Journal of Vector Borne Diseases最新文献

Background objectives: Cutaneous (CL) and mucocutaneous leishmaniasis (MCL) are vector-borne infections with overlapping etiologies but distinct clinical presentations and therapeutic challenges. Data on factors influencing treatment duration in these forms remain limited, particularly in endemic regions. To compare clinical characteristics of CL and MCL and to identify predictors of treatment duration among patients treated with intramuscular pentavalent antimonials.

Methods: This retrospective cohort study analyzed 306 laboratory-confirmed leishmaniasis cases (274 CL, 32 MCL) diagnosed via smear, biopsy, or PCR from 2007 to 2023. Demographic and clinical data, lesion characteristics, and treatment responses were compared using nonparametric statistical methods.

Results: Among 306 patients (54.9% female; median age 22 years), MCL cases exhibited significantly smaller lesion diameters (1.73 cm vs. 2.2 cm, p = 0.001), more frequent papular lesions (25.0% vs. 11.3%, p = 0.024), and unclear lesion margins (34.4% vs. 10.2%, p = 0.001). Facial involvement was universal in MCL (100%) and common in CL (85.8%, p = 0.021). Median treatment duration was 15 days [IQR: 12-18]; secondary infection was significantly associated with prolonged treatment (p = 0.042). Clinical improvement was achieved in 97.4% of cases; recurrence occurred in 3.9%.

Interpretation conclusion: This study identifies distinct lesion features in MCL and underscores secondary infection as a key modifiable factor associated with prolonged therapy. These findings support the need for early recognition, infection control, and tailored clinical strategies to improve leishmaniasis outcomes in endemic settings.

The pathogenesis of dengue virus (DENV) is a complex interaction of both host immune responses and viral factors. One of the main mediators of this process is the non-structural protein (NS1) antigen that is released in early infection and has a direct causal effect on endothelial damage and an enhanced immune response. The structural similarity of NS1 with host proteins (e.g. glycocalyx constituents, endothelial cell-surface proteins, and coagulation factors) creates cross-reactive antibodies and attacks host tissues. This molecular mimicry leads to endothelial dysfunction, vascular permeability etc., which are characteristic of severe manifestations of Dengue such as dengue haemorrhagic fever (DHF) and dengue shock syndrome (DSS). Moreover, these cross-reactive antibodies have the capacity of binding to the antigens on the surface of the platelets that subsequently undergo Fc-mediated phagocytosis by the macrophages and cause thrombocytopenia. Homology between NS1 and coagulation factors can also interact with clotting cascades, which can lead to haemorrhagic tendencies among the infected cases. Antibody-dependent enhancement (ADE) facilitates DENV infection into Fc receptor, which carries immune cells, which increases viral replication and cytokine storms that enhance tissue destruction and vascular leakage in secondary infections. NS1 act as a key immunopathological mediator between the imbalances that are related to coagulation, vascular occlusion, and altered immune reaction to DENV infection. Knowledge of these NS1 mediated mechanisms helps in the implementation of targeted interventions to control severe clinical outcomes which will improve current treatment modalities as well as understanding of the strategy of vaccination.

Background objectives: Malaria vector resistance to insecticides is a major threat to the recent progresses in malaria control highlighting the need for continuous epidemiological surveillance in Kenya.

Methods: WHO tube bioassay tests were used against 0.1% bendiocarb and 0.75% permethrin on Anopheles gambiae s.l. to determine phenotypic resistance. Real-time Polymerase chain reaction (RT-PCR) was used to identify G119S Acetylcholinesterase (ace1R) and L1014S mutation.

Results: Anopheles arabiensis was the most prevalent species, with a frequency of 72% in Malava, 76% in Lurambi, 68% in Mumias East and 58% in Ikolomani. Possible resistance to bendiocarb was observed in all study sites. An. arabiensis exhibited possible resistance across all sites, while Anopheles gambiae sensu stricto showed phenotypic resistance in Lurambi with 87.5% mortality, but fully susceptible in Malava with 100% mortality. The G119S mutation frequency ranged from 0.6% to 2.2% in An. arabiensis while An. gambiae s.s. had a frequency of 0.0% to 1.5%. The frequency of allele was high in An. arabiensis as compared to An. gambiae s.s. across study sites with no significant deviation from Hardy-Weinberg equilibrium.

