5 ǀ HEV IN WATER AND WATER-BORNE OUTBREAKS
Genotypes 1 and 2 are mainly reported in Asia including Afghanistan,
India, Bangladesh, China, Nepal, and Pakistan, and some African
countries such as Chad, the Central African Republic, Mexico, Nigeria,
and Sudan.112 Genotype 1 and possibly 2 caused several
water-borne outbreaks in many parts of the
world.3,24,113 Qualitative analysis of drinking and
sewage water samples by using RT-PCR from Faisalabad, Pakistan, showed
the presence of HEV genotype 1 strain.114 Another
study from Italy reported a high prevalence of HEV in water samples with
the presence of HEV genotype 1 and 3 in sewage water samples in which 11
out of 19 WWTPs were positive for HEV RNA.96
In Spain, the HEV genome was detected from slaughterhouse sewage mainly
from pigs and showed 92-94% nucleotide similarity with strain detected
from the human.115 A high positivity rate of 20/46
(43.5%) of HEV was reported in sewage samples from Barcelona,
Spain.116 Another study from Spain showed the presence
of both genotypes 1 and 3 in samples from WWTPs.117 In
Spain, the HEV genotype 1 and 3 were detected from sewage and biosolid
samples from urban sewage treatments.118 In Colombia
of the total sixty environmental samples, the HEV genome was detected in
23.3% (7/30) of drinking water plants/creek and in 16.7% (5/30) of
sewage samples.119 Several HEV outbreaks have been
reported in some countries in particular in developing countries. The
recent HEV outbreaks associated with water contamination are presented
in Table 1.