Journal of Vector Borne Diseases最新文献

Dengue continues to escalate as a major global health challenge, driven by rapid urbanization, ecological change, and the expanding distribution of Aedes aegypti . Conventional surveillance systems, dominated by larval indices, provide limited predictive value and fail to capture the real-time transmission risk posed by infective adult females the sole vectors of dengue virus. This review re-examines dengue surveillance by emphasizing the epidemiological and operational significance of adult mosquito monitoring. Existing traps such as BG-Sentinel, CDC light and gravid traps, and gravid Aedes -specific devices are critically evaluated for their sensitivity, adaptability, and diagnostic utility. Metrics like threshold vector density and minimum infection rate (MIR) are identified as reliable indicators of transmission potential. The paper advocates for the development and large-scale deployment of next-generation adult traps that combine dual-attractant systems, power-free operation, and compatibility with molecular and digital diagnostic tools. Such innovations can transform dengue surveillance from reactive control to predictive, evidence-based intervention, offering a pathway toward sustainable, anticipatory vector management.

Background objectives: Malaria during pregnancy remains a significant public health concern, contributing to maternal and neonatal morbidity and mortality. This study aimed to assess the prevalence of malaria and its associated factors among pregnant women attending antenatal care (ANC) at Maraki Health Center, Northwest Ethiopia, 2025.

Methods: A facility-based cross-sectional study was conducted among 271 pregnant women using structured interviews and laboratory testing (RDT and microscopy) for malaria diagnosis. Socio-demographic, clinical, behavioral, and environmental data were collected. Binary and multiple logistic regression analyses were performed to identify factors associated with malaria infection.

Results: The prevalence of malaria among the participants was 13.4%. Factors independently associated with malaria infection included not using insecticide-treated nets(ITN), (AOR=3.2; 95% CI: 1.4-7.5), not receiving Intermittent Preventive Treatment in Pregnancy with Sulfadoxine-Pyrimethamine (IPTp-SP), (AOR = 2.8; 95% CI: 1.1-6.9), attending fewer than four ANC visits (AOR = 4.6; 95% CI: 1.9-11.2), living near stagnant water (AOR = 2.5; 95% CI: 1.1-5.8), and attending Antenatal care during the rainy season (AOR = 1.9; 95% CI: 1.0-3.7).

Interpretation conclusion: The prevalence of malaria among pregnant women in the study area was considerable. Behavioral and environmental factors significantly contributed to malaria risk. Strengthening Insecticide-Treated Net (ITN) distribution, ensuring Intermittent Preventive Treatment in Pregnancy with Sulfadoxine-Pyrimethamine (IPTp-SP uptake), promoting regular ANC attendance, improving environmental sanitation, and increasing malaria prevention education, particularly during the rainy season, are recommended to reduce the burden of malaria in pregnancy.

Chikungunya is a viral fever caused by a single stranded RNA virus of the genus alpha virus of the family Togaviridae and transmitted to human by the bite of Aedes Aegypti mosquito. The incubation time frame of this virus is short, enduring about 2- 4 days. Chikungunya virus disease is typically self-constrained, non-lethal, with fever settling inside a couple of days. A number of conventional methods such as ELISA, RT-PCR and PCR are available for determination of chikungunya virus. Besides the advantages of being highly sensitive and selective, these methods have some drawbacks like time-consuming, requirement of sample pre-treatment, high cost instrumental set-up and skilled persons to operate. The sensors/biosensors overcome these drawbacks, as these are fast, easy, cost effective and highly sensitive. During the past five decades, biosensors have consolidated their impact in several fields, including clinical diagnosis, due to advantages such as high selectivity and sensitivity, potential for miniaturization, portability, low cost and rapid response. The chikungunya sensors/biosensors reported so far, have worked ideally within 10s, at a working potential -0.6-10.4 V, at the optimum pH, 7.0 and optimum temperature 35°C and linear range, 0.1-100μM, with the detection limits between 0.1 to 3.4nM. These biosensors measure chikungunya virus 2 in DNA of serum and had maximum storage stability of 540 days. The future perspective for further improvement and commercialization of chikungunya biosensors are discussed.

Background and objectives: Psychological well-being among dengue patients has often been rather unnoticed, despite evidence showing a notable proportion experience psychological distress during illness and the post-infectious period. This study aimed to assess the prevalence and associated factors of stress one month after hospital discharge among adults with dengue fever in the Colombo District, Sri Lanka.

Methods: A longitudinal study was conducted in 2019 among 480 patients discharged after Dengue treatment. Participants were selected using systematic sampling and followed up one month after fever onset. Prevalence of stress was assessed using the validated Depression, Anxiety and Stress - 21. Selected correlates were assessed using a pre-tested interviewer-administered questionnaire. Binomial multiple logistic regression was used for analysis.

