As of now in the United States, most people who get mosquito bites only need to deal with the an annoying, itchy skin irritation. After washing the area with mild soap and water, a topical ointment can be applied and life can continue as usual. Meanwhile, tropical areas of the world are home to mosquitos that carry a deadly virus known as Dengue Fever Virus (DFV). Millions of people are infected annually. In recent years, dengue infection has been particularly prevalent in India, Southeast Asia, Brazil, and Guangdong Province, China.” (Qi, Zhang, Chi, 2008) People experience awful headaches with fever and rashes that last for weeks. (Goodsell, 2008). According to the Protein Data Bank, the virus causes the immune system to weaken in humans and it can result in deadly hemorrhaging. (2008) The World Health Organization lists further symptoms to include (but not limited to) persistent vomiting, swollen glands, severe organ impairment and abdominal pain. (2017) The good news is that scientists are trying to develop drugs that will rid the body of DFV infection and also prevent infection before it starts.
Dengue Virus Type 2
Viruses are incredibly simple. They are not regarded by the scientific community as being living things because they are powerless without the mechanical tools of a living host’s cell. On the other hand, they are also quite complex. This is true because of their diverse origins, vectors and clinical manifestations. They are described according to their genome (either as DNA or RNA), their physical appearance in electron micrograph images, taxonomical classification and their functions. One example featured in this review is the Dengue Fever Virus Type 2. The purpose of this explanation of Dengue Fever Virus is to the explain the genome structure, capsid structure and the status of present research that includes Dengue Fever Type 2.
The Aedes aegypti mosquito is the host and vector of the Dengue virus type 2 (also called DENV-2). The mosquito gets the virus from ingesting the blood of infected humans. Dengue Fever is caused by this arbovirus virus that has a genome made up of single stranded ribonucleic acid (RNA) (Sanchez-Vargas, et.al., 2009). Using an outer-envelope protein as an anchoring tool, it attaches to the surface of the host’s cells in order to begin the infection process. The proteins of this virus have designated functions. For instance, of the ten encoded proteins in the DFV genome, three of them form the viral coat and act as structural proteins. They insert the viral RNA into the cells that are targeted for infection. After the virus successfully enters the host’s cell, the remaining seven proteins begin the process of creating new viruses. Images of electron micrographs on the web show the virus as a ball-shaped cluster known as the capsid (Goodsell, 2008) Once membrane fusion begins, the virus enters the cell and comes into contact with lysosomes. At this point, the capsid takes on an elongated, tetrahedral form. This new form contains a hydrophobic tail that fuses with the lysozome and the hazard to human cells ensues.
In conclusion, Dengue Fever gains access to human hosts by using the Aedes aegypti mosquito as a vector. Scientists are studying the mosquito and the virus to gain a better understanding of the biological relationship between them. In 2007, a team of researchers including M. Salazar discovered that the concentration of the virus varied in different parts of mosquito anatomy. This enabled them to “understand better the effect of vector-virus interactions on dengue transmission.” With this knowledge and more to come, scientists hope to develop vaccines and preventative medicine to rid the world of this deadly disease.
- Protein Data Bank, & Goodsell, D. (2008, July). Molecular explorations through biology and medicine PDB-101: Dengue Virus. Retrieved from http://pdb101.rcsb.org/
- Qi, R., Zhang, L., & Chi, C. (2008). Biological characteristics of dengue virus and potential targets for drug design. Acta Biochimica et Biophysica Sinica, 40(2), 91-101.
- Salazar, M. I., et. al (2007, January 30). Dengue virus type 2: replication and tropisms in orally infected Aedes aegypti mosquitoes. Retrieved from https://bmcmicrobiol.biomedcentral.com/
- Sánchez-Vargas, I., Scott, J. C., Poole-Smith, B. K., Franz, A. W., Barbosa-Solomieu, V., Wilusz, J., Blair, C. D. (2009). Dengue Virus Type 2 Infections of Aedes aegypti Are Modulated by the Mosquito’s RNA Interference Pathway. PLoS Pathogens, 5(2), e1000299.
- World Health Organization. (2017, January 3). Dengue Control: Dengue/Severe dengue frequently asked questions. Retrieved from http://www.who.int/