Survival and recovery of seeded HIV in water and wastewater

Abstract

Acquired Immunodeficiency Syndrome (AIDS) is one of the major public health concerns in the world today. The Human Immunodeficiency Virus (HIV), the causative agent of AIDS, has been isolated from blood, semen, and other body fluids as well as excretions from infected individuals as both free virions, cell‐free virus, and as productively infected cells, cell‐associated virus. These body fluids and excretions, when discharged into wastewater collection systems, may contribute to the presence of HIV in wastewater. This raw wastewater, which may contain HIV, passes through wastewater treatment systems and may pose a potential health threat to wastewater treatment plant workers. The objectives of this research were to develop a better understanding of the survival of cell‐associated HIV in wastewater and to develop reliable methods for the concentration and recovery of HIV from wastewater. Casson et al. (1992) reported survival of cell‐free HIV in primary and secondary effluent ≤12 h followed by a reduction in titer 1‐ to 2‐ log in 24–48 hr. The infectivity of cell‐associated HIV was observed to be reduced rapidly after exposure to distilled water. However, a subpopulation of cell‐associated HIV was observed to remain stable through 48 h and remain infectious for ≤96 h in distilled water. Preliminary results indicate that cell‐associated HIV infectivity in nonchlorinated secondary effluent was less stable than in distilled water. Using a bentonite adsorption‐elution procedure, the authors have been able to recover HIV from distilled water and primary and secondary effluent at an efficiency of 30–50% to achieve an 8‐ to 10‐fold concentration depending on the initial HIV concentration. The bentonite‐adsorption elution procedure combined with RT‐PCR amplification provided a highly sensitive procedure for the detection of HIV in water and wastewater as low as one HIV particle per 25 m1.