Arboviral Diseases Research Articles

The epidemiology of imported and locally acquired dengue in Australia, 2012-2022.

Dengue is the most important arboviral disease globally and poses ongoing challenges for control including in non-endemic countries with competent mosquito vectors at risk of local transmission through imported cases. We examined recent epidemiological trends in imported and locally acquired dengue in Australia, where the Wolbachia mosquito population replacement method was implemented throughout dengue-prone areas of northern Queensland between 2011 and 2019. We analysed dengue cases reported to the Australian National Notifiable Disease Surveillance System between January 2012 and December 2022, and Australian traveller movement data. Between 2012 and 2022, 13 343 dengue cases were reported in Australia (median 1466 annual cases); 12 568 cases (94.2%) were imported, 584 (4.4%) were locally acquired and 191 (1.4%) had no origin recorded. Locally acquired cases decreased from a peak in 2013 (n = 236) to zero in 2021-22. Annual incidence of imported dengue ranged from 8.29/100 000 (n = 917 cases) to 22.10/100 000 (n = 2203) annual traveller movements between 2012 and 2019, decreased in 2020 (6.74/100 000 traveller movements; n = 191) and 2021 (3.32/100 000 traveller movements; n = 10) during COVID-19-related border closures, then rose to 34.79/100 000 traveller movements (n = 504) in 2022. Imported cases were primarily acquired in Southeast Asia (n = 9323; 74%), Southern and Central Asia (n = 1555; 12%) and Oceania (n = 1341; 11%). Indonesia (n = 5778; 46%) and Thailand (n = 1483; 12%) were top acquisition countries. DENV-2 (n = 2147; 42%) and DENV-1 (n = 1526; 30%) were predominant serotypes. Our analysis highlights Australia's successful control of locally acquired dengue with Wolbachia. Imported dengue trends reflect both Australian travel destinations and patterns and local epidemiology in endemic countries.

Development of Vaccines against Emerging Mosquito-Vectored Arbovirus Infections.

Among emergent climate-sensitive infectious diseases, some mosquito-vectored arbovirus infections have epidemiological, social, and economic effects. Dengue virus (DENV), West Nile virus (WNV), and Chikungunya virus (CHIKV) disease, previously common only in the tropics, currently pose a major risk to global health and are expected to expand dramatically in the near future if adequate containment measures are not implemented. The lack of safe and effective vaccines is critical as it seems likely that emerging mosquito-vectored arbovirus infections will be con-trolled only when effective and safe vaccines against each of these infections become available. This paper discusses the clinical characteristics of DENV, WNV, and CHIKV infections and the state of development of vaccines against these viruses. An ideal vaccine should be able to evoke with a single administration a prompt activation of B and T cells, adequate concentrations of protecting/neutralizing antibodies, and the creation of a strong immune memory capable of triggering an effective secondary antibody response after new infection with a wild-type and/or mutated infectious agent. Moreover, the vaccine should be well tolerated, safe, easily administrated, cost-effective, and widely available throughout the world. However, the development of vaccines against emerging mosquito-vectored arbovirus diseases is far from being satisfactory, and it seems likely that it will take many years before effective and safe vaccines for all these infections are made available worldwide.

Breeding habitats, bionomics and phylogenetic analysis of Aedes aegypti and first detection of Culiseta longiareolata, and Ae. hirsutus in Somali Region, eastern Ethiopia.

