Documenting the epidemiologic patterns of polyomaviruses in human populations by studying their presence in urban sewage

Abstract

This is the first description, to our knowledge, of the distribution of human polyomavirus and simian virus 40 (SV40) in urban sewage. Using a nested-PCR procedure, we report the detection of human polyomaviruses JC virus (JCV) and BK virus (BKV) but not SV40 in a high percentage of urban sewage samples obtained from widely divergent geographical areas in Europe and Africa. For a total of 28 samples analyzed, JCV was detected in 26, BKV was detected in 22, and none was positive for SV40. All geographical areas showed a high prevalence of these viruses with mean estimated values of JC viral particles per ml on the order of 10(3) in Barcelona (Spain) and Nancy (France) and 10(2) in Pretoria (South Africa) and Umeå (Sweden) and mean values of BK viral particles on the order of 10(2) in Pretoria and Barcelona and 10(1) in Nancy and Umeå. This compares with estimated mean values of 10(2) to 10(3) for human adenovirus that was evaluated as a control. Nucleotide sequence analysis of the amplified DNA from some of the samples is also presented and represents the sequence of the most abundant JC and BK viral strains in these samples. The nucleotide sequence of the JCV detected was also analyzed in a phylogenetic study and for genomic characterization in the regulatory region. This study has shown that human polyomaviruses are spread in high concentrations in the sewage of different geographical areas and are present in contaminated environments. The frequency and concentration of JCV detected in the environment and the absence of described animal hosts suggest that JCV may be useful as a marker for fecal pollution of anthropogenic origin. The results also support the idea previously described that the strains of JCV are closely related to the ethnic origin of the population studied. The procedure applied should also be useful in future studies of population patterns of viral excretion and as a tool in epidemiological studies for the detection of changes in the prevalence of specific viral pathogens.

FIG. 1

Agarose gel electrophoresis showing amplified DNA after nested PCR of one sewage sample that was positive for human Ad, BKV, and JCV and negative for SV40 (lanes 1, 2, 3, and 4, respectively). Lanes 5, 6, 7, and 8 are the corresponding negative controls. Lanes 9, 10, 11, and 12 are positive controls. Lane M, molecular weight standard, φX174 HaeIII digest.

FIG. 2

Sequence alignment of the IG regions of 12 JCV-positive samples. Dots indicate sequence identities. R = A + G; W = A + T.

FIG. 3

Phylogenetic analysis of the IG regions of 12 sequenced JCV strains compared with previously described JCV subtypes (Table 3) by the maximum likelihood method.

FIG. 4

Sequences of the R regions of JCV from nine analyzed samples. CSFE and CSFB are clinical samples of CSF from two patients. Archetypal sequences are observed in samples BCNU, BCN15, BCN16, BCN8, BCN2, NANCY2, and UMEA3. Underlined nucleotides are identical to the archetypal sequence. Nucleotides in boldface and in italics represent duplications present in these sequences.

FIG. 5

Sequence alignment of the VP1 regions of five BKV-positive samples. Dots indicate sequence identities.