Search Results (63)

Background: Although China has eliminated indigenous malaria, imported cases, particularly among young and middle-aged workers returning from Africa, constitute a major challenge for current epidemic prevention and control. In contrast, imported malaria in children is extremely rare and often subject to diagnostic delays in non-endemic areas due to atypical clinical presentations. Case presentation: We report a case of a 2-year-11-month-old boy who returned from Sudan, a malaria-endemic region, presenting with fever and diarrhea as the initial symptoms. The case was identified by the laboratory through the blood routine re-examination rules, crucially informed by the patient’s epidemiological history. The diagnosis was ultimately confirmed as Plasmodium falciparum malaria by rapid diagnostic testing and microscopic examination. Conclusion: This diagnostic pathway exemplifies a closed-loop model of “clinical suspicion → targeted laboratory testing → definitive pathogen identification.” It provides a practical framework for the early detection and diagnosis of pediatric imported malaria with atypical presentations in non-endemic areas. Full article

Our article presents a holistic analysis aimed at discerning patterns from ancient–modern comparative contexts of malaria. The article’s interdisciplinary and consilient methodology is drawn from a range of disciplines: the humanities and social sciences, medical knowledge (particularly epidemiology and pathology), molecular phylogenetics, demography, archaeology, paleopathology, numismatics, complex systems theory, etc. The article begins with a detailed exploration of a 463 BCE epidemic event that likely marked the, ultimately transformative, debut of P. falciparum evolutionary lineage malaria for ancient Roman civilization. It is important to note that the concept of evolutionary lineage is defined herein as a sequence of organisms, descended from a common ancestor and culminating, for the present at least, in the form existing currently. An interdisciplinary retrospective diagnosis methodology is utilized to establish, with what we believe to be a high degree of probability, a conclusion that effectively marks the beginning point for the ancient side of our comparative example. The deep interdisciplinary/historical methods used to elucidate the ancient side of the disease equation both lead to a clear conclusion and suggest potential modern analogies or even “prophecies.” These are used to highlight the threats emanating from the current spread of zoonotic P. knowlesi malaria in Southeast Asia. The article also utilizes six broader holistic and interdisciplinary factors in its contextual and comparative analysis: (A) political, military and security contexts; (B) the effects of cultural perceptions; (C) the role of climate and climate change; (D) additional anthropogenic environmental factors; (E) perceptions, practices and capabilities of prevailing medical systems and (F) holistic underlying states of the health of affected populations. Full article

This study introduces a novel Fuzzy Piecewise Fractional Derivative (FPFD) framework to enhance epidemiological modeling, specifically for the multi-phasic co-infection dynamics of Omicron and malaria. We address the limitations of traditional models by incorporating two key realities. First, we use fuzzy set theory to manage the inherent uncertainty in biological parameters. Second, we employ piecewise fractional operators to capture the dynamic, phase-dependent nature of epidemics. The framework utilizes a fuzzy classical derivative for initial memoryless spread and transitions to a fuzzy Atangana–Baleanu–Caputo (ABC) fractional derivative to capture post-intervention memory effects. We establish the mathematical rigor of the FPFD model through proofs of positivity, boundedness, and stability of equilibrium points, including the basic reproductive number (R0). A hybrid numerical scheme, combining Fuzzy Runge–Kutta and Fuzzy Fractional Adams–Bashforth–Moulton algorithms, is developed for solving the system. Simulations show that the framework successfully models dynamic shifts while propagating uncertainty. This provides forecasts that are more robust and practical, directly informing public health interventions. Full article

