The adventurous tourist, obliviously hacking his way through the jungles of Brazil, is first aware of a faint buzzing noise, then a tiny sting on his arm. The smack of his hand seems to have taken care of the problem: he has merely been bitten by a mosquito, so it seems there is no reason to panic. However, this mosquito wields a formidable threat. It carries the microscopic virema of Dengue Haemorhaggic Fever, for which there is no known cure. During the next few days, as the virus toys with the tourist's immune system, a highly uncomfortable set of symptoms will arise. This chain of events may have begun in a small flowerpot, overflowing with rain from a hurricane brought on indirectly by global warming and a collection of small, Japanese automobiles. A look at the larger picture will reveal that a myriad of factors is at play in the battle against dengue, a virus with a wicked, and fourfold attack method. If only the problem could be stamped out with the resounding smack of one man's palm.
[...] Much about the pathogenesis of the Dengue virus remains a mystery. Recently, scientists have been struggling to uncover the processes that occur in between the time of the seemingly innocuous mosquito bite and the terminal stages of Dengue Shock Syndrome. From the results of various experiments with flaviviruses, however, one can piece together a general sketch of the virus' tropism (movement). During the first stages of Dengue the virus enters the bloodstream from the belly of the mosquito. It is the events of this first stage that remain the most obscure and difficult to study, but the virus is thought to remain, at least tentatively, limited to the bloodstream, liver, and bone marrow cells. [...]
[...] Occasionally, these beginning symptoms will dissipate and then reappear, a tendency known as “saddleback pattern (Spira, 1998).” Lapses in pain during dengue I often deceptively cloak neutralization reactions are occurring between the immune system and a mutating strain of dengue II, or DHF (Guzman et al., 2000). Unfortunate is the patient who contracts dengue II (DHF) after the primary infection, for this elder brother induces more gruesome ramifications than dengue which may run its course in as little as a week(Guzman et al., 2000). [...]
[...] have formulated a recombinant virus using a vaccine strain of chimeric yellow fever (another flavivirus) as a “backbone,” and inserting the dengue type 2 (DHF) single-stranded RNA and protein coat. This mutant was tested on rhesus monkeys which were then infected with a wild-type dengue 2 virus. After sixty-two days, virema were found in all control groups (administered a placebo of the vaccine), but virtually none 1.7 log10 FFU/ml) were found in the vaccinated monkeys (Guirakhoo et al., 2000). Another strategy involves manipulating cellular machinery, specifically the endoplasmic reticulum, to produce alpha- glucosidase inhibitors, molecules that are demonstrated to halt further proliferation of the dengue virus as it takes over individual cells (Courageot et al., 2000). [...]
[...] Journal of Virology 8867- Spira, A Dengue Fever, http://www.armchair.com/info/spira7.html. Srichaikul Nimmannitya S Haematology in dengue and dengue haemorrhagic fever. Baillieres-Best-Pract-Res-Clin-Haematol. 13(2). 261- Diamond, M.S., Edgil, D Infection of human cells by dengue virus is modulated by different cell types and viral Strains. Journal of Virology 7814- Didcock, L., Goodbourn, S., Randall, R.E Interferons: cell signaling, immune modulation, antiviral response and virus countermeasures. Journal of General Virology 2341- Webster, M Mirriam Webster Medical Dictionary Online. http://medical-dictionary.com/ 7. World Health Organization http://www.who.int/health-topics/dengue.html 8. [...]
[...] Likewise, Hurricane Mitch is thought to be tied to thousands of dengue infections that occurred in 1998. The link between weather and increase infection is the upheaval and translocation of contaminated water, as well as the accumulation of excess regular water in urban areas where the profusion of hosts and vectors can coincide (Epstein, 2000). Global warming is also a friend to Aegis aegipti in that the mosquito fares better in warmer temperatures. Chilled and frozen water makes mosquito breeding impossible. [...]
Online readingwith our online reader
Content validatedby our reading committee