Elevated oxidase and esterase levels associated with permethrin tolerance in Anopheles gambiae from Kenyan villages using permethrin-impregnated nets.

The permethrin tolerance (PT) of a population of the mosquito Anopheles gambiae (Diptera: Culicidae) increased following the introduction of permethrin-impregnated nets for malaria control in certain villages near Kisumu, western Kenya. Using a biochemical test that indirectly measures oxidases associated with permethrin resistance, we found that this population had higher oxidase levels than a comparison population from villages without impregnated nets. Mosquitoes from a colony of An. gambiae selected for PT, the RSP (reduced susceptibility to permethrin) strain, were exposed to permethrin with or without the oxidase inhibitor piperonyl butoxide (PB). Significantly higher mortality rates occurred when permethrin was synergized by PB, presumably by suppression of oxidases responsible for PT. An unselected (UNS) colony of An. gambiae that was more susceptible than RSP in a permethrin-susceptibility bioassay (i.e. LT50 22 min for UNS, vs. 42min for RSP) was compared with the RSP colony for levels of oxidases and esterases. The levels of both enzymes were very significantly higher in the RSP strain (P<0.0001). We speculate that use of impregnated nets selected for higher oxidase and esterase levels in An. gambiae to metabolize permethrin acquired from the nets. Both oxidase and esterase mechanisms could confer cross-resistance to other pyrethroids.

Independent selection of multiple mechanisms for pyrethroid resistance in Guatemalan Anopheles albimanus (Diptera: Culicidae).

Isofemale lines were established containing either, both, or neither of the elevated esterase and oxidase resistance mechanisms conferring pyrethroid resistance in a Guatemalan strain of Anopheles albimanus (Wiedemann). Plots of esterase and oxidase levels for individual mosquitoes from these single families correlated with data obtained using oxidase and esterase synergists in bioassays run in the bottle format. Mixed populations of pyrethroid-resistant A. albimanus adult females were selected using DDT, permethrin, or malathion; and the esterase and oxidase levels of the individual progeny were plotted. These data showed that the 3 classes of insecticide selected the 2 mechanisms differently. These results are discussed in terms of the problem of multiresistance surveillance in the field, especially concerning pyrethroid insecticides and the interaction of agricultural and public health insecticide application.

Insecticide resistance and vector control.

Insecticide resistance has been a problem in all insect groups that serve as vectors of emerging diseases. Although mechanisms by which insecticides become less effective are similar across all vector taxa, each resistance problem is potentially unique and may involve a complex pattern of resistance foci. The main defense against resistance is close surveillance of the susceptibility of vector populations. We describe the mechanisms of insecticide resistance, as well as specific instances of resistance emergence worldwide, and discuss prospects for resistance management and priorities for detection and surveillance.

Simplification of adult mosquito bioassays through use of time-mortality determinations in glass bottles.

A simple method is described for treating 250-ml glass Wheaton bottles with insecticide, and using them as test chambers for detecting insecticide resistance in mosquito and sandfly populations. The methods for treating bottles, obtaining baseline data, and applying this technique to insects from the field are described. Sample data are presented from tests run on different vector species using a variety of insecticides. Time-mortality data from the bottle bioassay are presented alongside results from biochemical detection methods applied to the same mosquito population. The potential role, advantages, and limitations of the time-mortality bottle method are discussed.

Heme peroxidase activity measured in single mosquitoes identifies individuals expressing an elevated oxidase for insecticide resistance.

Optimum conditions are described for a simple, rapid, microplate-based assay that indirectly measures the differences in oxidase levels between individual susceptible, resistant, or induced mosquitoes. A small proportion (0.01-0.1) of a single mosquito is used, allowing multiple replicates of the oxidase assay. Cytochrome C is used as a positive control. The levels of oxidase found in sample populations of pyrethroid-susceptible, pyrethroid-resistant, and phenobarbital-induced Anopheles albimanus mosquitoes are characterized with the assay.

Task analysis of home care pharmacy.

