Lead levels in blood bank blood.

Although blood bank blood is usually screened for dangerous pathogens, the presence of toxic metals in blood has received little attention. Population blood lead levels have been declining in the United States, but occasional high outliers in blood lead concentration can be found--even when mean levels of blood lead are low. We sampled 999 consecutive blood bank bags from the King/Drew Medical Center, used between December 1999 and February 2000. The geometric mean blood lead level was 1.0 microg/dl (0.048 micromol/l), but 0.5% of the samples had lead levels that exceeded 10 microg/dl, and 2 samples had lead levels that exceeded 30 microg/dl. The 2 samples with the highest lead levels could have presented an additional risk to infants if they were used for blood replacement. Therefore, even in countries with generally low population blood lead levels, blood bank blood should be screened for lead concentration prior to use with infants.

Molecular epidemiology of HIV-1 infection in the Philippines, 1985 to 1997: transmission of subtypes B and E and potential emergence of subtypes C and F.

The molecular epidemiology of HIV-1 infection in the Philippines from 1985 to 1997 was investigated following subtyping of 54 (33 women, 21 men) prospectively collected clinical specimens using the heteroduplex mobility assay (HMA). In contrast with other Asian countries, subtype B accounted for most (70%) of the infections in the population studied, among female commercial sex workers (CSWs, 18 of 28), overseas contract workers (OCWs, 7 of 10), and men who have sex with men (MSM, 8 of 10). However, although viral specimens from HIV-seropositive persons diagnosed before 1993 (n = 16) were all of subtype B, diagnoses in more recent years (1993-present, n = 38) indicate the existence of subtypes E (29%), F (8%), and C (5%) in the population. Since its estimated introduction in the early 1990s, subtype E has accounted for 60% of the infections among female CSWs diagnosed after 1992 (n = 15). This genotype distribution shift occurred in parallel with a shift in transmission focus from the U.S. military bases to the the Philippine national capital region. So far, both events appear to have had no significant effect on the stability of HIV-1 transmission in the country. The recent identification of non-B subtypes in the Philippines may present novel insights on the dynamics of HIV-1 transmission in a high-risk but low-HIV prevalence setting in Asia.