Background & objectives: Dengue virus (DENV) is an RNA virus that infects approximately 2.5 billion people around the world. The incidence of dengue fever has rapidly increased at an alarming rate in the last few years and has affected thousands of people in Pakistan. This review explores the prevalence, serotypes and pathogenesis of dengue virus circulating in Pakistan. Methods: A systematic review of observational studies published between 1994 and December 2019 was performed. All records of the confirmed outbreak of dengue fever in Pakistan were reviewed and articles containing no primary data were excluded. Results: Four identified serotypes of dengue virus (DENV 1-4) circulate in different regions of the world causing epidemics. The most prevalent serotype, which is still epidemic and dominant in Pakistan, is DENV-2. Many factors like over-population, rapid urbanization, travelling, lack of vector control in dengue endemic areas and inadequate health-care are responsible of dynamic and huge raise of dengue in Pakistan. Interpretation & conclusion: Currently there is no specific treatment for prevention of dengue virus. Recently some antiviral compounds were being tested to eradicate this disease. There is a need to develop an efficient and safe vaccine for all four serotypes to combat dengue viral infection globally and particularly in Pakistan.

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Background & objectives: Weather and climate are directly linked to human health including the distribution and occurrence of vector-borne diseases which are of significant concern for public health. Methods: In this review, studies on spatiotemporal distribution of dengue, Barmah Forest Virus (BFV) and Ross River Virus (RRV) in Australia and malaria in Papua New Guinea (PNG) under the influence of climate change and/ or human society conducted in the past two decades were analysed and summarised. Environmental factors such as temperature, rainfall, relative humidity and tides were the main contributors from climate. Results: The Socio-Economic Indexes for Areas (SEIFA) index (a product from the Australian Bureau of Statistics that ranks areas in Australia according to relative socio-economic advantage and disadvantage) was important in evaluating contribution from human society. Interpretation & conclusion: For future studies, more emphasis on evaluation of impact of the El Niño-Southern Oscillation (ENSO) and human society on spatio-temporal distribution of vector borne diseases is recommended to highlight importance of the environmental factors in spreading mosquito-borne diseases in Australia and PNG.

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Vector borne diseases (VBDs) remain one of the greatest dangers to global health. At least seven VBDs of public health concern are prevalent in Egypt, including schistosomiasis, fascioliasis, lymphatic filariasis, leishmaniasis, malaria, dengue, and Rift Valley fever. Although many of these diseases are preventable by using evidence-based protective measures, VBD expansion patterns over the past few decades pose a significant challenge for modern parasitology and tropical medicine. In their action plan, Egypt did not identify populations at risk of VBDs. Egypt intends to improve its regional and international communication to identify pathogens and infections and develop “One Health”- compliant preparedness and prevention strategies. However, cross-border collaborations are required for the control of VBDs. In this context, we provide a situational analysis and comprehensive review of the epidemiological data on Egypt’s most prevalent VBDs based on an exhaustive search of the major electronic databases and literature from 1950 to 2019. We identified the gaps in Egypt’s preparedness for vector-borne disease threats, including adaptation documents, surveillance and monitoring, environmental management, and preparations for the health system. There is a lack of implementation of an integrated vector management strategy that integrates chemical, environmental, and biological control as well as health education. This necessitates cross-sectoral coordination and community involvement to improve vector control activities and the use, storage, and disposal of pesticides.

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Malaysia Mosquito Autocidal Trap (MyMAT) is a green technology Aedes mosquito trap that does not use harmful chemical substances. This study aimed to evaluate the efficiency of MyMAT in reducing dengue cases and relating the cases to rainfall. An experimental field study was conducted for 42 weeks at Pangsapuri Nilam Sari, Shah Alam, Selangor. A total of 624 MyMAT was allocated at four blocks: inside each apartment and outside at the corridors in each level. Mosquito and rainfall data were collected weekly using MyMAT and a mobile rain gauge, respectively. The dengue cases data was retrieved from the e-dengue system obtained from the Malaysia Ministry of Health. The findings showed that MyMAT could catch 97% of Aedes mosquitoes and reduced dengue cases on average of 78%, indicating MyMAT is a reliable Aedes mosquito trap. Interestingly the findings also revealed a significant relationship between dengue cases, the number of Aedes mosquitoes, and rainfall. This week notified dengue cases increased when last two weeks mosquitoes increased due to previous two weeks rainfall increment. Thus indicating an indirect but significant relationship between this week notified dengue cases with the last four weeks rainfall. These relationships can be used in establishing a dengue outbreak forecasting model, which can act as an early warning system.