Arboviral diseases, such as dengue, chikungunya, yellow fever, and Zika, are caused by viruses that are transmitted to humans through mosquito bites. However, the status of arbovirus vectors in eastern Ethiopia is unknown. The aim of this study was to investigate distribution, breeding habitat, bionomics and phylogenetic relationship of Aedes aegypti mosquito species in Somali Regional State, Eastern Ethiopia. Entomological surveys were conducted in four sites including Jigjiga, Degehabur, Kebridehar and Godey in 2018 (October to December) to study the distribution of Ae. aegypti and with a follow-up collection in 2020 (July-December). In addition, an investigation into the seasonality and bionomics of Ae. aegypti was conducted in 2021 (January-April) in Kebridehar town. Adult mosquitoes were collected from indoor and outdoor locations using CDC light traps (LTs), pyrethrum spray collection (PSCs), and aspirators. Larvae and pupae were also collected from a total of 169 water-holding containers using a dipper between October and November 2020 (rainy season) in Kebridehar town. The species identification of wild caught and reared adults was conducted using a taxonomic key. In addition, species identification using mitochondrial and nuclear genes maximum likelihood-based phylogenetic analysis was performed. In the 2018 collection, Ae. aegypti was found in all study sites (Jigjiga, Degahabour, Kebridehar and Godey). In the 2020-2021 collection, a total of 470 (Female = 341, Male = 129) wild caught adult Ae. aegypti mosquitoes were collected, mostly during the rainy season with the highest frequency in November (n = 177) while the lowest abundance was in the dry season (n = 14) for both February and March. The majority of Ae. aegypt were caught using PSC (n = 365) followed by CDC LT (n = 102) and least were collected by aspirator from an animal shelter (n = 3). Aedes aegypti larval density was highest in tires (0.97 larvae per dip) followed by cemented cisterns (0.73 larvae per dip) and the Relative Breeding Index (RBI) was 0.87 and Container Index (CI) was 0.56. Genetic analysis of ITS2 and COI revealed one and 18 haplotypes, respectively and phylogenetic analysis confirmed species identification. The 2022 collection revealed no Ae. aegpti, but two previously uncharacterized species to that region. Phylogenetic analysis of these two species revealed their identities as Ae. hirsutus and Culiseta longiareolata. Data from our study indicate that, Ae. aegypti is present both during the wet and dry seasons due to the availability of breeding habitats, including water containers like cemented cisterns, tires, barrels, and plastic containers. This study emphasizes the necessity of establishing a national entomological surveillance program for Aedes in Somali region.

Protein localization of aquaporins in the adult female disease vector mosquito, Aedes aegypti.

The female Aedes aegypti mosquito is a vector for several arboviral diseases, due to their blood feeding behavior and their association with urban communities. While ion transport in Ae. aegypti has been studied, much less is known about mechanisms of water transport. Rapid water and ion excretion occurs in the adult female mosquito post blood meal and involves a set of organs including the midgut, Malpighian tubules (MTs), and hindgut. The MTs are responsible for the formation of primary urine and are considered the most important site for active transport of ions. Within the cells of the MTs, along with various ion transporters, there are aquaporin water channels that aid in the transport of water across the tubule cell membrane. Six aquaporin genes have been molecularly identified in Ae. aegypti (AQP1-6) and found to be responsible for the transport of water and in some cases, small solutes such as glycerol. In this study, we used immunohistochemistry to localize AaAQP1, 2, 4, 5, and 6 in the adult female Ae. aegypti, in non-blood fed and post blood feeding (0.5 and 24hr) conditions. We further examined the main water transporting aquaporin, AaAQP1, using western blotting to determine protein abundance changes in isolated MTs pre- and post-blood feeding. Using fluorescence in situ hybridization, aqp1 mRNA was found exclusively in the principal cells of female MTs. Finally, we used immunogold staining with transmission electron microscopy to determine subcellular localization of AaAQP1 in the Malpighian tubules under non-blood fed conditions. Interestingly, AaAQP1 was found to be predominantly in the principal cells of the MTs, dispersed throughout the brush border; however, there was also evidence of some AaAQP1 localization in the stellate cells of the MTs.

Climate change and infectious diseases in pediatric global health

In recent years, the consequences of climate change on global health have drawn increasing attention. Climate change is known to trigger extreme weather events, alter rainfall patterns, raise ocean/sea levels, and disrupt ecosystems, resulting in devastating effects on human life and the environment. Children, especially those living in low-income countries, are particularly susceptible to climate change-related health risks. This article explores the implications of climate change on pediatric global health, particularly through its impact on infectious diseases. Infectious diseases, notably those transmitted by vectors like mosquitoes, are acutely sensitive to climate fluctuations. Warmer temperatures expand the geographic range of disease-carrying vectors, fostering the transmission and outbreak of diseases such as arboviral diseases (dengue, chikungunya, etc.), malaria, and other vector-borne infections. Climate-induced changes in water availability and food security heighten the risk of diarrheal diseases, disproportionately affecting vulnerable populations like young children. HIV and other viral diseases are also influenced by climate change. As well as in tuberculosis, these diseases are strongly determined by socioeconomical factors; and poverty, poor housing, forced population movement, or health system disruptions driven by climate change exacerbate disease burden and hinder their effective epidemiological control. Moreover, new infectious diseases may emerge from adaptation of microorganisms to higher temperatures. For example, fungal infections pose a significant concern, particularly for immunocompromised children. Addressing the multifaceted challenges of climate change on infectious diseases and child health demands urgent action. Establishing robust disease surveillance systems, implementing public health interventions, and fostering international collaboration are crucial in mitigating the incoming threats.

