Existence and Removal of Rotaviruses Group A and Cryptosporidium Species in a Wastewater Treatment Plant

Abstract

Rotavirus group A (RV-A) and Cryptosporidium spp. are recognized as important pathogens causing gastroenteritis, even with very low doses in all age groups and representing a public health risk. Seventy-two wastewater samples were collected and concentrated for detecting Cryptosporidium spp. and RV-A. PCR was performed for identification of genus Cryptosporidium using generic primers and species specific primers for Cryptosporidium parvum / Cryptosporidium hominis. Multiplex seminested RT-PCR was performed to identify the genotypes P and G of RV-A. Our findings showed that the rotavirus genome was detected in 29 (40.3%) out of 72 analyzed wastewater samples. Rotavirus rates in raw wastewater samples were higher (47.2%) than those detected in treated wastewater (33.3%). Cryptosporidium was found in 33.3% of 72 tested wastewater samples. All Cryptosporidium-positivesamples were related to Cryptosporidium parvum. The prevalence of Cryptosporidium parvum in influents and effluents reached 41.7% and 25%, respectively. The removal rates of rotavirus and Cryptosporidium parvum in the examined WWTP were 29.4% and 40%, respectively. The largest percentage of positive rotavirus in raw wastewater samples was detected in winter (77.8%), followed by 66.7% in autumn. Three P types and two G types of RV-A strains were identified in wastewater samples. The most prevalent types of RV-A strains in raw and treated sewage samples were G1 and P[8] genotypes. In conclusion, wastewater treatment processes, including a trickling filter, were not sufficient to eliminate several RV-A strains and Cryptosporidium parvum, leading to the potential release of these pathogens from domestic sewage into water sources.

Occurrence of various viruses and recent evidence of SARS-CoV-2 in wastewater systems

“…Although person-to-person transmission is an important route, the main RoV transmission route is the faecal-oral route. More than 1000 RoV particles can be present in one gram of faeces, and these viruses have been detected at significant levels in wastewater in many countries, such as South Africa ( Adefisoye et al, 2016 , Osuolale and Okoh, 2017 ), Japan ( Yasui et al, 2016 ), Canada ( Qiu et al, 2016 ), the USA ( Schmitz et al, 2016 , Gerba et al, 2018 ), Tunisia ( Ibrahim et al, 2016 ), Italy ( Mezzanotte et al, 2016 ), France ( Kaas et al, 2019 ), Japan ( Kobayashi et al, 2017 ), Uruguay ( Lizasoain et al, 2018 ), Egypt ( Rizk et al, 2019 ), the UK ( Adriaenssens et al, 2018 ), Brazil ( Assis et al, 2018 ), New Zealand ( Gyawali et al, 2018 ), Canada ( Qiu et al, 2018 ), New Zealand ( Clemens et al, 2020 ), and Tunisia ( Ibrahim et al, 2020 ).…”

Performance Assessment of Natural Wastewater Treatment Plants by Multivariate Statistical Models: A Case Study

“…The release of such poorly treated wastewater (i.e., not compliant with the Egyptian decree) into water bodies has negative impacts on humans and the environment in the short and long term. Several studies have reported a high level of human enteric parasites, bacteria, protozoa, and viruses in treated wastewater [14,17,41,[57][58][59]. There have been reports of cholera and diarrhea outbreaks in developing countries due to the drinking of wastewater-contaminated water [7,14,60].…”

Epidemiological significance of the occurrence and persistence of rotaviruses in water and sewage: a critical review and proposal for routine microbiological monitoring

“…The activated sludge treatment produced a mean log10 removal range of 2–2.83 while that of the coagulative precipitation method was 0.72 ± 0.08. Rizk et al 137 determined a total RV removal rate of 29.4% for a WWTP that uses chlorine for disinfection and operates with a trickling filter technology. A Canadian study by Qiu et al 67 revealed high concentrations of RVs by qPCR in both pre-UV and post-UV samples and the infectious form was also confirmed in 5.9% (3/51) of pre-UV samples and 8% (4/50) of post-UV samples by integrated cell culture with qPCR (ICC-qPCR).…”

“…101,120 In genotyping of RV-A in water samples, the multiplex RT-PCR is semi-nested. 137 The rst round of PCR usually involves amplication of the VP7 or VP4 gene sequences with the consensus oligonucleotide primers. The VP4 or VP7 amplicons are then used as a template in the second round of PCR with P-and G-type specic oligonucleotide primers targeting P [4], P [6], P [8], P [9], P [10] and P [11] or G1, G2, G3, G4, G8, G9, G10 and G11, respectively.…”

“…Based on the amplicon size visualized on gel under ultraviolet light, the VP7 and VP4 genes are assigned to their corresponding G-and Ptypes. 137,138 The sensitivity of multiplex qPCR has been likened to singleplex PCR in their ability to detect RVs in raw sewage samples. 91 The technique is rapid as it can simultaneously detect several rotavirus genotypes in a single reaction at reduced cost and labor compared to singleplex PCR-based assays.…”