initially detected in Holstein/Gyr. Notably, the CPD animals restored their packed cell volume (PCV) values to the normal range 74 days after inoculations. In the chronic phase, two of the six CPD animals were positive by cPCR until D + 522 following immunosuppression with dexamethasone. Regarding serological aspects, the two CPD animals had positive tests until D + 532. The absence of T. vivax in blood during the chronic phase did not correspond to "self-cure". Holstein/Gyr animals exhibited fever on more evaluation days than CPD animals. Both breeds experienced weight loss, with Holstein/Gyr animals losing significantly more weight. On D + 25, the Holstein/Gyr group required treatment. During the 532 days, none of the CPD animals required treatment, even after being sensitized with dexamethasone. Animals from Group 3 tested negative for T. vivax throughout the experiment. This study demonstrated that CPD cattle fulfill the mentioned trypanotolerant criteria.


Asunto(s)
Trypanosoma vivax , Animales , Bovinos , Enfermedades de los Bovinos/parasitología , Enfermedades de los Bovinos/epidemiología , América Latina , Anticuerpos Antiprotozoarios/sangre , Tripanosomiasis Africana/veterinaria , Tripanosomiasis Africana/sangre , Tripanosomiasis Africana/parasitología , Masculino , Femenino , Tripanosomiasis Bovina/epidemiología , Tripanosomiasis Bovina/sangre
10.
Front Public Health ; 12: 1423004, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39238542

RESUMEN

Background: Plasmodium vivax malaria has been one of the most troublesome diseases in the Democratic People's Republic of Korea (DPRK). Given that a majority of malaria cases are concentrated near the demilitarized zone, concerted elimination efforts from both the Republic of Korea (ROK) and DPRK are essential for a malaria-free Korean Peninsula. This study assessed the impact of rapid diagnostic tests (RDTs) and tafenoquine on malaria incidence in DPRK. Methods: We patterned the current model structure from the previously developed Plasmodium vivax malaria dynamic transmission model for ROK. Model parameters were adjusted using demographic and climate data from malaria-risk areas in DPRK, and the model was calibrated to annual malaria incidences from 2014 to 2018 in DPRK, as reported by the World Health Organization. Subsequently, we estimated the preventable malaria cases over a decade after introducing RDTs and tafenoquine compared to using microscopy alone and primaquine, respectively. Sensitivity analysis was performed to account for uncertainty in model parameters. Results: When comparing RDTs to microscopy, a one-day reduction in diagnostic time due to the introduction of RDTs led to a reduction in malaria incidence by 26,235 cases (65.6%) over the next decade. With a two-day reduction, incidences decreased by 33,635 (84.1%). When comparing a single dose of tafenoquine with a 14-day primaquine regimen, the former prevented 1,222 (77.5%) relapse cases and 4,530 (11.3%) total cases over the years. Conclusion: The continuous and simultaneous implementation of RDTs and tafenoquine emerges as a potent strategy to considerably reduce malaria in DPRK.


Asunto(s)
Antimaláricos , Malaria Vivax , Malaria Vivax/epidemiología , Malaria Vivax/prevención & control , Humanos , Antimaláricos/uso terapéutico , Incidencia , República Popular Democrática de Corea/epidemiología , Plasmodium vivax/efectos de los fármacos , Aminoquinolinas/uso terapéutico , Pruebas Diagnósticas de Rutina/estadística & datos numéricos , Adulto , Masculino , Persona de Mediana Edad
11.
Malar J ; 23(1): 271, 2024 Sep 10.
Artículo en Inglés | MEDLINE | ID: mdl-39256842