Detection of arboviruses in Aedes aegypti through transovarian analysis: A study in Goiânia, Goiás.

Arboviral diseases are a group of infectious diseases caused by viruses transmitted by arthropods, mainly mosquitoes. These diseases, such as those caused by the dengue (DENV), Zika (ZIKV), chikungunya (CHIKV), and yellow fever (YFV) viruses, have a significant impact worldwide. In this context, entomological surveillance plays a crucial role in the control and prevention of arboviruses by providing essential information on the presence, distribution, and activity of vector mosquitoes. Based on entomological surveillance, transovarian transmission provides information regarding the maintenance and dissemination of arboviruses. The objective of this study was to detect these arboviruses in Goiânia, Goiás, and analyze the occurrence of transovarian transmission. Aedes aegypti eggs were collected from different regions of Goiânia and cultivated under controlled laboratory conditions until the emergence of adult mosquitoes. Adult females were grouped into pools containing their heads and thoraxes. These pools were subsequently evaluated using reverse-transcription quantitative polymerase chain reaction (RT-qPCR) assay. A total of 157 pools (N=1570) were analyzed, with two pools testing positive for CHIKV and one pool testing positive for ZIKV, indicating that the offspring resulting from transovarian transmission are potentially infectious. In summary, the demonstration of the vertical transmission mechanisms of CHIKV and ZIKV in A. aegypti serves as an alert to health authorities, as these diseases are still underreported, and their primary urban vector has likely acquired this capacity, contributing to the dissemination of these infections.

Seroprevalence and Co-Circulation of Rift Valley Fever Virus and West Nile Fever Virus in Livestock Population of Afar Region, Northeast Ethiopia.

The distribution, epidemiology, and socioeconomic impact of Rift Valley fever (RVF) and West Nile (WN) viruses are poorly known in areas of sub-Saharan countries like Ethiopian pastoral region. The human and livestock density in the area has increased greatly in recent years, but little work has been done on arboviral diseases and their potential impact on human and livestock health. The aim of this study was to detect the circulation of zoonotic arboviruses such as Rift Valley fever virus and West Nile viruses in the livestock population and to estimate seroprevalence in Afar pastoral area northeast Ethiopia. Cross-sectional serological survey was carried out in 736 serum samples from which cattle (224), camel (155), goats (121), sheep (144), and donkeys (92) were tested for the presence of anti-RVFV and anti-WNV IgG using a competitive enzyme-linked immunosorbent assay (c-ELISA) in two purposively selected districts of the Afar region. The present study revealed a 9.1% (95% CI = 8.86-9.29) seroprevalence of co-circulation of RVF and WNV. High 32/155 (20.7%) seroprevalence of co-circulation was seen in camels, followed by goat 14/121 (11.6%), cattle 16/224 (7.14%), and sheep 5/144 (3.5%), respectively, and higher 41/421 (9.7%) seroprevalence of co-circulation was observed in Amibara district than Haruka district. Camels were seven times (OR: 7.016, 95% CI = 2.639-18.653) more likely to be seropositive for the co-circulation than sheep (p ≤ 0.001). Livestock herds found in Amibara district were 1.2 times (OR: 1.165, 95% CI = 0.680-1.996) more likely to be seropositive for RVFV infection than those in Haruka areas. Given the co-occurrence of RVFV and WNV circulations, along with often suboptimal human and animal health surveillance in many similar areas' attention should be given. Investigation of the potential socioeconomic and health impacts of zoonotic arbovirus infections in such areas is crucial. Since both RVFV and WNFV are transmitted through a mosquito vector, avoiding mosquito bites is the primary method of prevention.

