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The influence of host factors (tobacco use, dentition, bleeding gums, oral rinsing, nasal medications, and time since the last meal) on immunoglobulin G (IgG) concentration in oral fluids (OF) was determined by univariate and multivariate analysis. Significant differences in IgG concentration were found to be associated with human immunodeficiency virus (HIV) status (HIV antibody positive, +16.60 μg/ml, P = 0.0001), sex (female, +1.23 μg/ml, P = 0.004), dentition (+2.83 μg/ml, edentulous versus dentulous, P = 0.0001), bleeding gums (+6.35 μg/ml, P = 0.0001), and time since the last meal (+3.55 μg/ml, >6 h, P = 0.0001). These factors could impact diagnostic methods that rely on the immunoglobulin concentration in OF specimens.

Simian immunodeficiency viruses (SIVs) are primate lentiviruses that are morphologically similar and biologically related to human immunodeficiency viruses (HIVs)1–4. SIVs naturally infect some nonhuman primate species, such as African green monkeys and sooty mangabey monkeys, without causing immunodeficiency. In contrast, experimental SIV infection of other susceptible primate species, such as macaques, can cause chronic wasting syndromes and a disease similar to the human acquired immunodeficiency syndrome (AIDS)5–10. Because of the similarities between the human and nonhuman lentiviruses, SIV and its susceptible primate host have become the principal model for studying the pathogenesis of AIDS and developing . . .

We have developed a combination immunoblot (combi-blot) for simultaneous detection and differentiation of HIV-1 and HIV-2 antibodies using HIV-1 lysate and HIV-1 and HIV-2 synthetic peptide antigens in a single assay. Minimal modification in antigen strip preparation and no modification in assay procedure of the current HIV-1 Western blot protocol was required. Implementation of this combi-blot following the use of the combination HIV-1/-2 enzyme immunoassay would simplify the current HIV testing algorithm and increase the accuracy of HIV-2 surveillance.

The development and subsequent licensure by the U.S. Food and Drug Administration (FDA) of enzyme immunoassays (EIA) for human immunodeficrency virus (HIV) antibody provided a low-cost test that was well suited for diagnosis, mass screening of populations, and testing blood donations for HIV infection. Each year the number of tests performed as well as the number of laboratories performing tests increases in the United States, but programs for quality control (QC) of laboratory testing have not kept pace. Standard panels of serum for quality control and evaluation of EIA and western blot tests are not generally available. Quality control programs for serologic tests are crude compared to the sophisticated computer-driven programs used in clinical chemistry laboratories. In fact, some serology laboratories do no more than run the controls supplied by the kit manufacturer. Some serology laboratories, however, have adapted the QC procedures similar in design to those used for clinical chemistry to monitor testing for HIV infections. This chapter will describe these adaptations and recommend a simple and inexpensive system for quality control of HIV tests.

Persons infected with the human immunodeficiency virus (HIV) have a spectrum of clinical features, ranging from persons who are infected but appear completely healthy to those with rapid disease progression and mortality. All groups, regardless of clinical stage, possess several biologic indicators of viral infection or replication (Figure 5.1). These include viremia, antibodies against viral proteins, circulating viral proteins, and nonspecific markers such as neopterin, beta2-microglobulins, and T4 cell counts. A variety of immunologic tests currently exists for the detection of viral antibodies and protein antigens. These assays have permitted testing programs to protect the blood supply from infected units and to conduct seroprevalence surveys to define the epidemic. More recently, the presence or absence of viral and nonspecific markers have been used to predict the onset of clinical disease.

To identify cost-effective testing strategies for HIV-1 and HIV-2 infections, we evaluated different combinations of tests on serum specimens from 1134 consecutive patients attending tuberculosis treatment centers in Abidjan, Cote d'Ivoire. Virus-specific whole-virus enzyme-linked immunosorbent assay (WVE), Western blot (WB) and synthetic peptide enzyme-linked immunosorbent assay (SPE) were used in sequential fashion to determine the true prevalence of infection; 27% were reactive to HIV-1, 5% to HIV-2, and 10% to both viruses. Of 239 specimens positive on WB for both HIV-1 and HIV-2, SPE diagnosed 38% as HIV-1-reactive and 16% as HIV-2-reactive, while 46% remained reactive to both viruses. Using WVE or one of two rapid (5–10 min) mixed (HIV-1 and HIV-2) antigen tests (RMATs) as a screening test, followed by SPE as a supplemental test, gave results with sensitivity of 97.3–99.2%, specificity of 99.5–99.7%, and positive predictive value for diagnosing HIV infection of 99.4–99.6%, with important savings in time and reagent costs. SPE allows more specific distinction between HIV-1 and HIV-2 infections than WB, and could replace it as a supplemental test in many settings. WB may be required for specimens reactive on screening tests but negative on SPE, until sensitivity of the SPE is further evaluated. A mixed antigen screening test followed by SPE seems to be an efficient testing strategy for diagnosing HIV-1 and HIV-2 infections.

