Journal of Vector Borne Diseases最新文献

Background objectives: Dengue fever is one of the most common causes of undifferentiated tropical fevers in hospitalized children across India with the highest recorded morbidity and mortality in children less than 15 years. Although common, there is still a knowledge gap regarding epidemiological factors. The aim was to study the clinical profile and demographic trend over the past 5 years in children with confirmed dengue infection.

Methods: Observational study of children admitted as inpatients over the past 5 years and diagnosed with dengue infection by serology. Categorical data were presented as percentages. Data regarding rainfall was collected from rainfall statistics from the Indian Meteorological website and correlated based on the T-test. The incidence of dengue infection in COVID-19 predominant years was analyzed using the correlation plot and trend of severe dengue infection over the years was noted by Line plot.

Results: The study showed a positive correlation between rainfall and an increase in the incidence of cases. There were relatively reduced number of cases during COVID-19 which was interpreted from the correlation plot. The Line plot determined the trend of severity of presentation and more severe cases presented in the years 2019, 2021 and 2022.

Interpretation conclusion: Other than the pathophysiology, studies to understand the change in the severity of clinical presentation each year could help in augmenting the vector control measures accordingly.

Background and objectives: Occurrence and distribution of vector population are crucial for entomological study in context of prevention, control and elimination of vector-borne diseases. To update some entomological aspects in three districts of Tamil Nadu state namely Kumbakonam, Nagapattinam and Thriuvarur districts, the study was undertaken. The objective of the study was to understand the prevalence of mosquitoes; to assess insecticide resistance and phylogenetic analysis of dengue vectors [Aedes (Ae.) aegypti and Ae.albopictus].

Methods: The immature stages of mosquitoes were collected from different localities by standard WHO methods marking with GPS and mapping was done using ArcGIS 10.4 software for all three districts. Insecticide resistance test was conducted using WHO susceptibility test kits. The F1 generation of female adult mosquitoes of Ae. aegypti and Ae. albopictus were exposed to DDT 4% and Malathion 5% with the control paper of Risella oil and olive oil respectively. Further, genomic DNA of individual mosquito was isolated, and the sequencingwas done through Eurofins, Bangalore, India. The FASTA sequence was analyzed and the phylogenic tree was constructed using the Maximum likelihood method in Molecular Evolutionary Genetics Analysis (MEGA) software (version 10.0).

Results: A totally 5307 specimens were collected through expanded survey in all three study areas. The collection yielded 16 species from six genera of mosquitoes. In total collection, the Ae. albopictus was the dominant species in Kumbakonam and Thiruvarur districts and Ae. aegypti was dominant in Nagapattinam district. The predominant breeding sources were discarded tyre with rainwater, plastic cups, coconut shells, aluminum vessels, sliver containers, bottles, grinding stones and earthen pots etc. The study revealed high pupal indices in all three study areas. Insecticide resistance monitoring revealed possible resistance in Ae. aegypti against DDT in all three districts whereas against Malathion, possible resistance was recorded in Kumbakonam and Nagapattinam and in Thiruvarur district, the species was found to be susceptible. Ae. albopictus showed resistance against DDT in all three districts but susceptible to Malathion. The sequences obtained for Dengue vectors showed 99% similar with Genbank. The phylogenetic tree was constructed using COI region sequences. Certainly, observed the different genetic relationship among Ae. aegypti and Ae. albopictus between the study areas.

Interpretation conclusion: The study confirmed the presence of Ae. aegypti and Ae. albopictus in all three districts. The study further revealed that these vectors are susceptible to Malathion but resistance to DDT. The continue surveillance of dengue vector and monitoring of insecticide resistance will strengthen the control programme for appropriate vector control measurements.

Background objectives: Crimean-Congo Hemorrhagic Fever disease (CCHF) is a potentially deadly viral disease and Turkey is the country in which the disease is seen the most. The purpose of this study is to estimate the frequency and case fatality ratio (CFR) of CCHF disease in Erzurum/Turkey between years 2015-2021.

Methods: The CCHF positivity in patients was detected on serum samples via RT-PCR method with RNA detection. Demographic data belonging to positive patients, such as, age, sex, region of residence, tick contact was analyzed retrospectively.

Results: It was detected that the RT-PCR test of 521 patients out of a total of 1378 sent to the laboratory were positive. Each sample belonged to a single patient and repeating samples were left out of the research. The year with least positive patient ratio in relation to potential CCHF positive samples was 2017 (21.12%) whereas the year with the most positivity ratio was 2020 (55.48%) The case fatality ratio in the six-year period was calculated to be 1.34%.

Interpretation conclusion: This study has demonstrated that there is a significant rise in CCHF patient numbers, especially in 2020 when the Covid-19 pandemic started. In order to prevent this rise, it is crucial that the effect of Covid-19 pandemic on the increase in interactions of humans with ticks is researched thoroughly, a biological intervention is made and the public awareness on CCHF disease is increased.