Interpretation conclusion: There is widespread insecticide resistance in malaria vectors within Kakamega County, with Anopheles arabiensis being the most prevalent species in the County. The detection of bendiocarb possible resistance in An. arabiensis across all sites and resistance in Anopheles gambiae s.s. suggests a challenge for vector control. The low frequency of the G119S ace-1R mutation indicates that resistance may be due to metabolic rather than target-site mechanisms.

Background objectives: The aim of this study was to identify the risk factors associated with mortality in patients diagnosed with Crimean-Congo hemorrhagic fever (CCHF) through the application of machine learning models and to evaluate their predictive performance.

Methods: The study included patients with a definitive diagnosis who were admitted to the Department of Infectious Diseases and Clinical Microbiology of Tokat State Hospital between February 1, 2011 and October 1, 2022 with suspicion of CCHF. Five models, namely XGboost, Logistic regression, Random Forest, LightGBM, and Gradient Boosting Classifier, were constructed using machine learning algorithms to predict mortality in CCHF patients. The performance of these models was subsequently evaluated.

Results: A total of 1,881 cases of suspected CCHF were admitted to the hospital, of which 891 were confirmed, resulting in a fatality rate of 3.3%. In the study, the receiver operating characteristic (ROC) analysis was performed to predict the risk of mortality in CCHF patients with the XGboost, logistic regression, and Gradient Boosting Classifier models. The area under the curve (AUC) results were 0.849, 0.919, and 0.853, respectively. In the evaluation of the relative importance of the features of these models, platelet count, neutrophil-to-lymphocyte ratio (NLR), and neutrophil count were identified as being among the top five.

Interpretation conclusion: Statistically significant predictive models were created using machine learning techniques, specifically XGboost, logistic regression, and Gradient Boosting Classifier. The results of our analysis suggest that platelet count, NLR and neutrophil count are the most effective parameters for predicting mortality.

Background objectives: CD5L (CD5 antigen-like) is a secreted glycoprotein involved in immune regulation, macrophage polarization, and lipid metabolism. While its role in inflammatory and bacterial diseases has been described, its function in viral infections such as dengue virus (DENV) infection remains unclear. This study aimed to evaluate serum CD5L levels in dengue-infected individuals and investigate its association with serological markers and disease severity. A cross-sectional study involving dengue-positive and dengue-negative individuals was conducted to compare serum CD5L concentrations and assess correlations with NS1, IgM, IgG status, and disease severity.

Methods: Serum samples were collected from confirmed dengue-positive patients and dengue-negative controls. CD5L concentrations were quantified using enzyme-linked immunosorbent assay (ELISA) and analyzed according to serological profiles (NS1, IgM, and IgG). Two-group comparisons were performed using the Mann-Whitney U test, and multiple groups were analyzed using the Kruskal-Wallis test with Dunn's post hoc test. A P-value < 0.05 was considered statistically significant.

Results: CD5L levels were significantly elevated in dengue-positive individuals compared to dengue-negative controls (P < 0.05), with the highest levels observed in IgG-positive only individuals (P < 0.01). No significant differences were seen in NS1-positive only or IgM-positive only groups, suggesting that CD5L upregulation is associated with IgG seropositivity rather than acute-phase markers. Similarly, CD5L levels did not significantly differ among individuals with combined serological markers (NS1 & IgM-positive, NS1 & IgG-positive, IgM & IgG-positive). Among IgG-positive only individuals, CD5L levels were significantly higher in non-severe dengue cases compared to severe dengue cases (P < 0.05). No significant differences were observed in CD5L levels between severe and non-severe NS1-positive only or IgM-positive only individuals. These findings suggest a potential association between increased CD5L and later stages of dengue virus infection with less severe outcomes.

Interpretation conclusion: This study highlights CD5L's potential role in dengue pathogenesis, particularly its association with IgG seropositivity and non-severe disease. Further research is needed to clarify its mechanisms and evaluate its potential as a biomarker or therapeutic target in dengue virus infection.