TaqMan real-time RT‒PCR assay with an internal amplification control for rapid detection of Bluetongue virus

Bluetongue (BT) is an arbovirus disease caused by Bluetongue virus (BTV), which has spread all over the world. In this study, a qRT-PCR assay with an internal amplification control was established for preventing false-negative results in Bluetongue virus (BTV) detection. The primers and probes for BTV NS3 were based on the qRT-PCR method for the detection of BTV in the Manual of Diagnostic Tests and Vaccines for Terrestrial Animals (2022) of the World Organization for Animal Health (WOAH). The GAPDH gene was selected as the internal amplification control, and the primers and probes for the GAPDH gene were designed based on the analysis of conserved sequences in the genome sequences of cattle, sheep and goats. Optimization of the reaction conditions, specificity, sensitivity and repeatability tests were conducted, and a qRT-PCR method was established for the simultaneous detection of BTV and the reference gene GAPDH. The results showed that the optimal primers and probe concentrations of BTV-NS3 were 0.30 μmol/L and 0.25 μmol/L, and were 0.15 μmol/L and 0.20 μmol/L for the reference gene GAPDH. The established method has no cross-reaction with other viruses, which showed good specificity. The minimum detection of BTV- and GAPDH-positive plasmid standard copies was 6.685 copies/μL and 209 copies/μL, respectively. The intra-assay and interassay CVs of the Ct values measured by BTV were less than 1.2%, and the intra-assay and interassay CVs of the Ct values measured by GAPDH were less than 0.7%, which suggested a high degree of repeatability and stability for this assay. The established BTV qRT-PCR method was used to detect BTV in 88 sheep serum samples stored in the laboratory, revealing 4 BTV-positive samples with a positive rate of 4.55%, which was consistent with the result obtained by nested PCR for detecting BTV recommended by WOAH. The qRT-PCR method established in this study for simultaneously detecting BTV and the internal reference gene GAPDH has high sensitivity, strong specificity and high repeatability. The addition of an internal reference gene can effectively control the detection accuracy and enable false-negative results to be avoided. It can provide a reference for the standardization of qRT-PCR methods for Bluetongue disease.

The emerging cause and threats of Arboviral diseases and its control measures: A comprehensive review

The emerging cause and threats of Arboviral diseases and its control measures: A comprehensive review

Thrombocytopenia in Dengue Fever and Its Correlation with Serum Vitamin B12 Level

Background: The most prevalent and significant arboviral disease affecting humans is dengue. It is spread by the Aedes genus of mosquitoes, which are common in tropical and subtropical regions of the world. Thrombocytopenia occurs commonly among patients suffering from dengue fever, making them more prone to hemorrhagic complications. The predisposing factors leading to thrombocytopenia and bleeding manifestations after dengue infection are not well-known Objective: We attempted to determine the frequency of thrombocytopenia and its co-relation with serum vitamin B12 levels among dengue patients. Methods: This Cross-sectional study after taking approval from the hospital ethical committee was carried out at the Department of Medicine PNS Rahat Hospital from 01/06/2022 to 30/11/2022 over six months. A total of 145 diagnosed patients suffering from dengue fever fulfilling the inclusion criteria were enrolled. Patients with concomitant sepsis, malignancy, autoimmune disorder, hematological disorder, and drugs causing thrombocytopenia were not included in the study. Precise history and bio data were entered in the Pro forma. Patients were investigated for CBC, VIT B12 LEVEL, and other routine investigations. SPSS v27 was used for data analysis. P-value≤0.05 was considered as significant. Results: Out of a total of 145 patients, 78 (53.8%) were males and 64 (46.2%) were females With a mean age of 38.22±15.93 years.139 patients (95%) had thrombocytopenia with variable severity, and platelet count is positively correlated with serum vitamin B12 Level (p=0.000). Conclusion: Dengue fever patients with thrombocytopenia were found to have vitamin B12 deficiency. Thrombocytopenic patients may require more platelet transfusion and longer hospitalizations.