Background objectives: The mosquito Armigeres subalbatus (Coquillett, 1898) is a significant vector for Japanese encephalitis infection, and breeds in high organic polluted water. Understanding mosquito diversity and there abundance in relation to mosquito-borne diseases is an important component for public health managers. Though the conventional methods for systematic position of mosquito species by using morphological characteristics is a classical method, but it requires perfect expertise and well preserved specimen. Conversely, the molecular analysis of mitochondrial cytochrome C oxidase subunit I (COI) serves as a gene-centric DNA barcoding approach and offers a promising alternative method for mosquito species identification.

Methods: The study at hand delves into the morphological characteristics of Armigeres subalbatus were compared with COI- gene to ensure a more dependable verification for identification of mosquito species found in Hyderabad region of Telangana.

Results: The 489 base pair amplicons were acquired and deposited into the NCBI Gene Bank nucleotide database under the accession number MG686500. The maximum likelihood tree infers that, the Hyderabad species was diverged from USA and Japan species but had ancestral relationship with Tamil Nadu, Karnataka, Maharastra, Kerala and Goa species.

Interpretation conclusion: Mitochondrial gene (COI) based DNA barcoding is the most reliable and potential alternative technique to identify the mosquito species.

Background objectives: Aedes aegypti and Aedes albopictus are two sympatric mosquito species that compete with each other for resources when their breeding habitats overlap. This study examines what happens when sympatric Ae. aegypti and Ae. albopictus mosquitoes' mate with each other and other species by looking at insemination rates, fecundity, and hatchability rate.

Methods: We performed controlled mating experiments in laboratory setting, assessing both conspecific and interspecific crosses. We measured insemination rates, egg numbers, and hatching success to examine the reproductive interference dynamics between these two distinct mosquito species.

Results: In the context of conspecific mating, it was observed that both female Ae. aegypti and Ae. albopictus exhibited high insemination rates, with percentages of 98% and 94% respectively. However, interspecific mating exhibited interesting asymmetries: Ae. albopictus males achieved a notable insemination success rate of 28% when mating with Ae. aegypti females, while Ae. aegypti males achieved only an 8% insemination success with Ae. albopictus females. Additionally, females that mated with interspecific males had reduced production of viable eggs compared to conspecific mating. Most notably, interspecific mating resulted in the production of infertile eggs, while conspecific mating led to successful hatching.

Interpretation conclusion: The study reveals that Ae. aegypti and Ae. albopictus can asymmetrically interfere with each other's reproduction, causing a 'satyr' effect. This understanding of interspecific competition and reproductive interference in these mosquito species could impact their coexistence in shared breeding habitats.

Background objectives: Although associated with conflict, epidemic typhus was endemic across Europe into the modem period. The extent of the problem it caused is uncertain as record keeping in the most affected socioeconomic groups was rare. Google Ngram Viewer details the frequency of word usage in written language over time. The objective was to examine whether use of the word typhus reflected potential patterns in epidemic typhus.

Methods: The frequency of the word 'typhus' was used in British English was studied between 1800 and 2019 and trends were examined.

Results: Clear differences in word usage were apparent; use increased throughout the 19 th century corresponding to increasing industrialization. Peaks coinciding with World Wars 1 and 2 were apparent. Strong correlations with the words "conflict", "warfare" and "industry" were seen. Mean shifts corresponded to public health legislation in the UK and the introduction of antibiotics.

Interpretation conclusion: This study illustrates how examination of word usage can illuminate aspects of disease occurrence where official data sources are lacking.

Background objectives: The battle against malaria has witnessed remarkable progress in recent years, characterized by increased funding, development of life-saving tools, and a significant reduction in disease prevalence. Yet, the formidable challenge of drug resistance persists, threatening to undo these gains.

Methods: To tackle this issue, it is imperative to identify new effective drug candidates against the malaria parasite that exhibit minimal toxicity. This study focuses on discovering such candidates by targeting PfRecQ1, also known as PfBLM, a vital protein within the malaria parasite Plasmodium falciparum . PfRecQ1 plays a crucial role in the parasite's life cycle and DNA repair processes, making it an attractive drug development target. The study employs advanced computational techniques, including molecular modeling, structure-based virtual screening (SBVS), ADMET profiling, molecular docking, and dynamic simulations.

Results: The study sources ligand molecules from the extensive MCULE database and utilizes strict filters to ensure that the compounds meet essential criteria. Through these techniques, the research identifies MCULE-3763806507-0-9 as a promising antimalarial drug candidate, surpassing the binding affinity of potential antimalarial drugs. However, it is essential to underscore that drug-like properties are primarily based on in silico experiments, and wet lab experiments are necessary to validate these candidates' therapeutic potential.

Interpretation conclusion: This study represents a critical step in addressing the challenge of drug resistance in the fight against malaria.

Background objectives: Malaria is one of the critical public health problems globally as well as in India. Recent times have seen an increase in the importance of the possible effects of environmental and demographic factors on the local transmission of malaria. We conducted a community-level study between urban and rural areas to find out the factors associated with malaria infection.

