Subtropical Countries Research Articles

Knowledge, attitude, and practices of the community about Chikungunya in selected Districts of Afar Region, Northeast Ethiopia; its implications for controlling the disease: a community-based quantitative and qualitative cross-sectional study

BackgroundChikungunya (CHIK) is a viral disease spread by Aedes mosquitoes in tropical and subtropical countries, including Ethiopia. It is important to educate communities and implement behavioral and social interventions to prevent and control the spread of disease. This study assessed the community’s knowledge, attitude, and practices (KAP) about CHIK disease in the Afar Region, Northeast Ethiopia.MethodsA community-based quantitative and qualitative cross-sectional study was conducted between September 2022 and January 2023 in two districts in the Afar Region, Ethiopia. A household survey (HHS) using a structured questionnaire was conducted through face-to-face interviews for the quantitative study. For the qualitative research, focus group discussions (FGDs) were conducted using a semi-structured questionnaire. Data was analyzed using descriptive statistics, Pearson’s correlation coefficient, and multiple linear regressions.ResultsThe study included 296 and 116 adult community members for quantitative and qualitative studies, respectively. Of 296 respondents, 67.3% had previously heard of CHIK, and of those who heard of it, 44.7% knew that CHIK is caused by a virus. While a majority (68.8%) of participants believed that CHIK could be prevented, only 45.6% considered it a serious illness. Additionally, over half (56.8%) of the respondents knew that not all mosquitoes transmit CHIK. About 48.7% were able to identify the Aedes mosquito, but only 16.5% of those knew that Aedes mosquitoes bite during the daytime. The overall mean correct/positive response scores for knowledge, attitudes, and practices were 63.2%, 60.0%, and 60.0%, respectively. Being a student and having educational levels of grade 9-12th and college or above were associated with good knowledge while being single, having an educational level of 9-12th, and being within the age group of 45–59 years old were found to be associated with positive attitude scores.ConclusionThe study revealed a limited understanding of CHIK and the role of the Aedes mosquito in the study area. The community had uncertainty about the disease, its transmission, and prevention measures. The lack of understanding may affect attitudes towards the disease and risk perceptions, leading to less practice in prevention and control measures. The findings suggest the need for community-based educational initiatives to improve awareness and promote prevention and control measures.

Assessment of Pigeonpea (Cajanus cajan) Based Intercropping System under Varying Planting Patterns

Pigeonpea (Cajanus cajan (L.) Millsp.), one of the main grain legume crops grown in tropical and subtropical countries, is mostly grown under rainfed conditions. After chickpea, pigeonpea is India's second most significant crop in terms of area and yield. It makes up 23 per cent of all pulse production (3.33 million tons) and 1.76 per cent of the nation's gross planted land (3.88 million hectares). When grown as a lone crop, pigeonpea is not a highly efficient crop Willey et al., 1980 due to its low harvest index and delayed start growth rate. It is therefore grown as an intercrop, helping to increase productivity and profit by making efficient use of available resources. The field experiment was conducted at the Rajola Farm, Mahatma Gandhi Chitrakoot Gramodaya Vishwavidyalay Chitrakoot, Satna, Madhya Pradesh-4853 (M.P.) during the kharif season of 2014. In the treatments, cropping patterns and intercropping systems could be combined in seven different ways. The experiment was set up using a randomized block design with three replications. Our study revealed that in all intercrop cropping systems, the pigeonpea equivalent yield (PEY), LER, and ATER were significantly higher than under the pigeonpea sole system. PEY was found to be significantly maximum under T6: PP + Sesame alternate row (20.75 q ha-1) followed by T7: PP + Sesame paired row planting (19.54 q ha-1) and T4: PP + BG alternate row (19.51 q ha-1). However, LER and ATER were calculated significantly higher under T4: PP + BG alternate row (1.74 and 1.32, respectively), T2: PP + GG alternate row (1.73 and 1.31, respectively) and T6: PP + Sesame alternate row (1.71 and 1.29, respectively). The lowest values of PEY, LER, and ATER were found under pigeonpea sole system.