Background/Objectives: Climate change is intensifying vector-borne disease (VBD) transmission globally, causing over 700,000 annual deaths, yet systematic evidence comparing climate–health pathways across urban and rural settlements remains fragmented. This scoping review aimed to synthesize evidence on the differential impacts of extreme weather events on vector-borne disease transmission between urban and rural environments and identify settlement-specific prevention and healthcare preparedness strategies. Methods: A scoping review following PRISMA-ScR guidelines searched PubMed, EMBASE, Web of Science, and Scopus databases for studies examining climate–vector-borne disease relationships across settlement types. Sixteen empirical studies were analyzed using narrative synthesis, with urban–rural comparisons largely inferential given limited direct comparative studies. Results: From 6493 records identified, 4875 were screened after duplicate removal, yielding 16 studies for analysis. Studies covered multiple vector-borne diseases, including malaria, dengue, leishmaniasis, chikungunya, and Zika, across diverse geographic regions. Urban environments demonstrated infrastructure-mediated transmission dynamics characterized by heat island amplification exceeding vector survival thresholds, drainage system vulnerabilities creating breeding habitats, and density-driven epidemic spread affecting healthcare surge capacity. Rural settings exhibited ecosystem-mediated pathways involving diverse vector communities, agricultural breeding sites, and seasonal spillover from wildlife reservoirs, with healthcare accessibility challenges during extreme weather events. Critical research gaps included a limited number of longitudinal comparative studies and geographic variations in evidence generation. Conclusions: Extreme weather events create fundamentally distinct vector-borne disease transmission pathways across urban–rural gradients, necessitating settlement-specific prevention strategies and healthcare preparedness approaches. Evidence-based recommendations include urban infrastructure improvements, rural early warning systems, and cross-sectoral coordination frameworks to enhance the adaptive capacity for climate-resilient vector-borne disease prevention. Full article

Bacterial natural ecological niches are characterized by variations in the availability of nutrients, resulting in a complex metabolism. Their impressive ability to adapt to changeable nutrient conditions is possible through the utilization of large amounts of substrates. Recent discoveries in bacterial metabolism have suggested the importance of polyamine metabolism in bacteria, particularly in those of the order Actinomycetales, in enabling them to survive in their natural habitats. This makes such enzymes promising targets to inhibit their growth. Since the polyamine metabolisms of soil bacteria of the genus Streptomyces and the human pathogenic Mycobacteria are surprisingly similar, target-based drug development in Streptomyces and Mycobacterium spp. is an alternative approach to the classical search for antibiotics. The recent development of drugs to treat epidemic diseases like tuberculosis (TB) has gained attention due to the occurrence of multidrug-resistant strains. In addition, drug repurposing plays a crucial role in the treatment of various complex diseases, such as malaria. With that notion, the treatment of TB could also benefit from this approach. For example, molecular chaperones, proteins that help other proteins to fold properly, are found in almost all living organisms, including the causative agents of TB. Therefore, targeting these molecules could help in the treatment of TB. We aim to summarize our knowledge of the nitrogen and carbon metabolism of the two closely related actinobacterial genera, Streptomyces and Mycobacterium, and of the identification of new potential drug targets. Full article

In recent decades, the world has observed the emergence and re-emergence of a multitude of previously non-existent or re-emerging infectious diseases, for which there is a paucity of timely and effective preventative measures. The WHO has published a catalogue of priority pathogens that are likely to trigger future epidemics, with the objective of designing effective prophylactic and therapeutic interventions. The rationale behind these interventions is rooted in a comprehensive understanding of the aetiology, epidemiology, and pathogenesis of the target diseases. While it is imperative to acknowledge the pivotal role that evolutionary changes in pathogens play, it is equally important to recognise the influence of a multifaceted interplay of factors on the emergence and re-emergence of infectious diseases. These include changes in human populations, the vectors and reservoirs of exposure, and environmental changes. This review summarises the aetiology, epidemiology, and pathogenesis of the ten WHO priority diseases, as well as those with high epidemic potential that are already the focus of specific control programme initiatives, such as HIV/AIDS, tuberculosis, and malaria diseases. Furthermore, this review concentrated on the means of addressing these infections through public health surveillance and response systems. Such systems must be designed to rapidly detect unusual and unexpected disease patterns, track and share information in real time, and rapidly mobilise global responses, which are the most important ways to effectively contain transmission. Full article

