<p>Influenza is a common respiratory pathogen. Its severity can be unpredictable, but people with chronic illness are at increased risk of severe infection, complications, and death from influenza. This review examines evidence to support various strategies to protect pediatric oncology patients from influenza-related morbidity. Influenza vaccination should be considered standard. Additional evidence-supported measures include antiviral treatment, antiviral prophylaxis, cohorting of patients, and hospital infection control measures. Data from other high-risk populations support the vaccination of family members, double-dose or high-dose vaccination, and the use of barrier methods. These measures have the potential to optimize patient outcomes because there will be fewer treatment interruptions for acute illness. These strategies can also protect patients from prolonged hospitalizations and morbidity related to influenza.</p>

<p><strong>BACKGROUND: </strong>Adolescents are at high risk for pelvic inflammatory disease (PID). Because accurate diagnosis of PID is difficult, and complications of untreated PID are significant, novel methods to improve diagnosis are essential.</p>

<p><strong>OBJECTIVES: </strong>To determine if patients with PID have unique RNA expression patterns compared to controls.</p>

<p><strong>METHODS: </strong>Peripheral blood was collected from adolescent females with PID in the emergency department, and from control patients in the operating room. RNA was isolated, and microarray analysis was performed. Initial analysis involved a training set of 18 patients (9 PID patients with either Neisseria gonorrhoeae or Chlamydia trachomatis infection and 9 control patients). Supervised and unsupervised cluster analyses were performed, followed by network analysis. The training set was used to classify a set of 15 additional PID patients and 2 controls.</p>

<p><strong>RESULTS: </strong>Supervised cluster analysis of the training set revealed 170 genes which were differentially expressed in PID patients versus controls. Network analysis indicated that several differentially expressed genes are involved in immune activation. Analysis of additional PID patients based on the training set findings revealed that patients with positive testing for Trichomonas vaginalis partitioned with the PID group, whereas patients with no organism identified partitioned with both groups.</p>

<p><strong>CONCLUSIONS: </strong>RNA sample collection from adolescents in the emergency department is feasible. Genes were identified which were differentially expressed in PID patients versus controls, many of which are involved in inflammation. Future studies should confirm the training set findings on a larger sample and may lead to improved accuracy of PID diagnosis.</p>