The genus Malassezia contains three member species: Malassezia furfur and Malassezia sympodialis, both obligatory lipophilic, skin flora yeasts of humans, and Malassezia pachydermatis, a nonobligatory lipophilic, skin flora yeast of other warm-blooded animals. Several characteristics suggest the basidiomycetous nature of these yeasts, although a perfect stage has not been identified. Classically, these organisms are associated with superficial infections of the skin and associated structures, including pityriasis versicolor and folliculitis. Recently, however, they have been reported as agents of more invasive human diseases including deep-line catheter-associated sepsis. The latter infection occurs in patients, primarily infants, receiving parenteral nutrition (including lipid emulsions) through the catheter. The lipids presumably provide growth factors required for replication of the organisms. It is unclear how deep-line catheters become colonized with Malassezia spp. Skin colonization with M. furfur is common in infants hospitalized in neonatal intensive care units, whereas colonization of newborns hospitalized in well-baby nurseries and of older infants is rarely observed. Catheter colonization, which may occur without overt clinical symptoms, probably occurs secondary to skin colonization, with the organism gaining access either via the catheter insertion site on the skin or through the external catheter hub (connecting port). There is little information on the colonization of hospitalized patients by M. sympodialis or M. pachydermatis. Diagnosis of superficial infections is best made by microscopic examination of skin scrapings following KOH, calcofluor white, or histologic staining. Treatment of these infections involves the use of topical or oral antifungal agents, and it may be prolonged. Diagnosis of Malassezia catheter-associated sepsis requires detection of the organism in whole blood smears or in buffy coat smears of blood drawn through the infected catheter or isolation of the organism from catheter or peripheral blood or the catheter tip. Culture of M. furfur from blood is best achieved with Isolator tubes and plating onto a solid medium supplemented with a lipid source. Appropriate treatment of patients requires removal of the infected catheter with or without temporary stoppage of lipid emulsions; administration of antifungal therapeutic agents does not appear to be necessary. Because many patients who develop Malassezia catheter-associated sepsis have severe underlying illnesses, caution must be exercised in attributing all clinical deterioration to Malassezia infection. Our better understanding of how these organisms cause disease awaits the development of a useful typing scheme for epidemiologic studies and further studies on microbial virulence factors and the role of the immune response in pathogenesis.

We report the first documented mixed outbreak of B. pertussis and B. holmesii infections. Bordetella holmesii particularly affected adolescents. Although laboratory capacity limitations might inhibit routine use of multitarget PCR for clinical diagnosis, focused testing and enhanced surveillance might improve understanding the burden of B. holmesii infection.

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The Quidel QuickVue influenza test was compared to viral culture and reverse transcriptase PCR by the use of three different respiratory specimen types. Of 122 pediatric subjects enrolled, 59 had influenza virus infections: 44 were infected with influenza A virus and 15 were infected with influenza B virus. The sensitivity of the QuickVue test was 85% with nasopharyngeal swabs, 78% with nasal swabs, and 69% with nasopharyngeal washes. Specificities were equivalent (97% to 98%) for all three collection methods.During annual outbreaks of influenza A and B virus infection, it is estimated that 10 to 20% of the residential population of the United States may be affected and that the highest attack rates occur in school-age children (1,5,6,16,18,20). The rapid and accurate diagnosis of cases of influenza is desirable for management of children presenting to a pediatric hospital's emergency department (ED). A laboratory-confirmed diagnosis of influenza supports the appropriate use of antiviral therapy for patients to be admitted to the hospital as well as for patients to be discharged from the ED and managed as outpatients. A specific diagnosis also decreases the inappropriate use of antibiotics, other diagnostic testing, and the patient's length of stay in the ED (1,15,18,20).Several methods for laboratory diagnosis of influenza are available; these include viral culture, direct antigen detection, and direct nucleic acid amplification and detection. Viral culture is still considered the "gold standard" method, but traditional culture generally requires at least 3 days or longer to obtain a positive result. Rapid viral culture methods using "shell vial" assays have been applied to speed up the time to detection (8-11). Nucleic acid amplification methods offer very high test sensitivities and same-day results, but there are no FDA-cleared nucleic acid amplification tests for influenza virus detection. Respiratory virus antigen detection by direct or indirect immunofluorescence assay is widely used in laboratories with expertise in fluorescence microscopy, but these assays are often performed as "batch tests" a few times per day and are thus not truly rapid. Antigen detection methods which utilize single-use immunoassay test devices offer the potential for widespread test availability, relative ease of testing, and rapid turnaround (2-4, 8, 10, 12-14, 17, 21).There are limited published data on the impact of specimen type from the respiratory tract on the relative efficiencies of rapid immunoassay tests for influenza diagnosis (7, 12). Studies have examined nasopharyngeal (NP) aspirates and washes, posterior NP and throat swabs, and sputa; however, most studies have not included the collection of multiple specimen types from the same subjects. Aspirates and washes are generally considered superior to swab collections for detection of a variety of respiratory viruses, but swab samples are easier and faster to collect and may be preferred by healthcare providers in a busy ambulatory setting. In this study, we evaluated th...