Hemodynamic Effects of Viperidae and Elapidae Snake Bites: A Comprehensive Review

Snakebite is a health issue frequently overlooked in tropical and subtropical countries. Despite snake bites from the families of Viperidae and Elapidae have been reported, there is limited information on the range of clinical manifestations on hemodynamics in adults. This study aims to describe the clinical manifestations of hemodynamic disorders in adults due to snake bites from the Viperidae and Elapidae families. The data for the literature review on hemodynamic disorders caused by Viperidae and Elapidae snake bites in adults was collected through a systematic search on Sciencedirect and PubMed from 2018 to 2023, along with manual searches on Google Scholar. This literature review was conducted using a systematic search on ScienceDirect and PubMed from 2018 to 2023 and a manual search on Google Scholar. The findings were 21,431 snakebite cases from 47 published research studies successfully acquired in this study. There are 36% of coagulopathy cases worldwide, 2% of internal bleeding cases, 25% of arrhythmia cases, and 21% of cardiomyopathy cases. The majority of the cases (70%) were Viperidae bite cases, with some (20%) being Viperidae and Elapidae bite cases and a tiny number (10%) being Elapidae bite cases. The study underscores the importance of a comprehensive approach to snakebite management based on a thorough understanding of the hemodynamic effects induced by these snake families.

The molecular and histopathological investigations of TLR2 rs5743708 and TLR4 (rs4986790 and rs4986791) polymorphisms effects on cutaneous leishmaniasis lesions

Cutaneous leishmaniasis (CL), a zoonotic and neglected disease, is prevalent in numerous regions, particularly in tropical and sub-tropical countries. In Iran, endemic foci of leishmaniasis exist in specific regions, with zoonotic cutaneous leishmaniasis (ZCL) caused by Leishmania major being common in most rural areas. Toll-like receptors (TLRs) play a crucial role in both innate and adaptive immunities, and the investigation of TLR2 rs5743708 and TLR4 (rs4986790 and rs4986791) polymorphisms in parasitic diseases can have significant implications for patient treatment. In the present study, a total of 88 leishmaniasis patients using the patients' lesions from Khuzestan province health-treatment centers, Iran, including 50 cases (56.8%; Central region) and 38 cases (43.2%; Western region) underwent examination between the years 2022 and 2023. Two direct smears from the lesions of each patient were prepared and one of the smears was stained with Giemsa for parasitological examination. Among the 88 patients, the highest frequency was observed in the 21–30 years' age group (35.2%), while the lowest was in the 11–20 years’ age group (10.2%). No statistically significant relationship was found between gender and age (P > 0.05). Following disease confirmation via microscopic examination, TLR2 rs5743708 and TLR4 (rs4986790 and rs4986791) polymorphisms in the patients were assessed using PCR-RFLP. Fragments of 264, 249, and 406 base pairs were successfully amplified, targeting the TLR2 and TLR4 genes, respectively. Out of the 88 leishmaniasis patients, 14 cases (15.9%) exhibited polymorphisms. Notably, all individuals in the polymorphism group carried both the TLR2 rs5743708 homozygous and the TLR4 rs4986791 heterozygous genotype combinations. There were no observations of TLR2 rs5743708 heterozygous, TLR4 rs4986790 heterozygous and homozygous and TLR4 rs4986791 homozygous genotypes within the polymorphism group. Biopsies from lesions for all contributors were prepared for histopathological examination. All patients with polymorphism showed larger lesions than patients without polymorphism (P < 0.05). Histophatological study showed abnormal cases in patients with polymorphism including mild hyperkeratosis, mild acanthosis, focal parakeratosis in the epithelium surface and mild hyperpigmentation of melanocytes in the basal layer. Furthermore, a strong infiltration of immune cells such as PMNs and a small number of lymphocytes was observed in the epidermal region of patients with polymorphisms. There was no statistically significant relationship between age and the quantity of lesions (P > 0.05). Additionally, some regions of the epidermal surface layer displayed pustule formation in patients with polymorphisms. No significant difference was discerned in the dermal layers of patients with polymorphisms compared to other patients. Considering that all patients with polymorphisms concurrently had TLR2 rs5743708 homozygous and TLR4 rs4986791 heterozygous genotype combinations, the anomalies observed in conjunction with histological changes in the skin lesions of patients with CL may plausibly be linked to the polymorphisms. Nonetheless, a more expansive dataset involving a larger population is imperative to comprehensively elucidate the pathogenesis of the Leishmania parasite and the potential impact of TLR2 rs5743708 and TLR4 (rs4986790 and rs4986791) gene polymorphisms in individuals afflicted with CL across diverse geographical locales.