Background objectives: Malaria continues to be a serious public health problem in tropical and subtropical countries of the world including India, resulting in millions of cases and deaths annually. Global efforts to eliminate malaria are continuously being scaled up and helping countries to move towards elimination by 2030. India is also accelerating its efforts and has shown significant progress in last few years with few pockets of uncertainties. This study aimed to explore the epidemiological profile of malaria in Haryana State of India during past five decades and its correlation with climatic variability into public health planning as well as implementation of integrated vector control strategies together with enhanced surveillance networks which could help to mitigate the malaria transmission in the State.

Methods: Literature search related to the malaria epidemiology in Haryana was carried out using the electronic medical secondary databases i.e. Google Scholar and PubMed for the past five decades with the appropriate key words and inclusion & exclusion criteria as well as annual malaria data for the past 7 years was captured from the National Centre for Vector Borne Disease Control (NCVBDC) website.

Results: The literature search using the secondary databases as mentioned above revealed a total of 134 research articles, out of which only 18 research papers were found relevant to Haryana and were reviewed further for epidemiological profile and correlation with climatic variability and disease control. Based on the epidemiological studies and data captured from National Centre for Vector Borne Diseases Control (NCVBDC) from 2018-2024, it was found that the number of malaria cases in Haryana decreased from 3149 to 52 cases (98.34%), in 2022 but thereafter cases started rising and reached to 270 cases in 2024, showing a rising trend that needs to be addressed urgently in view of the elimination targets of 2030.

Interpretation conclusion: This study indicates a slight increase in the malaria incidence in Haryana, which require an immediate and early action. There is a need to understand the rising incidence of malaria, which can be due to climate related factors, affecting mosquitoes proliferation and survival resulting in enhanced malaria transmission or gaps in the health systems for effective implementation of vector control measures. Hence, it is suggested to strengthen disease surveillance, promote robust clinical management and take effective vector control measures to bring the rising incidence down and sustain the malaria elimination efforts.

Background objectives: Urban malaria remains a significant public health challenge, driven by population mobility, and complex transmission dynamics. To characterize the epidemiological profile of malaria cases, with emphasis on demographic patterns, parasite species distribution, and contribution of imported malaria in South-West Delhi.

Methods: The clinical records from the Fever Clinic at ICMR-NIMR, New Delhi were analysed. Febrile patients were screened for malaria using rapid diagnostic tests and microscopic examination of peripheral blood smears. Data on age, gender, parasite species, stage and travel history (past 30-days) to malaria-endemic areas were extracted. Cases were classified as imported or indigenous based on established epidemiological criteria.

Results: Among 7,257 fever cases, 58 (0.8%) were tested malaria positive. Plasmodium vivax accounted for 94.8% (55/58) of cases and P. falciparum for 3.4% (2/58). Males (70.7%) and individuals aged 18-45 years (60.3%) were most affected. Imported cases accounted for 51.7% (30/58), with 76.7% (23/30) from Aligarh, Amorha, Budaun, Bulandshahr, Hardoi and Shahjahanpur districts. The proportion of imported cases increased from 52.2% in 2020 to 66.7% in 2024, concurrent with a decline in indigenous malaria cases.

Interpretation conclusion: Malaria persists in South-West Delhi, with low transmission, P. vivax predominance and substantial, increasing proportion of imported cases from neighbouring districts of Uttar Pradesh and other endemic areas. These findings highlight the critical need for strengthening cross-notification to State, case-based surveillance and inter-state collaboration, targeted vector control and pre-emptive interventions in both recipient area and districts from where population migrates to Delhi with malaria infection to sustain malaria elimination in urban India.

Background objectives: Algeria has been certified as malaria-free since 2019 by WHO and last indigenous case was reported in May 2013; however, imported cases remain a concern for possible for reintroduction. This study aimed to describes the epidemiological, clinical, and therapeutic characteristics of imported malaria cases in the Tizi-Ouzou between 2018 and 2024.

