Detection and quantification of human immunodeficiency virus-1 (HIV-1) total nucleic acids in wastewater settled solids from two California communities

Abstract

AbstractWastewater surveillance for infectious agents has proved useful in identifying circulation of viruses within populations. We investigated the presence and concentration of human immunodeficiency virus (HIV)-1 total nucleic acids (including both viral RNA and proviral DNA) in wastewater solids. We retrospectively measured HIV-1 nucleic-acids in two samples per week for 26 months at two wastewater treatment plants serving populations with different prevalences of HIV infections in San Francisco and Santa Clara County, California, USA. We detected HIV nucleic-acids in a majority of samples with concentrations ranging from non-detect to 3.9×105cp/g (N=459 samples total). Concentrations of HIV-1 were significantly higher in samples from the wastewater treatment plant serving a population with a higher prevalence of people living with HIV than in the plant serving a population with lower prevalence. The HIV-1 nucleic-acids amplified were primarily DNA and thus represented proviral DNA shedding into wastewater. Additionally, we found that HIV-1 nucleic-acid concentrations in wastewater solids were orders of magnitude higher than those in liquid wastewater indicating that the HIV-1 target preferentially sorbs to solids. Whether concentrations of HIV-1 in wastewater solids can be used to identify numbers of incident cases remains unknown. Additional work on HIV-1 shedding from individuals with viremia and people living with HIV is needed to translate wastewater measurements to quantitative information on infections.