Nutritional Values of Foxtail Millet (Setaria italica) and other Millets Used for Common Diseases and Management

Abstract: The ever-increasing population and malnutrition in tropical and sub-tropical countries upsurge the demand and security for poor people’s food and nutrition. In erratic climatic conditions, millets can survive as they require less water, short cultivation period and are somewhat tolerant to biotic (bacteria and fungi) and biotic stresses (drought, salinity, nutrient deficiency, etc). Millets possess several nutrient rich components and several health benefits. Despite having superior nutritional, health and agricultural advantages, millets have not received their due attention. Among the millets, foxtail millet is one of the major millets in terms of its second in global production and millets’ yield, quality, and quantity are affected by various diseases. This review provides an overview of the origin and distribution of eight millets, their morphological characteristics with chemical composition, potential health benefits and the fungal, bacterial and viral diseases affecting the growth and yield of millets and their effective management in the framework of ensuring food and nutritional securities in the tropical and sub-tropical countries.

Effects of Daily Weather on Aedes Genus (Culicidae: Diptera) Arthropod Mosquito Vectors Profusion and Dengue Epidemics Transmission: A Systematic Review

Dengue is a vector borne flavivirus usually caused by DENV1 virus, and a quantity of cases reported with DENV2, DENV3, and DENV4 viruses transmitted by Aedes aegypti and Aedes albopictus (Diptera) day biting female vector mosquitoes, belongs to Culicidae family. The symptoms of dengue were first clinically confirmed in Japan during 1943, and later, it was recorded simultaneously in the Asia, Africa, and North America during the 1980. Dengue epidemics situation was reported in the 142 countries across the world Dengue and severe dengue, (Global Strategy for dengue prevention and control, (2012–2020), 2020) and the epidemics had been changed to endemic situation in many of the countries for the past 2 decades, and the people who have been living in the epidemic countries estimated at risk about 450 million. The occurrence of dengue outbreaks and it’s extend have been reported in the tropical and sub-tropical countries across the globe largely in metropolitan, small towns, and semi-urban settlements. The climate variables viz. temperature, relative humidity, saturation deficiency, and rainfall, are fuelled for conducing environment for the vector longevity, survival and also for dengue virus incubations in mosquitoes. Temperature ranges between &gt; 21 and &lt; 34, and relative humidity &gt;70% and &lt;90% has influence on the impact of variations on the vector survival, fecundity, fertility and longevity of female Aedes aegypti and flying capacity is reduced with temperature &lt; 10 0C, and laying egg is reduced with increase of mean temperature &gt;35 0C. Dengue epidemics clusters are directly correlated with abundance of Aedes species mosquitoes which are controlled by the annual average precipitation 300 mm to 1200 mm. The longitudinal dengue epidemics transmissions are mainly associated with monsoon and tend to have seasonal patterns, particularly, during and after the monsoon. Climatic factors are playing important role in the increase or decrease of vector mosquitoes as well as dengue epidemics. Therefore, the present study is addressed on the echelon of daily weather and seasonal change in climate condition and its control on the incidence of dengue outbreaks.

Polarization toward Tfh2 cell involved in development of MBC and antibody responses against Plasmodium vivax infection.

