Journal of Vector Borne Diseases最新文献

Background objectives: In malaria infection, quantifying blood parasitemia is a critical step for evaluating the severity of the disease. This has generally been conducted manually, and thus, its accuracy depends on the expertise of technicians. There is an urgent need for an automated technique to overcome manual errors. The aim of the study is to find an alternative method for counting malaria blood parasitemia.

Methods: This study evaluated the accuracy of automated counting using QuPath compared to manual counting. GraphPad Kappa evaluated agreement between high and low parasitemia in both counting methods using Cohen's test.

Results: QuPath was revealed to be a promising method that has fair agreement and no statistically significant differences compared to manual counting.

Interpretation conclusion: In conclusion, automated quantification is suggested to be a time- and effort-saving technique and, therefore, a worthwhile alternative to manual counting.

Background objectives: Temephos is being used regularly to control immature of vector borne diseases in various states in India.

Methods: World Health Organization method was used to evaluate larval susceptibility status of Aedes aegypti and Anopheles stephensi against temephos in Dehradun of Uttarakhand.

Results: The results of the study revealed that the larval mortality in different localities ranged from 67.11% to 98.22%, the-lowest mortality was recorded from Kedarpuram (67.11%) and highest larval was recorded from Vikash Nagar (98.88%). The study revealed that most of larval populations of Ae. aegypti were resistant or under verification required category against temephos at diagnostic concentrations collected from six different localities of study area of Dehradun while only one larval population of Ae. aegypti was found susceptible. However, Anopheles stephensi larvae collected from all sites were susceptible at diagnostic concentration of temephos.

Interpretation conclusion: The study highlights the potential development of resistance to temephos in Ae. aegypti across most of the study areas in Dehradun.

Malaria continues to remain a serious threat to public health, especially in regions with socio-economic and healthcare disparities. The paper attempts to contextualise the current scenario of malaria transmission, the advancement made towards its elimination and the multi-dimensional strategies that may be required to overcome cultural and regional barriers; with a focus on India's goal to eliminate malaria by 2030.

Background objectives: Area-specific identification and studies of Anopheles breeding habitat diversity, distribution, and productivity in different seasons are important in designing and advancing effective malaria vector control according to the local context and needs. This study identified and characterized Anopheles breeding habitats for targeted control of malaria vectors in Mazowe and Shamva districts.

Methods: Repeated cross-sectional surveys were conducted in Mazowe and Shamva districts between April and December 2023. Habitat productivity and physicochemical parameters were measured. Anopheles larvae were collected, reared to adults, and identified using morphological keys. SPSS software was used for data analysis. One-way ANOVA, Fisher's exact, Pearson's correlation, and simple linear regression tests were conducted.

Results: Seven different types of Anopheles breeding habitats were identified from 56 sites. The highest mean density of larvae was recorded in stream edge pools during the post-rainfall period. Anophelespretoriensis (67.4%), An. gambiae s.l. (23.1%), An. rufipes (9.2%) and An. coustani (0.38%) were breeding in the study area. Anopheles pretoriensis bred in all habitat types, An. coustani in swamps only while An. gambiae s.l. and An. rufipes preferred stream edge pools, roadside pools, and hoof prints. There was a significant positive correlation between larval density and dissolved oxygen (r = 0.535; p < 0.001) and conductivity (r = 0.288; p = 0.032).

Interpretation conclusion: Size, origin, and type of breeding habitat were positive indicators for different Anopheles species in the study area. Potential malaria vector breeding habitats should be targeted for larval control under the current malaria control and elimination phases in the two districts.

Background objectives: There is a persistent high microfilaria rate and variable reporting of coverage of Mass Drug Administration (MDA). The study aims to estimate the coverage, effective coverage, and compliance of drugs administered under MDA and to determine the predictors affecting the effective coverage.

Methods: A community-based cross-sectional study was conducted in Amethi, Lucknow, Raebareli and Sultanpur districts of Uttar Pradesh, India. The study participants were selected using multi-stage random sampling using Probability Proportional to Estimated Size (PPES). The coverage, effective coverage and compliance of drugs were presented as proportion. The multivariable logistic regression model was applied to identify the significant predictors for effective coverage.

Results: Of 4151 participants, 997 (24.0%), 340 (8.2%), 1158 (27.9%) and 1656 (39.9%) belonged to Amethi, Lucknow, Raebareli and Sultanpur districts respectively. The coverage ranged from 49.8% to 87.9% and effective coverage ranged from 51.8% to 73.2% across districts. The compliance was the poorest (70.7%) in Sultanpur. The source of information about MDA, the sex of the study participants and the area of residence emerged as predictors for effective coverage in the districts.

Interpretation conclusion: The effective coverage was poor with good drug complianceacross the districts. There is a need for a well-designed pre-MDA campaign addressing the fear of side effects of drugs and emphasising the presence of the community during the MDA round along with monitoring and evaluation of the round.

Background objectives: To understand the distribution and presence of West Nile (WN) among the acute encephalitis syndrome (AES) patients, a prospective facility-based study was conducted over 13 years (2007-2019).

Methods: During the period, 8957 patients hospitalized with AES in northeastern India were tested for the evidence of WN virus infection by IgM ELISA followed by Plaque reduction neutralization test (PRNT).

Results: Of the samples tested 324 (3.62%) were found positive for WN IgM antibodies and 73 paired sera showed a fourfold rise in neutralizing antibody titre by PRNT. The study establishes WN as a noteworthy cause of encephalitis in an erstwhile endemic area for Japanese encephalitis (JE).