The demographics of home care pharmacists and the frequency and perceived importance of home care pharmacy tasks were studied. Two questionnaires were mailed in August 1994 to each of 1420 sites that provide home care pharmacy services. Home care pharmacists were asked to provide information on themselves and their companies and to rate 47 home care pharmacy tasks (administrative, clinical, distributive, and miscellaneous) on how often they are performed as part of the job and how essential they are for successful job performance. Of the 2840 surveys mailed to the 1420 sites, questionnaires for 87 sites were not deliverable, leaving an adjusted gross sample of 1333 sites. A total of 393 usable questionnaires were received from 326 sites (net site response rate 24.5%). Respondents tended to be male, have a B.S. degree only, and have more than six years' home care experience. The most commonly identified type of employer was an independent company. Some 34% of respondents said their company had only 1 site; another 33% stated more than 50 sites. Forty-three percent of locations had 2 pharmacist full-time equivalents. Distributive tasks had the highest frequency scores; clinical tasks were performed second most frequently. Distributive and clinical tasks also received high importance scores. The data suggests that, despite other demands on their time, home care pharmacists give considerable attention to tasks consistent with pharmaceutical care. A survey of home care pharmacists provided baseline information on demographics and the frequency and perceived importance of specific tasks.

Reservoir competence of Alphitobius diaperinus (Coleoptera:Tenebrionidae) for Escherichia coli (Eubacteriales:Enterobacteriaceae).

Larval and adult lesser mealworms, Alphitobius diaperinus (Panzer), were found to harbor a Congo red-binding strain of Escherichia coli (Migula) Castellani & Chalmers both on the external surface of their body and internally for 12 d. Thereafter, E. coli was not detected, even though the beetles were exposed continuously to a food source inoculated with the bacteria. Lesser mealworm larvae and adults discharge E. coli bacteria in their feces for up to 6 and 10 d, respectively. However, bacteria were no longer detected in their feces after larvae underwent a single molt to the next larval stage. This indicated there was no transstadial transmission of this strain of E. coli. Consumed infected larvae were found to cause more 1-d-old chicks to have positive cloacal swabs for Congo red-binding E. coli than consumed infected adults. The data indicated that the lesser mealworm may play a role in the direct transmission of E. coli and contribute to the spread of this bacteria in broiler production systems. This may be achieved by beetles being directly consumed by chickens or indirectly by spread of the bacteria throughout the broiler house by lesser mealworm feces.

Collaborating with re-engineering consultants: maintaining resources for the future.

The negotiations of a pharmacy department with a consulting firm hired to help cut the institution's staff are described. In July 1994 Duke University Medical Center announced its intention to reduce the number of full-time equivalents (FTEs) from 6500 to 5000 and hired a consulting firm. The pharmacy department was scheduled to be studied for 16 weeks. The entire pharmacy staff was educated about the initiative and about what management expected of the staff during the process. Each assistant director of pharmacy was asked to lead the "operations improvement process," as the re-engineering plan was called, in his or her area of responsibility. The assistant directors were to describe key work activities and their time requirements and develop instruments for measuring work activities. Data were collected on supplemental resource requirements for paid time off and educational and meeting time. Resource requirements for clinical pharmacy specialists and other selected staff members were determined separately. The data were collected for one fiscal month, and the assistant directors then began negotiating human-resource requirements with the consultants. The director finalized the negotiations and presented the results to the hospital's leaders and the consulting firm's executives. It was proposed to reduce total pharmacy FTEs by only 5%, and the department actually gained 1 pharmacist FTE. Far greater reductions were proposed for most other departments (the entire medical center lost more than 800 FTEs). The pharmacy department at Duke dealt successfully with a re-engineering initiative. Strategies that contributed to the success included teamwork, active participation by the entire staff, empowering a core group to help lead in the process, and substantiating the value of the pharmacy's services to the medical center and its patients.

Isolation of infectious bursal disease virus from the lesser mealworm, Alphitobius diaperinus (Panzer).