RESUMEN

BACKGROUND: In most countries engaged on the last mile towards malaria elimination, residual transmission mainly persists among vulnerable populations represented by isolated and mobile (often cross-border) communities. These populations are sometimes involved in informal or even illegal activities. In regions with Plasmodium vivax transmission, the specific biology of this parasite poses additional difficulties related to the need for a radical treatment against hypnozoites to prevent relapses. Among hard-to-reach communities, case management, a pillar of elimination strategy, is deficient: acute malaria attacks often occur in remote areas, where there is limited access to care, and drugs acquired outside formal healthcare are often inadequately used for treatment, which typically does not include radical treatment against P. vivax. For these reasons, P. vivax circulation among these communities represents one of the main challenges for malaria elimination in many non-African countries. The objective of this article is to describe the protocol of the CUREMA study, which aims to meet the challenge of targeting malaria in hard-to-reach populations with a focus on P. vivax. RESULTS: CUREMA is a multi-centre, international public health intervention research project. The study population is represented by persons involved in artisanal and small-scale gold mining who are active and mobile in the Guiana Shield, deep inside the Amazon Forest. The CUREMA project includes a complex intervention composed of a package of actions: (1) health education activities; (2) targeted administration of treatment against P. vivax after screening against G6PD deficiency to asymptomatic persons considered at risk of silently carrying the parasite; (3) distribution of a self-testing and self-treatment kit (malakit) associated with user training for self-management of malaria symptoms occurring while in extreme isolation. These actions are offered by community health workers at settlements and neighbourhoods (often cross-border) that represent transit and logistic bases of gold miners. The study relies on hybrid design, aiming to evaluate both the effectiveness of the intervention on malaria transmission with a pre/post quasi-experimental design, and its implementation with a mixed methods approach. CONCLUSIONS: The purpose of this study is to experiment an intervention that addresses both Plasmodium falciparum and P. vivax malaria elimination in a mobile and isolated population and to produce results that can be transferred to many contexts facing the same challenges around the world.


Asunto(s)
Erradicación de la Enfermedad , Malaria Vivax , Humanos , Malaria Vivax/prevención & control , Erradicación de la Enfermedad/métodos , Erradicación de la Enfermedad/estadística & datos numéricos , Masculino , Femenino , Antimaláricos/uso terapéutico , Adulto , Persona de Mediana Edad , Adolescente , Adulto Joven , Niño , Plasmodium vivax/fisiología
12.
Front Cell Infect Microbiol ; 14: 1451063, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39258252

RESUMEN

Background: Transmission-blocking vaccines (TBVs) can effectively prevent the community's spread of malaria by targeting the antigens of mosquito sexual stage parasites. At present, only a few candidate antigens have demonstrated transmission-blocking activity (TBA) potential in P. vivax. Quiescin-sulfhydryl oxidase (QSOX) is a sexual stage protein in the rodent malaria parasite Plasmodium berghei and is associated with a critical role in protein folding by introducing disulfides into unfolded reduced proteins. Here, we reported the immunogenicity and transmission-blocking potency of the PvQSOX in P. vivax. Methods and findings: The full-length recombinant PvQSOX protein (rPvQSOX) was expressed in the Escherichia coli expression system. The anti-rPvQSOX antibodies were generated following immunization with the rPvQSOX in rabbits. A parasite integration of the pvqsox gene into the P. berghei pbqsox gene knockout genome was developed to express full-length PvQSOX protein in P. berghei (Pv-Tr-PbQSOX). In western blot, the anti-rPvQSOX antibodies recognized the native PvQSOX protein expressed in transgenic P. berghei gametocyte and ookinete. In indirect immunofluorescence assays, the fluorescence signal was detected in the sexual stages, including gametocyte, gamete, zygote, and ookinete. Anti-rPvQSOX IgGs obviously inhibited the ookinetes and oocysts development both in vivo and in vitro using transgenic parasites. Direct membrane feeding assays of anti-rPvQSOX antibodies were conducted using four field P. vivax isolates (named isolates #1-4) in Thailand. Oocyst density in mosquitoes was significantly reduced by 32.00, 85.96, 43.52, and 66.03% with rabbit anti-rPvQSOX antibodies, respectively. The anti-rPvQSOX antibodies also showed a modest reduction of infection prevalence by 15, 15, 20, and 22.22%, respectively, as compared to the control, while the effect was insignificant. The variation in the DMFA results may be unrelated to the genetic polymorphisms. Compared to the P.vivax Salvador (Sal) I strain sequences, the pvqsox in isolate #1 showed no amino acid substitution, whereas isolates #2, #3, and #4 all had the M361I substitution. Conclusions: Our results suggest that PvQSOX could serve as a potential P. vivax TBVs candidate, which warrants further evaluation and optimization.


