Work is under way to expand the number of viruses detected by MPCR and to determine whether newly discovered viruses, such as human metapneumovirus, contribute to the burden of pediatric LRI hospitalizations.

Newly available assays offer alternatives to conventional microscopic examination for Cryptosporidium spp. We compared two enzyme immunoassays, ProSpect Cryptosporidium microtiter assay (Alexon, Inc., Mountain View, Calif.) and Color Vue Cryptosporidium assay (Seradyn, Indianapolis, Ind.), and a direct immunofluorescent assay, Merifluor Cryptosporidium kit (Meridian Diagnostics, Cincinnati, Ohio), with acid-fast Kinyounstaining for the detection of Cryptosporidium spp. Examinations were performed on 129 stool specimens received from patients during a recent waterborne outbreak. A specimen was considered positive when organisms could be identified visually by acid-fast and immunofluorescent stains or if organisms could be visualized by either acid-fast or immunofluorescent stain and detected by both enzyme immunoassays. The final number of positive specimens was 55. No single procedure detected all 55 positive specimens. Of these, ProSpect and Color Vue detected 52 (sensitivity, 94.5%), and the Kinyoun stain and Merifluor detected 53 (sensitivity, 96.4%). The final number of negative specimens was 74. One false-positive result was seen with both the Kinyoun stain and the ProSpect assay. The Color Vue and ProSpect assays required the most hands-on technologist time. The ProSpect assay and Merifluor kit were easiest to perform. The acid-fast stain was difficult to interpret. The Merifluor kit was easiest to read and was adaptable to both batch and single testing. Overall, the Kinyoun stain and the Merifluor test were preferable to both of the enzyme immunoassays because of the high reagent cost and hands-on time required for the enzyme immunoassays. The difficult interpretation of the Kinyoun stain smears made the Merifluor a more desirable test despite its higher cost. We conclude that all methods tested were equally sensitive and specific for the detection of Cryptosporidium spp. Ease of use, adaptability to batch testing, and cost are important criteria in determining the method of choice.

During the past 6 to 7 years, the problem of antimicrobial resistance in Streptococcus pneumoniae has grown dramatically in the United States. Currently, approximately 26.5% of pneumococcal isolates express intermediate levels of resistance to penicillin; approximately 17.5% are highly penicillin resistant. We studied whether clonal relationships exist among current isolates of high-level penicillin-resistant S. pneumoniae (PRSP) in the United States. One hundred forty-seven PRSP isolates recovered in a 30-center surveillance study in the United States during 1994-1995 were characterized with respect to serotype, antimicrobial susceptibility pattern, and pulsed-field gel electrophoresis (PFGE) profile. Only six serotypes were observed among the 147 PRSP isolates examined in this study: 6A, 6B, 9A, 14, 19F, and 23F. One hundred three (70.1%) of the 147 strains were characterized by one of only nine PFGE types; 76 (51.7%) of the 147 isolates were characterized by only four PFGE profiles. Currently in the United States, most PRSP strains are represented by relatively few clonal groups.