Reduction of the body burden of PCBs and DDE by dietary intervention in a randomized trial.

Serum polychlorinated biphenyls (PCBs) in Anniston, AL, residents have been associated with hypertension and diabetes. There have been no systematic interventions to reduce PCB body burdens in Anniston or other populations. Our objective was to determine the efficacy of 15 g/day of dietary olestra to reduce PCBs in Anniston residents. Blood PCBs and 1,1-bis-(4-chlorophenyl)-2,2-dichloroethene were measured at baseline and 4-month intervals in a double-blind, placebo-controlled, 1-year trial. Participants with elevated serum PCBs were randomized into two groups of 14 and received potato crisps made with olestra or vegetable oil (VO). Elimination rates during the study period were compared with 5-year prestudy rates. Eleven participants in the olestra group and 12 in the VO group completed the study. Except for one participant in the VO group, reasons for dropout were unrelated to treatments. The elimination rate of 37 non-coplanar PCB congeners during the 1-year trial was faster during olestra consumption compared to the pretrial period (-0.0829 ± 0.0357 and -0.00864 ± 0.0116 year(-1), respectively; P=.04), but not during VO consumption (-0.0413 ± 0.0408 and -0.0283 ± 0.0096 year(-1), respectively; P=.27). The concentration of PCBs in two olestra group participants decreased by 27% and 25% during the trial. There was no significant time by group interaction in change from baseline. However, group main effects for total PCBs and PCB 153 were of borderline significance. This pilot study has demonstrated that olestra can safely reduce body burdens of PCBs and supports a larger intervention trial that may also determine whether reduction in PCBs will reduce the risk of hypertension and diabetes.

Multiple diagnostic techniques identify previously vaccinated individuals with protective immunity against monkeypox.

Approximately 50% of the US population received smallpox vaccinations before routine immunization ceased in 1972 for civilians and in 1990 for military personnel. Several studies have shown long-term immunity after smallpox vaccination, but skepticism remains as to whether this will translate into full protection against the onset of orthopoxvirus-induced disease. The US monkeypox outbreak of 2003 provided the opportunity to examine this issue. Using independent and internally validated diagnostic approaches with >or=95% sensitivity and >or=90% specificity for detecting clinical monkeypox infection, we identified three previously unreported cases of monkeypox in preimmune individuals at 13, 29 and 48 years after smallpox vaccination. These individuals were unaware that they had been infected because they were spared any recognizable disease symptoms. Together, this shows that the US monkeypox outbreak was larger than previously realized and, more importantly, shows that cross-protective antiviral immunity against West African monkeypox can potentially be maintained for decades after smallpox vaccination.