Synthesis, Characterization and in vitro Evaluation of 4-(2-Aminoethyl)benzenesulfonamide Schiff Bases against Arboviruses

This study presents the synthesis and characterization of five Schiff bases derived from the reaction of 4-(2-aminoethyl)-benzenesulfonamide (compound 1) with corresponding aldehydes, (benzaldehyde, 2-pyridinecarboxaldehyde, 2-quinolinecarboxaldehyde, 8-hydroxy2-quinolinecarboxaldehyde and 4-imidazolecarboxaldehyde, for compounds 2-6, respectively). Characterization was performed by various spectroscopic techniques and supported by density functional theory (DFT) calculations. The crystal structures revealed how the substituent groups influenced the present supramolecular interactions. Compounds 1-4 and 6 showed no cytotoxicity to BHK-21 and VERO E6 cells at the highest concentration of 50 µmol L-1, while compound 5 was cytotoxic at this concentration. Compound 5 was active against the Chikungunya virus at the concentration of 10 µmol L-1, highlighting the effect of the 8-hydroxyquinoline substituent for the antiviral activity. For Zika virus, compound 6 was the only one active at 50 µmol L-1. The results suggest the potential of combining sulfonamides with other chemotypes for further development of antiviral agents, especially in the treatment of arboviral diseases.

Serological and molecular detection of dengue virus in animals: A systematic review and meta-analysis.

Dengue is a vector-borne disease, especially important in tropical and subtropical areas. The first presentation of many arboviral diseases occurred mainly in animals, including multiple Alphaviruses and Flaviviruses, such as dengue. To determine the serological and molecular frequency of the dengue virus in animals. A systematic literature review was carried out in five databases for the proportion of animals infected with dengue, defined by molecular and serological tests. A meta-analysis was performed using a random-effects model to calculate the pooled prevalence and 95% confidence intervals (CI). Cochran?s Q test and the I2 statistic were used to assess the heterogeneity between the two studies. The presence of dengue in bats, primates, birds, sheep, horses, cattle, pigs, rodents and buffaloes, according to serological methods, had a prevalence of 10%, 29%, 8%, 1%, 11%, 0%, 49%, 2%, 7%, respectively. According to molecular methods, the presence of dengue in bats had a seroprevalence of 6.0%. The present study confirms the presence of the Dengue virus in a large group of animal species, with potential implications as possible reservoirs of this virus, raising the possibility of zoonotic transmission.

Estimating the potential risk of transmission of arboviruses in the Americas and Europe: a modelling study

Estimates of the spatiotemporal distribution of different mosquito vector species and the associated risk of transmission of arboviruses are key to design adequate policies for preventing local outbreaks and reducing the number of human infections in endemic areas. In this study, we quantified the abundance of Aedes albopictus and Aedes aegypti and the local transmission potential for three arboviral infections at an unprecedented spatiotemporal resolution in areas where no entomological surveillance is available. We developed a computational model to quantify the daily abundance of Aedes mosquitoes, leveraging temperature and precipitation records. The model was calibrated on mosquito surveillance data collected in 115 locations in Europe and the Americas between 2007 and 2018. Model estimates were used to quantify the reproduction number of dengue virus, Zika virus, and chikungunya in Europe and the Americas, at a high spatial resolution. In areas colonised by both Aedes species, A aegypti was estimated to be the main vector for the transmission of dengue virus, Zika virus, and chikungunya, being associated with a higher estimate of R0 when compared with A albopictus. Our estimates highlighted that these arboviruses were endemic in tropical and subtropical countries, with the highest risks of transmission found in central America, Venezuela, Colombia, and central-east Brazil. A non-negligible potential risk of transmission was also estimated for Florida, Texas, and Arizona (USA). The broader ecological niche of A albopictus could contribute to the emergence of chikungunya outbreaks and clusters of dengue autochthonous cases in temperate areas of the Americas, as well as in mediterranean Europe (in particular, in Italy, southern France, and Spain). Our results provide a comprehensive overview of the transmission potential of arboviral diseases in Europe and the Americas, highlighting areas where surveillance and mosquito control capacities should be prioritised. EU and Ministero dell'Università e della Ricerca, Italy (Piano Nazionale di Ripresa e Resilienza Extended Partnership initiative on Emerging Infectious Diseases); EU (Horizon 2020); Ministero dell'Università e della Ricerca, Italy (Progetti di ricerca di Rilevante Interesse Nazionale programme); Brazilian National Council of Science, Technology and Innovation; Ministry of Health, Brazil; and Foundation of Research for Minas Gerais, Brazil.

