Hot Dengue

I received a Steve Reprieve because Death came off Holiday on many fronts of my mental and emotional landscape.  But Death is an Interloper, and it is best not to indulge his blood lust.  "Life marches on."

Death is also omnipresent in the Discover magazine article in its December 2010 issue entitled "The Hot Zone."  The magazine hasn't posted this article to its website, so here is a brief summary:

Classic dengue fever has existed in the US, but in 2005, dengue hemhorragic fever made its first well-documented appearance in Brownsville, Texas.  Doctors were unprepared for its appearance.  Its symptoms include vomiting, perilously low blood pressure, racking chills, and bloody urine.  A survey of the local population on both sides of the border (Brownsville, Matamoros, and the surrounding colonias) showed that the infection was not a fluke, a chance occurrence:

"Health officials discovered that nearly 1,300 people were infected with dengue fever as of the end of August 2005.  The results of a random survey were even more startling:  The officials found that 76 percent of the residents surveyed in Matamoros had dengue antibodies, indicating prior exposure to the virus.  They also found evidence of past dengue infection in nearly 40 percent of those tested in Brownsville.  Of the 24 Brownsville residents who had never traveled outside the United States, 25 percent tested positive for dengue -- which meant the illness was now firmly entrenched here.  Patient zero was merely the visible manifestation of a tropical disease that had already put down roots in the United States." (p. 41)

Dengue fever is spread by only two varieties of mosquito: Aedes aegypti and Aedes albopictus.  They have spread into temperate areas of the US, as far north as New York and New Hampshire.

Mosquitoes are "exquisitely sensitive"  to climate change, and hotter and more humid climates create a fiesta bowl of opportunity to spread contagion like dengue fever:

1. "Heat speeds up the incubation of the dengue virus, making it infectious much sooner and for more of the insect's life span."
2. The hotter it gets, the more the female mosquito bites human and animal hosts.
3. Climate change is likely to usher in a period of more extreme weather -- including heavier rains, a wider distribution of hot temperatures, extreme fluctuations in weather patterns on the hotter end of the temperature spectrum.

These conditions are also ripe breeding grounds for other disease carriers: ticks, mice, desert rodents, among others.  They carry a variety of pathogens: "Lyme disease, Rocky Mountain spotted fever, equine encephalitis, St. Louis encephalitis, anaplasmosis, and babesiosis."

In addition to hotter weather, the modern world is increasingly mobile.  In the past, the New World felt itself to be relatively insulated from disease infection.  That is no longer the case.  New York City and other east coast villages are only an 8-hour flight away from London, and anyone catching a connecting flight there from Africa.  World-wide infection can catch hold unobserved in a matter of multiplying hours, not days, in the case of viral infections.  Mosquito- and tick-borne diseases are only slightly slower.