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Malaria is one of the major causes of health and disability globally, even after tremendous efforts to eradicate it. Till date no highly effective vaccine is available for its control. The primary reason for the low efficacy of vaccines is extensive polymorphism in potential vaccine candidate antigen genes and HLA polymorphisms in the human population. This problem can be resolved by developing a vaccine using promiscuous peptides to combine the number of HLA alleles. This study predicted T and B cell epitopes (promiscuous peptides) by targeting PPPK-DHPS and DHFR-TS proteins of Plasmodium vivax, using different in silico tools. Selected peptides were characterized as promiscuous peptides on the basis of their immunogenicity, antigenicity and hydrophobicity. Furthermore, to confirm their immunogenicity, these peptides were utilized for molecular modelling and docking analysis. For determining the requisite affinity with distinct HLA Class-I, and HLA Class-II alleles, only five peptides for DHFR-TS and 3 peptides for PPPK-DHPS were chosen as promiscuous peptides. The D1 peptide has the maximum binding energy with HLA alleles, according to HLA-peptide complex modelling and binding interaction analyses. These findings could lead to the development of epitope-based vaccinations with improved safety and efficacy. These epitopes could be major vaccine targets in P. vivax as they possess a higher number of promiscuous peptides. Also, the B cell epitopes possess maximum affinity towards different alleles as analyzed by docking scores. However, further investigation is warranted in vitro and in vivo.

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We aimed to assess the effect of gamma radiation on the expression of heat shock proteins Hsc70 and Hsp83 in Aedes aegypti. Adult males were irradiated with 50Gy of gamma radiation, and changes in the expression of proteins in SDS-PAGE gel bands corresponding to molecular weights ~60–75kDa and ~80–95kDa were analyzed at two different time points 6 and 12-hour post-irradiation, using a temporal mass spectrometry based semi-quantitative analysis. A 2-3-fold increase was observed in both proteins Hsc70 and Hsp83, at both time points. In addition, the experiment also revealed the overexpression of several other molecules such as Arginine Kinase - known to be upregulated in certain insects during stress, Esterase B1- implicated in insecticide resistance, and also down-regulation of the 26S proteasome non-ATPase regulatory subunit 1 and ubiquitin-activating enzyme E1 - both known to be involved in ubiquitin-mediated protein degradation. The results taken together with existing data on Hsp83 and Hsc70, indicate that these proteins may enhance the survival of Ae. aegypti following gamma radiation and could serve as molecular markers for the detection of radiation-induced stress.

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Japanese encephalitis (JE) is a mosquito borne viral zoonotic disease and JE virus (JEV) is responsible for causing several children deaths every year in India. Since 1978, cases of JE have been reported from Gorakhpur district of Uttar Pradesh state annually. The knowledge on the role played by wildlife reservoirs in the sylvatic transmission and maintenance of JE virus remains limited. Bats are reservoir hosts for several emerging and re-emerging viral pathogens but their role in zoonotic cycle of JEV has not been elucidated yet. In Gorakhpur district of Uttar Pradesh, 52 fruit bats were found dead on 26 May 2020. The post-mortem report of the bat samples conducted at the Indian Veterinary Research Institute stated that the bats died due to brain hemorrhage, caused by excessive heat. The brain tissue samples of the bats were subjected to investigation using molecular techniques to determine the presence of JEV. The present work reports for the first time the detection of JEV in brain samples of bats from India. The viral load ranging from 8 to 18 copies/reaction was detected in brain samples by TaqMan real Time RT-PCR. The low viral load might be the reason for the absence of apparent clinical signs in bats and suggests the probable role of fruit bats in maintaining the JEV in nature.

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Background & objectives: In Mediterranean countries, infection of Toscana virus is a public health problem during the summer season, related to sandflies activity; it may cause aseptic meningitis and mild meningoencephalitis. We investigated the presence of antibodies (IgG) against the Toscana virus in the sera of individuals living in the area of Yafran, Libya. Methods: During the period from December 2013 to February 2014, a total of 232 sera samples were collected from Yefran hospital. Demographic information of participants collected in a questionnaire; samples were analyzed by the serological method of enzyme-linked immunoassays specific for Toscana IgG antibodies. Results: Seroprevalence of IgG antibodies among samples was 25% (n = 232). Seroprevalence varied among genders, age groups. The differences were not statically significant. Interpretation & conclusion: Our findings indicate and confirm local circulation of the Toscana virus. It also indicates that TOSV infection is neglected, and needs to be considered as one of the causes of meningitis or meningoencephalitis.

