Association between ancillary services and clinical and behavioral outcomes among HIV-infected women.

The purpose of this study was to evaluate the association between ancillary services, including case management, and clinical and behavioral outcomes for human immunodeficiency virus (HIV)-infected women. Data were obtained from databases systematically maintained by Family Advocacy, Care and Education Services (FACES) and the HIV Outpatient Program (HOP) in New Orleans. HIV-infected women receiving primary care from HOP and ancillary services from FACES between January 1, 1997 and December 31, 1998 were eligible. Data were analyzed using generalized estimating equations (GEE) with STATA software. The majority of women included in the study were African American (86.7%), infected heterosexually (78.8%), and had absolute CD4 counts greater than 200 (58.6%). After adjusting for age, time, entry time into HOP, pregnancy, CD4 count, substance abuse status, and social and clinical stressors, receipt of more than four combined case manager contacts or ancillary services per month was significantly associated with being prescribed a protease inhibitor, improved adherence and retention in primary care, and enrolling on a research protocol. Receiving more than one transportation service per month was significantly associated with improved adherence, improved retention, one or more emergency room visits per month, and one or more hospitalizations per month. Receiving more than one contact with case managers per month was associated with improved retention in primary care. Findings suggest that receipt of case management and ancillary services is associated with improvements in multiple outcomes for HIV-infected women. A client-centered approach to providing ancillary services appears to be effective in improving behavioral and utilization characteristics in this population of low-income, high-risk women.

A simplified model for predicting malaria entomologic inoculation rates based on entomologic and parasitologic parameters relevant to control.

Malaria transmission intensity is modeled from the starting perspective of individual vector mosquitoes and is expressed directly as the entomologic inoculation rate (EIR). The potential of individual mosquitoes to transmit malaria during their lifetime is presented graphically as a function of their feeding cycle length and survival, human biting preferences, and the parasite sporogonic incubation period. The EIR is then calculated as the product of 1) the potential of individual vectors to transmit malaria during their lifetime, 2) vector emergence rate relative to human population size, and 3) the infectiousness of the human population to vectors. Thus, impacts on more than one of these parameters will amplify each other's effects. The EIRs transmitted by the dominant vector species at four malaria-endemic sites from Papua New Guinea, Tanzania, and Nigeria were predicted using field measurements of these characteristics together with human biting rate and human reservoir infectiousness. This model predicted EIRs (+/- SD) that are 1.13 +/- 0.37 (range = 0.84-1.59) times those measured in the field. For these four sites, mosquito emergence rate and lifetime transmission potential were more important determinants of the EIR than human reservoir infectiousness. This model and the input parameters from the four sites allow the potential impacts of various control measures on malaria transmission intensity to be tested under a range of endemic conditions. The model has potential applications for the development and implementation of transmission control measures and for public health education.

The potential impact of integrated malaria transmission control on entomologic inoculation rate in highly endemic areas.

We have used a relatively simple but accurate model for predicting the impact of integrated transmission control on the malaria entomologic inoculation rate (EIR) at four endemic sites from across sub-Saharan Africa and the southwest Pacific. The simulated campaign incorporated modestly effective vaccine coverage, bed net use, and larval control. The results indicate that such campaigns would reduce EIRs at all four sites by 30- to 50-fold. Even without the vaccine, 15- to 25-fold reductions of EIR were predicted, implying that integrated control with a few modestly effective tools can meaningfully reduce malaria transmission in a range of endemic settings. The model accurately predicts the effects of bed nets and indoor spraying and demonstrates that they are the most effective tools available for reducing EIR. However, the impact of domestic adult vector control is amplified by measures for reducing the rate of emergence of vectors or the level of infectiousness of the human reservoir. We conclude that available tools, including currently neglected methods for larval control, can reduce malaria transmission intensity enough to alleviate mortality. Integrated control programs should be implemented to the fullest extent possible, even in areas of intense transmission, using simple models as decision-making tools. However, we also conclude that to eliminate malaria in many areas of intense transmission is beyond the scope of methods which developing nations can currently afford. New, cost-effective, practical tools are needed if malaria is ever to be eliminated from highly endemic areas.