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Research has demonstrated that oral mucosal transudate (OMT), a serum-derived fluid that enters saliva from the gingival crevice and across oral mucosal surfaces, can be preferentially concentrated by a novel collecting system to yield detectable levels of immunoglobulins (i.e., IgG and IgM antibodies) against various bacterial and viral diseases. Assays based on OMT can aid in the diagnosis of disease and in the management of therapeutic drugs. A reliable and accurate OMT-based test to detect human immunodeficiency virus (HIV) antibodies is commercially available. Additional tests based on similar technologies may aid in the diagnosis of viral hepatitis, measles, mumps, and rubella as well as in monitoring levels of therapeutic drugs such as theophylline. The future use of OMT-based testing will likely increase because of the inherent advantages of this technology: convenience; avoidance of inadvertent transmission of blood-borne pathogens; ease of use in pediatric and geriatric populations; as well as the potential for blood-free home and workplace collection of patient samples.

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 . . .

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

Objective. —To determine accuracy of a human immunodeficiency virus type 1 (HIV-1) antibody testing system using a device to collect and stabilize oral mucosal transudate (OMT), a fluid with increased levels of IgG; an enzyme immunoassay (EIA) screening test optimized for OMT; and a Western blot confirmatory test designed for use with OMT. Design. —The OMT specimens were tested by EIA and, if indicated, confirmatory Western blot according to a standard testing algorithm. The OMT results were compared with true HIV status as determined by serum testing and/or clinical diagnosis. Patients. —Specimens from 3570 subjects (2382 at low risk, 698 at high risk, 242 with acquired immunodeficiency syndrome [AIDS], and 248 "nonspecificity" [persons with diseases associated with an increased frequency of false-positive results in HIV testing]) were collected at 11 geographically diverse sites (including blood banks, public health clinics, general medical clinics, HIV clinics, sexually transmitted disease clinics, and a hemophilia center) in the United States. Main Outcome Measures. —Overall accuracy of testing OMT for HIV-1 antibodies compared with true HIV-1 antibody status; sensitivity and specificity of OMT EIA and Western blot. Results. —Sensitivity of OMT EIA testing in 673 true-positive subjects was 99.9% (672/673). The OMT Western blot results in the 673 true-positive subjects were positive in 665 and indeterminate in 8. The EIA followed by Western blot (if EIA was repeatedly reactive) yielded a negative result in 99.9% (2893/2897) of OMT samples from true negatives and an indeterminate result in 4. The OMT testing system provided the correct result or would trigger appropriate follow-up testing in 3569 (>99.9%) of 3570 cases. Conclusion. —HIV-1 antibody testing of OMT samples is a highly accurate alternative to serum testing.

Objective. —To compare mother-to-child transmission of human immunodeficiency virus types 1 and 2 (HIV-1 and HIV-2, respectively) and to assess the impact of maternal HIV-1 and HIV-2 infections on child survival. Design. —Prospective cohort study. Setting. —Maternal and child health center in a lower socioeconomic class district of Abidjan, Ivory Coast. Participants. —A total of 18 099 women delivering between 1990 and 1992 were tested for HIV-1 and HIV-2 antibodies. A cohort of 613 pregnant women and their infants was followed prospectively (138 women reactive to HIV-1,132 reactive to HIV-2, 69 reactive to both viruses, and 274 HIV-seronegative). Main Outcome Measures.—Rates of perinatal transmission for HIV-1, HIV-2, and both viruses, determined from results of serological and polymerase chain reaction tests on children; survival of infants born to HIV-1—positive, HIV-2—positive, dually reactive, and HIV-seronegative women. Results. —Of the 18 099 women tested, 9.4% were reactive to HIV-1 alone, 1.6% to HIV-2 alone, and 1.0% to both viruses. The rate of perinatal transmission of HIV-1 was 24.7% (95% confidence interval [CI], 15.8% to 33.7%), compared with 1.2% (95% CI, 0.0% to 3.5%) for HIV-2 (relative risk, 21.3; 95% CI, 2.9 to 154.3). Overall, 19.0% (95% CI, 9.0% to 29.0%) of infants of dually reactive women became infected; of the 11 children concerned, 10 were infected with HIV-1 and one with HIV-1 and HIV-2. Infants of HIV-seropositive mothers had a reduced survival; mortality rates were 15.1, 13.0, 6.5, and 3.4 deaths per 100 child-years, respectively, for children of HIV-1—positive, dually reactive, HIV-2—positive, and HIV-seronegative women. Conclusions. —The rate of perinatal transmission of HIV-2 (1.2%) was much lower than the rate of perinatal transmission of HIV-1 (24.7%), and this was associated with more favorable survival for infants of HIV-2—infected mothers. Dually reactive women could transmit both viruses, although transmission usually involved HIV-1 only. Public health guidelines should incorporate advice that perinatal transmission of HIV-2 is rare. ( JAMA . 1994;272:462-466)

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 national, population-based survey was initiated in 1988 to measure the prevalence of human immunodeficiency virus (HIV) infection in women giving birth to infants in the United States. Following standardized procedures, residual dried-blood specimens collected on filter paper for newborn metabolic screening were tested anonymously in state public health laboratories for maternal antibody to HIV. As of September 1990, annual survey data were available from 38 states and the District of Columbia. The highest HIV seroprevalence rates were observed in New York (5.8 per 1000), the District of Columbia (5.5 per 1000), New Jersey (4.9 per 1000), and Florida (4.5 per 1000). Nationwide, an estimated 1.5 per 1000 women giving birth to infants in 1989 were infected with HIV. Assuming a perinatal transmission rate of 30%, we estimate that approximately 1800 newborns acquired HIV infection during one 12-month period. Preventing transmission of HIV infection to women and infants is an urgent public health priority. (JAMA. 1991;265:1704-1708)

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.