Background & objectives: Dakshina Kannada is one of the districts of Karnataka state of India with high incidences of mosquito-borne diseases, especially malaria and dengue. The larval stages of the mosquitoes are very important in determining the prevalence of adult mosquitoes and associated diseases. Hence, the occurrence of mosquito species was investigated by sampling different water bodies present in the Dakshina Kannada district from June 2014 to May 2017. Methods: Random sampling was carried out from permanent and temporary, artificial and natural water bodies belonging to 11 types of microhabitats using dippers and suction pumps. Results: A maximum of 37 mosquito species belonging to 12 genera were recorded with the dominant genera being Culex. Most species have been recorded from temporary bodies of water with the highest number of species in receptacles. Monsoon is the most productive season, both in terms of occurrence and abundance followed by post-monsoon and pre-monsoon. The abundance of mosquito larvae was significantly higher in temporary water bodies compared to the permanent. Interpretation & conclusion: Abundant rainfall in the study area which produces many natural and domestic temporary water bodies accounts for mosquito breeding throughout the year.

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Background & objectives: Crimean-Congo Hemorrhagic Fever Virus (CCHFV) is a vector borne pathogen, well-known for causing endemic hemorrhagic fever in Asia, Europe and Africa. There is no specific drug or vaccine available against CCHFV. The recent upsurge of Crimean-Congo Hemorrhagic Fever around the globe has made it a major health issue and this demands investigation for specific inhibitors to viral proteins. The objective of this study was to assess inhibitors that may have the potential to dock CCHFV nucleoprotein which plays an important role in viral assembly. Methods: We performed structure-based virtual screening and molecular docking by using potent inhibitors against nucleoprotein of CCHFV. Screening was performed by a webserver, MtiOpenScreen which gave 1000 drug-like molecules from PubChem. PyRx Autodock vina was utilized to dock the protein. The docking poses were observed for interaction analysis by LigPlot+. This study provided ten potential candidates capable of binding to the active site of NP of CCHFV. The selected hits were then subjected to toxicity prediction by ProTox-II. Results: Four hits were identified that specifically dock nucleoprotein at the presumed binding site. Furthermore, these compounds have less binding energy i.e., 9.7 kcal/mol, 9.8 kcal/mol and 10.4 kcal/mol and with equal toxicity measures when compared to an FDA approved drug. Interpretation & conclusion: This study illustrates that virtual screening is an efficient in silico approach to identify target-specific inhibitors. Researchers in this area who investigate drugs or synthesize agents against CCHFV with better efficacy could utilize reported inhibitors rather than trying random compounds ambivalently.

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Background & objectives: This study aimed to review the effectiveness of lactic acid when combined with other types of attractants for Aedes spp. Methods: A systematic review was conducted according to the protocol for a systematic review and meta-analysis (PRISMA). Literature search used Cinahl, Medline/PubMed, ScienceDirect, ProQuest and Ebsco electronic databases. Research articles used in the systematic review were experimental articles that reported the effectiveness of mosquito traps using lactic acid or a combination of lactic acid with other attractants. Results: From a total of 42 articles reviewed, there were 6 articles fulfilling the inclusion criteria. The highest synergistic combination of lactic acid in the ketone group was shown in the acetone compound, in the sulfides class, dimethyl sulfides, and in the chloroalkanes group, chloroform. The combination of lactic acid with two effective attractants can be seen in the incorporation of ammonia + caproic acid, and for the incorporation of lactic acid with three other effective attractants illustrated by combining ammonia + caproic acid + CO₂. Interpretation & conclusion: Lactic acid as an attractant can be combined with other various compounds (ketone compounds, sulfides and chloroalkanes). Lactic acid increases its effectiveness in trapping Ae. aegypti and/or Ae. albopictus if combined with acetone, dimethyl sulfides, and/or chloroform.