Methods: A community-based observational cross-sectional study was conducted between October 2020 and September 2022 among 330 households from urban areas of Chetla, Kolkata and rural areas of Singur district of West Bengal state of India. Households were selected by two stage random sampling method. Study was done by face-to-face interview, review of medical records and observation of the households. SPSS software was used for data analysis. Multivariable logistic regression (hierarchical model) was done and p-value equal to or less than 0.05 was taken as significant.

Results: The prevalence of malaria infection among participants and household level risks of malaria infection were found to be 6.1%, 1.8% and 18.8%, 6.7%, respectively in the urban and rural areas. Significant predictors of malaria infection were households with ≥5 family members [AOR=2.91{CI (1.19-7.15)}], households not using any mosquito protective measures [AOR=3.71{CI (1.04-13.13)}], presence of mosquito breeding places [AOR=4.93{CI (1.53-15.93)}], absence of effective window screen [AOR=3.19{CI (1.16-8.71)}], absence of separate kitchen [AOR=2.38{CI (1.06-5.34)}], and inadequate lighting condition in the house [AOR=4.35{CI (1.78-10.64)}].

Interpretation conclusion: This study provides important insights into the epidemiology of malaria in a high and low-transmission setting in West Bengal, India. Intensified efforts strengthening community mobilization for preventing breeding places for mosquito. Policy should strengthen investment in housing programs that may complement reduction of malaria transmission. Disease reduction effects of Government and local non-governmental organizations should be directed towards those areas in order to decrease disease load.

Background objectives: Mosquito-bome diseases are increasing problems in various parts of the world, causing high mortality and morbidity for humans. This study was done to assess the vector protection measures taken by rural below poverty line (BPL) families, and to assess the awareness about vector-borne diseases along with Total Sanitation Campaign (TSC) in rural BPL families.

Methods: A cross-sectional study was conducted in a rural area which won "Nirmal Gram Puraskar" Award i.e., "clean village" among 96 below BPL families for a period of three months. These families (every 5 th ) were selected by systematic random sampling until we reached a sample size. Basic socio-demographic details, status of vector protection measures, solid waste management, vector-borne diseases and total sanitation campaign details were collected from the study participants. Pretested, semi-structured questionnaire was applied to the head of the families which included sanitation status at home by house-to-house visit. Data collected was analysed using SPSS version 20 and presented as frequency, percentages, mean and standard deviation.

Results: Among 96 families studied (454 adults and children), 84 (87.5%) were males and 12 (12.5%) were females. Among these, 291 (64.1%) were using one or the other mosquito protection measures, 52 (54.2%) were using bednets and 23 (23.9%) used coils. 12 families (12.5%) were not using any mosquito protection measures. In our study, 66 (68.8%) families had individual household latrine (IHHL) and 50 (52.1%) had open drainage. Even though 314 participants had an access to individual household latrine, 20 (6.36%) had practice of open air defecation compared to 127 (90.7%) who practiced open air defecation without an access to individual household latrine. When asked about the awareness regarding vector-borne diseases, 56 (58.3%) were aware about chikungunya, 47 (48.9%) about dengue, 46 (47.9%) about malaria, 14 (14.6%) and only 5 (5.2%) families were aware about Japanese encephalitis. In this study, 37 (38.5%) were aware about the total sanitation campaign and 40 (41.6%) about the government support for sanitation.

Interpretation conclusion: While there is a general awareness of vector-borne diseases, the implementation of vector protection measures is not uniform across the village. There is a need for targeted interventions to improve the effectiveness of vector protection measures and increase awareness among the community.

Background objectives: Surveillance of canine leishmaniasis in Colombia is restricted to the appearance of visceral leishmaniasis cases in humans, and is mainly performed by serological tests. This requires blood sampling by veterinarians or technicians according to Colombian laws. The aim of this study was to evaluate the utility of conjunctival swabs in the molecular detection of Leishmania in dogs from the municipality of Ovejas, Sucre.

Methods: The present study was cross-sectional and descriptive. The collection source of samples and information was primary. Blood samples and conjunctival swabs from 121 dogs were analysed by PCR-ITS1 to detect Leishmania spp. Positive samples were used to amplify a conserved region of the Leishmania infantum kinetoplast minicircle. Performance of both sample types was calculated by proportion of positive samples of each type and the degree of agreement between them was determined by Cohen's kappa (κ) agreement index.

Results: Leishmania infection was detected in 17.4% (21/121) of blood samples and in 16.5% (20/121) of conjunctival swabs. In total, 28.1% (34/121) of the canines were infected, of which 11.8% (4/34) were infected with L. infantum in the conjunctival swabs and 5.9 % (2/34) in the blood samples. The agreement between blood and conjunctiva was medium (κ = 0.207) by PCR-ITS1 amplification.

Interpretation conclusion: The use of conjunctival swab as a non-invasive sample could be used as an alternative method for surveillance of canine leishmaniasis.