Interpretation conclusion: Therefore, it is important that WN is recognized as an important acute encephalitis syndrome (AES) causing aetiology in this region and the National centre for vector borne disease control (NCVBDC) guidelines for detection of AES may be modified accordingly. Thus, inclusion of WN in routine diagnosis, along with establishment of an integrative surveillance network with one-health approach will be important.

Background objectives: Compressive mapping and in-depth analysis of malaria vulnerability risk foci are important tools for strategic planning, vector surveillance, implementing necessary interventions, and managing scarce resources to combat the daunting challenges of malaria infections in Nigeria.

Methods: The study utilized environmental risk factors and spatial multi-criteria decision analysis techniques to analyze and map the spatial variations in malaria-endemic prone areas within the Northern Zone of Plateau State.

Results: Analysis of the criteria's weights of environmental risk factors and the stratification of the malaria risk vulnerability revealed that high-risk areas covered a total of 4017.25 Km2, while low-risk areas covered 1294.83Km2, having a close resemblance to the corresponding ground conditions. The results showed that a significant 60% of the study areas were characterized by high risk of malaria transmission, particularly in most settlements around the Jos North, Jos South and Barkin Ladi Local Government Areas. The malaria risk map's predictive abilities demonstrated a high level of accuracy, as indicated by the area under the curve score of 0.989. Furthermore, the risk map demonstrates a high-performance rate in identifying malaria hotspots, with a sensitivity of 98%, a proficiency rate of 54%, and a statistical significance confidence level ranging from 90% to 99% for identifying malaria hotspots and coldspots.

Interpretation conclusion: The malaria risk analysis and mapping within the endemic prone areas of the Northern Zone of Plateau State not only equips policymakers with effective tools for identifying malaria foci but also offers a deeper comprehension of the appropriate intervention measures to be implemented.

Background objectives: Scrub typhus is an acute febrile zoonotic disease caused by the obligate intracellular gram-negative bacteria Orientia tsutsugamushi. Growing data over the last few years on the Indian subcontinent suggest that it is one of the most widespread but under-reported diseases. The study aimed to document the clinical and paraclinical profile and evaluate complications of scrub typhus in severe and nonsevere pediatric age groups.

Methods: A prospective observational study was conducted in pediatric patients. Frequency, mean, percentage and standard deviation were all included in the descriptive statistical analysis calculation. Multivariate analysis was conducted to predict the severity factor.

Results: A total of 189 patients met the eligibility criteria and were included in the final analysis. The mean and standard deviation (mean ± SD) age of the cohort was 5.54 ± 3.9 years, with a male predominance of 68.2%. The mean ± SD duration of fever was 6.64 ± 1.43 days. Patients with severe scrub typhus experienced complications including hepatic involvement (42, 64.6%), respiratory distress (23, 46.1%), neurological involvement (14, 24.6%), acute kidney injury (10, 15.4%), myocarditis (9, 13.8%), and (16, 24.6%) have multi-organ dysfunction. patients with raised transaminases (> 180 IU/L) have a 3.7 to 4.1 times greater chance of developing severity. Thrombocytopenia is found to be another independent predictor of severe scrub typhus in our study.

Interpretation conclusion: Clinical signs of hepatomegaly, skin rash, and lymphadenopathy were significant predictors of severity. Delays in treatment are a key contributor to the severity of pediatric scrub typhus.

Background objectives: Malaria, a vector-borne disease, is caused by Plasmodium species and transmitted by Anopheles species. Among these vectors, Anopheles subpictus has emerged as a potent malarial vector in coastal areas of India. Numerous studies have highlighted that bacterial communities within mosquito influence vector competence. The present study was designed to isolate and characterize bacterial microbiota from An. subpictus larvae.

Methods: Isolation and purification of the predominant bacterial strain (ALl) was carried out. Morphological, biochemical, antibiotic susceptibility and molecular characterization of the isolated bacteria was performed.

Results: Bacterial isolate (AL1) was found to be rod, gram negative, catalase positive and oxidase negative. AL1 was identified as Leclercia adecarboxylata (Accession number: OR649235) through 16S rRNA ribotyping. Further, the leaf extract of Nyctanthes arbortristis showed inhibitory effect against ALl.

Interpretation conclusion: The study provided the first report on the isolation of symbiotic bacteria (L. adecarboxylata) from An. subpictus and its control by leaf extract of Nyctanthes arbortristis. Isolated gram-negative bacterial strain might inhibit the development of mosquito vectors and can be implemented for various biological control strategies to combat malaria transmission.

Background objectives: Anopheles funestus is playing an increasingly important role in malaria transmission in sub-Saharan Africa. Trehalase, an enzyme required for trehalose breakdown, is important for mosquito flight and stress adaptation. Hence, its inhibition has emerged as a promising malaria management strategy.

Methods: A collection of 1900 natural compounds from the ZINC database were screened against the 3D modeled structure of An. funestus trehalase protein using in silico tools. ADMET-AI, a web-based platform, was used to predict the absorption, distribution, metabolism, excretion, and toxicity (ADMET) properties of the selected compounds.

Results: We report 5 natural compounds namely, ZINC00488388, ZINC00488525, ZINC00488566, ZINC00488304, and ZINC00488456 that demonstrated strong binding affinity to the trehalase protein. These compounds interacted with critical residues of the trehalase protein and exhibited good drug-like characteristics.

Interpretation conclusion: These compounds show promise as trehalase protein inhibitors for malaria management. Nonetheless, additional experimental studies are required to optimize these compounds as potential trehalase inhibitors.