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Background & objectives: In this study, we aimed to investigate the relationship between serum TGF-β1 and PDGF-B levels with the pathogenesis, clinical course and prognosis of adult Crimean-Congo hemorrhagic fever (CCHF) patients. Methods: 50 adult patients and 30 healthy individuals as a control group were included in the study, who were followed up and treated with the diagnosis of CCHF at the Atatürk University Faculty of Medicine Infectious Diseases and Clinical Microbiology Clinic, between March 2017 and September 2019 in Eastern Anatolia Region in Turkey. Blood samples were taken from patients on the first day of their hospitalization and on the sixth day of their complaints. TGF-β1 and serum PDGF-B levels were studied by ELISA method using commercial kits, from serum samples taken from CCHF patient group and individuals in healthy control group and stored at -80°C. Results: While the serum TGF- β1 levels of patients with CCHF were found to be significantly higher on the sixth day of their complaints compared to the first day of hospitalization (42.33 ± 15.42, 28.40 ± 7.06, p = 0.001, respectively), the serum PGDF-B levels were found to be significantly lower on the sixth day of their complaints compared to those measured on the day of hospitalization (62.14 ± 19.75, 93.96 ± 20.02, respectively, p = 0.001). Interpretation & conclusion: Serum TGF-β1 levels are higher and PDGF-B levels are lower in CCHF patients with severe disease, indicating that serum TGF-β1 and PDGF-B play an important role in the pathogenesis of CCHF.

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Background & objectives: Coexistence of tick-borne diseases in some regions in Latin America makes the diagnosis difficult due to shared initial signs and symptoms. Rickettsiosis, Lyme disease and recently, scrub typhus are gaining more importance. The objective of this study is to develop a multiplex-PCR assay for a differential diagnosis of rickettsiosis, Lyme disease and scrub typhus. Methods: By using bibliographic and bioinformatic analysis, we identify candidate regions to perform the multiplex- PCR assay for Rickettsia sp., Borrelia burgdorferi and Orientia tsutsugamushi as well as identify optimal melting temperature and sensibility analysis. Results: We identified specific primer pairs for Rickettsia sp, Borrelia burgdorferi and Orientia tsutsugamushi with different PCR fragment length but a common melting temperature, 58°C. Interpretation & conclusion: We successfully developed a Multiplex PCR assay for differential diagnosis of rickettsiosis, Lyme disease and scrub typhus that could be a rapid and easy option in clinical and epidemiological practice.

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Background & objectives: The Toscana virus (TOSV) is a neurotropic arbovirus that is transmitted through the bite of some Phlebotomus species. In 2009, the largest outbreak of leishmaniasis described so far in Europe, occurred in the Autonomous Community of Madrid, Spain, which was related to the population increase of P. perniciosus in this region. Methods: A seroprevalence study was conducted to determine the circulation of TOSV among the population of this geographic area. A total of 516 sera were collected in two different stages: 2007 (before the leishmaniasis outbreak) and 2018–19 (representative of the current situation). In the sera, presence of IgG antibodies against TOSV was determined by commercial ELISA. Results: The overall seroprevalence was 34.5%. The anti-TOSV IgG level was significantly higher in the samples collected in 2007 (41.5%) than 2018–19 (27.3%). Interpretation & conclusion: The results of this study show a very active TOSV circulation in the region that is greater than expected. The lower seroprevalence figures in 2018–19 may be related to the vector and environmental control measures that were put in place as a result of the leishmaniasis outbreak of 2009. This highlights the importance of such strategies to reduce the incidence of TOSV infection and other vector-borne diseases.

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Scrub typhus is a seriously neglected life threatening disease in Asia and the islands of the Pacific and Indian oceans. The causative agent is Orientia tsutsugamushi, an obligate intra-cytosolic bacterium transmitted to vertebrate animals such as human or rodent by larval trombiculid mites (chiggers). Here, we conducted an outbreak investigation in Madhya Pradesh state in central India after sudden upsurge in scrub typhus cases and mortality in humans. Sixty-five live traps were placed for capturing the rodents. The captured rodent species were identified and the samples were subjected to nested PCR targeting 56kDa TSA gene. Analysis revealed for the first-time predominant circulation of Karp genotype in this region. The vector species involved in transmission is Leptotrobidium deliense. In conclusion, we reported the circulation of Karp strain in outbreak regions of Madhya Pradesh and suggest that public health monitoring and surveillance needs to be improved. Studies on antigenic diversity, association of strains with clinical spectrum and pathogenicity in the local setup will be essential for development of region-specific diagnostics and vaccines.

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