Pesticide concentrations in Arkansas breast milk.

During an episode of pesticide dairy product contamination in Arkansas in 1986, breast milk samples from 942 women were analyzed for concentrations of chlorinated pesticides. The pesticides found most frequently in quantifiable concentrations were p,p'-DDE (100%), oxychlordane (84%), trans-nonachlor (77%), heptachlor epoxide (74%) and beta-HCH, an isomer of lindane (27%). The pesticides present in highest mean concentrations of all samples analyzed (reported as ppm in milk fat) were p,p'-DDE (0.952 ppm), trans-nonachlor (0.062 ppm), oxychlordane (0.051 ppm), heptachlor epoxide (0.045 ppm), p,p'-DDT (0.039 ppm), and beta-HCH (0.032 ppm). These concentrations are lower than previous reports from similar regions of the US. However, continued persistence in human breast milk is of concern due to potential adverse health effects from these chemicals.

Overview of the role of mupirocin.

Mupirocin is a novel antibiotic, for topical use only, which is unrelated in chemical structure and mode of action to any known class of antibacterial agent. It is active against a wide range of Gram-positive bacteria, including staphylococci and most streptococci, and is moderately active against Gram-negative bacteria. Mupirocin 2% ointment applied 2 or 3 times daily has demonstrable efficacy for the treatment of both primary and secondary skin infections and compares favourably with other topical and systemic treatments. In clinical studies, both elimination of the bacterial pathogen and clinical cure or improvement has been usual in over 90% of patients. Up to 40% of the normal population carry Staphylococcus aureus in the anterior nares and this carriage rate is often increased in hospitalized patients and their attendants. The increasing incidence of multiply- and methicillin-resistant S. aureus (MRSA) has been associated with hospital outbreaks leading to considerable morbidity and disruption of hospital services. Intranasal 2% calcium mupirocin has been shown to be effective in the eradication of nasal carriage; in bacteriologically controlled studies elimination of S. aureus, including MRSA, was achieved in over 95% of subjects. The role of mupirocin in preventing staphylococcal infection is currently undergoing evaluation.

The efficacy of calcium mupirocin in the eradication of nasal Staphylococcus aureus carriage.

In an open, non-comparative clinical study conducted at 102 hospitals in the UK and Ireland, 1,510 subjects were treated with 2% calcium mupirocin in a white soft paraffin/Softisan 649 base (Bactroban 'Nasal') during hospital outbreaks of methicillin-resistant Staphylococcus aureus (MRSA). In most subjects treatment was applied two or three times daily to both anterior nares for three to eight days. Of the 766 assessable subjects, nasal carriage of S aureus was cleared in 744 (97.1%). Initially, MRSA was present in 628 cases (79.4%), and the organism was eliminated in 609 of these (97.0%). Isolates of S aureus were tested for susceptibility to a variety of antibiotics by disc test: of 523 nasal isolates tested against mupirocin, 516 (98.7%) were sensitive. Treatment was very well tolerated. Adverse events were reported by 22 subjects (1.5%); these were mostly mild local effects and necessitated withdrawal of treatment only in three subjects. The results indicate that topical calcium mupirocin is a highly effective and well tolerated treatment for the eradications of nasal carriage of S aureus, including MRSA.