Ambiguity in the identification of Streptococcus pneumoniae. Optochin, bile solubility, quellung, and the AccuProbe DNA probe tests.

We prospectively evaluated 639 sequential clinical isolates of alpha-hemolytic gram-positive cocci as possible Streptococcus pneumoniae. On the basis of results of tests for optochin susceptibility, tube bile solubility, and the quellung reaction, 74 strains (11.6%) were categorized as unequivocal pneumococci (optochin positive, tube bile solubility positive, quellung reaction positive). Among 450 optochin- and tube bile solubility-negative organisms, a subset of 56 strains was tested for quellung reaction (all negative); these isolates were categorized as unequivocal nonpneumococci. A final 115 organisms with an inconsistent or discordant combination of susceptibility to optochin, tube bile solubility, and quellung reaction were categorized as equivocal strains. With the unequivocal isolates, a commercial molecular probe for S pneumoniae (AccuProbe; Gen-Probe, San Diego, Calif) showed 100% sensitivity (74/74) and 100% specificity (56/56). Among the 115 equivocal strains, however, 33 (28.7%) reacted with the AccuProbe, whereas only 3 (2.6%) showed a capsule that reacted in the quellung test. A subset of the equivocal strains identified in this group of primarily respiratory isolates may have been S pneumoniae that only partially expressed their classic phenotype of optochin susceptibility and bile solubility and only rarely expressed capsular antigens. A practical, cost-sparing algorithm is proposed to facilitate the routine clinical identification of S pneumoniae.

HIV infection in women and children.

AIDS is increasing more rapidly among women than men and has become the fourth-leading cause of death for women between the ages of 25 and 44 years in the United States. This changing epidemiological trend accounts for the increase in pediatric cases of HIV infection. This article summarizes features on women and children. We review epidemiology, clinical characteristics, vertical transmission, treatment, and prevention opportunities.

Congenital cytomegalovirus infection as a result of nonprimary cytomegalovirus disease in a mother with acquired immunodeficiency syndrome.

A pregnant woman with acquired immunodeficiency syndrome had nonprimary cytomegalovirus (CMV) viremia and died of complications from Pneumocystis carinii pneumonia and CMV sinusitis and pneumonitis. A boy was delivered by cesarean section at 34 weeks of gestation as the mother's health deteriorated and fetal distress developed. The infant died soon after delivery of interstitial pneumonitis and hyaline membrane disease with invasive CMV disease that affected the kidneys, adrenal glands, and placenta; the CMV strains from the mother and neonate were identical.

Current and future HIV/AIDS clinical research. HIV-related therapy improving--slowly.

More than 300,000 cases of AIDS have been reported in the United States since 1981. Despite major scientific advances and much effort, the benefits of treatment have been modest. The variable nature of the human immunodeficiency virus (HIV) and the complexity of the immune system are the major obstacles to advances in treatment. This article summarizes the current state of clinical research in pursuit of improved HIV therapy and takes a look into the future of anti-HIV therapeutics. It also provides an overview of HIV clinical research underway in Minnesota. Research efforts to improve therapy of HIV-induced immune deficiency will involve three strategies: better anti-HIV drugs and combinations of drugs aimed at slowing the replication of HIV, immune-based therapies intended to stimulate the immune system, and multiple opportunistic pathogen prophylaxis strategies to prevent HIV-related opportunistic infections. This approach will involve considerable cost and polypharmacy. Improvements in HIV/AIDS therapy are likely to occur incrementally, but the endeavor needs widespread support from patients, physicians, and the public. For now, the best strategy is prevention, which is where physicians can have the greatest impact on the epidemic.