Early warning systems rely on statistical prediction models, with environmental risks and remote sensing data serving as essential sources of information for their development. The present work is focused on the use of remote sensing for the estimation of transmission risk and the prediction of malaria cases in northwest Argentina. This study was conducted in the city of San Ramón de la Nueva Orán, where cases of the disease have been reported from 1986 to 2005. The relationship between reported malaria cases and climatic/environmental variables—including the normalized difference vegetation index (NDVI), normalized difference water index (NDWI), and land surface temperature (LST)—obtained from Landsat 5 and 7 satellite images was analyzed using multilevel Poisson regression analyses. An increased abundance of reported malaria cases was observed in summer. An ARIMA (autoregressive integrated moving average) temporal series model incorporating environmental variables was developed to forecast malaria cases in the year 2000. The analysis of the relationship between malaria cases and environmental and climatic factors showed that malaria cases were associated with increases in LST and mean temperature and a decrease in the NDVI. Early warning systems that provide information about spatial and temporal predictions of epidemics could help to control and prevent malaria outbreaks. Based on these findings, this study is expected to support the development of future prevention and control measures by health officials. Full article

Multiple forms of endemic malaria existed in the Mediterranean Basin from the 3rd millennium BCE until eradication regimes were imposed in the 20th century, with major societal health impacts across the history of the region. Little attention has been paid to the role endemic malaria played during the high medieval period, especially during the Crusades, when large Christian armies transited the Mediterranean to conquer the Levant, forging new states, trade lanes and pilgrimage routes in the process. This study utilizes a recent GIS-enabled malaria risk model validated for the pre-modern Mediterranean to re-evaluate contemporary accounts of illness and epidemics in the Crusader Levant. While medieval sources often provide ambiguous descriptions of disease, careful consideration of these accounts in light of the demonstrable spatial and temporal risk of malaria infection provides substantial evidence of these kinds of epidemics. The resulting evidence suggests that several malaria species, either on their own or in concert with other pathogens, afflicted numerous Crusade campaigns in low-lying landscapes during the warmest periods of the summer and fall in the Levant. In turn, these malaria epidemics had a major impact on the history of the Crusades and the Crusader States. Full article

Background: Noroviruses, which cause epidemic acute gastroenteritis, and Plasmodium parasites, which lead to malaria, are two infectious pathogens that pose threats to public health. The protruding (P) domain of norovirus VP1 and the αTSR domain of the circumsporozoite protein (CSP) of Plasmodium sporozoite are the glycan receptor-binding domains of the two pathogens for host cell attachment, making them excellent targets for vaccine development. Modified norovirus P domains self-assemble into a 24-meric octahedral P nanoparticle (P₂₄ NP). Methods: We generated a unique P₂₄-αTSR NP by inserting the αTSR domain into a surface loop of the P domain. The P-αTSR fusion proteins were produced in the Escherichia coli expression system and the fusion protein self-assembled into the P₂₄-αTSR NP. Results: The formation of the P₂₄-αTSR NP was demonstrated through gel filtration, electron microscopy, and dynamic light scattering. A 3D structural model of the P₂₄-αTSR NP was constructed, using the known cryo-EM structure of the previously developed P₂₄ NP and P₂₄-VP8* NP as templates. Each P₂₄-αTSR NP consists of a P₂₄ NP core, with 24 surface-exposed αTSR domains that have retained their general conformations and binding function to heparan sulfate proteoglycans. The P₂₄-αTSR NP is immunogenic, eliciting strong antibody responses in mice toward both the norovirus P domain and the αTSR domain of Plasmodium CSP. Notably, sera from mice immunized with the P₂₄-αTSR NP bound strongly to Plasmodium sporozoites and blocked norovirus VLP attachment to their glycan receptors. Conclusion: These data suggest that the P₂₄-αTSR NP may serve as a combination vaccine against both norovirus and Plasmodium parasites. Full article