Asunto(s)
Anticuerpos Antiprotozoarios , Vacunas contra la Malaria , Malaria Vivax , Plasmodium berghei , Plasmodium vivax , Proteínas Recombinantes , Plasmodium vivax/inmunología , Plasmodium vivax/genética , Plasmodium vivax/enzimología , Animales , Conejos , Vacunas contra la Malaria/inmunología , Anticuerpos Antiprotozoarios/inmunología , Malaria Vivax/prevención & control , Malaria Vivax/transmisión , Malaria Vivax/inmunología , Plasmodium berghei/inmunología , Plasmodium berghei/genética , Plasmodium berghei/enzimología , Proteínas Recombinantes/inmunología , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Ratones , Escherichia coli/genética , Antígenos de Protozoos/inmunología , Antígenos de Protozoos/genética , Proteínas Protozoarias/inmunología , Proteínas Protozoarias/genética , Proteínas Protozoarias/metabolismo , Femenino , Humanos , Inmunogenicidad Vacunal , Ratones Endogámicos BALB C
13.
Acta Parasitol ; 69(3): 1522-1529, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39164542

RESUMEN

PURPOSE: Primaquine (PQ) is recommended for radical cure of Plasmodium vivax (Pv) malaria, but its utilization is still limited due to high risk of severe haemolytic anaemia in patients with glucose-6-phosphate dehydrogenase deficiency (G6PD-d). The aim of the present study is to assess the different genotypic variants leading to G6PD-d in Delhi and Goa regions of India. METHODS: A total of 46 samples (34 retrospective Pv-mono-infected samples and 12 Pv-uninfected samples) were included in the study. Various genetic variants leading to G6PD-d were analysed by PCR amplification and DNA sequencing of different targeted exons of G6PD gene. RESULTS: Molecular analysis showed presence of four mutations in study population viz. 1311 C > T, 34.1% & IVSXI 93T > C, 45.5% and two novel mutations 1388G > T, 2.3% and 1398 C > T, 2.3% (silent mutation). The bioinformatics and computational analysis demonstrate that the slight conformational changes caused by R643L mutation in protein are deleterious in nature. CONCLUSION: The observed mutations do not clarify the role or association between G6PD-d and Pv-infected cases. Further investigation is required in order to fully comprehend and analyse the precise role of these mutations with context to malaria infections.


Asunto(s)
Deficiencia de Glucosafosfato Deshidrogenasa , Glucosafosfato Deshidrogenasa , Malaria Vivax , Plasmodium vivax , Humanos , Malaria Vivax/parasitología , India/epidemiología , Glucosafosfato Deshidrogenasa/genética , Plasmodium vivax/genética , Plasmodium vivax/enzimología , Deficiencia de Glucosafosfato Deshidrogenasa/genética , Estudios Retrospectivos , Genotipo , Mutación , Masculino , Variación Genética , Femenino , Adulto
14.
Malar J ; 23(1): 242, 2024 Aug 13.
Artículo en Inglés | MEDLINE | ID: mdl-39138510

RESUMEN

BACKGROUND: The effects of a diverse spectrum of malaria interventions were evaluated through a deterministic Plasmodium vivax transmission model. This approach aimed to provide theoretical evidence of the performance of these interventions once implemented for achieving malaria elimination. METHODS: An integrated intervention portfolio, including mass drug administration, insecticide treatment, and untreated bed nets, was analyzed through modeling. Additionally, data-driven calibration was implemented to infer coverages that effectively reproduced historical malaria patterns in China from 1971 to 1983. RESULTS: MDA utilizing primaquine emerged as the most effective single intervention, achieving a 70% reduction in malaria incidence when implemented at full coverage. Furthermore, a strategic combination of MDA with primaquine, chloroquine, untreated bed nets, and seasonal insecticide treatments effectively eradicated malaria, attaining elimination at a coverage level of 70%. It was conclusively demonstrated that an integrated approach combining MDA and vector control measures is essential for the successful elimination of malaria. CONCLUSION: High coverage of mass drug administration with primaquine and chloroquine before transmission was the key driver of the malaria decline in China from 1971 to 1983. The best-fit intervention coverage combinations derived from calibration are provided as a reference for malaria control in other countries.


