The presence of viruses and other pathogens in the environment
is an indicator of faecal pollution that poses a
potential risk to the exposed population, since such pathogens
do not constitute normal gastrointestinal microbiota,
and are only excreted by sick individuals [7].
Rotavirus is recognized as being responsible for diarrheal
disease in young children with a worldwide mortality rate
of 600,000 per year [8]. Astrovirus is also considered one
of the most important agents of viral gastroenteritis
[9,10], and is ranked second after rotavirus as the major
cause of diarrheal disease in young children and adults
[11]. While the actual contribution of rotavirus to total
incidence of diarrheal disease is between 25% and 52%,
astrovirus is much lower being responsible for between
5% and 10% of cases [12].