Malaria poses a serious global health problem, with half the world population being at risk. Regular screening is crucial for breaking the transmission cycle and combatting the disease spreading. However, current diagnostic tools relying on blood samples face challenges in many malaria-epidemic areas. In the present study, we demonstrate the detection of the malaria-causing Plasmodium parasite in non-invasive saliva samples (N = 61) from infected individuals by combining a DNA-based Rolling-circle-Enhanced-Enzyme-Activity-Detection (REEAD) sensor system with a chemiluminescence readout that could be detected with an in-house-developed affordable and battery-powered portable reader. We successfully transferred the technology to sub-Saharan Africa, where the malaria burden is high, and demonstrated a proof of concept in a small study (N = 40) showing significant differences (p < 0.00001) between malaria-positive individuals (N = 33) and presumed asymptomatic negative individuals (N = 7) all collected in Gabon. This is the first successful application of the REEAD sensor system for the detection of malaria in saliva in a high-epidemic area and holds promise for the potential future use of REEAD for malaria diagnosis or surveillance based on non-invasive specimens in sub-Saharan Africa. Full article

Vector-borne infections pose serious public health challenges due to the complex interplay of biological, environmental, and social factors. Therefore, comprehensive approaches are essential to mitigate the burden of vector-borne infections and minimize their impact on public health. In this research, an epidemic model for the vector-borne disease malaria is structured with a saturated incidence rate via fractional calculus and preventive measures. The essential results and concepts are introduced to examine the proposed model. The solution of the system is examined for some necessary results, and the threshold parameter of the model, indicated by ${\mathcal{R}}_0$, is calculated. In this paper, the proposed malaria model is analyzed both quantitatively and qualitatively. The fixed-point theorems of Banach and Schaefer are utilized to examine the uniqueness and existence of the solution dynamics. Furthermore, the necessary conditions for the stability of the model have been determined. A numerical approach is offered to visualize the solution pathways of the system and identify its key factors. Through the results, the most influential factors for the control and management of the disease are highlighted. Full article

Djibouti is confronted with malaria resurgence, with malaria having been occurring in epidemic proportions since a decade ago. The current epidemiology of drug-resistant Plasmodium falciparum is not well known. Molecular markers were analyzed by targeted sequencing in 79 P. falciparum clinical isolates collected in Djibouti city in 2023 using the Miseq Illumina platform newly installed in the country. The objective of the study was to analyze the key codons in these molecular markers associated with antimalarial drug resistance. The prevalence of the mutant Pfcrt CVIET haplotype (92%) associated with chloroquine resistance and mutant Pfdhps-Pfdhfr haplotypes (7.4% SGEA and 53.5% IRN, respectively) associated with sulfadoxine-pyrimethamine resistance was high. By contrast, Pfmdr1 haplotypes associated with amodiaquine (YYY) or lumefantrine (NFD) resistance were not observed in any of the isolates. Although the “Asian-type” PfK13 mutations associated with artemisinin resistance were not observed, the “African-type” PfK13 substitution, R622I, was found in a single isolate (1.4%) for the first time in Djibouti. Our genotyping data suggest that most Djiboutian P. falciparum isolates are resistant to chloroquine and sulfadoxine-pyrimethamine but are sensitive to amodiaquine, lumefantrine, and artemisinin. Nonetheless, the presence of an isolate with the R622I PfK13 substitution is a warning signal that calls for a regular surveillance of molecular markers of antimalarial drug resistance. Full article

Vaccination in pregnancy is important to protect the mother and fetus from infectious diseases. The transfer of maternal antibodies across the placenta during pregnancy can continue to protect the neonate for several months after birth while the neonatal adaptive immune system develops. Several pathogens have been shown to impair the transplacental transfer of maternal antibodies, including human immunodeficiency virus, malaria, the severe acute respiratory syndrome coronavirus 2, and cytomegalovirus. This review discusses the mechanisms contributing to decreased transplacental antibody transfer in the setting of maternal infections, such as changes in antibody glycosylation profile, maternal hypergammaglobulinemia, and placental injury. The frequency of epidemics is increasing, and pregnant people are more likely to become exposed to novel pathogens now than they were in the past. Understanding the mechanisms by which infectious diseases impair maternal–fetal antibody transfer is important for pandemic preparedness to maximize the impact of maternal vaccination for child health. Full article