Plasmodium vivax is the dominant Plasmodium spp. causing malaria throughout tropical and sub-tropical countries. Humoral immunity is induced during P. vivax infection. However, data on longevity of antibody and memory B cell (MBC) responses is lacking. Follicular helper T cells (Tfh) are drivers of high-affinity and long-lived antibody responses. Understanding of Tfh-mediated immunity against malaria is valuable for vaccine development. We enrolled 31 acutely infected P. vivax patients in low malaria transmission areas of Thailand to detect frequencies, phenotypes and kinetics of different subsets of circulating Tfh (cTfh) and MBCs, and to evaluate their association with humoral immunity following natural P. vivax infection. Expansion of cTfh2 cells, activated and atypical MBCs were shown during acute malaria. To relate increased cTfh2 cells to humoral immunity, P. vivax-specific MBCs and antibodies were assessed. High anti-PvCSP and -PvDBPII seropositivity was detected and most subjects produced MBCs specific to these antigens. The increased cTfh2 cells were positively related to atypical MBCs, plasmablasts/plasma cells, and anti-PvDBPII IgM and IgG levels. Distributions of memory cTfh cell subsets were altered from central memory (CM) to effector memory (EM) during infection. The highest ratios of cTfh-EM/cTfh-CM were represented in cTfh2 cells. Positive correlation of cTfh17-EM with activated and atypical MBCs was observed, while cTfh2-CM and cTfh17-CM cells were positively related to PvDBPII-specific MBCs and IgM levels. Present study demonstrated that P. vivax infection induced cTfh polarization into cTfh2 subset, and alteration of memory cTfh2 phenotype from CM to EM phase. These P. vivax-induced cTfh responses significantly associated with generation of MBCs and antibody responses. Therefore, cTfh2 cells might possibly influence humoral immunity by inducing expansion of activated and atypical MBCs, and by generating P. vivax-specific MBCs and antibody responses following natural infection.

Role of C-C chemokine receptor type 5 in pathogenesis of malaria and its severe forms.

Malaria is a mosquito-borne disease caused by Plasmodium parasites, responsible for a significant impact on public health in several tropical and sub-tropical countries. The majority of infection cases are classified as uncomplicated malaria, causing mild symptoms such as fever and headache. However, the disease may progress to severe malaria and death if the infection is not properly treated. Furthermore, malaria poses a major concern for children, pregnant women and immunosuppressed individuals. Exacerbated inflammation is characteristic of severe malaria cases. The C-C chemokine receptor type 5 (CCR5) is an important molecule for leukocyte migration and regulation of inflammation. Although widely known as an HIV-1 co-receptor, CCR5 also affects the susceptibility and progression of autoimmune and inflammatory diseases. There is evidence supporting the participation of CCR5 in malaria manifestations, with the evaluation of CCR5 gene expression levels suggested as a marker to monitor malaria severity. Certain genetic variants in the CCR5 gene affect CCR5 expression, potentially altering CCR5-mediated inflammatory responses during malaria infection. However, the complex influences of CCR5 on malaria remain underexplored. Therefore, this review examines and updates the role of CCR5 in various contexts of malaria infection, including uncomplicated malaria, Plasmodium/HIV co-infection, pregnancy and severe (cerebral) malaria.

Design, synthesis, in vitro and in vivo trypanosomaticidal efficacy of novel 5-nitroindolylazines

Leishmaniasis and trypanosomiasis rank among lethal vector-borne parasitic diseases that are endemic in tropical and sub-tropical countries. There are currently no preventive vaccines against them, and once diagnosed, a handful of less effective drugs clinically accessible are the only therapeutic options offered to treat these ailments. And although curable, the eradication and elimination of these diseases are hampered by the emergence of multidrug-resistant strains of the causal pathogens. Hence, there is accrued necessity for the development of new, effective, and affordable drugs. In recent decades, several molecular scaffolds, including nitroaromatics, endoperoxides, etc., have been attempted as building blocks to generate new effective clinical antitrypanosomatid agents with low toxicity so far to no avail. In this regard, a series of nitroindolylazine derivatives was synthesised in a three-step process involving nucleophilic substitution (SN), hydrazination and Schiff base condensation reactions, and was evaluated against various Leishmania and Trypanosoma species and strains. Several promising hits portraying leishmanicidal and trypanocidal with in vitro submicromolar activities, and devoid of toxicity on mammalian cells were uncovered. Among these, nitrofurylazine 11 (Tc IC50: 0.08 ± 0.03 μM) and nitrothienylazine 13 (Tc IC50: 0.09 ± 0.01 μM) were evaluated in vivo against Trypanosoma congolense, the causative agent of nagana, which is livestock most virulent trypanosome species in mice-infected preliminary study. However, only partial efficacy was observed as all mice succumbed due to high parasitemia within 13 days post-infection during the treatment. The translational potential of antileishmanial and antichagasic hits, as well as further identification of their molecular targets, will be assessed in future research.

Chromobacterium violaceum: An incidental finding in a neonate.

