Contributions of fish and other foods to variance of selenium and mercury status were studied in British adults.

Plasma and red-cell selenium and whole-blood mercury concentrations were measured during the National Diet and Nutrition Survey of Adults aged 19–64 years in mainland Britain, 2000–2001 (n = 1216). Food intake was weighed for seven consecutive days, and foods were combined in groups for data analysis. Four subsidiary groups characterised fish intakes: fried white fish, ‘other’ white fish, shellfish and oily fish.

Geometric means and 5–95% ranges were: for whole-blood mercury, 5.61 (1.30–22.2) nmol l− 1; for plasma selenium, 1.09 (0.83–1.43) μmol l− 1; for red-cell selenium, 1.64 (1.14–2.40) μmol l− 1. Twenty-eight per cent had no fish intake recorded during 7 days; the remaining 72% had a median intake of 237 g over the 7-day period, 5–95% range 45–780 g. Total fish intake was strongly and directly correlated with blood mercury, and moderately with red-cell and plasma selenium. Thus, sqrt(total fish intake) was correlated with: loge(blood Hg), t = +19.7; loge(plasma Se), t = +9.8; and loge(red-cell Se), t = +9.6, all P < 0.0001. All three biochemical (mercury and selenium) indices were strongly correlated with oily fish intake, and moderately correlated with shellfish and ‘other’ ( = non-fried) white fish, but none was significantly correlated with fried white fish. Blood mercury was strongly and directly correlated with red-cell and plasma selenium, and both increased with age.

Dietary fish, especially oily fish, is a strong predictor of blood mercury and selenium in British adults.

To assess the efficacy of a standard cleaning and sterilization protocol employed during reuse of cardiac electrophysiology catheters on the infectivity of duck hepatitis B virus (DHBV; a surrogate for human hepatitis B virus), bovine viral diarrhea virus (BVDV; a surrogate for human hepatitis B virus), and human Coxsackie type B3 virus (CB3).

Public health virology laboratory.

Studies were performed on the distal, electrode-containing segments of 120 electrophysiology catheters previously used in up to 10 clinical procedures. Catheter segments were immersed for 1 hour in blood infected with high titers of DHBV, BVDV, or CB3. After air drying for 2 hours, subgroups of 8 catheters were subjected to no treatment, washing in general-purpose detergent, washing in enzyme cleaner, sterilization in ethylene oxide, or the full protocol of sequential detergent-enzyme cleaner-ethylene oxide exposure. Presence of residual virus was assessed by nucleic acid detection and infectivity studies.

DHBV nucleic acid was detected on catheters after individual steps and the full protocol, whereas BVDV and CB3 nucleic acids were detected after individual steps but not the full protocol. These findings were associated with the presence of infectious DHBV and CB3, but not BVDV, on catheters after washing in detergent or enzyme cleaner. However, ethylene oxide alone or the full protocol reduced infectivity of all three viruses to undetectable levels.

These experimental studies provide strong evidence that appropriate cleaning and sterilization of reused electrophysiology catheters inactivates blood-borne viruses such as hepatitis B and C and Coxsackie type B3.

To assess the effect of a standard decontamination and sterilization protocol employed during reuse of cardiac electrophysiology (EP) catheters on human immunodeficiency virus (HIV).

Public health viral research laboratory.

Studies were performed on distal, electrode-containing segments of 40 EP catheters previously used in up to 10 clinical EP procedures. EP catheter segments were immersed for 1 hour in blood contaminated with a high titer of HIV. After air drying for 2 hours, subgroups of 8 EP catheters were subjected to either (1) no treatment, (2) washing in general purpose detergent, (3) washing in enzyme cleaner, (4) sterilization in ethylene oxide, or (5) the full protocol of sequential detergent-enzyme cleaner-ethylene oxide exposure. HIV infectivity after treatment was determined by measuring HIV RNA and, in cell culture studies, assessing HIV-induced cytopathic effects (CPEs) and supernatant HIV-specific p24 antigen content.

With no treatment, all catheters had high HIV RNA levels associated with CPEs and high p24 antigen levels. After washing in detergent, 5 of 8 catheters had HIV RNA detected, but without CPEs or p24 antigen. HIV RNA was detected in all catheters after washing in enzyme cleaner, with CPEs and a high p24 antigen level in 1 of 8 catheters. HIV RNA, CPEs, and p24 antigen were absent after ethylene oxide. After the full protocol, HIV RNA levels were undetectable (n = 7) or low (n = 1), without evidence of CPEs or p24 antigen.

Appropriate decontamination and sterilization of EP catheters during reuse is highly effective in inactivating HIV.