Infectious bursal disease virus (IBDV) was isolated from adult lesser mealworms, Alphitobius diaperinus (Panzer), up to 14 d after exposure, but isolation of the virus was erratic over this period of time. The virus was undetected after 24 h in beetle larvae. Virus was isolated from the adult beetle's mouth parts, foregut, midgut, hindgut, and blood 24 h after they fed on feed inoculated with IBDV. Ten days after exposure, virus was isolated from the foregut but not the blood, mouth parts, or remaining digestive tract of the adult beetles. The adult lesser mealworm is capable of serving as a reservoir for IBDV, rather than a fomite, between broiler growouts.

The treatment of progressive coxa vara in children with bone softening disorders.

Fractures of the proximal femur frequently occur in children with osteogenesis imperfecta or fibrous dyplasia and may lead to progressive coxa vara and a "shepherds crook" deformity. We have found existing methods of fixation of the femoral neck in small children to be unsatisfactory. We have devised a method of fixation using a small signal arm nail. With a mean follow-up of 9.3 years there was a successful outcome in all 11 hips treated.

Reservoir competence of the lesser mealworm (Coleoptera: Tenebrionidae) for Salmonella typhimurium (Eubacteriales: Enterobacteriaceae).

The reservoir competence of the lesser mealworm, Alphitobius diaperinus (Panzer) is reported for Salmonella typhimurium (Loeffler) relative to broiler chicken production. Salmonella typhimurium was isolated from feces of the adult lesser mealworm at least 28 d after feeding for 24 h on 1 g of chicken feed inoculated with 3 x 10(8) bacteria/ml. All larvae fed S. typhimurium ceased voiding the bacteria in their feces before pupal molt, except one. One beetle continued to void S. typhimurium after it emerged as an adult, providing evidence that transstadial transmission of S. typhimurium may occur. The bacteria were found both on the external body surface and inside the body of surface-sterilized adults and larvae during 16 d of exposure. Salmonella-positive cloacal swabs were obtained from 1-day-old broiler chicks within 24 h after eating one infected lesser mealworm adult or larva.

What should a pharmacy manager do when a serious medication error occurs? A panel discussion.

Questions related to medication errors were discussed by a panel of hospital department managers. When a serious medication error occurs, the manager has a responsibility to help the employee, the patient, and the patient's family cope with its effects, as well as a responsibility to prevent such errors from recurring. The difficulty of dealing with medication errors may be compounded when the legal system and the news media get involved. Therefore, a system for handling a serious error should be in place before that error occurs. It is also necessary to decide whether to use medication error reports in the employee evaluation process; this could make employees reluctant to report their errors. Ultimately, pharmacy managers are responsible for medication errors that occur, and repercussions have varied from nothing to reprimands to termination. Past errors, if they are reported, can be used to improve the system in which they occurred and to educate other health-care professionals. Therefore, pharmacists need to cooperate with other health-care professionals in documenting medication error reports. A national reporting system is needed so that medication error information can be shared on a large scale without placing the people involved in legal jeopardy. Sharing information about medication errors is necessary to prevent future occurrences; mechanisms are needed to facilitate such sharing.

Pharmacist's role in home i.v. therapy.

The pharmacist's role in home i.v. therapy is described, and its relationship to the Medicare Catastrophic Coverage Act is discussed. Congress, in enacting the catastrophic coverage act, has recognized the need for pharmaceutical services in the provision of home i.v. therapy. Pharmacists must recognize their responsibilities in providing these services. These responsibilities include ensuring the quality of drug therapy, monitoring patient progress, advocating cost-effective therapy, and communicating with local health-care providers. Pharmacists should also educate hospital administrators about the effects of the act, suggest how the hospital can best provide home i.v. therapy, assume responsibility for overseeing the home i.v. therapy process, and help ensure compliance with the interpretive regulations of the act. Other responsibilities of pharmacists include educating potential beneficiaries about the need to pay the coinsurance and premiums for catastrophic coverage and advocating home i.v. therapy as a reasonable alternative to hospitalization. Pharmacists should become familiar with the Standards for the Accreditation of Home Care adopted by the Joint Commission on Accreditation of Healthcare Organizations because these standards may be considered when the conditions for provider participation are established by the Department of Health and Human Services. The home i.v. therapy provision of the catastrophic coverage act presents challenges for pharmacists. Appropriate pharmacist involvement should help reduce costs and ensure optimal health care.