Asunto(s)
Antimaláricos , Malaria Vivax , Malaria Vivax/prevención & control , Malaria Vivax/epidemiología , China/epidemiología , Humanos , Antimaláricos/uso terapéutico , Plasmodium vivax/efectos de los fármacos , Primaquina/uso terapéutico , Administración Masiva de Medicamentos , Cloroquina/uso terapéutico , Control de Mosquitos/métodos
15.
J Parasit Dis ; 48(3): 581-592, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39145373

RESUMEN

Lake Burullus is an important source of fish production in Egypt; it produces 20.5% of the Egyptian fisheries' production. There is intense controversy about the heavy metal pollution in Burullus water and its effects on fish health and safety for human consumption. Heavy metals represent a major concern for aquatic life and could negatively affect fish health. Agricultural and industrial water drainage represents a considerable part of the lake water supply. The present work was conducted to determine heavy metal concentrations in lake water and blue tilapia Oreochromis aureus musculature. Water samples were collected from six locations to determine cadmium, copper, lead, zinc and iron. Sixty O. aureus fish samples were also collected from the same sampling points to assess the prevalent parasites infesting fish and to determine the heavy metal (Cd, Cu, Pb, Zn and Fe) concentrations in fish musculature then study the relationship between heavy metals concentration and prevailing fish parasites. Results indicated that 53.34% of the examined fish were infested with encysted metacercaria. Centrocestus formosanus, Prohemistomum vivax, and Euclinostomum heterostomum were retrieved from gills, musculature, hepatopancreas and the posterior kidney. The parasitic intensity in fish tissues was between 1 and 9 cyst g-1. Centrocestus formosanus was identified using the polymerase chain reaction in the gill tissues of 16 fish. The gill parasitic copepod Lamproglena monodi was identified in one fish. Degenerative changes such as thickening, corrugation, and destruction of gill filament are the most dominant pathological changes in infested fish gills. Heavy metal concentrations in water samples were at normal levels, except for copper and iron in the southern part of the lake. All heavy metals in fish musculature were below the permissible limits. The parasitic infestation was more dominant in the northern part of the lake than in the southern region; this could be due to elevated copper concentration in the southern part of the lake that could negatively affect the survival of the first intermediate host and parasite cercaria. In conclusion, captured fish from Lake Burullus were safe for human consumption, and heavy metal pollution in lake water does not represent a severe risk.

16.
J Infect Dis ; 2024 Aug 05.
Artículo en Inglés | MEDLINE | ID: mdl-39102894

RESUMEN

Recent evidence challenges the belief that Duffy-negative individuals are resistant to Plasmodium vivax due to lacking Duffy Antigen Receptor for Chemokines (DARC). Erythrocyte Binding Protein (EBP/DBP2) has shown moderate binding to Duffy-negative erythrocytes in vitro. Reticulocyte Binding Protein 2b (RBP2b) interactions with Transferrin Receptor 1 (TfR1) suggest involvement in Duffy-negative infections. Gene copy number variations (CNVs) in PvDBP1, PvEBP/DBP2, and PvRBP2b were investigated in Duffy-positive and Duffy-negative P. vivax-infected individuals from Ethiopia. Among Duffy-positive samples, 34% displayed PvDBP1 duplications (Cambodian-type). In Duffy-negative infections, 30% showed duplications, mostly Cambodian-type. For PvEBP/DBP2 and PvRBP2b, Duffy-positive samples exhibited higher duplication rates (1-8 copies for PvEBP/DBP2, 1-5 copies for PvRBP2b 46% and 43% respectively) compared to Duffy-negatives (20.8% and 26% respectively). The range of CNVs was lower in Duffy-negative infections. Demographic and clinical factors associated with gene multiplications in both Duffy types were explored, enhancing understanding of P. vivax evolution in Duffy-negative Africans.

17.
medRxiv ; 2024 Jul 23.
Artículo en Inglés | MEDLINE | ID: mdl-39108527

RESUMEN

Osteoprotegerin (OPG) is a soluble decoy receptor for receptor activator of NF-ƙB ligand (RANKL) and TNF-related apoptosis-inducing ligand (TRAIL), and is increasingly recognised as a marker of poor prognosis in a number of diseases. Here we demonstrate that in Malaysian adults with falciparum and vivax malaria, OPG is increased, and its ligands TRAIL and RANKL decreased, in proportion to disease severity. In volunteers experimentally infected with P. falciparum and P. vivax, RANKL was suppressed, while TRAIL was unexpectedly increased, suggesting binding of OPG to RANKL prior to TRAIL. We also demonstrate that P. falciparum stimulates B cells to produce OPG in vitro, and that B cell OPG production is increased ex vivo in patients with falciparum, vivax and knowlesi malaria. Our findings provide further evidence of the importance of the OPG/RANKL/TRAIL pathway in pathogenesis of diseases involving systemic inflammation, and may have implications for adjunctive therapies. Further evaluation of the role of B cell production of OPG in host responses to malaria and other inflammatory diseases is warranted.