Methods: A retrospective descriptive study was conducted in the Department of Infectious Diseases at the University Hospital of Tizi-Ouzou. Data were collected from hospital registers and archived medical records. Only laboratory-confirmed cases, diagnosed by microscopic examination of Giemsa-stained blood smears, were included. Variables included demographics, travel history, Plasmodium species, incubation period, clinical presentation, disease severity, laboratory findings, treatment, preventive measures, and outcomes.

Results: Among 106 individuals screened, 16 were confirmed as imported malaria (positivity rate 15.1%). Annual cases fluctuated, with a notable increase from 2022 to 2024, reaching 40% positivity in 2024. Most patients were men (87.5%) and adults aged 20-50 yrs (87.5%), mainly Algerian nationals returning from West Africa. Plasmodium falciparum accounted for 87.5% of cases, often with low parasitemia (< 4 % in 68.8%). No patient had used chemoprophylaxis. Fever with chills and sweats was the most common symptom (92.9%). Uncomplicated malaria representes 78.6% of cases, while 21.4% were severe. The main biological abnormalities were anemia (92.8%), thrombocytopenia (42.8%), and hepatic cytolysis (43%). Mefloquine was the most prescribed treatment (71.4%).

Interpretation conclusion: Imported malaria in Tizi-Ouzou is characterized by P. falciparum predominance, absence of chemoprophylaxis, short post-travel incubation, and travel-linked seasonality. Strengthening pre-travel counseling, improving prophylaxis, uptake, and enhancing clinician awareness are crucial to prevent severe disease and reduce the risk of malaria reintroduction in Algeria.

Background objectives: Dengue fever remains a major global public health threat, responsible for millions of infections annually across tropical and subtropical regions. Despite extensive modeling efforts, most existing studies focus exclusively on mosquito-mediated transmission and overlook additional non-vectorial pathways that may influence outbreak persistence.

Methods: This study addresses this gap by developing the first fractional-order dengue transmission model that simultaneously integrates human-to-human, mosquito-to-mosquito, human-to-mosquito, and mosquito-to-human transmission routes. The Caputo fractional derivative is applied to capture memory effects and nonlocal temporal behavior inherent in real epidemic processes.

Results: Analytical results demonstrate that the model exhibits backward bifurcation when the mosquito-to-mosquito reproduction number exceeds unity, implying that dengue may persist even when the basic reproduction number falls below one. Numerical simulations reveal that fractional-order dynamics slow epidemic decay, delay infection peaks, and prolong outbreak duration compared with classical integer-order models. These findings indicate that memory effects significantly influence disease persistence and the effectiveness of control measures.

Interpretation conclusion: By bridging an important gap in dengue modeling, this framework highlights the combined epidemiological impact of multi-route transmission and fractional dynamics. The results provide insight into designing integrated and sustainable dengue control strategies that account for vectorial, non-vectorial, and memory-dependent transmission processes.

Background objectives: Malaria remains a major public health challenge in Sub-Saharan Africa, with Nigeria bearing a significant burden. Insecticide-treated nets (ITNs) are key to the WHO's malaria control strategy. This study examined sociodemographic factors associated with ITN use among children under five years and pregnant women in Nigeria.

Methods: Data from the 2021 Nigeria Malaria Indicator Survey were analyzed to assess sociodemographic factors associated with ITN use. Bivariate and multivariate analyses were conducted to evaluate the association between ITN use and sociodemographic variables.

Results: The survey included 13,727 households, with 14,476 women aged 15-49 years and 12,742 children under five. Of these, 56% of households owned at least one ITN, and 50% of women and 41.2% of children slept under an ITN. ITN utilization was higher in rural areas (p = 0.001), the North West and North East regions (p < 0.001 for both), and among lower wealth quintiles (p < 0.001). Younger children under 12 months old had a higher likelihood of sleeping under ITNs (p < 0.001). Pregnant women with no education (p = 0.048) or only primary education (p = 0.042) were also more likely to use ITNs.

Interpretation conclusion: Despite extensive ITN distribution efforts, gaps in utilization still persist among under-five children and pregnant women in Nigeria, more evident among older children, wealthier households, and women with higher education. Sustained community education, targeted interventions, and regular monitoring of sociodemographic trends are essential to enhance ITN use and achieve nationwide malaria prevention goals.