Controlling DengueRafi ur RahmanM. Phil (Biotechnology and Genetic Engineer)

Introduction:DengueCausative Agent, The VirusTransmissionThe MosquitoControl

The Dengue Fever Is an acute fever producing infectious

disease Mostly found in the tropics Pronounce DEN-ghee Complications can be fatal It is also known as Dengue fever , break-

bone fever. Complicated forms are DHF and DSS

Causative Agent: The Virus RNA Virus Genus Flavivirus. Family Flaviviridae. 11000bp which encodes a single large

poly protein. Other relatives: West-Nile virus, Yellow

fever virus, hepatitis C virus. Four Serotypes: DEN1-4. 60-80%

sequence homology and also Surface Protein Homology

Transmission: Aedes Aegypti: Cosmopolitan. Ae. Albopictus: South-East Asia. Biting around the ankles and knees close

to the ground in the daytime Distinct Physical Features. Life cycle.

The Mosquito: Dengue cases usually increase during

the rainy season The spread of the mosquito is attributed

to poor environmental sanitation When it rains the water gets stored in

any place such as discarded tires, broken bottles, and even shoes

Other examples are soda cans, birdbaths, rain gutters, toys, pool covers, tree stumps, and garbage cans.

More About the Causative Agent: Male feeds on plant nectar Female feeds on blood (Human, Animals,

Birds, Monkeys). Life Span: 14-21 days. Lays 300 eggs during her life span. The mosquito can travel up to 10 km.

Control: No specific vaccine or drug invented. Can be controlled by limiting 1) Eliminating the Mosquito vector and/or 2) Interrupting Human-vector Contact.THAT’S WHY; Clothing, that minimize skin exposure must be

used. Mosquito repellents. Mosquito nets. Don’t let clear water un-covered for more than

1 day. Put the cover on water container along with

cloth.

Contdd.. If the larvae are seen any where, put

some detergent(surf), wait for some time and then discard.

Do not leave any source into the water tanks(over-flow, air source), if left however, cover with some sort of net or long pipe.

Focus on neglected areas like water pots in bird cages etc..

Turn over all unused water containers.

Control: Control of Immature stages: Vector control: 1. Larviciding with

insecticides.2. Elimination of breeding sites Only Temephos, Permethrin, Bti, and Pyriproxyfen

are approved by WHO for use in drinking-water. Bti Toxins: Bacillus thuringiensis var.

israelensis (Bti), Bacillus Sphaericus (Bs). High larvicidal activity in mosquitoes. Should be used in Combinations: [BTi + Insecticide], [BTi + Copepods]: Excellent

results. Commercial Preparations: Liquid/Granular Preps

are available.

References: Akram, W., (n.d.). Aedes as a vector of Dengue: a possible threat to our lives.

Khwarzimig Science Society. University of Agriculture, Faisalabad. Retrieved April 19, 2010 from http://www.khwarzimic.org/takveen/dengue_kss.pdf

Bauman, R., (2006). Microbiology disease by systems. San Francisco , CA: Pearson Benjamin Cumming Publisher

Center for Disease Control and Prevention, (2009)Dengue epidemiology. Retrieved April 22, 2010 from http://www.cdc.gov/Dengue/epidemiology/index.htm

Center for Disease Control and Prevention, (2009). Other infectious disease related to travel, dengue fever (DF) and dengue hemorrhagic fever (DHF). Retrieved April 19, 2010 from http://wwwnc.cdc.gov/travel/yellowbook/2010/chapter-5/dengue-fever-dengue-hemorrhagic-fever.aspx

Center for Disease Control and Prevention, (2009). About CDC’s dengue branch. Retrieved April24, 2010 from http://www.cdc.gov/Dengue/about/index.html

Gubler, D.J., Clark, G.G., (1995)Dengue/dengue hemorrhagic fever: The emergence of a global health problem. Retrieved April 19, 2010 from ftp://ftp.cdc.gov/pub/EID/vol1no2/adobe/gubler.vol1no2.pdf

Gubler, D., (1998). Dengue and dengue hemorrhagic fever . Clinical Microbiology Reviews, July 1998, p.480-496. Retrieved April 24, 2010 from http:/www.cmr.asm.org/cgi/repreint/11/3/480

World Health Organization, (2009). Dengue and Dengue haemorrhagic fever. Retrieved April 19, 2010 from http://www.who.int/mediacentre/factsheets/fs117/en /

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