Nonadherence to medical appointments is associated with increased plasma HIV RNA and decreased CD4 cell counts in a community-based HIV primary care clinic.

This study examined the association of appointment nonadherence to markers of disease severity using one year of demographic and health information on 995 individuals with HIV in primary care at an urban community health centre. At the latest visit, 106 of 946 valid cases (11.2%) had a CD4 less than or equal to 200, and 454 of 936 valid cases (48.5%) had detectable plasma HIV RNA (greater than 50 copies/ml). Using logistic regression, appointment nonadherence (number of missed appointments) was a significant predictor (p < .03) of having an AIDS-defining CD4 count over and above the effects of number of kept appointments (p < .0001), and whether or not the patient was taking HAART (p < .002). Appointment nonadherence was also a significant predictor (p < .05) of having a detectable viral load over and above the effects of number of kept appointments (p < .003), HAART (p < .0001) and age (p < .004). Looking only at individuals with a detectable viral load at the earliest visit, the only significant unique predictor of improvement to an undetectable viral load at the latest visit was being on HAART (p < .05). Looking at those only with an undetectable viral load at the earliest visit, the only predictor of declining to a detectable viral load was number of kept appointments (p < 003), and being on HAART (p < .05).

Polychlorinated naphthalenes and polychlorinated biphenyls in benthic organisms of a Great Lakes food chain.

Invasion of zebra mussels, Dreissena polymorpha, and round gobies, Neogobius melanostomus, into the Great Lakes has altered the food web structure and thereby the pathways of toxic contaminants such as polychlorinated biphenyls (PCBs) and polychlorinated naphthalenes (PCNs). In this study, concentrations of PCNs and PCBs were measured in organisms of a Great Lakes benthic food chain encompassing zebra mussels. PCNs were found in all of the benthic organisms, including phytoplankton, algae, amphipods, zebra mussels, round goby, and smallmouth bass, Micropterus dolomieui. Concentrations of PCNs were greater in samples collected from the Raisin River than in samples from the St. Clair River. Biomagnification factors (BMF) for tetra- through octa-CN congeners in going from algae to zebra mussels from the St. Clair River ranged from 3 to 10. No major biomagnification of PCNs was found in round gobies, when concentrations were related to those in their prey species, zebra mussels. The biomagnification potential of PCNs appears to be similar to that of PCBs in the benthic food chain investigated in this study, despite the fact that PCNs may be metabolized by organisms higher in the food chain. Among several congeners, the BMFs of PCN congeners 35, 42, 43/45, 52/60, 58, and 66/67 were highest in round gobies. PCNs accounted for 1-22% of the total TEQs (toxic equivalents) of PCBs and PCNs in benthic organisms analyzed in this study. PCB congener 126 was the major contributor to TEQs, accounting for 72-99% of the PCB-TEQs in the food chain organisms analyzed.

New strategies for the control of the parthenogenetic chironomid (Paratanytarsus grimmii) (Diptera:Chironomidae) infecting water systems.

Control of the midge, Paratanytarsus grimmii, infesting municipal water systems has proven to be difficult, because it is a parthenogenetic species that can oviposit as a pharate adult and reproduce within the system. Mean densities of P. grimmii in a midwestern USA water distribution system ranged from approximately 140 to 560 individuals/sampling date, and all 4 instars and pupae were present throughout the sampling period. Two products were tested as potential chemical controls: Cat-Floc LS, a coagulant produced by the Calgon Corporation, and 35% hydrogen peroxide, a water purifier. The results of laboratory bioassays showed that Cat-Floc LS over a 15-day period was most effective against P. grimmii.