In Reply. —We agree with Dr Ryder's conclusion that "a positive EIA and indeterminate Western blot may be merely a false alarm." Oral mucosal transudate and blood HIV testing are subject to outcomes that are uncertain and require follow-up testing to arrive at a definitive result. When indeterminate HIV test results are interpreted by experts, inferences about true HIV status may be drawn from the magnitude of the EIA test signal and from the nature (viral vs nonviral) of individual Western blot bands. Thus, the tone of the message during counseling might differ depending on whether the test result is likely to be a false alarm or is distinctly worrisome. The predictive value of the "EIA component" of HIV testing may be of academic interest, but the clinically relevant factor is the full testing algorithm. Oral mucosal transudate testing never resulted in a false-positive outcome. Just as with blood, there are occasional

WITHIN the past year, the US Food and Drug Administration (FDA) has licensed two combined human immunodeficiency virus type 1 (HIV-1)/human immunodeficiency virus type 2 (HIV-2) enzyme immunoassays (EIAs) for screening donated blood and plasma. The FDA has also mandated that by June 1, 1992, US blood centers must implement testing for antibodies to HIV-2 in addition to testing for antibodies to HIV-1. Implementation of this policy and reports of HIV-2—infected US residents have raised important public health and clinical questions about HIV-2 infection in the United States. This article summarizes current information regarding the epidemiology and diagnosis of HIV-2 infection and discusses public health considerations that arise from the presence of HIV-2 in the United States. BACKGROUND: WORLDWIDE DISTRIBUTION, TRANSMISSION, AND NATURAL HISTORY Infection with HIV-2 is endemic in many countries in West Africa, but generally much rarer elsewhere in the world. 1,2 The highest prevalence of HIV-2 infection

A comparative study was made of the single radial immunodiffusion test and the classical quantitative precipitin test for determining the amount of precipitable antibodies present in streptococcal groups A and C antisera. The potency of 21 group A and 54 group C antisera was determined by both methods; purified group-specific carbohydrates were used as antigens. The coefficient of correlation between the results from the two methods was 0.976 for group A antisera and 0.946 for group C antisera. When the concentration of antigen, the volume of antiserum used, and the depth of the antigen-agar mixture are kept constant, the diameter of the precipitin disc is directly related to the concentration of precipitable antibodies present in the antiserum. The use of the radial immunodiffusion test for evaluating and standardizing streptococcal grouping antisera is discussed as well as the advantages and disadvantages of using a concentrated vaccine for producing these antisera.

To determine risk factors for HIV infection among abandoned Romanian infants and children living in a public institution.A cross-sectional study was conducted in June 1990 among 101 children between 0 and 4 years of age living in an orphanage. Orphanage and hospital records were reviewed and a blood specimen for hepatitis B and HIV serologic testing obtained from each child. A case-control study was conducted using data from the cross-sectional study. Cases were HIV-positive children; one HIV-negative control, matched by age, was selected for each case.Overall, 20 (20%) children were HIV-positive, 88 (87%) tested positive for antibody to hepatitis B core antigen, and 32 (32%) were hepatitis B surface antigen-positive. In the case-control study, HIV-positive children had received more therapeutic injections [mean, 280; median, 231] than age-matched HIV-negative children [mean; 142, median, 155; P = 0.02]. Cases were more likely than controls to have received over 200 lifetime injections (odds ratio, 5.7; 95% confidence interval, 1.2-32.7). Blood transfusions and mother-to-child transmission were excluded as routes of HIV transmission. By reviewing sterilization records and interviewing local health-care workers, we determined that needles and syringes were often re-used without proper disinfection in the orphanage.These data provide strong epidemiologic evidence that indiscriminate injections with contaminated needles and syringes were responsible for HIV transmission in this population.