Dengue Fever: A General Perspective

Dengue Fever or commonly known as Dengue, a mosquito-borne arboviral infection has emerged as havoc around the globe. Annually, about 50 million infections are reported, resulting in 22,000 deaths and almost 2.5 billion people are reported living at risk. Dengue infection is caused by Dengue Virus (DENV), which is a member of genus Flavivirus and comprised of ten proteins; three proteins, capsid (C), membrane (M), and envelope (E), play structural role and seven are identified as non-structural that direct DENV replication. Four distinct serotypes: DENV-1, DENV-2, DENV-3 and DENV-4 are transmitted via Aedes mosquitoes. Clinically, Dengue patients can be categorized into three groups according to WHO 2009 revised classification. Typical symptoms of dengue include: extreme fatigue; sudden fever (from 3-7 days), headache, joint, muscle, and back pain; vomiting and diarrhea, appetite loss; skin rash along minor bleeding. Aedes aegypti is geographically distributed in tropical areas and breeds in artificially filled water containers i.e. drums, tyres, flower vases plastic food containers, tin cans, etc. Due to four viral serotypes and non-availability of the model animal for dengue, producing vaccines is a challenging task. Thus, Dengue can be managed using various vector control strategies through physical, chemical and biological means

Genetic Analysis of Aedes aegypti using Random Amplified Polymorphic DNA (RAPD) Markers from Dengue Outbreaks in Pakistan

Background: Keeping in view the havoc situation of dengue fever in Pakistan, the current study was designed to demon­strate the genetic variations, gene flow and rate of migration from Lahore and Faisalabad. Methods: The larvae were collected from both natural and artificial breeding places from each collection site. The adult mosquitoes were collected by means of sweep net and battery-operated aspirator. DNA extraction was per­formed using TNE buffer method. Ten GeneLink-A series RAPD primers were used for PCR amplification and the data was analyzed through POPGENE. Results: The number of amplification products produced per primer varied from 8-12, ranging from 200 to 2000 bp with an average of 10.0 bands per primer. The percentage of polymorphic loci amplified by each primer varied from 22.5 to 51%. The UPGMA dendrogram demonstrates two distinct groups from Faisalabad and Lahore populations. The genetic diversity ranged from 0.260 in Faisalabad to 0.294 in Lahore with a total heterozygosity of 0.379. The GST value for nine populations within Lahore was 0.131 (Nm= 3.317), whereas for nine populations in Faisalabad GST value was 0.117 (Nm= 3.773). The overall genetic variation among eighteen populations showed GST= 0.341 and Nm= 1.966. Conclusion: The genetic relatedness and Nm value show that Ae. aegypti populations exhibit intra-population gene flow both in Faisalabad and Lahore. Although, both cities show a distinct pattern of genetic structure; however, few areas from both the cities show genetic similarity. The gene flow and the genetic relatedness in few populations of Lahore and Faisalabad cities need further investigation

Toxicity, Phytochemical Composition, and Enzyme Inhibitory Activities of Some Indigenous Weed Plant Extracts in Fruit Fly, Drosophila melanogaster

Drosophila melanogaster being used as model organism is considered as pest of homes, restaurants, and fruit markets. The damaged fruits are also reported to serve as a carrier for various diseases. The current study was designed to evaluate the toxicity of petroleum extract of some weed plants, namely, Euphorbia prostrata, Parthenium hysterophorus, Fumaria indica, Chenopodium murale, and Azadirachta indica, against D. melanogaster. Mortality at 10, 20, and 30% concentrations after 24 and 48 hours was found comparatively low. E. prostrata caused high mortality (51.64%) at 30% concentration and was found more toxic (LC50 27.76; P value 0.00) after 72 hours. A. indica showed high LC50 value (P value 0.15) compared to other weed plants. The combination of E. prostrata and Bti showed highest mortality (100%; LC50 12.49; P value 0.00) after 72 hours. Similarly, the same combination caused maximum reduction in the activity of AChE, AcP, AkP, α-Carboxyl, and β-Carboxyl enzymes. Phytochemical analysis showed the presence of flavonoids, saponins, tannins, steroids, cardiac glycosides, alkaloids, anthraquinones, and terpenoids. FTIR analysis of E. prostrata showed the presence of phenolic compounds. It is suggested that further studies are needed in order to incorporate weed plant extracts in combination with Bti for the management of fruit flies