Comparison of the Sofia and Veritor direct antigen detection assay systems for identification of influenza viruses from patient nasopharyngeal specimens.

Influenza antigen detection assays (Sofia fluorescent immunoassay [FIA] and Veritor) yield objective results, which are potentially useful for point-of-care testing. The assays were evaluated with reverse transcriptase PCR (RT-PCR) using 411 nasopharyngeal swab specimens. Sensitivity and specificity values (percentages) of 79.0/99.0 and 64.0/99.4 for influenza A and 92.9/96.7 and 78.6/98.7 for influenza B were obtained for the Sofia and Veritor assays, respectively.

Evaluation of respiratory syncytial virus (RSV) direct antigen detection assays for use in point-of-care testing.

RSV infections cause lower respiratory tract infections and result in surges in physician's office, emergency department visits and hospitalizations, especially in infants and toddlers. Point-of-care (POC) testing reduces healthcare costs and permits informed decisions on treatment, however, optimal POC assays must be sensitive, easy to perform and provide rapid results. A prospective study tested 230 patient nasopharyngeal specimens using 4 RSV direct antigen detection assays (Directigen, Quickvue, Sofia and Veritor) and RT-PCR. A RSV dilution study was also performed to evaluate sensitivity. RSV fluorescent antibody testing in 46/230 patients was also evaluated. Sensitivity values obtained for the Sofia, Veritor, Directigen and Quickvue assays (%) were 85, 72.5, 70 and 57.5, respectively. Fluorescent result interpretation may account for Sofia's enhanced sensitivity. Specificity (%) was 97-100 among assays. Sensitivity data were confirmed in the dilution studies. Fluorescent antibody testing demonstrated 64% sensitivity compared with RT-PCR. Objective result reporting, walk away testing and high sensitivity make the Sofia a valuable choice for POC testing. Veritor's sensitivity may also render it acceptable in POC. Lack of objective results by Directigen and the poor sensitivity observed by Quickvue may preclude their value in diagnostic testing.

Gangrenous herpetic whitlow in a human immunodeficiency virus-positive patient.

An unusual case of a gangrenous herpetic whitlow is reported. The patient, a 37-year-old man with a ten-year history of intravenous drug abuse, was antibody positive for human immunodeficiency virus. Progressive, extremely painful paronychia of the left third and fourth fingers gradually developed, which persisted despite a variety of treatment protocols, including antibiotics and radiotherapy, ultimately necessitating amputation of the distal portions of the digits. Characteristic herpes-type intranuclear inclusions within epidermal cells were identified in histologic sections of the specimen. Immunohistochemistry using rabbit antihuman herpes virus antibody confirmed the diagnosis. This apparently represents the first documented case of herpetic gangrene in an immunocompromised patient.

Lower Helicobacter pylori infection and peptic ulcer disease prevalence in patients with AIDS and suppressed CD4 counts.

OBJECTIVE: The prevalence of Helicobacter pylori (HP) has previously been reported to be lower in AIDS patients. This study evaluated the prevalence of HP and peptic ulcer disease in relation to absolute CD4 counts in HIV-seropositive patients with GI symptoms. DESIGN: Seventy-two patients (48 HIV-positive and 24 HIV-negative) with GI symptoms were evaluated with upper endoscopy and antral gastric biopsy. Samples were prepared with Giemsa stain and reviewed by a single pathologist to determine status of HP infection. The patients were stratified on the basis of HIV status and CD4 count: group A, HIV-positive patients with a CD4 count greater than 200, group B, HIV-positive patients with CD4 counts less than 200, and group C, an HIV-negative control group. RESULTS: The prevalence of HP infection in the three groups was as follows: group A 69% (11/16), group B 13% (4/32), and group C 63% (15/24). Peptic ulcer prevalence in group A was 19% (3/16), group B 3% (1/32), and group C 25% (6/24). CONCLUSIONS: The prevalence of HP in HIV-positive patients with a CD4 count less than 200 is significantly lower (p < 0.001) than that found in HIV-negative patients. The number of peptic ulcers in the HIV-positive group with CD4 < 200 was significantly less (p = 0.035) than that of the HIV-negative patients. These results suggest a role of CD4 cell and immune function in sustaining HP infection and HP-related peptic ulcer disease.