Arbovirus surveillance in South Carolina, 1996-98.

Arboviruses isolated and identified from mosquitoes in South Carolina (USA) are described, including new state records for eastern equine encephalitis virus (EEE), St. Louis encephalitis virus (SLE), Flanders virus, Tensaw virus (TEN), and a variant of Jamestown Canyon virus (JC). Mosquitoes were collected at 52 locations in 30 of 46 South Carolina counties beginning in June 1996, and ending in October 1998, and tested for arboviruses. Of 1,329 mosquito pools tested by virus isolation (85,806 mosquitoes representing 34 mosquito species or complexes), 15 pools were positive. Virus isolations included EEE from 1 pool each of Anopheles crucians complex and Culex erraticus; a variant of JC from 1 pool of An. crucians complex; a California serogroup virus from 1 pool of Aedes atlanticus/tormentor; TEN from 5 pools of An. crucians complex and 1 pool each of Culex salinarius and Psorophora ciliata; Flanders virus from 1 pool of Culiseta melanura; and Potosi virus from 1 pool each of Aedes vexans, Coquillettidia perturbans, and Psorophora columbiae. Of 300 mosquito pools tested by antigen-capture assay for EEE and SLE (14,303 mosquitoes representing 16 mosquito species or complexes), 21 were positive for EEE and I was positive for SLE. Positive EEE mosquito pools by antigen-capture assay included An. crucians complex (14 pools), Anopheles punctipennis (1 pool), Anopheles quadrimaculatus (1 pool), Cq. perturbans (4 pools), and Cs. melanura (1 pool). One pool of Cx. salinarius was positive for SLE by antigen-capture assay. Arbovirus-positive mosquito pools were identified from 12 South Carolina counties, all located in the Atlantic Coastal Plain, and from 4 of 8 Carolina bays surveyed.

Early retirees under Social Security: health status and economic resources.

Some proposals to change the Social Security program to ensure long-run solvency would reduce or eliminate benefits for early retirees. This article documents the health and financial resources of Old-Age and Survivors Insurance (OASI) beneficiaries aged 62-64. It identifies a substantial minority of early retirees who might be economically vulnerable if either the early eligibility age or normal retirement age was raised. Attention is directed at the extent to which poor health limits work in this age group and the extent to which curtailment of early OASI benefits might lead to increases in the Disability Insurance (DI) program rolls. Using a set of comprehensive health measures, we estimate that over 20 percent of OASI beneficiaries aged 62-64 have health problems that substantially impair their ability to work. This finding implies that in this age range, as many severely disabled persons receive OASI benefits as disability benefits. In fact, 12 percent of early beneficiaries would meet a more stringent criterion for being classified "disabled"--SSA's medical standard for disability benefits. The evidence therefore indicates that OASI functions as a substantial, albeit unofficial, disability program for early retirees. Compared with those who have no health problems or are less severely impaired, early OASI beneficiaries who meet the medical criteria for disability benefits are more likely to be living alone and more likely to be poor or "near poor." The great majority of the group--almost 80 percent--are women. Analysis of their earnings histories suggests that most of these beneficiaries do not satisfy the insured-status requirements for Disability Insurance benefits. The article considers the different roles of the OASI program and the DI program for health-impaired individuals aged 62-64. Disability modelers sometimes overlook an important aspect of program administration. Under customary screening procedures implemented in Social Security field offices, applicants for early OASI benefits who appear to be severely impaired simultaneously apply for DI benefits if they are disability insured. If they are found eligible for DI benefits, those applicants become DI beneficiaries. The implication is that raising the earliest entitlement age would have little impact on the DI rolls. Unless there are changes in eligibility criteria, the DI program would not serve as a safety net for many of the most severely disabled early retirees.

Modeling SSA's sequential disability determination process using matched SIPP data.

We model the Social Security Administration's (SSA's) disability determination process using household survey information exact matched to SSA administrative information on disability determinations. Survey information on health, activity limitations, demographic traits, and work are taken from the Survey of Income and Program Participation (SIPP). We estimate a multistage sequential logit model, reflecting the structure of the determination procedure used by State Disability Determination Services agencies. The findings suggest that the explanatory power of particular variables can be appropriately ascertained only if they are introduced at the relevant stage of the determination process. Hence, as might be expected by those familiar with the process, medical variables and activity limitations are major factors in the early stages of the process, while past work, age, and education play roles in later stages. The highly detailed administrative information on outcomes at each stage allows clarification of the roles of particular variables. Planned future work will include policy estimates, such as the number of persons in the general population eligible for the disability programs, as well as analysis of applications behavior in a household context.

Exploring the use of the public's views to set income poverty thresholds and adjust them over time.