Chromobacterium violaceum is a gram-negative saprophytic bacterium causing human infection in tropical and subtropical countries. Such infections are uncommon but cause high mortality when the bacterium enters the bloodstream through an open wound. We present a case of C. violaceum infection isolated from a blood culture sample in a neonate identified at a tertiary care teaching hospital in North East Uttar Pradesh. Timely diagnosis by microbiological methods and antimicrobial treatment led to a successful cure for this life-threatening infection. Thus, such bacteria should be included in the routine spectrum for differential diagnosis of sepsis, to provide a chance of cure.

Evaluation of Wolbachia infection in Aedes aegypti suggests low prevalence and highly heterogeneous distribution in Medellín, Colombia

Dengue virus, transmitted mainly by Aedes aegypti mosquitoes, is a significant public health challenge in tropical and subtropical countries, with an incidence that is growing at an alarming rate. The release of Wolbachia-carrying mosquitoes has been suggested as a strategy to reduce the incidence of multiple arboviruses. In Medellín, Colombia, large-scale releases of Wolbachia-infected Ae. aegypti mosquitoes were performed between 2017 and 2022 by the World Mosquito Program to facilitate population replacement. In this study, we evaluated the prevalence and distribution of Wolbachia-infected Ae. aegypti two years after completion of these releases. We conducted the sampling across 19 communes in Medellín, using 416 ovitraps to collect Ae. aegypti eggs from epidemiological weeks 26 to 41 in 2023. Upon hatching the collected eggs, we identified and pooled adult female Ae. aegypti for DNA extraction. Subsequently, we conducted PCR assays for the detection of Wolbachia infection in these mosquitoes. We used maximum likelihood estimation (MLE) and Bayesian methods to estimate the prevalence of Wolbachia infection, while using QGIS to analyze spatial distribution of infection in the region. A total of 774 female Ae. aegypti mosquitoes from 182 pools were evaluated. We detected Wolbachia in 33.5 % of pools, with an estimated individual minimum infection rate of 9.5 % and a maximum of 33.2 %. The prevalence varied significantly across communes, with the highest rates observed in the northeastern and southwestern areas. Spatial analysis revealed a highly heterogeneous island-like distribution of Wolbachia across Medellín with a few hotspots. The observed Wolbachia prevalence in this work was lower than previously reported. We suspect a decline in the prevalence of Wolbachia-infected Ae. aegypti mosquitoes in Medellín following the completion of their release.

Defense Molecules of the Invasive Plant Species Ageratum conyzoides

Ageratum conyzoides L. is native to Tropical America, and it has naturalized in many other tropical, subtropical, and temperate countries in South America, Central and Southern Africa, South and East Asia, Eastern Austria, and Europe. The population of the species has increased dramatically as an invasive alien species, and it causes significant problems in agriculture and natural ecosystems. The life history traits of Ageratum conyzoides, such as its short life cycle, early reproductive maturity, prolific seed production, and high adaptive ability to various environmental conditions, may contribute to its naturalization and increasing population. Possible evidence of the molecules involved in the defense of Ageratum conyzoides against its natural enemies, such as herbivore insects and fungal pathogens, and the allelochemicals involved in its competitive ability against neighboring plant species has been accumulated in the literature. The volatiles, essential oils, extracts, residues, and/or rhizosphere soil of Ageratum conyzoides show insecticidal, fungicidal, nematocidal, and allelopathic activity. The pyrrolizidine alkaloids lycopsamine and echinatine, found in the species, are highly toxic and show insecticidal activity. Benzopyran derivatives precocenes I and II show inhibitory activity against insect juvenile hormone biosynthesis and trichothecene mycotoxin biosynthesis. A mixture of volatiles emitted from Ageratum conyzoides, such as β-caryophyllene, β-bisabolene, and β-farnesene, may work as herbivore-induced plant volatiles, which are involved in the indirect defense function against herbivore insects. Flavonoids, such as nobiletin, eupalestin, 5′-methoxynobiletin, 5,6,7,3′,4′,5′-hexamethoxyflavone, and 5,6,8,3,4′,5′-hexamethoxyflavone, show inhibitory activity against the spore germination of pathogenic fungi. The benzoic acid and cinnamic acid derivatives found in the species, such as protocatechuic acid, gallic acid, p-coumaric acid, p-hydroxybenzoic acid, and ferulic acid, may act as allelopathic agents, causing the germination and growth inhibition of competitive plant species. These molecules produced by Ageratum conyzoides may act as defense molecules against its natural enemies and as allelochemicals against neighboring plant species, and they may contribute to the naturalization of the increasing population of Ageratum conyzoides in new habitats as an invasive plant species. This article presents the first review focusing on the defense function and allelopathy of Ageratum conyzoides.