Neuroinvasion of emerging and re-emerging arboviruses: A scoping review.

Arboviruses are RNA viruses and some have the potential to cause neuroinvasive disease and are a growing threat to global health. Our objective is to identify and map all aspects of arbovirus neuroinvasive disease, clarify key concepts, and identify gaps within our knowledge with appropriate future directions related to the improvement of global health. Sources of Evidence: A scoping review of the literature was conducted using PubMed, Scopus, ScienceDirect, and Hinari. Eligibility Criteria: Original data including epidemiology, risk factors, neurological manifestations, neuro-diagnostics, management, and preventive measures related to neuroinvasive arbovirus infections was obtained. Sources of evidence not reporting on original data, non-English, and not in peer-reviewed journals were removed. Charting Methods: An initial pilot sample of 30 abstracts were reviewed by all authors and a Cohen's kappa of κ = 0.81 (near-perfect agreement) was obtained. Records were manually reviewed by two authors using the Rayyan QCRI software. A total of 171 records were included. A wide array of neurological manifestations can occur most frequently, including parkinsonism, encephalitis/encephalopathy, meningitis, flaccid myelitis, and Guillain-Barré syndrome. Magnetic resonance imaging of the brain often reveals subcortical lesions, sometimes with diffusion restriction consistent with acute ischemia. Vertical transmission of arbovirus is most often secondary to the Zika virus. Neurological manifestations of congenital Zika syndrome, include microcephaly, failure to thrive, intellectual disability, and seizures. Cerebrospinal fluid analysis often shows lymphocytic pleocytosis, elevated albumin, and protein consistent with blood-brain barrier dysfunction. Arbovirus infection with neurological manifestations leads to increased morbidity and mortality. Risk factors for disease include living and traveling in an arbovirus endemic zone, age, pregnancy, and immunosuppressed status. The management of neuroinvasive arbovirus disease is largely supportive and focuses on specific neurological complications. There is a need for therapeutics and currently, management is based on disease prevention and limiting zoonosis.

School and community driven dengue vector control and monitoring in Myanmar: Study protocol for a cluster randomized controlled trial.

Dengue is the most common and widespread mosquito-borne arboviral disease globally estimated to cause >390 million infections and >20,000 deaths annually. There are no effective preventive drugs and the newly introduced vaccines are not yet available. Control of dengue transmission still relies primarily on mosquito vector control. Although most vector control methods currently used by national dengue control programs may temporarily reduce mosquito populations, there is little evidence that they affect transmission. There is an urgent need for innovative, participatory, effective, and locally adapted approaches for sustainable vector control and monitoring in which students can be particularly relevant contributors and to demonstrate a clear link between vector reduction and dengue transmission reduction, using tools that are inexpensive and easy to use by local communities in a sustainable manner. Here we describe a cluster randomized controlled trial to be conducted in 46 school catchment areas in two townships in Yangon, Myanmar. The outcome measures are dengue cases confirmed by rapid diagnostic test in the townships, dengue incidence in schools, entomological indices, knowledge, attitudes and practice, behavior, and engagement. The trial involves middle school students that positions them to become actors in dengue knowledge transfer to their communities and take a leadership role in the delivery of vector control interventions and monitoring methods. Following this rationale, we believe that students can become change agents of decentralized vector surveillance and sustainable disease control in line with recent new paradigms in integrated and participatory vector surveillance and control. This provides an opportunity to operationalize transdisciplinary research towards sustainable health development. Due to the COVID-19 pandemic and political instability in Myanmar the project has been terminated by the donor, but the protocol will be helpful for potential future implementation of the project in Myanmar and/or elsewhere.Registration: This trial was registered in the ISRCTN Registry on 31 May 2022 ( https://doi.org/10.1186/ISRCTN78254298).

Integrated control strategies for dengue, Zika, and Chikungunya virus infections.

