Environmental monitoring followed by clinical surveillance was successful in uncovering previously unrecognized cases of hospital-acquired Legionella pneumonia.

The possible reactivities of commonly used antibiotics of fungal, nonfungal, and nonmicrobial or synthetic sources with the Platelia Aspergillus galactomannan assay were assessed. For drugs that tested positive, the minimal concentration of the antibiotic in serum that yielded a positive test (index, >0.5) was determined. At undiluted concentrations, piperacillin and multiple lots of piperacillin-tazobactam tested positive, whereas amoxicillin, ampicillin-sulbactam, nafcillin, cefazolin, ceftazidime, erythromycin, gentamicin, and levofloxacin tested negative. All three lots of piperacillin-tazobactam and all bags within each lot tested positive, with a mean index value of 5.168. At achievable concentrations in serum, however, only one of three lots of piperacillin-tazobactam yielded a positive test. Concentrations of 75, 150, and 300 g/ml of serum tested positive with the Platelia Aspergillus enzyme immunoassay, whereas lower concentrations, mimicking the trough levels, tested negative. Thus, while achievable serum piperacillin-tazobactam concentrations may potentially result in a positive test for galactomannan, the timing of the collection of serum samples from patients may influence the test results, with reactivity being less likely in samples collected at trough levels or prior to the administration of a dose of the antibiotic.Galactomannan is a polysaccharide component of the cell wall of Aspergillus spp. that is released into the circulation in varying amounts during invasive aspergillosis (3, 7, 15). Galactomannan detection by the Platelia Aspergillus enzyme immunoassay (EIA) has proven to be a potentially promising tool for the early diagnosis of invasive aspergillosis. False-positive test results, however, have been reported for ϳ6 to 8% of neutropenic and hematopoietic stem cell transplant recipients, for 13% of liver transplant recipients, and for 20% of lung transplant recipients (4,5,9,10,12). Cytotoxic chemotherapeutic agents, autoreactive antibodies or paraproteins, or yet-unidentified serum components may account for the false-positive tests. The high rate of false EIA reactivity in neonates may result from cross-reactivity with the lipoteichoic acid of Bifidobacterium bifidum in the gut (P. E. Verweij, R. R. Klont, A. Warris, H. J. M. Op Den Camp, and M. A. S. MenninkKersten, Abstr. 43rd Intersci. Conf. Antimicrob. Agents Chemother., abstr. M-1027, 2003). Reactivity with the galactomannan of Paecilomyces and Penicillium spp. has been noted previously (13).In 1997, Ansorg et al. first reported that drugs of fungal origin, such as antibiotics and uricase, might be associated with false-positive test results (1a). Galactomannan was detected in a batch of ampicillin-sulbactam and in two batches of piperacillin (1a). Of our liver transplant recipients with false-positive test results, 55% had received these antibiotics (5). Recent reports from Europe have documented false-positive tests related to the use of piperacillin-tazobactam in patients with hematologic malignancy or those who had undergone b...

Intranasal challenge with both influenza A virus and Streptococcus pneumoniae promotes otitis media with S. pneumoniae in chinchillas. We investigated whether influenza A virus infection promotes oropharyngeal colonization with S. pneumoniae and other middle ear pathogens by selectively inhibiting commensal bacteria. On study day 0, 12 allergic and 15 nonallergic adult subjects were intranasally inoculated with influenza A/Kawasaki (H1N1) virus. Every subject was infected with the virus as demonstrated by nasal shedding or seroconversion. Average upper respiratory symptom scores and nasal secretion weights from the entire subject group were elevated between days 2 and 6 (acute phase) and were not significantly different between allergic and nonallergic subjects. S. pneumoniae was not isolated from any subject prior to the virus challenge but was isolated in heavy density from 4 (15%) subjects on day 6 (P ‫؍‬ 0.055). Staphylococcus aureus was isolated more frequently from the nonallergic subjects than from the allergic subjects on days 2 (80 versus 25%, respectively) 4, (67 versus 17%, respectively), and 6 (73 versus 25%, respectively) (P < 0.05). The isolation rates of other middle ear pathogens were not significantly different before virus challenge and during the acute and resolution phases (days 27 to 30) of the experimental infection for the entire subject group or either the allergic or nonallergic subgroup. Densities and isolation rates of commensal bacteria from the entire subject group were similar throughout the observational period. These results suggest that the virus infection promoted S. pneumoniae colonization of the oropharynx and that nonallergic persons may be more vulnerable to colonization with S. aureus than allergic persons. The altered colonization rates were not attributed to inhibition of commensal bacteria. Otitis media often occurs in children as a complication of upper respiratory viral infection and allergic rhinitis (4, 24, 34). Upper respiratory viral infection leads to eustachian tube blockage and dysfunction and middle ear underpressure (3, 7, 30). These conditions can promote the aspiration of upper respiratory bacterial flora into the middle ear. Studies of experimental respiratory virus infection have suggested that patients with allergic rhinitis develop an earlier onset of diminished mucociliary clearance and eustachian tube dysfunction, as well as more severe upper respiratory tract signs and symptoms, than nonallergic subjects (8, 13). However, the combined effects of upper respiratory tract viral infection and allergy on the pathogenesis of otitis media are poorly understood. Streptococcus pneumoniae is the most frequent isolate from middle ear fluid specimens of children with acute otitis media, accounting for 20 to 50% of the cases (9, 20, 35). Other pathogens isolated, in decreasing frequency, include Haemophilus influenzae, Moraxella catarrhalis, Staphylococcus aureus, and Streptococcus pyogenes (20). Studies with chinchillas suggest that influenza A virus infection pro...

Persistent thrombocytopenia portended a poor outcome in liver transplant recipients and was not related to low TPO levels. Thrombocytopenia preceded infections and identified a subgroup of liver transplant patients susceptible to early major infections; its precise role in fungal infections warrants validation in larger studies.

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