Phytochemical and Antioxidant Analysis of Artocarpus heterophyllus Peel Extracts

BACKGROUND: Plants have a diverse variety of bioactive compounds such as tannins, alkaloids, flavonoids, carbohydrates and steroids among many others that can offer significant physiological actions in the human body. Phytochemicals are naturally occurring chemical, biological and active compounds found in plants that are of benefit to human health apart from those that act as macronutrients and micronutrients. A. heterophyllus (Jackfruit) belongs to the family Moraceae. Jackfruit tree is native to India and is popular in several tropical and sub-tropical Countries. OBJECTIVE: The aim of this study is to determine the phytochemical constituents, antioxidant properties and gas chromatography mass spectroscopy (GC-MS) of the fruit peel of A. heterophyllus extracts using three different solvents. METHODS: Artocarpus heterophyllus fruits were collected from University of Ibadan botanical garden, identified at the Forestry Research Institute of Nigeria, Oyo State. The peel was extracted and dried at 35 ℃. Qualitative method and Gas Chromatography Mass Spectroscopy were used to determine the phytochemical and bioactive compounds present in the plant, whereas¬¬¬¬¬¬ 2, 2, Diphenylpicryl-1-hydrazyl (DPPH) was used for the antioxidant analysis. RESULTS: Secondary metabolites such as flavonoids, phenols, alkaloids, glycosides, saponins, tannins, steroids, and Terpenoids were present based on the solvents while anthraquinnes were absent. Flavonoid and phenol were abundant in the three extracts while saponin was moderate. Eight chemical compounds were observed in the plant extracts. Major bioactive components with highest and lowest retention peak were (65.55 %) bis(2- ethyl hexyl) phthalate and (6.06 %) Cis- 13(2- ethylhexyl)phthalate respectively. Antioxidant activity increased with increase in concentration of which acetone extract had the highest DPPH (75.00 %) at 100 μg/ml. CONCLUSION: The fundamental means of the usage of medicinal plants for medicine is due to their bioactive properties which are used as substrates for biochemical and enzymatic reactions. Phytochemical derivatives have antiviral, anti-inflammatory, anti-oxidant, immunomodulatory, anticancer, antimicrobial, antitumor, analgesic and many other properties harbor in them.

Value creation of copra meal mannan into functional manno-oligosaccharides (β-MOS) using the mannanase Bacillus man B (BlMan26B)

Agricultural wastes rich in β-mannan are an important environmental problem in tropical and sub-tropical countries. This research aims at dealing with this and investigates the valorization of mannan-rich copra meal from virgin coconut oil manufacturing into mannan-oligosaccharides (β-MOS) by enzymatic hydrolysis using β-mannanase from Bacillus licheniformis (BlMan26B). Lab-scale process, involving pre-treatment and bioconversion steps, were conducted and evaluated. Lyophilized β-MOS was analyzed and its biological activities were assessed. The size of oligosaccharides obtained ranged from dimers to hexamers with 36.7% conversion yields. The prebiotic effects of β-MOS were demonstrated in comparison with commercial inulin and fructo-oligosaccharides (FOS). In vitro toxicity assays of β -MOS on human dermal fibroblasts and monocytes showed no cytotoxic effect. Interestingly, β-MOS at concentrations ranging from 10 to 200 µg/mL also demonstrated potent anti-inflammatory activity against LPS-induced inflammation of human macrophage THP-1 in a dose-dependent manner. However, at high dose, β-MOS could also stimulate inflammation. Therefore, further investigation must be conducted to ensure its efficacy and safe use in the future. These results indicate that β-MOS have the potential to be used as valued-added health-promoting nutraceutical or feed additive after additional in-depth studies. These finding should be applicable for other agricultural wastes rich in mannan as well.