We study epidemic spreading in complex networks by a multiple random walker approach. Each walker performs an independent simple Markovian random walk on a complex undirected (ergodic) random graph where we focus on the Barabási–Albert (BA), Erdös–Rényi (ER), and Watts–Strogatz (WS) types. Both walkers and nodes can be either susceptible (S) or infected and infectious (I), representing their state of health. Susceptible nodes may be infected by visits of infected walkers, and susceptible walkers may be infected by visiting infected nodes. No direct transmission of the disease among walkers (or among nodes) is possible. This model mimics a large class of diseases such as Dengue and Malaria with the transmission of the disease via vectors (mosquitoes). Infected walkers may die during the time span of their infection, introducing an additional compartment D of dead walkers. Contrary to the walkers, there is no mortality of infected nodes. Infected nodes always recover from their infection after a random finite time span. This assumption is based on the observation that infectious vectors (mosquitoes) are not ill and do not die from the infection. The infectious time spans of nodes and walkers, and the survival times of infected walkers, are represented by independent random variables. We derive stochastic evolution equations for the mean-field compartmental populations with the mortality of walkers and delayed transitions among the compartments. From linear stability analysis, we derive the basic reproduction numbers $R_M,R_0$ with and without mortality, respectively, and prove that $R_M<R_0$. For $R_M,R_0>1$, the healthy state is unstable, whereas for zero mortality, a stable endemic equilibrium exists (independent of the initial conditions), which we obtained explicitly. We observed that the solutions of the random walk simulations in the considered networks agree well with the mean-field solutions for strongly connected graph topologies, whereas less well for weakly connected structures and for diseases with high mortality. Our model has applications beyond epidemic dynamics, for instance in the kinetics of chemical reactions, the propagation of contaminants, wood fires, and others. Full article

In 2013, an epidemic of falciparum malaria involving over 820 persons unexpectedly broke out in Shanglin County, Guangxi Zhuang Autonomous Region, China, after a large number of migrant workers returned from Ghana, where they worked as gold miners. Herein, we selected 146 isolates randomly collected from these patients to investigate the resistance characteristics of the parasite to sulfadoxine–pyrimethamine (SP) by screening mutations in the dhfr and dhps genes. All 146 isolates were successfully genotyped for dhps, and only 137 samples were successfully genotyped for dhfr. In the dhfr gene, point mutations occurred at three codons: 51 (83.2%, 114/137), 59 (94.9%, 130/137), and 108 (96.4%, 132/137). In the dhps gene, mutations occurred at four codons: 436 (36.3%, 53/146 for S436A, 0.7%, 1/146 for S436Y), 437 (95.2%, 139/146), 540 (3.4%, 5/146), and 613 (2.7%, 4/146). All 146 isolates had mutations in at least one codon, either within dhfr or dhps. Quadruple mutation I₅₁R₅₉N₁₀₈/G₄₃₇ (41.1%, 60/146) of partial or low resistance level was the most prevalent haplotype combination. Quintuple I₅₁R₅₉N₁₀₈/G₄₃₇E₅₄₀ accounted for 2.1% (3/146). Sextuple I₅₁R₅₉N₁₀₈/A₄₃₆G₄₃₇S₆₁₃ was also found and accounted for 1.4% (2/146). A chronological assay incorporating two sets of resistance data from the studies of Duah and Amenga-Etego provided an overview of the resistance trend from 2003 to 2018. During this period, the results we obtained generally coincided with the total development tendency of SP resistance. It can be concluded that Plasmodium falciparum samples collected from Chinese migrant workers from Ghana presented prevalent but relatively partial or low resistance to SP. A chronological assay incorporating two sets of data around 2013 indicates that our results possibly reflect the SP resistance level of Ghana in 2013 and that the possibility of increased resistance exists. Therefore, reasonable drug use and management should be strengthened while also maintaining a continuous screening of resistance to SP. These findings also underscore the need to strengthen the prevention of malaria importation from overseas and focus on preventing its reintroduction and transmission in China. Full article