This study considers how the views of the public at large may be used to define the poverty income level. The basic data for the study come from routine Gallup surveys conducted since the beginning of the post-World War II period that asked representative samples of adults in the United States to estimate the smallest amount of money that a family of four needs to "get along." Additional Gallup surveys undertaken in 1989 established the income corresponding to the poverty level using a similar approach. The author constructs a set of poverty thresholds, covering the post-World War II period, based on the single point-in-time poverty/get-along income relationship in 1989 and the full get-along series. Comparison of this set of thresholds with an alternative poverty series that is consistent with the Federal Government's official poverty measure yields three principal findings: (1) a poverty level consistent with the official measure was a good deal higher than the Gallup-based poverty threshold in the immediate post-World War II period, (2) the income level of the official measure was likely consistent with the public's views about the poverty level at the time when the official measure was introduced, and (3) since the late 1960's and the early 1970's, the income level of the official measure has fallen increasingly below the Gallup-based poverty threshold until 1989 when the official measure was 20 percent below the Gallup series. It is suggested that the two series have diverged over time because the views of the public about poverty level income have responded to increases in real income that have occurred since World War II while the official measure has remained fixed in real terms.

Income, assets, and health insurance: economic resources for meeting acute health care needs of the aged.

In this article, the authors use data from the Survey of Income and Program Participation (SIPP) to examine the relationship between economic resources and acute health care needs among the aged. The circumstances of individuals who rely on Medicare as their only form of health insurance are considered in detail because they are potentially more vulnerable when faced with health care expenses. Particular attention is given to the amount of family income and personal contingency assets held by this group and the level of out-of-pocket liability for acute care they might have been expected to face in 1984. The authors point out that their research findings would be strengthened by linkage of a more current SIPP data set to Medicare program records and the development of Medicaid eligibility simulation capability in the SIPP context.

Development and evaluation of a survey-based type of benefit classification for the Social Security program.

This attempt to classify Social Security beneficiaries by type of benefit using the new Survey of Income and Program Participation (SIPP) has yielded promising results. Evaluations of the classification algorithm based on comparison of the estimated number of beneficiaries in each of the several categories to independent estimates of the number of beneficiaries indicate that in most instances a high percentage of each category has been identified. For the most part, age and monthly benefit amount size distributions seem reasonable. Furthermore, very few persons in the sample who were identified as Social Security beneficiaries could not be assigned to one or another of the benefit groups. The classification procedure also represents a marked improvement over earlier efforts to classify type of beneficiary that relied on data from the March Supplement to the Current Population Survey (CPS). Most importantly, the benefit classification scheme based on SIPP data appears to provide reasonably reliable distinctions between retired-worker and widow benefits for widowed women and permits the identification of retired-worker benefits for those women dually entitled to retired-worker and spouse benefits. In addition, the distinction between disabled- and retired-worker benefits for recipients aged 62-64 appears to be reasonably reliable, and for women under age 65, the classification procedure distinguishes between disabled-worker benefits on the one hand and widow and widowed mother benefits on the other. Finally, SIPP procedures for identifying minor child beneficiaries yield markedly better estimates than those available from the Current Population Survey. These improvements in the SIPP context are due entirely to the presence of information not collected in the CPS. The enhancement of the SIPP data set in turn resulted directly from an assessment of earlier work carried out by Projector and Bretz in the CPS context and on extensive research into the nature of Social Security reporting errors in the CPS. The superiority of the SIPP data set is linked principally to the presence of three pieces of information: the Medicare BIC, the direct question on reasons for benefit receipt asked of persons under age 65, and the direct measurement of recipiency and amount of benefits for minor children. Other items of some import include self-reported work disability, retirement status (ever retired from a job), previous marital status for currently married women, age first prevented from working due to a health condition, and Supplemental Security Income misreporting items.(ABSTRACT TRUNCATED AT 400 WORDS)

Antibiotic identification by high voltage electrophoresis bioautography.

The high voltage electrophoresis bioautography method is applicable to meat, milk, and animal feeds. Meat is freeze-dried, powdered, and extracted with acetonitrile-water (9 + 1), and the extract is concentrated by evaporation at room temperature. Milk is examined directly or following acetonitrile-water extraction. Feed is extracted with acetonitrile-water. Samples or extracts are applied to preliminary assay plates of antibiotic medium No. 1 at pH 6 and 8, seeded with Micrococcus luteus (ATCC 9341), M. luteus DHSR (ATCC 9341A), Bacillus cereus (ATCC 11778), or B. cereus K250 TR (NCIB 11183), and nutrient agar at pH 7 seeded with B. subtilis BGA. Inactivation of penicillinase indicates beta-lactam antibiotics. Addition of trimethoprim increases sensitivity to sulfonamides. After 18-24 h incubation at 30 degrees C, plates yielding clear inhibition zones guide selection of conditions for subsequent electrophoresis bioautography. Extracts are applied (5-100 microL) to 10 mm diameter wells on electrophoresis plates 60 cm long and 40 cm wide, with a gel depth of 1.6 mm. The support medium is 1% agar and 1% agarose in Tris/succinic acid buffers pH 6 and pH 8. A potential of 1500 V is applied for 1.5 h at 15 degrees C. Following electrophoresis, the migrated antibiotics are visualized by over-layering with antibiotic medium No. 1, pH 6 or 8, seeded with M. luteus or B. cereus spore suspension; plates are incubated for 18-24 h at 30 degrees C. Identification is based on results of preliminary screening together with electrophoretic migration distances and inhibition zone appearances compared with standards.