Results: Of the 480 participants, 406 responded (response rate: 84.58). The majority were males (n = 244, 60.15%) and aged 18-35 years (n = 281, 69.2%). The prevalence of stress at one month post-infection was 7.9% (95% CI = 5.5 - 10.9). Significant correlates of stress included female gender (AOR = 3.24; 95% CI: 1.45-7.26), presence of headache (AOR = 3.26; 95% CI: 1.39-7.61), and myalgia (AOR = 4.16; 95% CI: 1.74-9.92) during the post-infection period.

Interpretation conclusion: Approximately one in twelve adults experienced stress one month after Dengue infection. Post-infection symptoms such as headache and myalgia were significant predictors of stress. These findings highlight the need for routine psychological screening and targeted interventions during follow-up care for Dengue patients.

Background objectives: With 13,924 dengue cases reported in Rajasthan (2023), understanding community knowledge gaps is crucial for vector control. This study assessed dengue awareness among rural patients through structured interviews to identify intervention priorities.

Methods: Fifty outpatient department patients (aged ≥21 years) from a rural Community Health Centre were interviewed using mixed-method approach. Structured questionnaires assessed 15 knowledge domains, supplemented by qualitative exploration of beliefs and practices.

Results: Overall knowledge score was 61.8% (9.28±2.07/15). Critical gaps included disease identification (18% correct), symptom awareness (42%), and vector behavior understanding (18%). However, 90% identified mosquitoes as vectors and 82% recognized disease severity. Qualitative analysis revealed person-to-person transmission misconceptions (42%) and strong traditional remedy reliance (70%).

Interpretation conclusion: Rural communities demonstrate significant dengue knowledge deficits, particularly regarding vector biting behavior and disease recognition. Interview methodology revealed cultural beliefs that quantitative surveys miss. Targeted health education focusing on Aedes mosquito behavior and culturally appropriate messaging is urgently needed.

Background objectives: Aedes (Neomelaniconion) contains two important arbovirus vectors, Ae. lineatopennis and Ae. mcintoshi for transmission of Flaviviridae, Togaviridae, and Bunyaviridae families. Aedes lineatopennis invaded the Oriental and Australasian regions and closely resembles Ae. mcintoshi in morphology is causing confusion and misidentification among researchers. The present study delineates Ae. lineatopennis from Ae. mcintoshi using integrated taxonomic approaches.

Methods: Morphological features and mitochondrial cytochrome c oxidase subunit I (COI) gene analyses were used to establish species delineation in Ae. lineatopennis. Sound attributes for adult males and females were also generated.

Results: Aedes lineatopennis was confirmed with the morphological features, i.e., thoracic broad lateral longitudinal yellow scale stripes, tergite basal pale bands, subcostal white scales, dark and white scales on various veins, and longer vein R2 (1.5X) than vein R2+3. Genetically, this population was closer to the Chinese, Japanese, Korean, and Thai in comparison to African populations. Sound fundamental frequency was 598.54 ± 3.1 Hz for males and 429.9 ± 2.8 Hz for females, with four harmonic bands and harmonic convergence at M2 + F3 and M3 + F4 between males and females.

Interpretation conclusion: The combined morphological, molecular, and acoustic evidence confirms that the specimens previously identified as Ae. mcintoshi in India is in fact Ae. lineatopennis. Therefore, the study recommends the retraction of Ae. mcintoshi from Indian mosquito records6. This study emphasises the need for accurate species identification using integrated approaches to assess proper biodiversity and other studies.

Background objectives: The Rajasthan state is one of the arid and semi-arid regions of India, characterized by extreme climatic conditions. In recent years, rising temperatures and altered rainfall patterns have created favourable conditions for the proliferation of mosquito vectors and contribute to the upsurge and sustained transmission of mosquito-borne diseases. The vector control largely depends on chemical insecticides, but their prolonged use can hinder effectiveness due to the emergence of resistance. Therefore, the present study aimed to assess the efficacy of pyrethroids and resistance status in Aedes aegypti populations of Jaipur, Rajasthan.

Methods: Adults and larvae of Ae. aegypti were collected from nine localities across Jaipur. Diagnostic doses and adult susceptibility for field-collected (F0) and laboratory-reared (F5) strains of Ae. aegypti were evaluated according to WHO and CDC protocols.

Results: Diagnostic doses for deltamethrin, permethrin, and lambda-cyhalothrin were determined 0.005 μg/ml, 0.01 μg/ml, and 0.05 μg/ml, respectively. Aedes mosquitoes showed 100% mortality against all determined diagnostic doses. Lethal concentrations (μg/ml) values indicated a clear susceptibility hierarchy, with deltamethrin showed the highest effectiveness (0.000152-0.000169), followed by lambda-cyhalothrin (0.00066-0.00070) and permethrin (0.00133-0.00155). However, Sanganer (3.66-4.32), Shastri Nagar (3.67-4.52) and Shyam Nagar (3.8-4.52) exhibited the higher levels of resistance ratios against tested pyrethroids.

