Aedes Albopictus – Asian Tiger Mosquito
# 8792
Up until about a decade ago, Chikungunya was a rarely seen mosquito-borne virus pretty much limited to central and eastern Africa. All of that changed in 2005 when it jumped to Reunion Island in the Indian Ocean, where it reportedly infected about 1/3rd of that island’s population (266,000 case out of pop.770,000) in a matter of a few months.
From there, apparently aided and abetted by a recent mutation that allowed it to be carried by the Aedes Albopictus `Asian tiger’ mosquito (see A Single Mutation in Chikungunya Virus Affects Vector Specificity and Epidemic Potential), it quickly cut a swath across the Indian ocean and into the Pacific.
That is, until about six months ago, when one (or more) infected travelers apparently arrived on the French Part of St. Martins, introducing the virus into the local mosquito population. On December 10th there were 2 confirmed, 4 probable and 20 suspected cases of chikungunya on the island.
A short six months later, and the virus has spread across nearly the entire Caribbean basin, and has infected at least 260,000 people.
Further expansion into North, South, and Central America seems but a matter of time.
A textbook example of what happens when a emerging infectious disease enters an immunologically naive population under favorable environmental conditions. And the reason why we talk so much about the global spread of disease in this age of globalization and increased international travel (see The Global Reach Of Infectious Disease).
Yesterday’s update from PAHO has already made headlines, as it shows an increase of roughly 93,000 cases over the previous week (a 40% increase), although not all of those cases emerged over the past 7 days.
As you’ll see by the chart below, some countries are still several weeks behind in their reporting, and surveillance and reporting in some regions is `sub-optimal’, so these numbers are still likely a significant undercount.
This week the WHO/PAHO Youtube Channel released several short videos showing the effects of the illness. The first one is more of a slide show, but shows the symptoms of the disease. The second video on Clinical Management is in Spanish, but has English sub-titles.
There are currently at total of five videos in their CHIKUNGUNYA Playlist.
For more on how the State of Florida and the CDC are working to meet the challenges of chikungunya, you may wish to revisit:
Florida Prepares For Chikungunya
Chikungunya Update & CDC Webinar Online
CDC HAN Advisory On Recognizing & Treating Chikungunya Infection
