Not only has the Western hemisphere seen more than 1 million dengue fever cases in 2014, a multitude of countries are reporting seeing more than one serotype of the mosquito borne virus, eight countries report seeing all four serotypes.
There are four distinct, but closely related, serotypes of the virus that cause dengue (DEN-1, DEN-2, DEN-3 and DEN-4). Reports of a fifth serotype, the first new subtype in 50 years, was reported one year ago.
Recovery from infection by one provides lifelong immunity against that particular serotype. However, cross-immunity to the other serotypes after recovery is only partial and temporary. Subsequent infections by other serotypes increase the risk of developing severe dengue.
According to the Pan American Health Organization (PAHO), the following countries have reported all 4 serotypes circulating: Guatemala, Mexico, Nicaragua, Colombia, Ecuador, Peru, Venezuela and Brazil. Nine other countries report 3 serotypes circulating.
As of Oct. 7, there has been 1,006,413 suspected and confirmed dengue fever cases reported in the Western hemisphere. Brazil accounts for 53% of the total cases. Colombia and Mexico follow with 111,092 and 82,734 cases, respectively.
Of this number, 537 dengue-related fatalities have been reported this year. The United States has confirmed 234 dengue fever cases, according to the data. For more infectious disease news and information, visit and “like” the Infectious Disease News Facebook page