Enteroviruses in sludge: multiyear experience with four wastewater treatment plants

Viruses in wastewater: occurrence, abundance and detection methods

This paper presents an updated and comprehensive review on the different methods used for detection and quantification of viruses in wastewater treatment systems. The analysis of viability of viruses in wastewater and sludge is another thrust of this review. Recent studies have mostly focused on determining the abundance and diversity of viruses in wastewater influents, in samples from primary, secondary, and tertiary treatment stages, and in final effluents. A few studies have also examined the occurrence and diversity of viruses in raw and digested sludge samples. Recent efforts to improve efficiency of virus detection and quantification methods in the complex wastewater and sludge matrices are highlighted in this review. A summary and a detailed comparison of the pre-treatment methods that have been utilized for wastewater and sludge samples are also presented. The role of metagenomics or sequencing analysis in monitoring wastewater systems to predict disease outbreaks, to conduct public health surveillance, to assess the efficiency of existing treatment systems in virus removal, and to re-evaluate current regulations regarding pathogenic viruses in wastewater is discussed in this paper. Challenges and future perspectives in the detection of viruses, including emerging and newly emerged viruses such as the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), in wastewater systems are discussed in this review.

Insights from a Systematic Search for Information on Designs, Costs, and Effectiveness of Poliovirus Environmental Surveillance Systems

Poliovirus surveillance plays a critical role in achieving and certifying eradication and will play a key role in the polio endgame. Environmental surveillance can provide an opportunity to detect circulating polioviruses prior to the observation of any acute flaccid paralysis cases. We completed a systematic review of peer-reviewed publications on environmental surveillance for polio including the search terms "environmental surveillance" or "sewage," and "polio," "poliovirus," or "poliomyelitis," and compared characteristics of the resulting studies. The review included 146 studies representing 101 environmental surveillance activities from 48 countries published between 1975 and 2016. Studies reported taking samples from sewage treatment facilities, surface waters, and various other environmental sources, although they generally did not present sufficient details to thoroughly evaluate the sewage systems and catchment areas. When reported, catchment areas varied from 50 to over 7.3 million people (median of 500,000 for the 25% of activities that reported catchment areas, notably with 60% of the studies not reporting this information and 16% reporting insufficient information to estimate the catchment area population size). While numerous studies reported the ability of environmental surveillance to detect polioviruses in the absence of clinical cases, the review revealed very limited information about the costs and limited information to support quantitative population effectiveness of conducting environmental surveillance. This review motivates future studies to better characterize poliovirus environmental surveillance systems and the potential value of information that they may provide in the polio endgame.

Direct Detection and Identification of Enteroviruses from Faeces of Healthy Nigerian Children Using a Cell-Culture Independent RT-Seminested PCR Assay

Recently, a cell-culture independent protocol for detection of enteroviruses from clinical specimen was recommended by the WHO for surveillance alongside the previously established protocols. Here, we investigated whether this new protocol will show the same enterovirus diversity landscape as the established cell-culture dependent protocols. Faecal samples were collected from sixty apparently healthy children in Ibadan, Nigeria. Samples were resuspended in phosphate buffered saline, RNA was extracted, and the VP1 gene was amplified using WHO recommended RT-snPCR protocol. Amplicons were sequenced and sequences subjected to phylogenetic analysis. Fifteen (25%) of the 60 samples yielded the expected band size. Of the 15 amplicons sequenced, 12 were exploitable. The remaining 3 had electropherograms with multiple peaks and were unexploitable. Eleven of the 12 exploitable sequences were identified as Coxsackievirus A1 (CVA1), CVA3, CVA4, CVA8, CVA20, echovirus 32 (E32), enterovirus 71 (EV71), EVB80, and EVC99. Subsequently, the last exploitable sequence was identified as enterobacteriophage baseplate gene by nucleotide BLAST. The results of this study document the first description of molecular sequence data on CVA1, CVA8, and E32 strains present in Nigeria. The result further showed that species A enteroviruses were more commonly detected in the region when cell-culture bias is bypassed.

Enterovirus Species B Bias of RD Cell Line and Its Influence on Enterovirus Diversity Landscape

Despite its widespread use in poliovirus isolation, studies show that most RD cell line isolates are species B enteroviruses (EB), it was therefore employed to further catalogue the EB diversity in two different regions of Nigeria. Concentrates of 18 environmental samples were inoculated into RD cell line. Isolates were subjected to PCR assays to detect enteroviruses, species C and B members and partial VP1 gene which was subsequently sequenced and used for identification and phylogenetic analysis. Isolates were further passaged in L20B cell line to detect polioviruses. Sixty-eight isolates were recovered from the 18 concentrates, all of which were positive for the enterovirus 5'-UTR screen. Thirteen of the 68 isolates were positive for the species C screen and replicated in L20B cell line, eleven of which also contained species B enteroviruses. Some of the mixed isolates were successfully typed, but as species B members. In all, isolates recovered in this study were identified as CVB5, E6, E7, E11, E13, E19, E20, E33, EVB75 and WPV3, while some could not be typed. Alongside the ten different enterovirus serotypes confirmed, results of this study document for the first time in Nigeria, EVB75. It showed the EB bias of RD cell line might indicate something much more fundamental in its biology. Finally, the finding of WPV3 in a region considered low risk for poliovirus emphasizes the need to expand poliovirus environmental surveillance to enable early detection of poliovirus silent circulation before occurrence of clinical manifestations.

Coxsackie virus infections in rheumatic fever

The close relationship between Group A beta Hemolytic Streptococci (GABS) and rheumatic fever is a well established one. However, the concept of the streptococcus as the sole etiologic agent of the rheumatic heart disease (RHD) has been challenged over the past years. Since coxsackievirus group B (CVB) has long been proposed as a cause of acquired valvular disease simulating rheumatic fever, we attempted in this study to document infections with this group of viruses in patients with rheumatic fever. We obtained blood samples from 106 patients with old (quiescent) rheumatic fever/rheumatic heart disease [group I], 94 patients with acute rheumatic fever (ARF) [group II], and 74 normal matched controls. We tested for the presence of neutralizing antibodies to the 6 serotypes of CVB by a micro neutralization test. We have found that infection with CVB, especially types B2 and B4, was common in the studied population. Forty-two percent of normal individuals had evidence of infection with any of the 6 serotypes of CVB. Patients of group I had significantly more frequent infections with CVB 2. Patients in group II had significantly more frequent infections with CVB 2 and CVB 6. There was no clear correlation between such infections and the clinical course of rheumatic fever. There was no difference in the incidence of CVB infections between patients with definite ARF, and patients with suspected ARF. We set a low order association between rheumatic fever and infection with CVB types B2 and B6. We emphasize the importance of pursuing the investigation of the role of CVB in relation to RHD.

Multiyear study of sludge application to farmland: prevalence of bacterial enteric pathogens and antibody status of farm families

We describe our experience with the isolation of salmonellae from sewage sludge from four treatment plants in different geographic areas of Ohio. Over 3 years, we isolated salmonellae 50 times from 311 sludge samples. Most isolations were made after enrichment in Selenite broth (BBL Microbiology Systems, Cockeysville, Md.). The largest proportion of isolations came from the plant serving the population of Columbus, a large metropolitan area. A significantly greater number of isolations from this plant were made during the first quarter of the year. Twenty-one different serotypes were isolated, along with five untypable strains. The most frequently isolated serotype was Salmonella infantis. Five of the strains were multiply resistant to antibiotics. We also describe the prevalence of antibodies to salmonellae in members of the families residing on the farms in the study. It was found that antibodies to group C salmonellae predominated.