Overview of Waterborne Pathogens - Waterborne Pathogens: Detection Methods and Applications - page 17

is very persistent in a water environment 13 and has been shown to resist
chlorination. 8
Of the 28 outbreaks and 12,000 associated cases of waterborne virus infec-
tions in the United States in the late nineteenth century, 75% were attributed
to NoV. 8 In 2008, in Lilla Edet, Sweden, 2400 people contracted gastroen-
teritis, with the majority of cases ascribed to NoV. 14 Among other recent out-
breaks, one occurred at a Dutch scout camp 15 and one occurred in Turkey. 16
2.1.6. Rotavirus
Rotavirus is the most significant single cause of infant mortality, and it
accounts for 50-60% of all hospitalizations of children with acute gastro-
enteritis. The disease burden varies significantly between high- and low-
income countries, and it is estimated at 14 and 480 disability-adjusted life
years (DALYs), respectively, per 1000 cases.
Rotavirus comprises segmented double-stranded RNA in a nonenvel-
oped icosahedral capsid. This structure has a diameter of 50-65 nm and is
then further enclosed in a layered shell, making the final virus size 80 nm
diameter. The outer shell looks wheel-like, thus inspiring the name of this
virus. A schematic of the virus structure can be seen in Fig. 2.4 .
There are two genera in the reoviridae virus family typically associated
with human infection, of which rotavirus is the most problematic from a
Figure 2.4 A schematic of a rotavirus virion. The 11 segmented dsRNA is surrounded
by a three-layered protein shell, made up of six different proteins. Source: From Figure 1
from Ref. 17 . (For color version of this figure, the reader is referred to the online version
of this topic.)