Diversity of DNA and RNA Viruses in Indoor Air As Assessed via Metagenomic Sequencing

Diverse bacterial and fungal communities
inhabit human-occupied
buildings and circulate in indoor air; however, viral diversity in
these man-made environments remains largely unknown. Here we investigated
DNA and RNA viruses circulating in the air of 12 university dormitory
rooms by analyzing dust accumulated over a one-year period on heating,
ventilation, and air conditioning (HVAC) filters. A metagenomic sequencing
approach was used to determine the identity and diversity of viral
particles extracted from the HVAC filters. We detected a broad diversity
of viruses associated with a range of hosts, including animals, arthropods,
bacteria, fungi, humans, plants, and protists, suggesting that disparate
organisms can contribute to indoor airborne viral communities. Viral
community composition and the distribution of human-infecting papillomaviruses
and polyomaviruses were distinct in the different dormitory rooms,
indicating that airborne viral communities are variable in human-occupied
spaces and appear to reflect differential rates of viral shedding
from room occupants. This work significantly expands the known airborne
viral diversity found indoors, enabling the design of sensitive and
quantitative assays to further investigate specific viruses of interest
and providing new insight into the likely sources of viruses found
in indoor air.