Mitochondrial Genome Characteristics and Phylogenetic Analysis of Fulmekiola serrata (Kobus) (Thysanoptera: Thripidae)

Sugarcane thrips, Fulmekiola serrata (Kobus) (Thysanoptera: Thripidae), is a common foliar pest that infests sugarcane and is found throughout tropical and subtropical countries. In this study, we obtained and analyzed the complete mitochondrial genome of F. serrata for the first time and explored the phylogenetic relationships of the higher-order elements of Thysanoptera members at the mitochondrial level. The complete mitochondrial genome of F. serrata is 16,596 bp in length and includes 13 protein-coding genes (PCGs), 22 transfer RNA (tRNA) genes, 2 ribosomal RNA (rRNA) genes, and 1 noncoding control region. A+T accounted for 75% of the total bases in the mitochondrial genome of F. serrata, revealing an obvious AT bias. Among the 13 PCGs, except for nad5, which had a start codon of TTG, the remaining genes had ATNs typical of insects (ATA, ATT, ATC, and ATG); nad1, nad2, nad3, and atp8 had incomplete termination codons of TA or T. The remaining nine PCGs were complete with the termination codon TAA. Of the 22 tRNA secondary structures, all were typical cloverleaf secondary structures except for trnS1, which was missing the DHU arm. Compared with the hypothetical ancestral gene arrangement of arthropods, F. serrata presented extensive gene rearrangement, with 23 translocated genes, 8 inverted genes, and 5 shuffled genes. Both maximum likelihood (ML) and Bayesian inference (BI) phylogenetic trees resulted in similar topologies: ((Thripidae + (Stenurothripidae + Aeolothripidae)) + Phlaeothripidae), with Thripidae, Aeolothripidae and Phlaeothripidae being monophyletic groups, whereas F. serrata is closely related to Thrips palmi, and the two are sister groups.

The ethanol extract of Sargassum duplicatum as an ovicidal agent against Aedes aegypti

Dengue hemorrhagic fever (DHF) is a major health concern in tropical and subtropical countries. Indonesia has DHF cases perennially every year. On the other hand, Indonesia is abundant with seaweed (Sargassum duplicatum), which can be found across its seashore. The macroalgae contains secondary metabolites with ovicidal activity; hence, it has the potential to be utilized in suppressing the Aedes aegypti. The aim of this study was to determine the ovicidal activity of S. duplicatum against the Ae. aegypti eggs. The algae were macerated with ethanol 70% before being subjected to qualitative phytochemical screenings. The ovicidal tests were conducted with an extract concentration of 50 ppm, 100 ppm, 500 ppm, 1000 ppm, and 1500 ppm, while distilled water was used as the control. The hatchability of Ae. aegypti was observed 24 hours a day for 4 days and the larval development was investigated under a microscope. Phytochemical screenings revealed that the extract was positive containing alkaloids, flavonoids, steroids, saponins, and phenols. The hatchability of Ae. aegypti eggs were significantly reduced following the S. duplicatum extract exposure for four days (p=0.000). The extract had LC50 of 828.653 ppm and LC50 of 1786.09 ppm for the ovicidal activity against Ae. aegypti eggs. The concentration of ethanol extract of S. duplicatum did not affect the mosquito development from larvae to adult stage (p=0.263). Further research is needed to explore the effect of specific compounds contained in the S. duplicatum and investigate their ovicidal potential.

Performance of Fujifilm Dengue NS1 Antigen Rapid Diagnosis Kit Compared to Quantitative Real-Time Polymerase Chain Reaction.

Dengue is a viral infection caused by the dengue virus (DENV), transmitted to humans through the bite of infected Aedes mosquitoes. About half of the world's population is now at risk of dengue, which represents a global public health concern, especially in tropical and subtropical countries. Early detection of the viral infection is crucial to manage the disease; hence, effective rapid diagnostic tests are essential. In this study, we evaluated the performance between the new Fujifilm Dengue non-structural antigen diagnosis kit (FF NS1 kit) and the SD Bioline NS1 antigen test kit (SD NS1 kit) against the quantitative real-time polymerase chain reaction (qRT-PCR) assays. The 140 acute serum samples collected from the Yangon General Hospital and Yangon Children's Hospital, Myanmar, from 2017 to 2019 were characterised by the three assays. With the qRT-PCR as the standard, the FF NS1 kit and the SD NS1 kit exhibited sensitivity of 94.3% and 88.6%, respectively, and specificity of 100% in both kits. Moreover, the positivity rates of the FF NS1 kit and the SD NS1 kit were 97.5% and 95% in primary infection and 90% and 80% in secondary infection, respectively. Our overall results suggest that the FF NS1 kit is reliable and accurate for detecting DENV infection.

