Cycloviruses were first discovered in fecal samples from South-Asian children (Li et al., 2010) and have been described in farm animals, chimpanzees, bats, cockroaches, and dragonflies. We recently identified a novel cyclovirus species which was subsequently found in 15% and 10% of serum and CSF samples, respectively, in humans with paraplegia inMalawi(Smits et al., 2013). Similar observations were reported inVietnam, where a related novel cyclovirus was detected in 4% of 642 CSF specimens from Vietnamese patients with suspected CNS infections and none of 122 CSFs from patients with noninfectious neurological disorders (Van Tan et al., 2013). Whether cycloviruses play a role in development of paraplegia or CNS infections remains to be determined.
These observations expand the knowledge of cycloviruses in humans and show how epidemiologic baseline information on virus host range and tropism in animals may provide indications for the presence of similar viruses in different organ systems of humans. To clarify the epidemiology and pathogenicity of cycloviruses in humans, additional surveillance should be carried out.