IMPROVING DIAGNOSTIC ACCURACY AND DEFINING THE EPIDEMIOLOGY OF CELLULITIS

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 蜂窝织炎是一种常见的皮肤及其下层组织感染。 2004年，美国有24万成人因蜂窝织炎住院治疗，花费了37亿美元。 然而，罗切斯特大学的一项试点研究表明，20%的假定诊断为蜂窝织炎的患者被错误地诊断。 我们假设可视化临床决策支持系统VisualDx将帮助医生诊断蜂窝织炎，这将有助于避免不必要的住院，抗生素管理和医疗保健支出。 从历史上看，A组链球菌是蜂窝织炎最常见的原因，金黄色葡萄球菌是少数病例的原因。 与此观点相反，Loren米勒博士的共同研究者及其同事回顾了文献，发现在接受针吸培养的蜂窝织炎患者中，金黄色葡萄球菌与A组链球菌分离株的比例大于3：1。 20世纪40年代，青霉素被引入治疗葡萄球菌感染后，金黄色葡萄球菌中的抗生素耐药性就出现了，它限制并重塑了治疗选择。 社区爆发和社区相关MRSA CA-MRSA疾病的急剧增加发生在许多人群中，包括：囚犯，军人，运动员，日托人员和家庭。 CA-MRSA是洛杉矶县的地方病，通常会导致未与所谓的高危人群接触的人感染。 蜂窝织炎和CA-MRSA的交叉是重要的。鉴于蜂窝织炎最常见的已知原因是金黄色葡萄球菌，并且社区中大多数金黄色葡萄球菌感染是由CA-MRSA引起的，我们假设蜂窝织炎的经验性治疗可能需要合并MRSA治疗。 本研究的目的是确定疑似蜂窝组织炎或丹毒（通常由化脓性链球菌引起的类似浅表感染）患者诊断的准确性，确定与蜂窝组织炎感染相关的危险因素，并分析蜂窝组织炎患者中CA-MRSA定植的分子流行病学。 我们将招募160例在Harbor-UCLA住院病房住院的患者进行1：2配对病例对照研究。 首先，我们将招募60名疑似蜂窝织炎患者。 我们预计60例患者中有83%会有蜂窝织炎。 蜂窝织炎病例定义为经皮肤科医生确认诊断为无并发症蜂窝织炎或丹毒的住院患者。 将没有基于性别或种族/民族的入组限制。 对照组，以1：2的比例匹配，定义为住院病房的未感染受试者，根据3个标准与蜂窝织炎病例匹配：年龄在5年内，性别和种族/民族。 研究协调员将确定急诊科收治的初步诊断为蜂窝织炎或丹毒的患者。 如果患者提供知情同意书，研究协调员将进行问卷调查，拍摄皮肤病变照片，收集鼻和腹股沟褶细菌拭子培养物，收集相关既往病史，并进行定向体格检查。研究协调员还将记录实验室数据，收集住院医师使用计算机化临床决策支持工具生成的数据。 隐私的丧失是主要的风险，虽然对参与者没有直接的好处，但参与可能会帮助未来的蜂窝织炎患者。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Cellulitis is a common infection of the skin and its underlying tissues. In 2004, $3.7 billion were spent on 240,000 adult hospitalizations for cellulitis in the United States. However, a University of Rochester pilot study showed that 20% of patients admitted to the hospital with a presumed diagnosis of cellulitis were diagnosed incorrectly. We hypothesize that a visual clinical decision support system (VisualDx) will assist physicians in diagnosing cellulitis, which will help avoid unnecessary hospitalizations, antibiotic administration, and healthcare spending. Historically, group A streptococci was the most common cause of cellulitis, with Staph aureus responsible for a minority of cases. Contrary to this view, Dr. Loren Miller (co-investigator) and colleagues' review of the literature found that among patients with cellulitis who undergo needle aspiration cultures, the ratio of Staph aureus to group A streptococcal isolates is greater than three to one. Antibiotic resistance among Staph aureus emerged as soon as penicillin was introduced to treat staphylococcal infections in the 1940s, and it restricts and reshapes therapeutic options. Community outbreaks and dramatic increase of community-associated MRSA (CA-MRSA) disease have occurred in numerous populations including: prisoners, military personnel, athletes, daycare attendees, and families. CA-MRSA is endemic in Los Angeles County and typically causes infections in persons without contact with so-called "at risk" populations. The intersection of cellulitis and CA-MRSA is important. Given the most common known cause of cellulitis is Staph aureus, and the majority of Staph aureus infections from the community are caused by CA-MRSA, we hypothesize that empiric treatment of cellulitis may need to incorporate treatment for MRSA. The aims of this study are to determine the accuracy of diagnosis of patients with suspected cellulitis or erysipelas (a similar superficial infection often caused by Streptococcus pyogenes), to identify risk factors associated with cellulitis infection, and to analyze the molecular epidemiology of CA-MRSA colonization among patients with cellulitis. We will enroll 160 patients admitted to Harbor-UCLA inpatient wards in a 1:2 paired case-control study. First, we will enroll 60 patients with suspected cellulitis. We anticipate 83% of 60 patients (n=50) will have cellulitis. Cellulitis cases are defined as patients admitted to the inpatient wards with a dermatologist-confirmed diagnosis of uncomplicated cellulitis or erysipelas. There will be no gender or racial/ethnic-based enrollment restrictions. Controls, matched at a 1:2 ratio, are defined as uninfected subjects admitted to the inpatient wards who are matched to cellulitis cases by 3 criteria: age (within 5 years), gender, and race/ethnicity. The study coordinator will identify patients admitted from the Emergency Department with a primary diagnosis of cellulitis or erysipelas. If the patient provides consent, the study coordinator will administer a questionnaire, photograph skin lesions, collect nasal and inguinal fold bacterial swab cultures, collect pertinent past medical history, and perform a directed physical exam. The study coordinator will also record laboratory data, collect data generated by inpatient resident physicians utilizing the computerized clinical decision support tool. Loss of privacy is the main risk, and while there are no direct benefits for the participant, participating may help future patients with cellulitis.