What makes human immunodeficiency virus (HIV) resistant to dry heat inactivation?

Hepatitis C virus maintains infectivity for weeks after drying on inanimate surfaces at room temperature: implications for risks of transmission

BACKGROUND

Healthcare workers may come into contact with fomites that contain infectious hepatitis C virus (HCV) during preparation of plasma or following placement or removal of venous lines. Similarly, injection drugs users may come into contact with fomites. Hypothesizing that prolonged viability of HCV in fomites may contribute significantly to incidence, we determined the longevity of virus infectivity and the effectiveness of antiseptics.

METHODS

We determined the volume of drops misplaced during transfer of serum or plasma. Aliquots equivalent to the maximum drop volume of plasma spiked with the 2a HCV reporter virus were loaded into 24-well plates. Plates were stored uncovered at 3 temperatures: 4°C, 22°C, and 37°C for up to 6 weeks before viral infectivity was determined in a microculture assay.

RESULTS

The mean volume of an accidental drop was 29 µL (min-max of 20-33 µL). At storage temperatures 4°C and 22°C, we recovered viable HCV from the low-titer spots for up to 6 weeks of storage. The rank order of HCV virucidal activity of commonly used antiseptics was bleach (1:10) > cavicide (1:10) > ethanol (70%).

CONCLUSIONS

The hypothesis of potential transmission from fomites was supported by the experimental results. The anti-HCV activity of commercial antiseptics varied.

Factor VIII, HIV and AIDS in haemophiliacs: an analysis of their relationship

In this review, the association between the Acquired Immune Deficiency Syndrome (AIDS) and haemophilia has been carefully examined, especially the data that have been interpreted as indicating transmission of the human immunodeficiency virus (HIV) to the recipients of purportedly contaminated factor VIII preparations. In our view, the published data do not prove the hypothesis that such transmission occurs, and therefore HIV cannot account for AIDS in haemophiliacs.

Survival of human immunodeficiency virus in suspension and dried onto surfaces

Cell-free and cell-associated human immunodeficiency virus cultures suspended in 10% serum remained infectious for several weeks at room temperature. The stability was further increased when cell-associated virus was suspended in neat serum. When dried onto a glass coverslip, virus remained infectious for several days, although cell-associated virus lost infectivity more rapidly than cell-free virus.