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Background & objectives: There is limited evidence regarding the accuracy of dengue rapid diagnostic kits despite their extensive use in India. We evaluated the performance of four immunochromatographic Rapid Diagnostic Test (RDTs) kits: Multisure dengue Ab/Ag rapid test (MP biomedicals; MP), Dengucheck combo (Zephyr Biomedicals; ZB), SD bioline dengue duo (Alere; SD) and Dengue day 1 test (J Mitra; JM). Methods: This is a laboratory-based diagnostic evaluation study. Rapid tests results were compared to reference non-structural (NS1) antigen or immunoglobulin M (IgM) enzyme-linked immunosorbent assay (ELISA) results of 241 dengue-positive samples and 247 dengue-negative samples. Sensitivity and specificity of NS1 and IgM components of each RDT were calculated separately and in combination (either NS1 or IgM positive) against reference standard ELISA. Results: A total of 238, 226, 208, and 146 reference NS1 ELISA samples were tested with MP, ZB, SD, and JM tests, respectively. In comparison to the NS1 ELISA reference tests, the NS1 component of MP, ZB, SD, and JM RDTs demonstrated a sensitivity of 71.8%, 85.1%, 77.2% and 80.9% respectively and specificity of 90.1%, 92.8%, 96.1 %, and 93.6%, respectively. In comparison to the IgM ELISA reference test, the IgM component of RDTs showed a sensitivity of 40.0%, 50.3%, 47.3% and 20.0% respectively and specificity of 92.4%, 88.6%, 96.5%, and 92.2% respectively. Combining NS1 antigen and IgM antibody results led to sensitivities of 87.5%, 82.9%, 93.8% and 91.7% respectively, and specificities of 75.3%, 73.9%, 76.5%, and 80.0% respectively. Interpretation & conclusion: Though specificities were acceptable, the sensitivities of each test were markedly lower than manufacturers’ claims. These results also support the added value of combined antigen-and antibody-based RDTs for the diagnosis of acute dengue.

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Background & objectives: The present study proposed a series of computational techniques such as homology modelling, molecular simulation, and molecular docking to be performed to explore the structural features and binding mechanism of Cytochrome c oxidase subunit I (COX1) protein with known inhibitors. Methods: Elucidation of the three-dimensional structure of COX1 protein was carried out by using MODELLER software. The modelled protein was validated using GROMACS, structural qualitative tools and web servers. Finally the model was docked with carbon monoxide (CO) and nitric oxide (NO) using Auto Dock Tools. Results: The three-dimensional structure of mitochondrial transmembrane protein COX1 was built using homology modelling based on high-resolution crystal structures of Bos taurus. Followed by inserting the lipid bilayer, molecular dynamics simulation was performed on the modelled protein structure. The modelled protein was validated using qualitative structural indices. Known inhibitors such as carbon monoxide (CO) and nitric oxide (NO) inhibit their active binding sites of mitochondrial COX1 and the inhibitors were docked into the active site of attained model. A structure-based virtual screening was performed on the basis of the active site inhibition with best scoring hits. The COX1 model was submitted and can be accessible from the Model Archive site through the following link https://www.modelarchive.org/doi/10.5452/ma-at44v. Interpretation & conclusion: Structural characterization and active site identification can be further used as target for the planning of potent mosquitocidal compounds, thereby assisting the information in the field of research.

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Background & objectives: Chagas disease is a vector-borne life-threatening illness originally confined to the Americas. Seroprevalence studies have been reported in the Mexican state of Chiapas; nevertheless, no clinical/cardiological studies have been conducted to detect underage cases. The aim of the present work was to detect underage cases in the Mexican state of Chiapas. Methods: A serological screening by ELISA was conducted on 1556 blood samples from school pupils; seropositiv- ity was confirmed by indirect ELISA and indirect immunofluorescence. Seropositive cases were clinically assessed in a hospital, and electrocardiographic and echocardiographic studies were performed. Descriptive statistics were used for analysis. Results: Seropositivity was confirmed in three cases in the population under study (0.19%). Cardiological studies confirmed the presence of alterations associated to Chagasic cardiomyopathy in two of the three patients. Interpretation & conclusion: The conditions for an active transmission of T. cruzi infection are met in the rural localities under study. Additionally, the presence of Chagasic cardiomyopathy in underage patients highlights the relevance of an early detection of cases to provide specific treatment at the onset of the infection and to implement epidemiological surveillance as suggested by PAHO/WHO.

