Abstract:
Hepatitis A virus (HAV) is a waterborne pathogen of public health importance. In South
Africa (SA), unique HAV subgenotype IB strains have been detected in surface and wastewater
samples, as well as on fresh produce at the point of retail. However, due to the use of molecular-based
assays, the infectivity of the detected strains was unknown. Considering the potential shift of
HAV endemicity from high to intermediate, which could increase the risk of severe symptomatic
disease, this study investigated the identity of HAV strains detected before and after viability
treatment of selected wastewater discharge samples. For one year, 118 samples consisting of sewage,
treated wastewater discharge and downstream dam water were collected from five wastewater
treatment plants (WWTP 1, 2, 3, 4 and 5). Unique HAV IB strains were detected in samples from all
five WWTPs, with 11 of these strains carrying amino acid mutations at the immunodominant and
neutralisation epitopes. A quasispecies dynamic of HAV has also been detected in sewage samples.
The subsequent application of viability PCR revealed that potentially infectious HAV strains were
discharged from WWTP 1, 2, 4 and 5 into the dam. Therefore, there is a potential risk of HAV exposure
to communities using water sources downstream the WWTPs.
Description:
Supplementary file 1 of Figure 1: Fasta file of the sequence alignment used to infer phylogenetic analysis targeting
the VP1 region of hepatitis A virus (HAV) strains detected in samples from all five wastewater treatment plants
(WWTPs). Supplementary file 2 of Figure 3: Fasta file of the sequence alignment used to infer phylogenetic analysis
targeting the VP1/P2B junction of hepatitis A virus (HAV) strains detected in samples from all five wastewater
treatment plants (WWTPs). Supplementary file 3 of Figure 5: Graphic view of the complete protein alignment
(from position 1 to 300) of the deduced amino acid sequences of the VP1 region of the HM175 strain and hepatitis
A virus (HAV) strains carrying mutations at immunodominant and neutralisation epitopes. Supplementary file 4
of Figure 5: Fasta file of the sequence alignment of the VP1 region of the HM175 strain and hepatitis A virus (HAV)
strains carrying mutations at immunodominant and neutralisation epitopes. Supplementary file 5 of Figure 6:
Fasta file of the sequence alignment of the VP1 region of the HM175 strain and hepatitis A virus (HAV) strains
carrying in-frame deletions. Supplementary file 6 of Figure 7: Graphic view of the amino acid sequence alignment
of the VP1/P2B junction of the HM175 strain and 47 hepatitis A virus (HAV) strains carrying the C70S and/or
M104I changes. Supplementary file 7 of Figure 7: Fasta file of the sequence alignment of the VP1/P2B junction of
the HM175 strain and 47 hepatitis A virus (HAV) strains carrying the C70S and/or M104I changes.