Arboviruses are a major threat to public health in tropical regions, encompassing over 534 distinct species, with 134 capable of causing diseases in humans. These viruses are transmitted through arthropod vectors that cause symptoms such as fever, headache, joint pains, and rash, in addition to more serious cases that can lead to death. Among the arboviruses, dengue virus stands out as the most prevalent, annually affecting approximately 16.2 million individuals solely in the Americas. Furthermore, the re-emergence of the Zika virus and the recurrent outbreaks of chikungunya in Africa, Asia, Europe, and the Americas, with one million cases reported annually, underscore the urgency of addressing this public health challenge. In this manuscript we discuss the epidemiology, viral structure, pathogenicity and integrated control strategies to combat arboviruses, and the most used tools, such as vaccines, monoclonal antibodies, treatment, etc., in addition to presenting future perspectives for the control of arboviruses. Currently, specific medications for treating arbovirus infections are lacking, and symptom management remains the primary approach. However, promising advancements have been made in certain treatments, such as Chloroquine, Niclosamide, and Isatin derivatives, which have demonstrated notable antiviral properties against these arboviruses in vitro and in vivo experiments. Additionally, various strategies within vector control approaches have shown significant promise in reducing arbovirus transmission rates. These encompass public education initiatives, targeted insecticide applications, and innovative approaches like manipulating mosquito bacterial symbionts, such as Wolbachia. In conclusion, combatting the global threat of arbovirus diseases needs a comprehensive approach integrating antiviral research, vaccination, and vector control. The continued efforts of research communities, alongside collaborative partnerships with public health authorities, are imperative to effectively address and mitigate the impact of these arboviral infections on public health worldwide.

Population genetics of Aedes albopictus in the port cities of Hainan Island and Leizhou Peninsula, China

BackgroundAedes albopictus is an important vector of arboviral diseases, transmitting yellow fever, dengue fever, chikungunya and Zika. Monitoring its population genetic diversity and genetic differentiation has become essential for the control of infectious disease epidemics, especially in the functional areas of ports of entry. Population genetic monitoring of Ae. albopictus in the port area can help in the monitoring of port mosquito invasions and establishing port sanitary and quarantine measures to prevent the introduction and transmission of vector-borne diseases. MethodsSeventeen populations of Ae. albopictus were collected from five port cities on Hainan Island and the Leizhou Peninsula, 8 populations were collected from port areas, 4 from urban areas and 5 from rural areas. Nine microsatellite loci and the mitochondrial COI gene were used to study the population genetic diversity, population genetic structure and interpopulation gene flow of Ae. albopictus. ResultsThe nine microsatellite loci used were highly polymorphic, with an average PIC value of 0.768. The UPGMA genetic tree, STRUCTURE barplot and PCoA analyses showed that the 17 Ae. albopictus populations could be divided into three genetic groups. All 17 populations showed high haplotype diversity (Hd = 0.8069–0.9678) and formed 133 distinct haplotypes. These haplotypes can be divided into four genetic clades, but they are not associated with the geographical distribution of Ae. albopictus. Fst and Nm showed strong gene flow and little differentiation among populations. ConclusionAe. albopictus in port areas are not significantly different from urban and rural populations due to strong gene flow, which prevents differentiation and increases the genetic diversity of the populations. High genetic diversity facilitates mosquito adaptation to complex environmental changes, which is a challenge for vector-borne disease control in port areas.

Entomological risk assessment for transmission of arboviral diseases by Aedes mosquitoes in a domestic and forest site in Accra, Ghana