Vaccination against dengue fever for travellers.

Dengue fever, endemic to most tropical and subtropical countries, is a major cause of illness in travellers, but severe dengue, hospitalisation and death are considered rare in this population. Two vaccines against dengue fever, Dengvaxia®and Qdenga®, are available. While there is no recommendation for the use of Dengvaxia®in travellers, Qdenga®has been licensed for travellers in many European countries since December 2022, most recently (29 July 2024) in Switzerland by Swissmedic. The Swiss Expert Committee for Travel Medicine (ECTM), having assessed available data on the Qdenga®vaccine, issues the following recommendations: (1) Vaccination against dengue fever virus with Qdenga®is not recommended for persons with no previous dengue fever infection. (2) Vaccination with Qdenga®may be recommended for travellers aged 6 years and older who have evidence of previous dengue infection, defined as (a) a laboratory-confirmed dengue infection (PCR, antigen or seroconversion)or(b) a compatible history of dengue infection with a positive IgG serological test AND expected exposure to a region with significant dengue transmission. Travel medicine advisors should provide clear information in accessible language on the complexity of dengue vaccines and the risk/benefit evaluation for their use in travellers.

Clove essential oil and its major component, eugenol: a comparative study of their in vitro antioxidant and anticancer properties

Syzygium aromaticum L. (clove) is a species native to subtropical countries. Its dried flower buds are rich in essential oils, which have shown insecticidal, anti-inflammatory and anaesthetic effects. This work was aimed to study the differences in antioxidant and anticancer activities between clove essential oil (CEO) and its major component, eugenol. The chemical composition of the CEO was determined by GC-MS. The physicochemical properties and antioxidant activity were determined in CEO and eugenol. Finally, anticancer activities were assayed against seven cell lines. Chemical analysis revealed that 80% of the CEO was eugenol. The density and IR were similar, and the colour was ΔE*>3. CEO had a lower phenolic content, but similar antioxidant activity to eugenol. The anticancer activity of the CEO was greater than that of eugenol in all the cell lines except for HeLa cells. These results suggest that secondary compounds in CEO enhance its antioxidant and ­anticancer activities.

Modeling the Impacts of Diagnosis and Treatment of Snakebite Envenoming Victims with Anti-Snake Venom in a Community

Snakebite envenoming (SBE) is one of the major causes of deaths and disabilities in tropical and subtropical countries especially in the continents of Asia and Africa. Report revealed that on average, 5-8 and about 3,000 cases of SBE are recorded daily and yearly respectively in northeast Nigeria which population are largely agriculturists. Thus, snakebite (SB) led to economy setback and slows down productivity among the workforce as a result of disabilities induced by SBE. Consequently, the revenue generation even including income facing declined. This paper proposes population-based mathematical model for studying the dynamic impacts of diagnosis and treatment of snakebite envenoming victims with anti-snake venom in a community. The model is rigorously analyzed using relevant techniques and theorems in dynamical systems. The model was validated using monthly reported data on snakebite envenoming from 2020–2022, collected from snakebite treatment and research hospital (STRH) Kaltungo in northeast Nigeria. The qualitative study revealed that the model has snakebite-envenoming-free and snakebite-envenoming-endemic equilibrium points. It is shown via the Lyapunov function in conjunction with the Lassale invariance principle that these two equilibrium points are globally asymptotically stable. Furthermore, numerical simulations of the model were carried out to investigate the impact of the diagnosis of snakebite envenoming victims and the treatment of the same on the burden of snakebite envenoming. The results of the simulations revealed that appropriate diagnosis and treatment of snakebite envenoming victims with anti-snake venom could significantly reduce the number of snakebite-induced deaths and disabilities. This work can serve as a framework for making policy and decision in addressing the issues of SBE in the public healthcares in the study region and beyond.