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Anaplasma phagocytophilum is a gram-negative obligate intracellular tick-borne rickettsia with veterinary and public health importance worldwide. This organism is an etiologic agent of tick-borne fever (TBF) in domesticated animals and human granulocytic anaplasmosis (HGA) as well. Hard ticks (Ixodida: Ixodidae) are incriminated as the main biologic vectors for Anaplasma spp. Studies represent that Ixodes spp. are the main vectors for A. phago-cytophilum and few reports hinted that other tick species may play this role. So, the goal of the presented work was to investigate the A. phagocytophilum in 2000 hard ticks in Khuzestan province of Iran by specific nested-PCR performing two consecutive amplifications of 16SrRNA gene fragment with highly variable nucleotide region. Each reaction included 10 salivary glands of distinct tick species. Specific nested-PCR on accumulated salivary glands detected specific bands in 15.5% of reactions (31 of 200) in electrophoresis only in Rhipicephalus sanguineous and Hyalomma marginatum ticks. We concluded that the broad distribution of A. phagocytophilum infection is not only is due to the existence of Ixodes spp. but other hard ticks may also play a role in this issue.

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Background & objectives: Infections caused by arboviruses and transmitted by Aedes species mosquitoes are a serious health concern. India is endemic for diseases like Dengue, Chikungunya and recently Zika has been reported from few states. Vector control is the only way to contain these diseases, however, data regarding vectors from central India is lacking; to fulfill the lacuna we conducted this study. Methods: Entomological surveys were conducted from November 2017 to December 2018 for Aedes species in Dengue endemic areas of central India. The mosquitoes were identified, pooled and tested for the presence of Dengue, Chikungunya and Zika viruses by RT-PCR. The PCR products were sequenced to identify serotypes and genotypes of viruses. Results: A total of 2991 adults of Aedes specimens were collected and tested. Ae. aegypti (94.6%) was found to be the most abundant species. Highest mosquito density was recorded in the monsoon periods. Dengue (n=5) and Chikungunya (n=4) virus were detected from pools of female Ae. aegypti. One pool of male Ae. aegypti was positive for Dengue virus-3 and Chikungunya virus. Zika virus was not detected from any pool. Interpretation & conclusion: The findings suggest that Ae. aegypti is the principal vector of Dengue and Chikungunya, which is capable to transmit these viruses vertically. The findings have epidemiological importance and will be helpful to program managers.

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Background & objectives: Dengue emerged as an important public health problem in Tamil Nadu from 2000 onwards, reported in all the districts as an endemic disease of Tamil Nadu except Nilgiris district. So this study was carried out to understand the dengue epidemiology in Nilgiris district. Methods: Block-wise study was made at the Nilgiris district. The clinicians at the Nilgiris Adivasi Welfare Association hospitals (NAWA) situated in Kotagiri, Kozhikarai and Primary Health Centers from Kunjpannai, Arayoor, and Soloor Mattam, examined and recorded symptoms and collected blood samples from the dengue-suspected patients. These samples were centrifuged at 4°C and stored. Serum samples (267 nos.) collected from dengue-suspected patients for two years period from 2014 to 2016 were screened for dengue infection. Results: First year study conducted during 2014-15 showed 13 dengue positives (8.39%) mainly from Kotagiri block (9 nos. - 69.2%) and the second year study conducted during 2015-16 showed 12 dengue positives (10.71%) found mostly from Udagamandalam block (6 nos.- 50%). People belonging to 6 different tribes - Irular, Toda, Kota, Kurumba, Kattunaickan, and Paniya were found infected with dengue and more Irular positives were recorded in both the years (5 Irular-2014-15 & 11 Irular -2015-16). First year detected more female positives (92.3%) whereas the second year showed 5 males (41.7%) and 7 females (58.3%). Interpretation & conclusion: This study unearthed the hidden disease dengue to be prevalent among the tribal community and emphasized the need for the establishment of a permanent dengue surveillance system with improved disease diagnostics, to initiate effective vector control efforts to stop dengue transmission from this hilly region.