Dengue, Zika and chikungunya are Aedes-borne viral diseases that have become great global health concerns in the past years. Several countries in Africa have reported outbreaks of these diseases and despite Ghana sharing borders with some of these countries, such outbreaks are yet to be detected. Viral RNA and antibodies against dengue serotype-2 have recently been reported among individuals in some localities in the regional capital of Ghana. This is an indication of a possible silent transmission ongoing in the population. This study, therefore, investigated the entomological transmission risk of dengue, Zika and chikungunya viruses in a forest and domestic population in the Greater Accra Region, Ghana. All stages of the Aedes mosquito (egg, larvae, pupae and adults) were collected around homes and in the forest area for estimation of risk indices. All eggs were hatched and reared to larvae or adults for morphological identification together with larvae and adults collected from the field. The forest population had higher species richness with 7 Aedes species. The predominant species of Aedes mosquitoes identified from both sites was Aedes aegypti (98%). Aedes albopictus, an important arbovirus vector, was identified only in the peri-domestic population at a prevalence of 1.5%, significantly higher than previously reported. All risk indices were above the WHO threshold except the House Index for the domestic site which was moderate (19.8). The forest population recorded higher Positive Ovitrap (34.2% vs 26.6%) and Container (67.9% vs 36.8%) Indices than the peri-domestic population. Although none of the mosquito pools showed the presence of dengue, chikungunya or Zika viruses, all entomological risk indicators showed that both sites had a high potential arboviral disease transmission risk should any of these viruses be introduced. Continuous surveillance is recommended in these and other sites in the Metropolis to properly map transmission risk areas to inform outbreak preparedness strategies.

Efficacy of Nilavembu Kudineer for Dengue Fever Management – An Overview of Clinical and Preclinical Evidences

BACKGROUND AND AIM: Dengue viral disease (DVD) is a tropical arboviral disease that is caused by dengue virus (DENV), which is transmitted mainly by the bite of female Aedes aegypti mosquitoes. No specific antiviral drug is approved yet to manage the patients with DENV infection, who are managed using symptomatic therapy and supportive care. AIM: As a consequence, we intend to review the potential of Nilavembu kudineer in the management of DENV infection. MATERIALS AND METHODS: To find articles pertinent to the clinical, in vitro, and in silico studies evaluating the effectiveness of Nilavembu Kudineer in the management of DENV infection, the literature was searched in databases such as Medline/PubMed Central/PubMed, Google Scholar, Science Direct, EBSCO, Scopus, Web of science, Embase, Directory of open access journals, and reference lists. RESULTS: Nilavembu Kudineer may be able to alleviate signs and symptoms experienced by patients with DENV infection, according to few clinical, in vitro, and in silico studies. CONCLUSION: The effectiveness of Nilavembu Kudineer in patients with DENV infection would further be demonstrated by additional randomized controlled clinical trials.

A Review on Epidemiology, Clinical Manifestation and Diagnostic Approach of Dengue in Bangladesh Perspective

Background: Dengue is an arboviral disease caused by dengue virus; single positive stranded RNA virus of the family Flaviviridae. Symptomatic dengue infection causes a wide range of clinical manifestations; from mild dengue fever (DF) to potentially fatal disease, such as dengue hemorrhagic fever (DHF) or dengue shock syndrome (DSS). Dengue is endemic in Bangladesh with recurrent outbreak and is one of the major public health concerns in current period. Therefore; we conducted a literature review to analyze demography, epidemiology, pathogenesis, clinical feature and diagnosis of dengue virus infection. Methods: According to the PRISMA guidelines, the references were selected from PubMed, Web of Science and Google Scholar database using search strings containing a combination of terms that included ”dengue”, “Bangladesh”, “epidemiology”, “outbreak”,” pathogenesis”, “clinical manifestation”, “demography “and “diagnosis”. Quality of references was evaluated by independent contributors. Results: About 167,700 confirmed dengue cases were reported at 16’september’2023 in Bangladesh. Although dengue is endemic in Bangladesh, the current dengue surge is unusual in terms of seasonality and the early sharp increase in comparison to previous years, where the surge started around –late June. Plasma leakages are the main pathophysiological hallmark that distinguishes DHF from DF. Severe plasma leakage can result in hypovolemic shock. Various factors are thought to impact disease presentation and severity. Virus segregation in cell cultures, nucleic acid demonstration by polymerase chain reaction (PCR), and serological detection of viral antigens (such as NS1) or particular antibodies are the preferred microbiological assays for dengue detection. Currently, no specific drugs and licensed vaccines are available to treat dengue disease in any of its clinical presentations for all age group. Conclusion: Understanding the clinical manifestation of dengue infection, prompt diagnosis, appropriate treatment, active and continuous surveillance of cases and vectors are the essential determinants for dengue prevention, control and reducing fatality rate. J Bangladesh Coll Phys Surg 2023; 41: 69-81