Journal of Vector Borne Diseases最新文献

Background objectives: Dengue is an emerging vector-borne viral disease in tropical and subtropical areas such as Burkina Faso that experienced dengue outbreak in, 2013, 2016, 2017 and more recently in 2023. This study aimed to determine the seroprevalence and dengue serotype in suspected patients in Ouagadougou, Burkina Faso.

Methods: The study was conducted during October and November 2023 and included suspected febrile patients seen at HOSCO and CERBA. Plasma or serum samples were used for the detection of non-structural proteins (NS1) and IgM and IgG antibodies against the dengue virus using SD Bioline Dengue Duo rapid detection kit. Viral RNA was extracted using the QIAamp Viral RNA Mini Kit and dengue serotypes were determined by real-time RT-PCR using the Dengue Real-TM Genotype kit.

Results: The study population consisted of 896 patients, including 397 (44.3%) men and 499 (55.7%) women. Dengue seroprevalence was 16.5% (148/896) with 14.1% (126/896) of patients positive for the NS1 antigen, 1.3% (12/896) positive for IgM, and 2.7% (24/896) positive for IgG. Serotyping among 40 out of 45 positive patients revealed 77.5% (31/40) DENV-3, 17.5% (7/40) DENV-1, and 5.0% (2/40) DENV-2.

Interpretation conclusion: The present study report a high seroprevalence of dengue virus infection among patients during the months considered as the peak of infection in Burkina Faso. The results revealed a predominance of DENV-3. Continuous surveillance of dengue virus serotypes circulating in Burkina Faso is crucial.

Background objectives: Dengue is arthropod-borne, acute potentially fatal viral infection, endemic in many tropical and sub-tropical countries having public health threat globally in recent era. Effective and prompt diagnosis is very essential to reduce morbidity and mortality associated with severe form. Diagnosis by dengue-specific markers like Non-Structural protein 1 antigen or IgM/IgG antibody by serological method is the choice of investigation and the most widely used non-specific biomarker is platelet count. To evaluate and correlate results of two serological diagnostic methods (Dengue NS1 Antigen and Dengue IgM antibodies by Enzyme-Linked Immunosorbent Assay) and with platelet count for diagnosis of Dengue infection.

Methods: Retrospective cross-sectional study for duration of 6 months from April 2022 to September 2022. Total 4063 serum samples of dengue suspected patients were tested according to duration of illness by ELISA for presence of NS1 Ag (≤5 days of illness) or IgM antibody (>5 days of illness).

Results: 393/4063 were detected positive by either method (NS1/IgM) and majority of patients were diagnosed between 3-8 days of illness. 248/2250 were tested positive for dengue NS1-Ag only, while 145/1813 were seropositive by dengue IgM only. Thrombocytopenia (platelet counts <100000/mm3) found in 301/393 seropositive cases which was also observed in NS1 (207/248 cases) and IgM (94/145 cases) seropositive patients.

Interpretation conclusion: Dengue specific parameters (NS1/IgM detection) in combination with platelet count helps in accurate, timely diagnosis and better monitoring in clinical management of patients.

Mosquitoes (Diptera: Culicidae) transmit many pathogens and parasites such as viruses, bacteria, protozoans and nematodes, which cause serious diseases such as malaria, dengue, yellow and Chikungunya fever, encephalitis or filariasis etc. Traditionally, control of these mosquitoes has relied on the use of several chemical insecticides. These insecticides have been used to control the various life stages of mosquitoes, but some of these insecticides are causing harm to the environment, human, plants and animals which in turn cause environmental pollution. Presently, NPs are thought to be used as an effective insecticide. Most of the NPs having insecticidal properties are prepared through green synthesis method, where extracts from plants, fungi, bacteria, and even dead insects have been efficaciously employed to decrease or to kill mosquito population. Biological and green synthesis method has resulted in the production of less toxic or nontoxic and sustainable NPs for further application in mosquito control. The evaluation of green chemistry or biological techniques for synthesizing metal NPs from plant extracts and other biological organisms has drawn the attention of many researchers. This review explores the usefulness of green synthesized various metal NPs on larvae, pupae and adults of mosquitoes.

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: 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.