18.
Cureus ; 16(7): e65743, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-39211654

RESUMEN

A young immigrant male presented to the hospital with multiple complaints and was found to be in septic shock with symptomatic anemia. After an extensive workup, the patient was found to have malaria, a disease caused by the bite of an infected mosquito. This case outlines the pertinent findings, relevant diagnostic tests, and appropriate treatment for a patient with malaria secondary to Plasmodium vivax. It also demonstrates the importance of social and travel history, especially when evaluating our immigrant populations.

19.
Pathogens ; 13(8)2024 Aug 09.
Artículo en Inglés | MEDLINE | ID: mdl-39204273

RESUMEN

Elucidation of pathways regulating parasite cell death is believed to contribute to identification of novel therapeutic targets for protozoan diseases, and in this context, apoptosis-like cell death has been reported in different groups of protozoa, in which metacaspases seem to play a role. In the genus Plasmodium, apoptotic markers have been detected in P. falciparum and P. berghei, and no study focusing on P. vivax cell death has been reported so far. In the present study, we investigated the susceptibility of P. vivax to undergo apoptotic cell death after incubating mature trophozoites with the classical apoptosis inducer staurosporine. As assessed by flow cytometry assays, staurosporine inhibited parasite intraerythrocytic development, which was accompanied by a decrease in cell viability, evidenced by reduced plasmodial mitochondrial activity. However, typical signs of apoptosis, such as DNA fragmentation, chromatin condensation, and nuclear segregation, were not detected in the parasites induced to cell death, and no significant alteration in metacaspase gene expression (PvMCA1) was observed under cell death stimulus. Interestingly, dying parasites positively modulated cell death (eryptosis) of host erythrocytes, which was marked by externalization of phosphatidylserine and cell shrinkage. Our study shows for the time that P. vivax blood stages may not be susceptible to apoptosis-like processes, while they could trigger eryptosis of parasitized cells by undergoing cell death. Further studies are required to elucidate the cellular machinery involved in cell death of P. vivax parasites as well as in the modulation of host cell death.

20.
Emerg Infect Dis ; 30(9): 1884-1894, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39174028

RESUMEN

Malaria is increasingly diagnosed in urban centers across the Amazon Basin. In this study, we combined repeated prevalence surveys over a 4-year period of a household-based random sample of 2,774 persons with parasite genotyping to investigate the epidemiology of malaria in Mâncio Lima, the main urban transmission hotspot in Amazonian Brazil. We found that most malarial infections were asymptomatic and undetected by point-of-care microscopy. Our findings indicate that as malaria transmission decreases, the detection threshold of microscopy rises, resulting in more missed infections despite similar parasite densities estimated by molecular methods. We identified genetically highly diverse populations of Plasmodium vivax and P. falciparum in the region; occasional shared lineages between urban and rural residents suggest cross-boundary propagation. The prevalence of low-density and asymptomatic infections poses a significant challenge for routine surveillance and the effectiveness of malaria control and elimination strategies in urbanized areas with readily accessible laboratory facilities.


Asunto(s)
Microscopía , Brasil/epidemiología , Humanos , Prevalencia , Microscopía/métodos , Femenino , Masculino , Adulto , Adolescente , Malaria Vivax/epidemiología , Malaria Vivax/parasitología , Niño , Malaria Falciparum/epidemiología , Malaria Falciparum/parasitología , Malaria Falciparum/prevención & control , Malaria/epidemiología , Malaria/transmisión , Malaria/prevención & control , Malaria/parasitología , Plasmodium vivax/genética , Población Urbana , Preescolar , Plasmodium falciparum/genética , Persona de Mediana Edad , Adulto Joven , Lactante , Historia del Siglo XXI
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