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Background & objectives: Malaria is a serious public health problem in Car Nicobar Island, Andaman & Nicobar Islands, India. Using larvivorous fishes has proved to be the cheapest method for vector management approach, with long suppression of mosquito population. This study aims to scale-up the diversity of larvivorous fishes and their potential larvivoracity to evolve an appropriate biological intervention strategy against the immature stages of malaria vectors. Methods: During 2003 (pre-tsunami) and 2014–2016 (post-tsunami), an ecological descriptive survey was carried out in the water bodies around Car Nicobar Island. Fishes were captured using fishing nets and cast nets; and placed in plastic jars and preserved in formalin solution. Fishes were identified and classified according to the available keys. Their abundance and data on the current conservation status was recorded and analyzed. Their potential larvivoracity was graded according to their feeding intensity. Results: Pre-tsunami, a total of 27 larvivorous fish species belonging to 11 orders, 23 families and 23 genera were identified. Order Perciformes and the family Cyprinidae were the most ascendant group constituting 51.9 and 11.1%, respectively. While, 80.8% of species were preferred to inhabit the freshwater region, only 37% of species were surface feeders (SF). According to the conservation, assessment and management plan (CAMP, 1998), 44.4% species were at lower risk least concern (LRlc), while 55.6% species were at least concerned (LC) as per the IUCN, 2017 categorization. However, after the tsunami, 17 fish species had gone extinct and 10 fish species were found to remain alive in the local water bodies. Interpretation & conclusion: Post-tsunami, the larvivoracity analysis indicated that Ophiocara aporos, Ophiocara procephala, Valamugil seheli, Channa punctata, Kuhlia rupestris, Khulia mugil, and Terapon jarbua possess high-level larvivorous potentiality in nature and are recommended for vector control in the study area. These fish species were facing several anthropogenic threats, such as human interference, loss of habitat, trade, overexploitation, and fishing. Therefore, it is important to protect the water bodies from external impact and implement the conservation strategies. Further, periodic fish fauna surveys, identification of breeding sites, scale-up of the larvivorous potentiality at the field level, creating public awareness through health education on establishment of larvivorous fish ponds and planning for mass rearing of the native fish species should be adopted as part of vector management approach in the endemic malarious region of Car Nicobar Island.

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Due to globalization, physicians have to be prepared with knowledge and understanding of cases and diseases from all over the world. Vector-borne diseases are a particular group of diseases for which the clinician should be prepared, especially in the context of returning travelers with tropical fever, as the symptoms are very similar among some of the pathogens. In this report we present a case of a returning traveler from Nigeria with fever as her chief complaint and with a final diagnosis of malaria and chikungunya. We discuss how co-infection with different pathogens could change the natural history or modify the clinical course of the disease.

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Background & objectives: Scrub typhus is caused by Orientia tsutsugamushi and transmitted by larval trombiculid chigger mites. Rodents and shrews are hosts for chigger mites in the transmission to humans. Wonder and Sherman traps are widely used for trapping rodents and shrews for the collection of ectoparasitic chigger mites. A comparative trapping study was undertaken in different villages in Vellore district, Tamil Nadu and Thiruvananthapuram district, Kerala, India to evaluate the efficiency of traps for trapping rodents & shrews. Methods: Wonder and Sherman traps were set in outdoors and indoors to capture the rodents. Wonder Traps, large wired cage, and Sherman Traps are foldable. These traps were employed for the rodents/ shrew surveillance to gather chigger vector mites. Identification of rodents, chigger mites and Trap index were observed. Results: Z Test comparing the capture rates showed wonder trap (P<0.001) to be significantly more efficient than the Sherman traps. The number of rodents /shrews collected in a Sherman trap was always one. But the number of rodents /shrews collected in a positive wonder tap was 2.83 in both states, 2.25 and 1.24 in Tamil Nadu and Kerala, respectively. Wonder traps (77%) were found more attractive in collecting more rodents in Tamil Nadu compared to Sherman traps (23%). But the Sherman trap (60.9%) was found efficient in collecting more shrews in Kerala compared to wonder traps (39.1%). Shrew’s collection was more in Sherman collections from both Tamil Nadu and Kerala. In Tamil Nadu and Kerala sex-wise collection of Male & female rodent/shrew was uniformly found in both the wonder (85% &75%) and Sherman traps (86% & 83%) with a maximum proportion of females. Interpretation & conclusion: Sherman traps can be used as single-capture live traps and on the other hand wonder traps can be used as multiple-capture live-traps. The geographical distribution pattern of various rodents trapped can be determined to identify the target areas for control of a particular species and also for the control of selected species. Mostly females were captured abundantly in both wonder and Sherman traps. In wonder traps, female rodents were trapped as family members in large numbers. Wonder traps are more attractive for trapping more rodents. This study addressed the careful choice of wonder traps for ectoparasitic chigger vector surveillance.

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