Interpretation conclusion: Pyrethroids are still effective in vector management, although some locations were observed emerging resistance. It highlights the necessity of continuous monitoring of insecticide resistance patterns in Aedes populations to ensure the long-term success of vector control programs.

Background objectives: Leishmaniasis is a major global public health concern but current control measures are unreliable. Vaccination is likely the best control method, but despite efforts to develop a vaccine, none has been approved for human use. This study evaluated the antileishmanial potential of a vaccine combining 2,6,10,14-tetramethylpentadecane (pristane) as an adjuvant plus soluble Leishmania major antigens (SLmAgs) in BALB/c mice.

Methods: Mice were randomly assigned to four groups and treated as: group 1 - SLmAgs + pristane; group 2 - SLmAgs alone; group 3 - BCG + SLmAg (positive control) and group 4 - phosphate buffered saline (negative control). At 31 days post-vaccination, immune response was assessed by measuring the production of interleukin-10 (IL-10); interferon-gamma (IFN-γ) and CD4+/CD8+ T cells using flow cytometry. Protection against cutaneous leishmaniasis was determined after infecting the mice with virulent L. major promastigotes (at 31 days post-vaccination) and measuring the footpad lesion size and determining parasite loads in infected footpads using the limiting dilution assay at 45 days post infection.

Results: Following vaccination with SLmAgs + pristane as an adjuvant, the mice produced higher amounts of Th 1 cytokine- IFN-γ compared to Th2 cytokine IL-10 and a significantly higher amount of CD4+ compared to CD8+ T cells, with corresponding smaller lesion sizes and lower parasite loads.

Interpretation conclusion: The findings in this study demonstrate the potential of pristane as an adjuvant for antileishmanial vaccines, effectively inducing protective Th1 responses. However, safety assessments, dosage optimization and evaluation in non-human primates are recommended to confirm its suitability and enhance vaccine efficacy.

The cases reported the clinical characteristics and viral kinetics of DEN-1 and DEN-4 in two cases of congenital dengue. We describe two neonates born to mothers with recent dengue infections, highlighting their clinical presentation, serological progression and outcomes. Both neonates had early onset of symptoms, with one tested positive for DEN-4 and the other for DEN-1. Both experienced thrombocytopaenia without signs of haemoconcentration and recovered uneventfully. Congenital dengue, although rare, should be considered in neonates with fever and other suggestive symptoms in dengue-endemic areas. The two reported cases are unique in that both had congenital dengue fever with different serotypes, yet demonstrated prolonged NS1 antigen positivity and delayed seroconversion.

Background objectives: Determining the host seeking and resting behaviours of malaria vectors in a locality is vital for the design and implementation of locally adapted vector control strategies. This study investigated the seasonal abundance, host seeking, and resting behaviours of malaria vectors in localities where insecticide-treated nets (ITNs) and indoor residual spraying (IRS) are persistently used in Mazowe and Shamva districts.

Methods: Anopheles mosquitoes were sampled from both living and non-living structures using CDC light traps, Prokopack aspirator, and artificial pit traps in April, July, October, and December 2023. Female Anopheles were identified using morphological keys. R software was used for data analysis. The Kruskal-Wallis test was used to assess differences in the abundance of female Anopheles across collection methods, while a negative binomial Generalized Linear Mixed Model (GLMM) was used to determine the effect of study site, season, and type of structure on the abundance of female Anopheles mosquitoes.

Results: Overall, 787 female Anopheles were caught, comprising An. gambiae sensu lato (s.l.) (33%), An. funestus s.l. (17.4%) and others (49.6%). Relative abundance of female Anopheles mosquitoes based on collection method showed significant difference (Kruskal-Wallis: X2 = 42.33, df = 3, p < 0.001). There were significantly more female Anopheles mosquitoes caught in Shamva district (p = 0.023), during the post-rainfall season (p < 0.001), in traditional-style bedrooms (p < 0.001) and grass thatch toilets (p = 0.045). Notable proportions of An. gambiae s.l. were caught seeking hosts pre-bedtime outdoors (19%) and early morning outdoors (14.3%), and An. funestus s.l. pre-bedtime indoors (14.5%) and early morning outdoors (10.9%). High percentages of An. gambiae s.l. (51.1%) and An. funestus s.l. (35.6%) were caught from non-living structures that lack insecticide treatment.

Interpretation conclusion: Malaria vectors are circumventing current control measures by biting people when they are not protected by ITNs and resting in outdoor areas or indoor structures where insecticides are not applied. Supplementary interventions, including larval source management (LSM) and repellents, are required to reduce the risks of residual malaria transmission.